Porting of apps to userspace

iso_root/limine.conf

@@ -8,4 +8,10 @@ timeout: 3
     module_path: boot():/bin/calculator.elf
     module_path: boot():/bin/crash.elf
     module_path: boot():/bin/hello.elf
+    module_path: boot():/bin/markdown.elf
+    module_path: boot():/bin/minesweeper.elf
     module_path: boot():/bin/notepad.elf
+    module_path: boot():/bin/paint.elf
+    module_path: boot():/bin/settings.elf
+    module_path: boot():/bin/txtedit.elf
+    module_path: boot():/bin/viewer.elf

src/kernel/boot.asm

@@ -7,15 +7,11 @@ extern kmain
 bits 64
 
 _start:
-    ; Ensure interrupts are disabled
     cli
     
-    ; (Limine guarantees 16-byte alignment)
 
-    ; Call the C kernel entry point
     call kmain
 
-    ; Halt if kmain returns
     hlt
 .loop:
     jmp .loop

src/kernel/cli_apps/txtedit.c

@@ -1,57 +0,0 @@
-#include "cli_utils.h"
-#include "fat32.h"
-#include "wm.h"
-
-// Forward declarations from editor.h and wm.c
-extern void editor_open_file(const char *filename);
-extern void editor_init(void);
-extern Window win_editor;
-extern Window win_explorer;
-extern Window win_cmd;
-
-void cli_cmd_txtedit(char *args) {
-    // Parse the file path argument
-    char filepath[256];
-    int i = 0;
-    
-    // Skip leading whitespace
-    while (args && args[i] && (args[i] == ' ' || args[i] == '\t')) {
-        i++;
-    }
-    
-    // Extract filepath
-    int j = 0;
-    while (args && args[i] && args[i] != ' ' && args[i] != '\t' && j < 255) {
-        filepath[j++] = args[i++];
-    }
-    filepath[j] = 0;
-    
-    // If no filepath provided, create a new empty file
-    if (j == 0) {
-        cli_write("Usage: txtedit <filename>\n");
-        cli_write("Example: txtedit myfile.txt\n");
-        cli_write("         txtedit /document.txt\n");
-        return;
-    }
-    
-    // Normalize the path (handles relative and absolute paths)
-    char normalized_path[256];
-    fat32_normalize_path(filepath, normalized_path);
-    
-    // Open the file in the GUI editor
-    editor_open_file(normalized_path);
-    
-    // Make editor window visible and focused, bring to front
-    win_editor.visible = true;
-    win_editor.focused = true;
-    
-    // Calculate max z_index to bring window to front
-    int max_z = 0;
-    if (win_explorer.z_index > max_z) max_z = win_explorer.z_index;
-    if (win_cmd.z_index > max_z) max_z = win_cmd.z_index;
-    win_editor.z_index = max_z + 1;
-    
-    cli_write("Opening: ");
-    cli_write(normalized_path);
-    cli_write("\n");
-}

src/kernel/cmd.c

@@ -513,7 +513,7 @@ static void internal_cmd_txtedit(char *args) {
         i++;
     }
     
-    // Extract filepath (args now includes drive prefix from cmd_exec_single)
+    // Extract filepath
     int j = 0;
     while (args && args[i] && args[i] != ' ' && args[i] != '\t' && j < 255) {
         filepath[j++] = args[i++];
@@ -523,50 +523,19 @@ static void internal_cmd_txtedit(char *args) {
     // If no filepath provided, show usage
     if (j == 0) {
         cmd_write("Usage: txtedit <filename>\n");
-        cmd_write("Example: txtedit myfile.txt\n");
-        cmd_write("         txtedit /document.txt\n");
         return;
     }
 
-    // Normalize the path (filepath already includes drive from cmd_exec_single)
+    // Normalize the path
     char normalized_path[256];
     fat32_normalize_path(filepath, normalized_path);
     
-    // Extract drive from normalized path to set it as current temporarily
-    char drive = 'A';
-    if (normalized_path[1] == ':') {
-        drive = normalized_path[0];
-        if (drive >= 'a' && drive <= 'z') drive -= 32;
-    }
-    
-    // Set global drive temporarily to match file's drive
-    char saved_drive = fat32_get_current_drive();
-    fat32_change_drive(drive);
-    
-    // Open the file in the GUI editor
-    extern void editor_open_file(const char *filename);
-    extern Window win_editor;
-    editor_open_file(normalized_path);
-    
-    // Restore the drive
-    fat32_change_drive(saved_drive);
-
-    // Make editor window visible and focused, bring to front
-    extern Window win_explorer;
-    extern Window win_cmd;
-    
-    win_editor.visible = true;
-    win_editor.focused = true;
-    
-    // Calculate max z_index to bring window to front
-    int max_z = 0;
-    if (win_explorer.z_index > max_z) max_z = win_explorer.z_index;
-    if (win_cmd.z_index > max_z) max_z = win_cmd.z_index;
-    win_editor.z_index = max_z + 1;
-    
     cmd_write("Opening: ");
     cmd_write(normalized_path);
     cmd_write("\n");
+
+    cmd_is_waiting_for_process = true;
+    process_create_elf("A:/bin/txtedit.elf", normalized_path);
 }
 
 static void internal_cmd_ls(char *args) {

src/kernel/control_panel.h

@@ -1,11 +0,0 @@
-#ifndef CONTROL_PANEL_H
-#define CONTROL_PANEL_H
-
-#include "wm.h"
-
-extern Window win_control_panel;
-
-void control_panel_init(void);
-void control_panel_reset(void);
-
-#endif

src/kernel/editor.h

@@ -1,11 +0,0 @@
-#ifndef EDITOR_H
-#define EDITOR_H
-
-#include "wm.h"
-
-extern Window win_editor;
-
-void editor_init(void);
-void editor_open_file(const char *filename);
-
-#endif

src/kernel/explorer.c

@@ -4,29 +4,17 @@
 #include "disk.h"
 #include "wm.h"
 #include "memory_manager.h"
-#include "editor.h"
-#include "markdown.h"
 #include "cmd.h"
-
 #include "process.h"
-#include "minesweeper.h"
-#include "viewer.h"
-#include "control_panel.h"
 #include "about.h"
-#include "paint.h"
-#include <stdbool.h>
-#include <stddef.h>
-
-// === File Explorer State ===
-Window win_explorer;
-
-#define EXPLORER_MAX_FILES 64
 #define EXPLORER_ITEM_HEIGHT 80
 #define EXPLORER_ITEM_WIDTH 120
 #define EXPLORER_COLS 4
 #define EXPLORER_ROWS 4
 #define EXPLORER_PADDING 15
 
+Window win_explorer;
+
 // Dialog states
 #define DIALOG_NONE 0
 #define DIALOG_CREATE_FILE 1
@@ -819,16 +807,13 @@ static void explorer_open_target(const char *path) {
         if (explorer_str_ends_with(path, ".elf")) {
             process_create_elf(path, NULL);
         } else if (explorer_is_markdown_file(path)) {
-            wm_bring_to_front(&win_markdown);
-            markdown_open_file(path);
+            process_create_elf("A:/bin/markdown.elf", path);
         } else if (explorer_str_ends_with(path, ".pnt")) {
-            paint_load(path);
-            wm_bring_to_front(&win_paint);
+            process_create_elf("A:/bin/paint.elf", path);
         } else if (explorer_str_ends_with(path, ".jpg") || explorer_str_ends_with(path, ".JPG")) {
-            viewer_open_file(path);
+            process_create_elf("A:/bin/viewer.elf", path);
         } else {
-            wm_bring_to_front(&win_editor);
-            editor_open_file(path);
+            process_create_elf("A:/bin/txtedit.elf", path);
         }
     }
 }
@@ -859,9 +844,9 @@ static void explorer_open_item(Window *win, int index) {
         } else if (explorer_strcmp(state->items[index].name, "Terminal.shortcut") == 0) {
             target = &win_cmd; cmd_reset();
         } else if (explorer_strcmp(state->items[index].name, "Minesweeper.shortcut") == 0) {
-            target = &win_minesweeper;
-        } else if (explorer_strcmp(state->items[index].name, "Control Panel.shortcut") == 0) {
-            target = &win_control_panel;
+            process_create_elf("/bin/minesweeper.elf", NULL); return;
+        } else if (explorer_strcmp(state->items[index].name, "Control Panel.shortcut") == 0 || explorer_strcmp(state->items[index].name, "Settings.shortcut") == 0) {
+            process_create_elf("/bin/settings.elf", NULL); return;
         } else if (explorer_strcmp(state->items[index].name, "About.shortcut") == 0) {
             target = &win_about;
         } else if (explorer_strcmp(state->items[index].name, "Explorer.shortcut") == 0) {
@@ -1781,17 +1766,7 @@ static void explorer_handle_file_context_menu_click(Window *win, int x, int y) {
         state->dialog_input_cursor = explorer_strlen(state->dialog_input);
         explorer_strcpy(state->dialog_target_path, full_path);
     } else if (clicked_action == 110) { // Open with Text Editor
-        win_editor.visible = true; win_editor.focused = true;
-        int max_z = 0;
-        for (int i = 0; i < explorer_win_count; i++) if (explorer_wins[i]->z_index > max_z) max_z = explorer_wins[i]->z_index;
-        if (win_cmd.z_index > max_z) max_z = win_cmd.z_index;
-        if (win_editor.z_index > max_z) max_z = win_editor.z_index;
-        if (win_markdown.z_index > max_z) max_z = win_markdown.z_index;
-        if (win_control_panel.z_index > max_z) max_z = win_control_panel.z_index;
-        if (win_about.z_index > max_z) max_z = win_about.z_index;
-        if (win_minesweeper.z_index > max_z) max_z = win_minesweeper.z_index;
-        win_editor.z_index = max_z + 1;
-        editor_open_file(full_path);
+        process_create_elf("A:/bin/txtedit.elf", full_path);
     } else if (clicked_action == ACTION_RESTORE) {
         explorer_restore_file(win, state->file_context_menu_item);
     } else if (clicked_action == ACTION_CREATE_SHORTCUT) {
@@ -2024,6 +1999,6 @@ void explorer_reset(void) {
     ExplorerState *state = (ExplorerState*)win_explorer.data;
     // Reset explorer to root directory on close/reopen
     explorer_load_directory(&win_explorer, "A:/");
-    win_explorer.focused = false;
     state->explorer_scroll_row = 0;
+    win_explorer.focused = false;
 }

src/kernel/fat32.c

@@ -577,7 +577,7 @@ static FAT32_FileHandle* realfs_open(char drive, const char *path, const char *m
                 if (entry[e].attributes & ATTR_VOLUME_ID) continue; // Volume label
                 
                 // Compare name (simplistic 8.3 matching)
-                char name[12];
+                char name[13];
                 int n = 0;
                 for (int k = 0; k < 8 && entry[e].filename[k] != ' '; k++) name[n++] = entry[e].filename[k];
                 if (entry[e].extension[0] != ' ') {
@@ -973,7 +973,7 @@ static bool realfs_delete(char drive, const char *path) {
                 if (entry[e].attributes & ATTR_VOLUME_ID) continue; // Skip volume label
                 
                 // Format name and compare
-                char name[12];
+                char name[13];
                 int n = 0;
                 for (int k = 0; k < 8 && entry[e].filename[k] != ' '; k++) name[n++] = entry[e].filename[k];
                 if (entry[e].extension[0] != ' ') {

src/kernel/graphics.c

@@ -4,34 +4,27 @@
 #include "io.h"
 
 static struct limine_framebuffer *g_fb = NULL;
-static uint32_t g_bg_color = 0xFF696969;  // Dark gray background
+static uint32_t g_bg_color = 0xFF696969;
 
-// Pattern support
 #define PATTERN_SIZE 128
 static uint32_t g_bg_pattern[PATTERN_SIZE * PATTERN_SIZE];
 static bool g_use_pattern = false;
 
-// Wallpaper image support
 static uint32_t *g_bg_image = NULL;
 static int g_bg_image_w = 0;
 static int g_bg_image_h = 0;
 static bool g_use_image = false;
 
-// Dirty rectangle tracking
 static DirtyRect g_dirty = {0, 0, 0, 0, false};
 
-// Double buffering - allocate a back buffer
-// Max screen size: 2048x2048 @ 32bpp = 16MB, but allocate for common sizes
-// Using a simple approach: allocate max size buffer
+
 #define MAX_FB_WIDTH 2048
 #define MAX_FB_HEIGHT 2048
 static uint32_t g_back_buffer[MAX_FB_WIDTH * MAX_FB_HEIGHT] __attribute__((aligned(4096)));
 
-// Clipping state
 static int g_clip_x = 0, g_clip_y = 0, g_clip_w = 0, g_clip_h = 0;
 static bool g_clip_enabled = false;
 
-// Custom Render Target
 static uint32_t *g_render_target = NULL;
 static int g_rt_width = 0;
 static int g_rt_height = 0;
@@ -256,24 +249,17 @@ void draw_rounded_rect_filled(int x, int y, int w, int h, int radius, uint32_t c
     draw_rect(x, y + radius, radius, h - 2*radius, color);
     draw_rect(x + w - radius, y + radius, radius, h - 2*radius, color);
     
-    // Draw rounded corners using scanline approach (fills gaps properly)
     for (int dy = 0; dy < radius; dy++) {
-        // For top corners: distance formula inverted (narrow at top, wide at junction)
         int dx_top = isqrt(radius*radius - (radius - dy) * (radius - dy));
         
-        // For bottom corners: distance formula normal (wide at junction, narrow at bottom)
         int dx_bottom = isqrt(radius*radius - dy*dy);
         
-        // Top-left corner - horizontal scanline
         draw_rect(x + radius - dx_top, y + dy, dx_top, 1, color);
         
-        // Top-right corner - horizontal scanline
         draw_rect(x + w - radius, y + dy, dx_top, 1, color);
         
-        // Bottom-left corner - horizontal scanline
         draw_rect(x + radius - dx_bottom, y + h - radius + dy, dx_bottom, 1, color);
         
-        // Bottom-right corner - horizontal scanline
         draw_rect(x + w - radius, y + h - radius + dy, dx_bottom, 1, color);
     }
 }
@@ -282,7 +268,6 @@ void draw_char(int x, int y, char c, uint32_t color) {
     unsigned char uc = (unsigned char)c;
     if (uc > 127) return;
 
-    // Fast rejection: if the character is entirely outside the clipping/dirty rect, skip it
     if (g_clip_enabled && !g_render_target) {
         if (x + 8 <= g_clip_x || x >= g_clip_x + g_clip_w ||
             y + 8 <= g_clip_y || y >= g_clip_y + g_clip_h) {

src/kernel/gui_ipc.h

@@ -14,11 +14,15 @@
 #define GUI_EVENT_RIGHT_CLICK 3
 #define GUI_EVENT_CLOSE       4
 #define GUI_EVENT_KEY         5
+#define GUI_EVENT_MOUSE_DOWN  6
+#define GUI_EVENT_MOUSE_UP    7
+#define GUI_EVENT_MOUSE_MOVE  8
 
 typedef struct {
     int type;
     int arg1; // For click: x
     int arg2; // For click: y
+    int arg3; // For click: button state
 } gui_event_t;
 
 #endif

src/kernel/main.c

@@ -15,7 +15,6 @@
 #include "memory_manager.h"
 #include "platform.h"
 #include "wallpaper.h"
-#include "viewer.h"
 
 // --- Limine Requests ---
 __attribute__((used, section(".requests")))
@@ -183,7 +182,6 @@ void kmain(void) {
     while (1) {
         wm_process_input();
         wallpaper_process_pending();
-        viewer_process_pending();
         asm("hlt");
     }
 }

src/kernel/markdown.h

@@ -1,11 +0,0 @@
-#ifndef MARKDOWN_H
-#define MARKDOWN_H
-
-#include "wm.h"
-
-extern Window win_markdown;
-
-void markdown_init(void);
-void markdown_open_file(const char *filename);
-
-#endif

src/kernel/minesweeper.h

@@ -1,10 +0,0 @@
-#ifndef MINESWEEPER_H
-#define MINESWEEPER_H
-
-#include "wm.h"
-
-extern Window win_minesweeper;
-
-void minesweeper_init(void);
-
-#endif

src/kernel/paint.c

@@ -1,205 +0,0 @@
-#include "paint.h"
-#include "graphics.h"
-#include "wm.h"
-#include "memory_manager.h"
-#include "fat32.h"
-
-#define CANVAS_W 300
-#define CANVAS_H 200
-#define PAINT_MAGIC 0x544E5042 // 'BPNT'
-
-Window win_paint;
-static uint32_t *canvas_buffer = NULL;
-static uint32_t current_color = COLOR_BLACK;
-static int last_mx = -1;
-static int last_my = -1;
-static char current_file_path[256] = "/Desktop/drawing.pnt";
-
-static void paint_strcpy(char *dest, const char *src) {
-    while (*src) *dest++ = *src++;
-    *dest = 0;
-}
-
-static void paint_paint(Window *win) {
-    // Toolbar area - dark mode
-    draw_rounded_rect_filled(win->x + 10, win->y + 30, 40, win->h - 40, 6, COLOR_DARK_PANEL);
-    
-    // Color Palette with rounded corners
-    uint32_t colors[] = {COLOR_BLACK, COLOR_RED, COLOR_APPLE_GREEN, COLOR_APPLE_BLUE, COLOR_APPLE_YELLOW, COLOR_WHITE};
-    for (int i = 0; i < 6; i++) {
-        int cy = win->y + 40 + (i * 25);
-        draw_rounded_rect_filled(win->x + 15, cy, 30, 20, 3, colors[i]);
-        
-        // Highlight selected color with border
-        if (current_color == colors[i]) {
-            draw_rounded_rect(win->x + 13, cy - 2, 34, 24, 4, COLOR_DARK_TEXT);
-        }
-    }
-
-    // Toolbar Buttons - dark mode with rounded corners
-    draw_rounded_rect_filled(win->x + 12, win->y + win->h - 65, 36, 20, 4, COLOR_DARK_BORDER);
-    draw_string(win->x + 18, win->y + win->h - 58, "CLR", COLOR_DARK_TEXT);
-    
-    draw_rounded_rect_filled(win->x + 12, win->y + win->h - 40, 36, 20, 4, COLOR_DARK_BORDER);
-    draw_string(win->x + 18, win->y + win->h - 33, "SAV", COLOR_DARK_TEXT);
-
-    // Canvas Area with dark background and rounded corners
-    int canvas_x = win->x + 60;
-    int canvas_y = win->y + 30;
-    draw_rounded_rect_filled(canvas_x - 2, canvas_y - 2, CANVAS_W + 4, CANVAS_H + 4, 4, COLOR_DARK_BG);
-    
-    if (canvas_buffer) {
-        for (int y = 0; y < CANVAS_H; y++) {
-            for (int x = 0; x < CANVAS_W; x++) {
-                uint32_t color = canvas_buffer[y * CANVAS_W + x];
-                put_pixel(canvas_x + x, canvas_y + y, color);
-            }
-        }
-    }
-}
-
-static void paint_put_brush(int cx, int cy) {
-    if (!canvas_buffer) return;
-    for (int dy = 0; dy < 2; dy++) {
-        for (int dx = 0; dx < 2; dx++) {
-            int px = cx + dx;
-            int py = cy + dy;
-            if (px >= 0 && px < CANVAS_W && py >= 0 && py < CANVAS_H) {
-                canvas_buffer[py * CANVAS_W + px] = current_color;
-            }
-        }
-    }
-    wm_mark_dirty(win_paint.x + 60 + cx, win_paint.y + 30 + cy, 2, 2);
-}
-
-void paint_handle_mouse(int x, int y) {
-    int cx = x - 60;
-    int cy = y - 30;
-
-    if (cx < 0 || cx >= CANVAS_W || cy < 0 || cy >= CANVAS_H) {
-        last_mx = -1;
-        return;
-    }
-
-    if (last_mx == -1) {
-        paint_put_brush(cx, cy);
-    } else {
-        // Bresenham's line algorithm to fill gaps
-        int x0 = last_mx, y0 = last_my;
-        int x1 = cx, y1 = cy;
-        int dx = (x1 - x0 > 0) ? (x1 - x0) : (x0 - x1);
-        int dy = (y1 - y0 > 0) ? (y1 - y0) : (y0 - y1);
-        int sx = x0 < x1 ? 1 : -1;
-        int sy = y0 < y1 ? 1 : -1;
-        int err = dx - dy;
-
-        while (1) {
-            paint_put_brush(x0, y0);
-            if (x0 == x1 && y0 == y1) break;
-            int e2 = 2 * err;
-            if (e2 > -dy) { err -= dy; x0 += sx; }
-            if (e2 < dx) { err += dx; y0 += sy; }
-        }
-    }
-    last_mx = cx;
-    last_my = cy;
-}
-
-void paint_reset_last_pos(void) {
-    last_mx = -1;
-    last_my = -1;
-}
-
-static void paint_save(const char *path) {
-    FAT32_FileHandle *fh = fat32_open(path, "w");
-    if (fh) {
-        uint32_t header[3] = {PAINT_MAGIC, CANVAS_W, CANVAS_H};
-        fat32_write(fh, header, sizeof(header));
-        fat32_write(fh, canvas_buffer, CANVAS_W * CANVAS_H * sizeof(uint32_t));
-        fat32_close(fh);
-        wm_show_message("Paint", "Image saved.");
-    }
-}
-
-void paint_load(const char *path) {
-    paint_strcpy(current_file_path, path);
-    FAT32_FileHandle *fh = fat32_open(path, "r");
-    if (fh) {
-        uint32_t header[3];
-        if (fat32_read(fh, header, sizeof(header)) == sizeof(header)) {
-            if (header[0] == PAINT_MAGIC) {
-                fat32_read(fh, canvas_buffer, CANVAS_W * CANVAS_H * sizeof(uint32_t));
-                win_paint.visible = true;
-                win_paint.focused = true;
-            }
-        }
-        fat32_close(fh);
-    }
-}
-
-static void paint_click(Window *win, int x, int y) {
-    (void)win;
-    // Check Buttons
-    if (x >= 12 && x < 48) {
-        if (y >= win->h - 65 && y < win->h - 45) {
-            paint_reset();
-            wm_mark_dirty(win->x, win->y, win->w, win->h);
-            return;
-        }
-        if (y >= win->h - 40 && y < win->h - 20) {
-            paint_save(current_file_path);
-            return;
-        }
-    }
-
-    // Check Palette
-    if (x >= 15 && x < 45) {
-        for (int i = 0; i < 6; i++) {
-            int cy = 40 + (i * 25);
-            if (y >= cy && y < cy + 20) {
-                uint32_t colors[] = {COLOR_BLACK, COLOR_RED, COLOR_APPLE_GREEN, COLOR_APPLE_BLUE, COLOR_APPLE_YELLOW, COLOR_WHITE};
-                current_color = colors[i];
-                wm_mark_dirty(win->x, win->y, win->w, win->h);
-                return;
-            }
-        }
-    }
-    paint_handle_mouse(x, y);
-}
-
-static void paint_mouse_move(Window *win, int x, int y, uint8_t buttons) {
-    if (buttons & 0x01) { // Left button down
-        paint_handle_mouse(x, y);
-        wm_mark_dirty(win->x, win->y, win->w, win->h);
-    } else {
-        paint_reset_last_pos();
-    }
-}
-
-void paint_init(void) {
-    win_paint.title = "Paint";
-    win_paint.x = 150;
-    win_paint.y = 100;
-    win_paint.w = 380;
-    win_paint.h = 260;
-    win_paint.visible = false;
-    win_paint.focused = false;
-    win_paint.z_index = 0;
-    win_paint.paint = paint_paint;
-    win_paint.handle_click = paint_click;
-    win_paint.handle_right_click = NULL;
-    win_paint.handle_key = NULL;
-
-    if (!canvas_buffer) {
-        canvas_buffer = (uint32_t*)kmalloc(CANVAS_W * CANVAS_H * sizeof(uint32_t));
-        paint_reset();
-    }
-}
-
-void paint_reset(void) {
-    if (canvas_buffer) {
-        for (int i = 0; i < CANVAS_W * CANVAS_H; i++) {
-            canvas_buffer[i] = COLOR_WHITE;
-        }
-    }
-}

src/kernel/paint.h

@@ -1,14 +0,0 @@
-#ifndef PAINT_H
-#define PAINT_H
-
-#include "wm.h"
-
-extern Window win_paint;
-
-void paint_init(void);
-void paint_reset(void);
-void paint_handle_mouse(int x, int y);
-void paint_load(const char *path);
-void paint_reset_last_pos(void);
-
-#endif

src/kernel/process.c

@@ -119,6 +119,8 @@ void process_create_elf(const char* filepath, const char* args_str) {
     new_proc->gui_event_head = 0;
     new_proc->gui_event_tail = 0;
     new_proc->ui_window = NULL;
+    new_proc->heap_start = 0x20000000; // 512MB mark
+    new_proc->heap_end = 0x20000000;
 
     // 2. Load ELF executable
     uint64_t entry_point = elf_load(filepath, new_proc->pml4_phys);
@@ -352,7 +354,6 @@ void process_push_gui_event(process_t *proc, gui_event_t *ev) {
     // Drop event if queue is full
     if (next_tail == proc->gui_event_head) {
         extern void serial_write(const char *str);
-        serial_write("PROC: GUI event queue full, dropping event!\n");
         return;
     }
     proc->gui_events[proc->gui_event_tail] = *ev;

src/kernel/process.h

@@ -30,6 +30,9 @@ typedef struct process {
     int gui_event_tail;
     void *ui_window; // Pointer to the active Window
     
+    uint64_t heap_start;
+    uint64_t heap_end;
+    
     void *fds[MAX_PROCESS_FDS];
     
     struct process *next;

src/kernel/syscall.c

@@ -5,7 +5,8 @@
 #include "process.h"
 #include "wm.h"
 #include "fat32.h"
-#include "fat32.h"
+#include "paging.h"
+#include "platform.h"
 
 // Read MSR
 static inline uint64_t rdmsr(uint32_t msr) {
@@ -69,6 +70,50 @@ static void user_window_click(Window *win, int x, int y) {
     process_push_gui_event(proc, &ev);
 }
 
+static void user_window_right_click(Window *win, int x, int y) {
+    process_t *proc = (process_t *)win->data;
+    if (!proc) return;
+    gui_event_t ev = { .type = GUI_EVENT_RIGHT_CLICK, .arg1 = x, .arg2 = y };
+    process_push_gui_event(proc, &ev);
+}
+
+static void user_window_mouse_down(Window *win, int x, int y) {
+    process_t *proc = (process_t *)win->data;
+    if (!proc) return;
+    gui_event_t ev = { .type = GUI_EVENT_MOUSE_DOWN, .arg1 = x, .arg2 = y };
+    process_push_gui_event(proc, &ev);
+}
+
+static void user_window_mouse_up(Window *win, int x, int y) {
+    process_t *proc = (process_t *)win->data;
+    if (!proc) return;
+    gui_event_t ev = { .type = GUI_EVENT_MOUSE_UP, .arg1 = x, .arg2 = y };
+    process_push_gui_event(proc, &ev);
+}
+
+static void user_window_mouse_move(Window *win, int x, int y, uint8_t buttons) {
+    process_t *proc = (process_t *)win->data;
+    if (!proc) return;
+    gui_event_t ev = { .type = GUI_EVENT_MOUSE_MOVE, .arg1 = x, .arg2 = y, .arg3 = buttons };
+    process_push_gui_event(proc, &ev);
+}
+
+// Helper function for WM to send mouse events
+void syscall_send_mouse_move_event(Window *win, int x, int y, uint8_t buttons) {
+    if (!win || !win->data) return;
+    user_window_mouse_move(win, x, y, buttons);
+}
+
+void syscall_send_mouse_down_event(Window *win, int x, int y) {
+    if (!win || !win->data) return;
+    user_window_mouse_down(win, x, y);
+}
+
+void syscall_send_mouse_up_event(Window *win, int x, int y) {
+    if (!win || !win->data) return;
+    user_window_mouse_up(win, x, y);
+}
+
 static void user_window_key(Window *win, char c) {
     process_t *proc = (process_t *)win->data;
     if (!proc) return;
@@ -185,9 +230,9 @@ uint64_t syscall_handler_c(uint64_t syscall_num, uint64_t arg1, uint64_t arg2, u
             // Set callbacks
             win->paint = user_window_paint;
             win->handle_click = user_window_click;
+            win->handle_right_click = user_window_right_click;
             win->handle_close = user_window_close;
             win->handle_key = user_window_key;
-            win->handle_right_click = NULL;
             
             proc->ui_window = win;
             wm_add_window(win);
@@ -398,6 +443,110 @@ uint64_t syscall_handler_c(uint64_t syscall_num, uint64_t arg1, uint64_t arg2, u
         extern void serial_write(const char *str);
         serial_write((const char *)arg2);
         return 0;
+    } else if (syscall_num == 9) { // SYS_SBRK
+        int incr = (int)arg1;
+        process_t *proc = process_get_current();
+        if (!proc || !proc->is_user) return (uint64_t)-1;
+        
+        uint64_t old_end = proc->heap_end;
+        if (incr == 0) return old_end;
+        
+        uint64_t new_end = old_end + incr;
+        
+        // If expanding, we might need to map new pages
+        if (incr > 0) {
+            uint64_t start_page = (old_end + 0xFFF) & ~0xFFF;
+            uint64_t end_page = (new_end + 0xFFF) & ~0xFFF;
+            
+            for (uint64_t page = start_page; page < end_page; page += 4096) {
+                void *phys = kmalloc_aligned(4096, 4096);
+                if (!phys) return (uint64_t)-1; // Out of memory
+                
+                extern void mem_memset(void *dest, int val, size_t len);
+                mem_memset(phys, 0, 4096);
+                
+                paging_map_page(proc->pml4_phys, page, v2p((uint64_t)phys), 0x07); // PT_PRESENT | PT_RW | PT_USER
+            }
+        }
+        
+        proc->heap_end = new_end;
+        return old_end;
+    } else if (syscall_num == 5) { // SYS_SYSTEM
+        int cmd = (int)arg1;
+        if (cmd == 1) { // SYSTEM_CMD_SET_BG_COLOR
+            uint32_t color = (uint32_t)arg2;
+            extern void graphics_set_bg_color(uint32_t color);
+            graphics_set_bg_color(color);
+            return 0;
+        } else if (cmd == 2) { // SYSTEM_CMD_SET_BG_PATTERN
+            uint32_t *user_pat = (uint32_t *)arg2;
+            if (!user_pat) {
+                extern void graphics_set_bg_pattern(uint32_t *pattern);
+                graphics_set_bg_pattern(NULL);
+            } else {
+                static uint32_t global_bg_pattern[128*128];
+                for (int i=0; i<128*128; i++) {
+                    global_bg_pattern[i] = user_pat[i];
+                }
+                extern void graphics_set_bg_pattern(uint32_t *pattern);
+                graphics_set_bg_pattern(global_bg_pattern);
+            }
+            extern void wm_refresh(void);
+            wm_refresh();
+            return 0;
+        } else if (cmd == 3) { // SYSTEM_CMD_SET_WALLPAPER
+            int wp_id = (int)arg2;
+            extern void wallpaper_request_set(int index);
+            wallpaper_request_set(wp_id);
+            return 0;
+        } else if (cmd == 4) { // SYSTEM_CMD_SET_DESKTOP_PROP
+            int prop = (int)arg2;
+            int val = (int)arg3;
+            extern _Bool desktop_snap_to_grid;
+            extern _Bool desktop_auto_align;
+            extern int desktop_max_rows_per_col;
+            extern int desktop_max_cols;
+            if (prop == 1) desktop_snap_to_grid = val;
+            if (prop == 2) desktop_auto_align = val;
+            if (prop == 3) desktop_max_rows_per_col = val;
+            if (prop == 4) desktop_max_cols = val;
+            extern void wm_refresh_desktop(void);
+            wm_refresh_desktop();
+            return 0;
+        } else if (cmd == 5) { // SYSTEM_CMD_SET_MOUSE_SPEED
+            extern int mouse_speed;
+            mouse_speed = (int)arg2;
+            return 0;
+        } else if (cmd == 6) { // SYSTEM_CMD_NETWORK_INIT
+            extern int network_init(void);
+            return network_init();
+        } else if (cmd == 7) { // SYSTEM_CMD_GET_DESKTOP_PROP
+            int prop = (int)arg2;
+            extern _Bool desktop_snap_to_grid;
+            extern _Bool desktop_auto_align;
+            extern int desktop_max_rows_per_col;
+            extern int desktop_max_cols;
+            if (prop == 1) return desktop_snap_to_grid;
+            if (prop == 2) return desktop_auto_align;
+            if (prop == 3) return desktop_max_rows_per_col;
+            if (prop == 4) return desktop_max_cols;
+            return 0;
+        } else if (cmd == 8) { // SYSTEM_CMD_GET_MOUSE_SPEED
+            extern int mouse_speed;
+            return mouse_speed;
+        } else if (cmd == 9) { // SYSTEM_CMD_GET_WALLPAPER_THUMB
+            int id = (int)arg2;
+            uint32_t *dest = (uint32_t *)arg3;
+            if (!dest) return -1;
+            extern uint32_t* wallpaper_get_thumb(int index);
+            extern _Bool wallpaper_thumb_valid(int index);
+            if (!wallpaper_thumb_valid(id)) return -1;
+            uint32_t *thumb = wallpaper_get_thumb(id);
+            if (!thumb) return -1;
+            for (int i=0; i<100*60; i++) dest[i] = thumb[i];
+            return 0;
+        }
+        return -1;
     }
     
     return 0;

src/kernel/syscall.h

@@ -3,6 +3,9 @@
 
 #include <stdint.h>
 
+// Forward declarations
+typedef struct Window Window;
+
 // MSRs used for syscalls in x86_64
 #define MSR_EFER       0xC0000080
 #define MSR_STAR       0xC0000081
@@ -32,4 +35,9 @@
 void syscall_init(void);
 uint64_t syscall_handler_c(uint64_t syscall_num, uint64_t arg1, uint64_t arg2, uint64_t arg3, uint64_t arg4, uint64_t arg5);
 
+// Mouse event helpers for WM
+void syscall_send_mouse_move_event(Window *win, int x, int y, uint8_t buttons);
+void syscall_send_mouse_down_event(Window *win, int x, int y);
+void syscall_send_mouse_up_event(Window *win, int x, int y);
+
 #endif // SYSCALL_H

src/kernel/userland/Makefile

@@ -8,7 +8,7 @@ LDFLAGS = -m elf_x86_64 -nostdlib -static -no-pie -Ttext=0x40000000 --no-dynamic
 LIBC_SOURCES = $(wildcard libc/*.c)
 LIBC_OBJS = $(LIBC_SOURCES:.c=.o) crt0.o
 
-APP_SOURCES = $(wildcard *.c)
+APP_SOURCES = $(filter-out nanojpeg.c, $(wildcard *.c))
 APP_OBJS = $(APP_SOURCES:.c=.o)
 APP_ELFS = $(APP_SOURCES:.c=.elf)
 
@@ -23,6 +23,9 @@ libc/%.o: libc/%.c
 %.o: %.c
 	$(CC) $(CFLAGS) -c $< -o $@
 
+viewer.elf: $(LIBC_OBJS) viewer.o nanojpeg.o
+	$(LD) $(LDFLAGS) $^ -o $@
+
 %.elf: $(LIBC_OBJS) %.o
 	$(LD) $(LDFLAGS) $^ -o $@
 

src/kernel/userland/calculator.c

@@ -4,7 +4,6 @@
 
 #define SCALE 1000000LL
 
-// Dark Mode Colors mapping to libui
 #define COLOR_DARK_BG       0xFF1E1E1E
 #define COLOR_DARK_PANEL    0xFF2D2D2D
 #define COLOR_DARK_TEXT     0xFFF0F0F0

src/kernel/userland/crash.c

@@ -4,7 +4,7 @@ int main() {
     const char* msg = "Attempting to crash via null dereference...\n";
     sys_write(1, msg, 45);
     
-    // Null pointer dereference
+    // Null pointer dereference (should not crash the system and instead get this process killed)
     volatile int* p = (int*)0;
     *p = 123;
     

src/kernel/userland/libc/libui.h

@@ -20,10 +20,15 @@
 #define GUI_EVENT_CLOSE       4
 #define GUI_EVENT_KEY         5
 
+#define GUI_EVENT_MOUSE_DOWN  6
+#define GUI_EVENT_MOUSE_UP    7
+#define GUI_EVENT_MOUSE_MOVE  8
+
 typedef struct {
     int type;
     int arg1; // For click: x
     int arg2; // For click: y
+    int arg3; // For click: button state
 } gui_event_t;
 
 // Window Handle

src/kernel/userland/libc/stdlib.c

@@ -0,0 +1,140 @@
+#include "stdlib.h"
+#include "syscall.h"
+
+// Simple block allocator over sys_sbrk
+typedef struct BlockMeta {
+    size_t size;
+    int free;
+    struct BlockMeta *next;
+} BlockMeta;
+
+#define META_SIZE sizeof(BlockMeta)
+
+static void *global_base = NULL;
+
+static BlockMeta *find_free_block(BlockMeta **last, size_t size) {
+    BlockMeta *current = global_base;
+    while (current && !(current->free && current->size >= size)) {
+        *last = current;
+        current = current->next;
+    }
+    return current;
+}
+
+static BlockMeta *request_space(BlockMeta* last, size_t size) {
+    BlockMeta *block;
+    block = (BlockMeta *)sys_sbrk(0);
+    // Ask for space, ensuring everything stays 8-byte aligned if sizes are odd.
+    // For simplicity, we just request exactly what is needed, 
+    // but typically `size` should be aligned.
+    size_t align = 8;
+    if (size % align != 0) {
+        size += align - (size % align);
+    }
+    
+    void *request = sys_sbrk(size + META_SIZE);
+    if (request == (void*)-1) {
+        return NULL; // sbrk failed
+    }
+
+    if (last) { // NULL on first request
+        last->next = block;
+    }
+    block->size = size;
+    block->next = NULL;
+    block->free = 0;
+    return block;
+}
+
+void *malloc(size_t size) {
+    BlockMeta *block;
+    if (size <= 0) {
+        return NULL;
+    }
+
+    // Align size to 8 bytes for safety
+    size_t align = 8;
+    if (size % align != 0) {
+        size += align - (size % align);
+    }
+
+    if (!global_base) { // First call
+        block = request_space(NULL, size);
+        if (!block) return NULL;
+        global_base = block;
+    } else {
+        BlockMeta *last = global_base;
+        block = find_free_block(&last, size);
+        if (!block) { // Failed to find free block
+            block = request_space(last, size);
+            if (!block) return NULL;
+        } else { // Found free block
+            block->free = 0;
+            // We could split the block here if block->size is much larger than size...
+        }
+    }
+
+    return (block + 1);
+}
+
+void free(void *ptr) {
+    if (!ptr) {
+        return;
+    }
+
+    BlockMeta *block = (BlockMeta*)ptr - 1;
+    block->free = 1;
+}
+
+void *calloc(size_t nelem, size_t elsize) {
+    size_t size = nelem * elsize;
+    void *ptr = malloc(size);
+    if (ptr) {
+        char *p = ptr;
+        for (size_t i = 0; i < size; i++) {
+            p[i] = 0;
+        }
+    }
+    return ptr;
+}
+
+void *realloc(void *ptr, size_t size) {
+    if (!ptr) {
+        return malloc(size);
+    }
+    if (size == 0) {
+        free(ptr);
+        return NULL;
+    }
+
+    BlockMeta *block = (BlockMeta*)ptr - 1;
+    if (block->size >= size) {
+        return ptr;
+    }
+
+    void *new_ptr = malloc(size);
+    if (!new_ptr) {
+        return NULL;
+    }
+
+    char *src = ptr;
+    char *dst = new_ptr;
+    for (size_t i = 0; i < block->size; i++) {
+        dst[i] = src[i];
+    }
+    free(ptr);
+    return new_ptr;
+}
+
+void *memset(void *s, int c, size_t n) {
+    unsigned char *p = s;
+    while (n--) *p++ = (unsigned char)c;
+    return s;
+}
+
+void *memcpy(void *dest, const void *src, size_t n) {
+    unsigned char *d = dest;
+    const unsigned char *s = src;
+    while (n--) *d++ = *s++;
+    return dest;
+}

src/kernel/userland/libc/stdlib.h

@@ -0,0 +1,14 @@
+#ifndef STDLIB_H
+#define STDLIB_H
+
+#include <stddef.h>
+#include <stdint.h>
+
+void* malloc(size_t size);
+void free(void* ptr);
+void* calloc(size_t nmemb, size_t size);
+void* realloc(void* ptr, size_t size);
+void *memset(void *s, int c, size_t n);
+void *memcpy(void *dest, const void *src, size_t n);
+
+#endif

src/kernel/userland/libc/syscall.c

@@ -70,6 +70,14 @@ int sys_write(int fd, const char *buf, int len) {
     return (int)syscall3(SYS_WRITE, (uint64_t)fd, (uint64_t)buf, (uint64_t)len);
 }
 
+void *sys_sbrk(int incr) {
+    return (void *)syscall1(SYS_SBRK, (uint64_t)incr);
+}
+
+int sys_system(int cmd, uint64_t arg1, uint64_t arg2, uint64_t arg3, uint64_t arg4) {
+    return (int)syscall5(SYS_SYSTEM, (uint64_t)cmd, arg1, arg2, arg3, arg4);
+}
+
 int sys_open(const char *path, const char *mode) {
     return (int)syscall3(SYS_FS, FS_CMD_OPEN, (uint64_t)path, (uint64_t)mode);
 }

src/kernel/userland/libc/syscall.h

@@ -8,6 +8,8 @@
 #define SYS_WRITE 1
 #define SYS_GUI   3
 #define SYS_FS    4
+#define SYS_SYSTEM 5
+#define SYS_SBRK  9
 
 // FS Commands
 #define FS_CMD_OPEN 1
@@ -33,6 +35,8 @@ extern uint64_t syscall5(uint64_t sys_num, uint64_t arg1, uint64_t arg2, uint64_
 // Public API
 void sys_exit(int status);
 int sys_write(int fd, const char *buf, int len);
+void *sys_sbrk(int incr);
+int sys_system(int cmd, uint64_t arg1, uint64_t arg2, uint64_t arg3, uint64_t arg4);
 
 // FS API
 int sys_open(const char *path, const char *mode);

src/kernel/userland/markdown.c

@@ -1,20 +1,19 @@
-#include "markdown.h"
-#include "graphics.h"
-#include "fat32.h"
-#include "wm.h"
+#include "libc/syscall.h"
+#include "libc/libui.h"
 #include <stdbool.h>
 #include <stddef.h>
-
-// === Markdown Viewer State ===
-Window win_markdown;
+#include <stdint.h>
 
 #define MD_MAX_CONTENT 16384
 #define MD_MAX_LINES 256
 #define MD_CHAR_WIDTH 8
 #define MD_LINE_HEIGHT 16
-#define MD_CONTENT_Y 40
-#define MD_PADDING_X 12
-#define MD_CONTENT_WIDTH 400
+
+#define COLOR_DARK_PANEL    0xFF202020
+#define COLOR_DARK_BG       0xFF121212
+#define COLOR_DARK_TEXT     0xFFE0E0E0
+#define COLOR_DARK_TITLEBAR 0xFF303030
+#define COLOR_BLACK         0xFF000000
 
 typedef enum {
     MD_LINE_NORMAL,
@@ -40,7 +39,8 @@ static int line_count = 0;
 static int scroll_top = 0;
 static char open_filename[256] = "";
 
-// === Helper Functions ===
+static int win_w = 600;
+static int win_h = 400;
 
 static size_t md_strlen(const char *str) {
     size_t len = 0;
@@ -63,64 +63,42 @@ static int md_strncpy(char *dest, const char *src, int n) {
     return i;
 }
 
-static int md_strcmp(const char *s1, const char *s2) {
-    (void)s1;  // Suppress unused warning
-    (void)s2;  // Suppress unused warning
-    return 0;
-}
-
-// Check if string starts with pattern
-static bool md_starts_with(const char *str, const char *pattern) {
-    (void)str;  // Suppress unused warning
-    (void)pattern;  // Suppress unused warning
-    return false;
-}
-
-// Parse markdown line and extract formatted text
 static void md_parse_line(const char *raw_line, char *output, MDLineType *type, int *indent) {
     int i = 0;
     int out_idx = 0;
     *indent = 0;
     *type = MD_LINE_NORMAL;
     
-    // Skip leading whitespace and count indentation
     while (raw_line[i] == ' ' || raw_line[i] == '\t') {
         if (raw_line[i] == '\t') *indent += 2;
         else *indent += 1;
         i++;
     }
     
-    // Detect line type
     if (raw_line[i] == '#') {
-        // Heading
         int hash_count = 0;
         while (raw_line[i] == '#') {
             hash_count++;
             i++;
         }
-        // Skip space after hashes
         if (raw_line[i] == ' ') i++;
         
         if (hash_count == 1) *type = MD_LINE_HEADING1;
         else if (hash_count == 2) *type = MD_LINE_HEADING2;
         else if (hash_count <= 6) *type = MD_LINE_HEADING3;
     } else if (raw_line[i] == '-' || raw_line[i] == '*') {
-        // Could be list or horizontal rule
         if ((raw_line[i] == '-' || raw_line[i] == '*') && (raw_line[i+1] == ' ' || raw_line[i+1] == '\t')) {
             *type = MD_LINE_LIST;
-            i += 2;  // Skip '- ' or '* '
-            while (raw_line[i] == ' ' || raw_line[i] == '\t') i++;  // Skip extra spaces
+            i += 2;
+            while (raw_line[i] == ' ' || raw_line[i] == '\t') i++;
         }
     } else if (raw_line[i] == '>') {
-        // Blockquote
         *type = MD_LINE_BLOCKQUOTE;
         i++;
         if (raw_line[i] == ' ') i++;
     }
     
-    // Parse inline formatting and copy content
     while (raw_line[i] && out_idx < 255) {
-        // Handle bold **text**
         if (raw_line[i] == '*' && raw_line[i+1] == '*') {
             i += 2;
             while (raw_line[i] && !(raw_line[i] == '*' && raw_line[i+1] == '*') && out_idx < 255) {
@@ -129,8 +107,6 @@ static void md_parse_line(const char *raw_line, char *output, MDLineType *type,
             if (raw_line[i] == '*' && raw_line[i+1] == '*') i += 2;
             continue;
         }
-        
-        // Handle italic *text* or _text_
         if ((raw_line[i] == '*' || raw_line[i] == '_') && out_idx > 0 && raw_line[i-1] != '\\') {
             char delim = raw_line[i];
             i++;
@@ -140,8 +116,6 @@ static void md_parse_line(const char *raw_line, char *output, MDLineType *type,
             if (raw_line[i] == delim) i++;
             continue;
         }
-        
-        // Handle inline code `code`
         if (raw_line[i] == '`') {
             i++;
             while (raw_line[i] && raw_line[i] != '`' && out_idx < 255) {
@@ -150,29 +124,23 @@ static void md_parse_line(const char *raw_line, char *output, MDLineType *type,
             if (raw_line[i] == '`') i++;
             continue;
         }
-        
-        // Handle links [text](url) - keep only text
         if (raw_line[i] == '[') {
             i++;
             while (raw_line[i] && raw_line[i] != ']' && out_idx < 255) {
                 output[out_idx++] = raw_line[i++];
             }
             if (raw_line[i] == ']') i++;
-            // Skip (url)
             if (raw_line[i] == '(') {
                 while (raw_line[i] && raw_line[i] != ')') i++;
                 if (raw_line[i] == ')') i++;
             }
             continue;
         }
-        
         output[out_idx++] = raw_line[i++];
     }
-    
     output[out_idx] = 0;
 }
 
-// Clear all markdown lines
 static void md_clear_all(void) {
     for (int i = 0; i < MD_MAX_LINES; i++) {
         lines[i].content[0] = 0;
@@ -185,29 +153,20 @@ static void md_clear_all(void) {
     open_filename[0] = 0;
 }
 
-// Load and parse markdown file
 void markdown_open_file(const char *filename) {
     md_clear_all();
     md_strcpy(open_filename, filename);
     
-    FAT32_FileHandle *fh = fat32_open(filename, "r");
-    if (!fh) {
-        // File not found
-        return;
-    }
+    int fd = sys_open(filename, "r");
+    if (fd < 0) return;
     
-    // Read file content
-    char buffer[MD_MAX_CONTENT];
-    int bytes_read = fat32_read(fh, buffer, sizeof(buffer) - 1);
-    fat32_close(fh);
-    
-    if (bytes_read <= 0) {
-        return;
-    }
+    static char buffer[MD_MAX_CONTENT];
+    int bytes_read = sys_read(fd, buffer, sizeof(buffer) - 1);
+    sys_close(fd);
     
+    if (bytes_read <= 0) return;
     buffer[bytes_read] = 0;
     
-    // Parse into markdown lines
     int line = 0;
     int col = 0;
     char raw_line[256] = "";
@@ -215,10 +174,8 @@ void markdown_open_file(const char *filename) {
     
     for (int i = 0; i < bytes_read && line < MD_MAX_LINES; i++) {
         char ch = buffer[i];
-        
         if (ch == '\n') {
             raw_line[col] = 0;
-
             if (raw_line[0] == '`' && raw_line[1] == '`' && raw_line[2] == '`') {
                 in_code_block = !in_code_block;
             } else {
@@ -240,7 +197,6 @@ void markdown_open_file(const char *filename) {
                     line++;
                 }
             }
-
             col = 0;
             raw_line[0] = 0;
         } else if (col < 255) {
@@ -248,7 +204,6 @@ void markdown_open_file(const char *filename) {
         }
     }
     
-    // Handle last line if no trailing newline
     if (col > 0 && line < MD_MAX_LINES) {
         raw_line[col] = 0;
         if (raw_line[0] == '`' && raw_line[1] == '`' && raw_line[2] == '`') {
@@ -270,48 +225,38 @@ void markdown_open_file(const char *filename) {
             line++;
         }
     }
-    
     line_count = line;
 }
 
-// === Paint Function ===
-
-// Helper to draw text with emphasis (bold effect by overlaying)
-static void md_draw_text_bold(int x, int y, const char *text, uint32_t color) {
-    draw_string(x, y, text, color);
-    draw_string(x + 1, y, text, color);
+static void md_draw_text_bold(ui_window_t win, int x, int y, const char *text, uint32_t color) {
+    ui_draw_string(win, x, y, text, color);
+    ui_draw_string(win, x + 1, y, text, color);
 }
 
-static void md_paint(Window *win) {
-    int offset_x = win->x + 4;
-    int offset_y = win->y + 24;
-    int content_width = win->w - 8;
-    int content_height = win->h - 28;
+static void md_paint(ui_window_t win) {
+    int offset_x = 4;
+    int offset_y = 24;
+    int content_width = win_w - 8;
+    int content_height = win_h - 28;
     
-    // Draw filename bar below title (dark mode)
-    draw_rounded_rect_filled(offset_x, offset_y, content_width, 20, 6, COLOR_DARK_PANEL);
-    draw_string(offset_x + 4, offset_y + 4, "File", COLOR_DARK_TEXT);
-    draw_string(offset_x + 50, offset_y + 4, open_filename, COLOR_DARK_TEXT);
+    ui_draw_rounded_rect_filled(win, offset_x, offset_y, content_width, 20, 6, COLOR_DARK_PANEL);
+    ui_draw_string(win, offset_x + 4, offset_y + 4, "File", COLOR_DARK_TEXT);
+    ui_draw_string(win, offset_x + 50, offset_y + 4, open_filename, COLOR_DARK_TEXT);
     
-    // Draw scroll buttons on top right with rounded style
     int btn_x_up = offset_x + content_width - 50;
     int btn_y = offset_y + 2;
-    draw_rounded_rect_filled(btn_x_up, btn_y, 20, 16, 4, COLOR_DARK_TITLEBAR);
-    draw_string(btn_x_up + 6, btn_y, "^", COLOR_DARK_TEXT);
-    draw_rounded_rect_filled(btn_x_up + 24, btn_y, 20, 16, 4, COLOR_DARK_TITLEBAR);
-    draw_string(btn_x_up + 30, btn_y, "v", COLOR_DARK_TEXT);
+    ui_draw_rounded_rect_filled(win, btn_x_up, btn_y, 20, 16, 4, COLOR_DARK_TITLEBAR);
+    ui_draw_string(win, btn_x_up + 6, btn_y, "^", COLOR_DARK_TEXT);
+    ui_draw_rounded_rect_filled(win, btn_x_up + 24, btn_y, 20, 16, 4, COLOR_DARK_TITLEBAR);
+    ui_draw_string(win, btn_x_up + 30, btn_y, "v", COLOR_DARK_TEXT);
     
-    // Content area - starts below filename bar
     int content_start_y = offset_y + 24;
     int content_start_x = offset_x + 4;
-    int usable_content_width = content_width - 8 - 20;  // Reserved space for scroll button
+    int usable_content_width = content_width - 8 - 20;
     int usable_content_height = content_height - 28;
     int max_display_lines = usable_content_height / MD_LINE_HEIGHT;
     
-    // Draw content background (dark mode)
-    draw_rounded_rect_filled(win->x + 4, content_start_y, win->w - 24, usable_content_height, 6, COLOR_DARK_BG);
-    
-
+    ui_draw_rounded_rect_filled(win, 4, content_start_y, win_w - 24, usable_content_height, 6, COLOR_DARK_BG);
     
     int display_line = 0;
     int i = scroll_top;
@@ -319,7 +264,6 @@ static void md_paint(Window *win) {
     while (i < line_count && display_line < max_display_lines) {
         MDLine *line = &lines[i];
         
-        // Determine spacing and text properties based on heading level (dark mode colors)
         int line_height = MD_LINE_HEIGHT;
         int extra_spacing = 0;
         uint32_t text_color = COLOR_DARK_TEXT;
@@ -327,148 +271,117 @@ static void md_paint(Window *win) {
         
         switch (line->type) {
             case MD_LINE_HEADING1:
-                line_height = MD_LINE_HEIGHT * 2;  // Double height
-                text_color = 0xFF87CEEB;  // Light blue
+                line_height = MD_LINE_HEIGHT * 2;
+                text_color = 0xFF87CEEB;
                 use_bold = true;
                 extra_spacing = 4;
                 break;
             case MD_LINE_HEADING2:
-                line_height = MD_LINE_HEIGHT + 6;  // 1.5x height
-                text_color = 0xFF4A90E2;  // Medium blue
+                line_height = MD_LINE_HEIGHT + 6;
+                text_color = 0xFF4A90E2;
                 use_bold = true;
                 extra_spacing = 2;
                 break;
             case MD_LINE_HEADING3:
-                line_height = MD_LINE_HEIGHT + 2;  // Slightly larger
-                text_color = 0xFF87CEEB;  // Light blue
+                line_height = MD_LINE_HEIGHT + 2;
+                text_color = 0xFF87CEEB;
                 use_bold = false;
                 break;
             case MD_LINE_BLOCKQUOTE:
-                text_color = 0xFFA0A0A0;  // Light gray
+                text_color = 0xFFA0A0A0;
                 break;
             case MD_LINE_CODE:
-                text_color = 0xFF90EE90;  // Light green for code
+                text_color = 0xFF90EE90;
                 break;
             default:
                 text_color = COLOR_DARK_TEXT;
                 break;
         }
         
-        // Check if this heading will fit on the screen
-        if (display_line + (line_height / MD_LINE_HEIGHT) > max_display_lines) {
-            break;  // Stop rendering if heading won't fit
-        }
+        if (display_line + (line_height / MD_LINE_HEIGHT) > max_display_lines) break;
         
-        // Adjust X position based on indentation
         int x_offset = content_start_x + (line->indent_level * 4);
         int available_width = usable_content_width - (line->indent_level * 4);
         int max_chars_per_line = available_width / MD_CHAR_WIDTH;
-        
         if (max_chars_per_line < 1) max_chars_per_line = 1;
         
-        // Handle line wrapping (word-based)
         const char *text = line->content;
         int text_len = line->length;
         int char_idx = 0;
         int local_display_line = 0;
         int wrapped_line_count = 0;
         
-        while (char_idx < text_len) {
+        while (char_idx < text_len || (text_len == 0 && local_display_line == 0)) {
             int line_y = content_start_y + display_line * MD_LINE_HEIGHT + (local_display_line * MD_LINE_HEIGHT);
             
-            // Extract line segment - copy up to max_chars_per_line characters
             char line_segment[256];
             int segment_len = 0;
             int segment_start = char_idx;
             
-            // Copy characters up to max_chars_per_line OR until end of string
             while (char_idx < text_len && segment_len < max_chars_per_line) {
                 line_segment[segment_len++] = text[char_idx++];
             }
             line_segment[segment_len] = 0;
             
             if (char_idx < text_len && segment_len > 0) {
-                // Look for the last space in the segment
                 int last_space = -1;
-                for (int i = segment_len - 1; i >= 0; i--) {
-                    if (line_segment[i] == ' ') {
-                        last_space = i;
-                        break;
+                for (int j = segment_len - 1; j >= 0; j--) {
+                    if (line_segment[j] == ' ') {
+                        last_space = j; break;
                     }
                 }
-                
                 if (last_space > 0) {
                     segment_len = last_space;
                     line_segment[segment_len] = 0;
-                    // Backtrack char_idx to position after the space
                     char_idx = segment_start + last_space + 1;
-                    // Skip any additional spaces at the start of next line
-                    while (char_idx < text_len && text[char_idx] == ' ') {
-                        char_idx++;
-                    }
+                    while (char_idx < text_len && text[char_idx] == ' ') char_idx++;
                 }
             }
             
             if (line->type == MD_LINE_CODE && segment_len > 0) {
-                draw_rect(x_offset - 2, line_y - 2, (segment_len * MD_CHAR_WIDTH) + 4, 12, COLOR_BLACK);
+                ui_draw_rect(win, x_offset - 2, line_y - 2, (segment_len * MD_CHAR_WIDTH) + 4, 12, COLOR_BLACK);
             }
 
-            // Draw special elements for first wrapped line of this markdown line
             if (local_display_line == 0) {
                 switch (line->type) {
                     case MD_LINE_LIST:
-                        // Draw bullet point
-                        draw_rect(x_offset, line_y + MD_LINE_HEIGHT/2 - 1, 2, 2, COLOR_BLACK);
+                        ui_draw_rect(win, x_offset, line_y + MD_LINE_HEIGHT/2 - 1, 2, 2, COLOR_BLACK);
                         x_offset += 12;
-                        // Redraw segment without leading space
                         if (segment_len > 0 && line_segment[0] == ' ') {
-                            for (int j = 0; j < segment_len - 1; j++) {
-                                line_segment[j] = line_segment[j + 1];
-                            }
+                            for (int j = 0; j < segment_len - 1; j++) line_segment[j] = line_segment[j + 1];
                             segment_len--;
                         }
                         break;
                     case MD_LINE_BLOCKQUOTE:
-                        // Draw left border
-                        draw_rect(x_offset - 4, line_y, 2, line_height, 0xFF404080);
-                        break;
-                    default:
+                        ui_draw_rect(win, x_offset - 4, line_y, 2, line_height, 0xFF404080);
                         break;
+                    default: break;
                 }
             }
             
-            // Draw the text segment with appropriate styling
             if (segment_len > 0) {
                 if (use_bold) {
-                    md_draw_text_bold(x_offset, line_y + extra_spacing, line_segment, text_color);
+                    md_draw_text_bold(win, x_offset, line_y + extra_spacing, line_segment, text_color);
                 } else {
-                    draw_string(x_offset, line_y, line_segment, text_color);
+                    ui_draw_string(win, x_offset, line_y, line_segment, text_color);
                 }
             }
             
             local_display_line++;
             wrapped_line_count++;
-            
             if (char_idx >= text_len) break;
         }
         
-
-        display_line += wrapped_line_count;
-        
+        display_line += (wrapped_line_count > 0 ? wrapped_line_count : 1);
         i++;
     }
 }
 
-// === Input Handling ===
-
-static void md_handle_key(Window *win, char c) {
-    (void)win;  // Suppress unused warning
-    
-
-    if (c == 'w' || c == 'W' || c == 17) {  // Page up or UP arrow
+static void md_handle_key(char c) {
+    if (c == 'w' || c == 'W' || c == 17) {
         scroll_top -= 3;
         if (scroll_top < 0) scroll_top = 0;
-    } else if (c == 's' || c == 'S' || c == 18) {  // Page down or DOWN arrow  
+    } else if (c == 's' || c == 'S' || c == 18) {
         scroll_top += 3;
         int max_scroll = line_count - 10;
         if (scroll_top > max_scroll) scroll_top = max_scroll;
@@ -476,24 +389,18 @@ static void md_handle_key(Window *win, char c) {
     }
 }
 
-static void md_handle_click(Window *win, int x, int y) {
-    // x and y are relative to window origin
-    int content_width = win->w - 8;
-    
-    // Top right up button: 4 + content_width - 50, 24 + 2, 20x16
+static void md_handle_click(int x, int y) {
+    int content_width = win_w - 8;
     int btn_x_up = 4 + content_width - 50;
     int btn_y = 24 + 2;
     if (x >= btn_x_up && x < btn_x_up + 20 && y >= btn_y && y < btn_y + 16) {
-        // Scroll up
         scroll_top -= 3;
         if (scroll_top < 0) scroll_top = 0;
         return;
     }
     
-    // Top right down button: 4 + content_width - 50 + 24, 24 + 2, 20x16
     int btn_x_down_top = 4 + content_width - 50 + 24;
     if (x >= btn_x_down_top && x < btn_x_down_top + 20 && y >= btn_y && y < btn_y + 16) {
-        // Scroll down
         scroll_top += 3;
         int max_scroll = line_count - 10;
         if (scroll_top > max_scroll) scroll_top = max_scroll;
@@ -502,21 +409,33 @@ static void md_handle_click(Window *win, int x, int y) {
     }
 }
 
-// === Initialization ===
-
-void markdown_init(void) {
-    win_markdown.title = "Markdown Viewer";
-    win_markdown.x = 150;
-    win_markdown.y = 180;
-    win_markdown.w = 600;
-    win_markdown.h = 400;
-    win_markdown.visible = false;
-    win_markdown.focused = false;
-    win_markdown.z_index = 0;
-    win_markdown.paint = md_paint;
-    win_markdown.handle_key = md_handle_key;
-    win_markdown.handle_click = md_handle_click;
-    win_markdown.handle_right_click = NULL;
+int main(int argc, char **argv) {
+    ui_window_t win = ui_window_create("Markdown Viewer", 150, 180, win_w, win_h);
+    if (!win) return 1;
 
     md_clear_all();
+    if (argc > 1) {
+        markdown_open_file(argv[1]);
+    }
+
+    gui_event_t ev;
+    while (1) {
+        if (ui_get_event(win, &ev)) {
+            if (ev.type == GUI_EVENT_PAINT) {
+                md_paint(win);
+                ui_mark_dirty(win, 0, 0, win_w, win_h);
+            } else if (ev.type == GUI_EVENT_CLICK) {
+                md_handle_click(ev.arg1, ev.arg2);
+                md_paint(win);
+                ui_mark_dirty(win, 0, 0, win_w, win_h);
+            } else if (ev.type == GUI_EVENT_KEY) {
+                md_handle_key((char)ev.arg1);
+                md_paint(win);
+                ui_mark_dirty(win, 0, 0, win_w, win_h);
+            } else if (ev.type == GUI_EVENT_CLOSE) {
+                sys_exit(0);
+            }
+        }
+    }
+    return 0;
 }

src/kernel/userland/minesweeper.c

@@ -1,10 +1,23 @@
-#include "minesweeper.h"
-#include "graphics.h"
-#include "wm.h"
+#include "libc/syscall.h"
+#include "libc/libui.h"
 #include <stdbool.h>
 #include <stddef.h>
+#include <stdint.h>
 
-Window win_minesweeper;
+#define COLOR_DARK_BG       0xFF121212
+#define COLOR_DARK_PANEL    0xFF202020
+#define COLOR_DARK_BORDER   0xFF404040
+#define COLOR_DARK_TEXT     0xFFE0E0E0
+#define COLOR_TRAFFIC_RED   0xFFFF6B6B
+
+// Debugging helper
+static void debug_print(const char *msg) {
+    sys_write(1, msg, 0);
+    int i = 0;
+    while (msg[i]) i++;
+    sys_write(1, msg, i);
+    sys_write(1, "\n", 1);
+}
 
 // Game constants
 #define GRID_WIDTH 10
@@ -73,9 +86,6 @@ static void init_game(void) {
     revealed_count = 0;
 }
 
-static void reveal_cell(int x, int y);
-
-// Flood fill for empty cells
 static void flood_fill(int x, int y) {
     if (x < 0 || x >= GRID_WIDTH || y < 0 || y >= GRID_HEIGHT) return;
     if (revealed[y][x] || flagged[y][x]) return;
@@ -131,41 +141,24 @@ static void flag_cell(int x, int y) {
     flagged[y][x] = !flagged[y][x];
 }
 
-static void minesweeper_right_click(Window *win, int x, int y) {
-    // x and y are relative to window content (0,0 is top-left of window)
-    int grid_start_x = 10;
-    int grid_start_y = 50;
+static void minesweeper_paint(ui_window_t win) {
+    int win_w = 240, win_h = 340;
     
-    // Check grid cells
-    if (x >= grid_start_x && x < grid_start_x + GRID_WIDTH * CELL_SIZE &&
-        y >= grid_start_y && y < grid_start_y + GRID_HEIGHT * CELL_SIZE) {
-        
-        if (game_over || game_won) return;
-        
-        int cell_x = (x - grid_start_x) / CELL_SIZE;
-        int cell_y = (y - grid_start_y) / CELL_SIZE;
-        
-        flag_cell(cell_x, cell_y);
-        wm_mark_dirty(win->x, win->y, win->w, win->h);
-    }
-}
-
-static void minesweeper_paint(Window *win) {
     // Background - dark mode
-    draw_rect(win->x + 4, win->y + 30, win->w - 8, win->h - 34, COLOR_DARK_BG);
+    ui_draw_rect(win, 4, 30, win_w - 8, win_h - 34, COLOR_DARK_BG);
     
     // Game status
     if (game_over) {
-        draw_string(win->x + 10, win->y + 36, "Game Over!", COLOR_TRAFFIC_RED);
+        ui_draw_string(win, 10, 36, "Game Over!", COLOR_TRAFFIC_RED);
     } else if (game_won) {
-        draw_string(win->x + 10, win->y + 36, "You Won!", 0xFF00FF00);  // Bright green
+        ui_draw_string(win, 10, 36, "You Won!", 0xFF00FF00);  // Bright green
     } else {
-        draw_string(win->x + 10, win->y + 36, "", COLOR_DARK_TEXT);
+        ui_draw_string(win, 10, 36, "", COLOR_DARK_TEXT);
     }
     
     // Draw grid
-    int grid_start_x = win->x + 10;
-    int grid_start_y = win->y + 56;
+    int grid_start_x = 10;
+    int grid_start_y = 56;
     
     for (int y = 0; y < GRID_HEIGHT; y++) {
         for (int x = 0; x < GRID_WIDTH; x++) {
@@ -174,45 +167,42 @@ static void minesweeper_paint(Window *win) {
             
             if (revealed[y][x]) {
                 // Revealed cell - dark mode
-                draw_rounded_rect_filled(px, py, CELL_SIZE, CELL_SIZE, 2, COLOR_DARK_PANEL);
+                ui_draw_rounded_rect_filled(win, px, py, CELL_SIZE, CELL_SIZE, 2, COLOR_DARK_PANEL);
                 
                 if (grid[y][x] == -1) {
                     // Mine
-                    draw_string(px + 8, py + 6, "*", COLOR_TRAFFIC_RED);
+                    ui_draw_string(win, px + 8, py + 6, "*", COLOR_TRAFFIC_RED);
                 } else if (grid[y][x] > 0) {
                     // Number
                     char num[2] = { '0' + grid[y][x], 0 };
-                    draw_string(px + 8, py + 6, num, COLOR_DARK_TEXT);
+                    ui_draw_string(win, px + 8, py + 6, num, COLOR_DARK_TEXT);
                 }
-                // 0 = empty, nothing to draw
             } else {
-                // Unrevealed cell - raised/button look
-                draw_rounded_rect_filled(px, py, CELL_SIZE, CELL_SIZE, 2, COLOR_DARK_BORDER);
+                // Unrevealed cell
+                ui_draw_rounded_rect_filled(win, px, py, CELL_SIZE, CELL_SIZE, 2, COLOR_DARK_BORDER);
                 
                 if (flagged[y][x]) {
-                    draw_string(px + 7, py + 6, "F", COLOR_TRAFFIC_RED);
+                    ui_draw_string(win, px + 7, py + 6, "F", COLOR_TRAFFIC_RED);
                 }
             }
         }
     }
     
-    // Draw new game button (narrower, less dead space)
+    // Draw new game button
     int btn_y = grid_start_y + GRID_HEIGHT * CELL_SIZE + 10;
-    draw_rounded_rect_filled(grid_start_x, btn_y, 70, 24, 4, COLOR_DARK_BORDER);
-    draw_string(grid_start_x + 6, btn_y + 8, "New Game", COLOR_DARK_TEXT);
+    ui_draw_rounded_rect_filled(win, grid_start_x, btn_y, 70, 24, 4, COLOR_DARK_BORDER);
+    ui_draw_string(win, grid_start_x + 6, btn_y + 8, "New Game", COLOR_DARK_TEXT);
 }
 
-static void minesweeper_click(Window *win, int x, int y) {
-    // x and y are relative to window content (0,0 is top-left of window)
+static void minesweeper_handle_click(ui_window_t win, int x, int y, int button) {
     int grid_start_x = 10;
-    int grid_start_y = 50;
+    int grid_start_y = 56;
     int btn_y = grid_start_y + GRID_HEIGHT * CELL_SIZE + 10;
     
     // Check "New Game" button
-    if (x >= grid_start_x && x < grid_start_x + 90 &&
+    if (x >= grid_start_x && x < grid_start_x + 70 &&
         y >= btn_y && y < btn_y + 24) {
         init_game();
-        wm_mark_dirty(win->x, win->y, win->w, win->h);
         return;
     }
     
@@ -225,25 +215,46 @@ static void minesweeper_click(Window *win, int x, int y) {
         int cell_x = (x - grid_start_x) / CELL_SIZE;
         int cell_y = (y - grid_start_y) / CELL_SIZE;
         
+        if (button == GUI_EVENT_RIGHT_CLICK) {
+            debug_print("[MINESWEEPER] Flagging cell");
+            flag_cell(cell_x, cell_y);
+        } else {
+            debug_print("[MINESWEEPER] Revealing cell");
             reveal_cell(cell_x, cell_y);
-        
-        wm_mark_dirty(win->x, win->y, win->w, win->h);
+        }
     }
 }
 
-void minesweeper_init(void) {
-    win_minesweeper.title = "Minesweeper";
-    win_minesweeper.x = 250;
-    win_minesweeper.y = 100;
-    win_minesweeper.w = 240;
-    win_minesweeper.h = 340;
-    win_minesweeper.visible = false;
-    win_minesweeper.focused = false;
-    win_minesweeper.z_index = 0;
-    win_minesweeper.paint = minesweeper_paint;
-    win_minesweeper.handle_click = minesweeper_click;
-    win_minesweeper.handle_right_click = minesweeper_right_click;
+int main(int argc, char **argv) {
+    (void)argc;
+    (void)argv;
+    ui_window_t win = ui_window_create("Minesweeper", 250, 100, 240, 340);
+    if (!win) return 1;
 
-    // Initialize game
+    // Use current time or something for seed? No syscall for time right now.
+    random_seed = 987654321;
     init_game();
+
+    gui_event_t ev;
+    while (1) {
+        if (ui_get_event(win, &ev)) {
+            if (ev.type == GUI_EVENT_PAINT) {
+                minesweeper_paint(win);
+                ui_mark_dirty(win, 0, 0, 240, 340);
+            } else if (ev.type == GUI_EVENT_CLICK) {
+                debug_print("[MINESWEEPER] LEFT CLICK");
+                minesweeper_handle_click(win, ev.arg1, ev.arg2, ev.type);
+                minesweeper_paint(win);
+                ui_mark_dirty(win, 0, 0, 240, 340);
+            } else if (ev.type == GUI_EVENT_RIGHT_CLICK) {
+                debug_print("[MINESWEEPER] RIGHT CLICK DETECTED");
+                minesweeper_handle_click(win, ev.arg1, ev.arg2, ev.type);
+                minesweeper_paint(win);
+                ui_mark_dirty(win, 0, 0, 240, 340);
+            } else if (ev.type == GUI_EVENT_CLOSE) {
+                sys_exit(0);
+            }
+        }
+    }
+    return 0;
 }

src/kernel/userland/nanojpeg.c

@@ -0,0 +1,967 @@
+// NanoJPEG -- KeyJ's Tiny Baseline JPEG Decoder
+// version 1.3 (2012-03-05)
+// by Martin J. Fiedler <martin.fiedler@gmx.net>
+//
+// This software is published under the terms of KeyJ's Research License,
+// version 0.2. Usage of this software is subject to the following conditions:
+// 0. There's no warranty whatsoever. The author(s) of this software can not
+//    be held liable for any damages that occur when using this software.
+// 1. This software may be used freely for both non-commercial and commercial
+//    purposes.
+// 2. This software may be redistributed freely as long as no fees are charged
+//    for the distribution and this license information is included.
+// 3. This software may be modified freely except for this license information,
+//    which must not be changed in any way.
+// 4. If anything other than configuration, indentation or comments have been
+//    altered in the code, the original author(s) must receive a copy of the
+//    modified code.
+
+
+///////////////////////////////////////////////////////////////////////////////
+// DOCUMENTATION SECTION                                                     //
+// read this if you want to know what this is all about                      //
+///////////////////////////////////////////////////////////////////////////////
+
+// INTRODUCTION
+// ============
+//
+// This is a minimal decoder for baseline JPEG images. It accepts memory dumps
+// of JPEG files as input and generates either 8-bit grayscale or packed 24-bit
+// RGB images as output. It does not parse JFIF or Exif headers; all JPEG files
+// are assumed to be either grayscale or YCbCr. CMYK or other color spaces are
+// not supported. All YCbCr subsampling schemes with power-of-two ratios are
+// supported, as are restart intervals. Progressive or lossless JPEG is not
+// supported.
+// Summed up, NanoJPEG should be able to decode all images from digital cameras
+// and most common forms of other non-progressive JPEG images.
+// The decoder is not optimized for speed, it's optimized for simplicity and
+// small code. Image quality should be at a reasonable level. A bicubic chroma
+// upsampling filter ensures that subsampled YCbCr images are rendered in
+// decent quality. The decoder is not meant to deal with broken JPEG files in
+// a graceful manner; if anything is wrong with the bitstream, decoding will
+// simply fail.
+// The code should work with every modern C compiler without problems and
+// should not emit any warnings. It uses only (at least) 32-bit integer
+// arithmetic and is supposed to be endianness independent and 64-bit clean.
+// However, it is not thread-safe.
+
+
+// COMPILE-TIME CONFIGURATION
+// ==========================
+//
+// The following aspects of NanoJPEG can be controlled with preprocessor
+// defines:
+//
+// _NJ_EXAMPLE_PROGRAM     = Compile a main() function with an example
+//                           program.
+// _NJ_INCLUDE_HEADER_ONLY = Don't compile anything, just act as a header
+//                           file for NanoJPEG. Example:
+//                               #define _NJ_INCLUDE_HEADER_ONLY
+//                               #include "nanojpeg.c"
+//                               int main(void) {
+//                                   njInit();
+//                                   // your code here
+//                                   njDone();
+//                               }
+// NJ_USE_LIBC=1           = Use the malloc(), free(), memset() and memcpy()
+//                           functions from the standard C library (default).
+// NJ_USE_LIBC=0           = Don't use the standard C library. In this mode,
+//                           external functions njAlloc(), njFreeMem(),
+//                           njFillMem() and njCopyMem() need to be defined
+//                           and implemented somewhere.
+// NJ_USE_WIN32=0          = Normal mode (default).
+// NJ_USE_WIN32=1          = If compiling with MSVC for Win32 and
+//                           NJ_USE_LIBC=0, NanoJPEG will use its own
+//                           implementations of the required C library
+//                           functions (default if compiling with MSVC and
+//                           NJ_USE_LIBC=0).
+// NJ_CHROMA_FILTER=1      = Use the bicubic chroma upsampling filter
+//                           (default). // 图像resize的一种算法
+// NJ_CHROMA_FILTER=0      = Use simple pixel repetition for chroma upsampling
+//                           (bad quality, but faster and less code).
+
+
+// API
+// ===
+//
+// For API documentation, read the "header section" below.
+
+
+// EXAMPLE
+// =======
+//
+// A few pages below, you can find an example program that uses NanoJPEG to
+// convert JPEG files into PGM or PPM. To compile it, use something like
+//     gcc -O3 -D_NJ_EXAMPLE_PROGRAM -o nanojpeg nanojpeg.c
+// You may also add -std=c99 -Wall -Wextra -pedantic -Werror, if you want :)
+
+
+///////////////////////////////////////////////////////////////////////////////
+// HEADER SECTION                                                            //
+// copy and pase this into nanojpeg.h if you want                            //
+///////////////////////////////////////////////////////////////////////////////
+
+#ifndef _NANOJPEG_H
+#define _NANOJPEG_H
+
+// nj_result_t: Result codes for njDecode().
+typedef enum _nj_result {
+    NJ_OK = 0,        // no error, decoding successful
+    NJ_NO_JPEG,       // not a JPEG file
+    NJ_UNSUPPORTED,   // unsupported format
+    NJ_OUT_OF_MEM,    // out of memory
+    NJ_INTERNAL_ERR,  // internal error
+    NJ_SYNTAX_ERROR,  // syntax error
+    __NJ_FINISHED,    // used internally, will never be reported
+} nj_result_t;
+
+// njInit: Initialize NanoJPEG.
+// For safety reasons, this should be called at least one time before using
+// using any of the other NanoJPEG functions.
+void njInit(void);
+
+// njDecode: Decode a JPEG image.
+// Decodes a memory dump of a JPEG file into internal buffers.
+// Parameters:
+//   jpeg = The pointer to the memory dump.
+//   size = The size of the JPEG file.
+// Return value: The error code in case of failure, or NJ_OK (zero) on success.
+nj_result_t njDecode(const void* jpeg, const int size);
+
+// njGetWidth: Return the width (in pixels) of the most recently decoded
+// image. If njDecode() failed, the result of njGetWidth() is undefined.
+int njGetWidth(void);
+
+// njGetHeight: Return the height (in pixels) of the most recently decoded
+// image. If njDecode() failed, the result of njGetHeight() is undefined.
+int njGetHeight(void);
+
+// njIsColor: Return 1 if the most recently decoded image is a color image
+// (RGB) or 0 if it is a grayscale image. If njDecode() failed, the result
+// of njGetWidth() is undefined.
+int njIsColor(void);
+
+// njGetImage: Returns the decoded image data.
+// Returns a pointer to the most recently image. The memory layout it byte-
+// oriented, top-down, without any padding between lines. Pixels of color
+// images will be stored as three consecutive bytes for the red, green and
+// blue channels. This data format is thus compatible with the PGM or PPM
+// file formats and the OpenGL texture formats GL_LUMINANCE8 or GL_RGB8.
+// If njDecode() failed, the result of njGetImage() is undefined.
+unsigned char* njGetImage(void);
+
+// njGetImageSize: Returns the size (in bytes) of the image data returned
+// by njGetImage(). If njDecode() failed, the result of njGetImageSize() is
+// undefined.
+int njGetImageSize(void);
+
+// njDone: Uninitialize NanoJPEG.
+// Resets NanoJPEG's internal state and frees all memory that has been
+// allocated at run-time by NanoJPEG. It is still possible to decode another
+// image after a njDone() call.
+void njDone(void);
+
+#endif//_NANOJPEG_H
+
+
+///////////////////////////////////////////////////////////////////////////////
+// CONFIGURATION SECTION                                                     //
+// adjust the default settings for the NJ_ defines here                      //
+///////////////////////////////////////////////////////////////////////////////
+
+#ifndef NJ_USE_LIBC
+    #define NJ_USE_LIBC 1
+#endif
+
+#ifndef NJ_USE_WIN32
+  #ifdef _MSC_VER
+    #define NJ_USE_WIN32 (!NJ_USE_LIBC)
+  #else
+    #define NJ_USE_WIN32 0
+  #endif
+#endif
+
+#ifndef NJ_CHROMA_FILTER
+    #define NJ_CHROMA_FILTER 1
+#endif
+
+
+///////////////////////////////////////////////////////////////////////////////
+// EXAMPLE PROGRAM                                                           //
+// just define _NJ_EXAMPLE_PROGRAM to compile this (requires NJ_USE_LIBC)    //
+///////////////////////////////////////////////////////////////////////////////
+
+#ifdef  _NJ_EXAMPLE_PROGRAM
+
+#include <stdio.h>
+#include "libc/stdlib.h"
+#include "libc/string.h"
+
+int main(int argc, char* argv[]) {
+    int size;
+    char *buf;
+    FILE *f;
+
+    if (argc < 2) {
+        printf("Usage: %s <input.jpg> [<output.ppm>]\n", argv[0]);
+        return 2;
+    }
+    f = fopen(argv[1], "rb");
+    if (!f) {
+        printf("Error opening the input file.\n");
+        return 1;
+    }
+    fseek(f, 0, SEEK_END);
+    size = (int) ftell(f); // 字节
+    buf = malloc(size);
+    fseek(f, 0, SEEK_SET);
+    size = (int) fread(buf, 1, size, f); // 读取整个文件内容到buf
+    fclose(f);
+
+    njInit(); // 初始化nj_context_t
+    if (njDecode(buf, size)) {
+        printf("Error decoding the input file.\n");
+        return 1;
+    }
+
+    f = fopen((argc > 2) ? argv[2] : (njIsColor() ? "nanojpeg_out.ppm" : "nanojpeg_out.pgm"), "wb");
+    if (!f) {
+        printf("Error opening the output file.\n");
+        return 1;
+    }
+    fprintf(f, "P%d\n%d %d\n255\n", njIsColor() ? 6 : 5, njGetWidth(), njGetHeight());
+    fwrite(njGetImage(), 1, njGetImageSize(), f);
+    fclose(f);
+    njDone();
+    return 0;
+}
+
+#endif
+
+// 解释什么是stride http://msdn.microsoft.com/en-us/library/windows/desktop/aa473780(v=vs.85).aspx
+
+///////////////////////////////////////////////////////////////////////////////
+// IMPLEMENTATION SECTION                                                    //
+// you may stop reading here                                                 //
+///////////////////////////////////////////////////////////////////////////////
+
+#ifndef _NJ_INCLUDE_HEADER_ONLY
+
+#include <stddef.h>  // For NULL in freestanding mode
+
+#ifdef _MSC_VER
+    #define NJ_INLINE static __inline
+    #define NJ_FORCE_INLINE static __forceinline
+#else
+    #define NJ_INLINE static inline
+    #define NJ_FORCE_INLINE static inline
+#endif
+
+#if NJ_USE_LIBC
+    #include "libc/stdlib.h"
+    #define njAllocMem malloc
+    #define njFreeMem  free
+    #define njFillMem  memset
+    #define njCopyMem  memcpy
+#elif NJ_USE_WIN32
+    #include <windows.h>
+    #define njAllocMem(size) ((void*) LocalAlloc(LMEM_FIXED, (SIZE_T)(size)))
+    #define njFreeMem(block) ((void) LocalFree((HLOCAL) block))
+    NJ_INLINE void njFillMem(void* block, unsigned char value, int count) { __asm {
+        mov edi, block
+        mov al, value
+        mov ecx, count
+        rep stosb
+    } }
+    NJ_INLINE void njCopyMem(void* dest, const void* src, int count) { __asm {
+        mov edi, dest
+        mov esi, src
+        mov ecx, count
+        rep movsb
+    } }
+#else
+    extern void* njAllocMem(int size);
+    extern void njFreeMem(void* block);
+    extern void njFillMem(void* block, unsigned char byte, int size);
+    extern void njCopyMem(void* dest, const void* src, int size);
+#endif
+
+typedef struct _nj_code {
+    unsigned char bits, code;
+} nj_vlc_code_t;
+
+typedef struct _nj_cmp {
+    int cid;
+    int ssx, ssy; // 水平/垂直因子
+    int width, height;
+    int stride;
+    int qtsel; // Quantization Table量化表
+    int actabsel, dctabsel; // AC/DC Huffman Table
+    int dcpred; // DC prediction
+    unsigned char *pixels;
+} nj_component_t; // 颜色分量
+
+typedef struct _nj_ctx {
+    nj_result_t error;
+    const unsigned char *pos; // 待解码数据指针(按字节来)
+    int size; // 整个数据的长度
+    int length; // 某一个marker内容的长度
+    int width, height; // 图片宽和高度
+    int mbwidth, mbheight; // MCU水平/垂直个数
+    int mbsizex, mbsizey; // MCU宽/高
+    int ncomp; // 颜色分量数
+    nj_component_t comp[3]; // YCbCr
+    int qtused, qtavail; // 这两个目前看不出来很大用处
+    unsigned char qtab[4][64]; // 但是目前似乎只有2个
+    nj_vlc_code_t vlctab[4][65536]; // 构造所有16位数的Huffman基数
+									// 目前基本上是4个(直/交/0/1)
+    int buf, bufbits; // 这是用来做什么的 buf是存放内容的 bufbits是计数器，存放了多少个bits
+    int block[64];
+    int rstinterval;
+    unsigned char *rgb; // 解析出来的RGB所要占用的内存 // 每1个点包含3个字节，按找RGB的顺序
+} nj_context_t;
+
+static nj_context_t nj;
+
+static const char njZZ[64] = { 0, 1, 8, 16, 9, 2, 3, 10, 17, 24, 32, 25, 18,
+11, 4, 5, 12, 19, 26, 33, 40, 48, 41, 34, 27, 20, 13, 6, 7, 14, 21, 28, 35,
+42, 49, 56, 57, 50, 43, 36, 29, 22, 15, 23, 30, 37, 44, 51, 58, 59, 52, 45,
+38, 31, 39, 46, 53, 60, 61, 54, 47, 55, 62, 63 };
+
+/*
+0   1   2   3   4   5   6   7
+
+8   9   10  11  12  13  14  15
+
+16  17  18  19  20  21  22  23
+
+24  25  26  27  28  29  30  31
+
+32  33  34  35  36  37  38  39
+
+40  41  42  43  44  45  46  47
+
+48  49  50  51  52  53  54  55
+
+56  57  58  59  60  61  62  63
+*/
+
+NJ_FORCE_INLINE unsigned char njClip(const int x) { // 限定范围是0 ~ 255之间
+    return (x < 0) ? 0 : ((x > 0xFF) ? 0xFF : (unsigned char) x);
+}
+
+#define W1 2841
+#define W2 2676
+#define W3 2408
+#define W5 1609
+#define W6 1108
+#define W7 565
+
+NJ_INLINE void njRowIDCT(int* blk) { // 按行来操作的 0 ~ 7 // 8 ~ 15
+    int x0, x1, x2, x3, x4, x5, x6, x7, x8;
+    if (!((x1 = blk[4] << 11)
+        | (x2 = blk[6])
+        | (x3 = blk[2])
+        | (x4 = blk[1])
+        | (x5 = blk[7])
+        | (x6 = blk[5])
+        | (x7 = blk[3])))
+    {
+        blk[0] = blk[1] = blk[2] = blk[3] = blk[4] = blk[5] = blk[6] = blk[7] = blk[0] << 3;
+        return;
+    }
+    x0 = (blk[0] << 11) + 128;
+    x8 = W7 * (x4 + x5);
+    x4 = x8 + (W1 - W7) * x4;
+    x5 = x8 - (W1 + W7) * x5;
+    x8 = W3 * (x6 + x7);
+    x6 = x8 - (W3 - W5) * x6;
+    x7 = x8 - (W3 + W5) * x7;
+    x8 = x0 + x1;
+    x0 -= x1;
+    x1 = W6 * (x3 + x2);
+    x2 = x1 - (W2 + W6) * x2;
+    x3 = x1 + (W2 - W6) * x3;
+    x1 = x4 + x6;
+    x4 -= x6;
+    x6 = x5 + x7;
+    x5 -= x7;
+    x7 = x8 + x3;
+    x8 -= x3;
+    x3 = x0 + x2;
+    x0 -= x2;
+    x2 = (181 * (x4 + x5) + 128) >> 8;
+    x4 = (181 * (x4 - x5) + 128) >> 8;
+    blk[0] = (x7 + x1) >> 8;
+    blk[1] = (x3 + x2) >> 8;
+    blk[2] = (x0 + x4) >> 8;
+    blk[3] = (x8 + x6) >> 8;
+    blk[4] = (x8 - x6) >> 8;
+    blk[5] = (x0 - x4) >> 8;
+    blk[6] = (x3 - x2) >> 8;
+    blk[7] = (x7 - x1) >> 8;
+}
+
+NJ_INLINE void njColIDCT(const int* blk, unsigned char *out, int stride) {
+    int x0, x1, x2, x3, x4, x5, x6, x7, x8;
+    if (!((x1 = blk[8*4] << 8)
+        | (x2 = blk[8*6])
+        | (x3 = blk[8*2])
+        | (x4 = blk[8*1])
+        | (x5 = blk[8*7])
+        | (x6 = blk[8*5])
+        | (x7 = blk[8*3])))
+    {
+        x1 = njClip(((blk[0] + 32) >> 6) + 128);
+        for (x0 = 8;  x0;  --x0) {
+            *out = (unsigned char) x1;
+            out += stride;
+        }
+        return;
+    }
+    x0 = (blk[0] << 8) + 8192;
+    x8 = W7 * (x4 + x5) + 4;
+    x4 = (x8 + (W1 - W7) * x4) >> 3;
+    x5 = (x8 - (W1 + W7) * x5) >> 3;
+    x8 = W3 * (x6 + x7) + 4;
+    x6 = (x8 - (W3 - W5) * x6) >> 3;
+    x7 = (x8 - (W3 + W5) * x7) >> 3;
+    x8 = x0 + x1;
+    x0 -= x1;
+    x1 = W6 * (x3 + x2) + 4;
+    x2 = (x1 - (W2 + W6) * x2) >> 3;
+    x3 = (x1 + (W2 - W6) * x3) >> 3;
+    x1 = x4 + x6;
+    x4 -= x6;
+    x6 = x5 + x7;
+    x5 -= x7;
+    x7 = x8 + x3;
+    x8 -= x3;
+    x3 = x0 + x2;
+    x0 -= x2;
+    x2 = (181 * (x4 + x5) + 128) >> 8; // Y，Cb和Cr的值都范围都是-128 ~ 127，并且在FDCT的时候有先减去128，所以现在要IDCT之后再加上128
+    x4 = (181 * (x4 - x5) + 128) >> 8;
+    *out = njClip(((x7 + x1) >> 14) + 128);  out += stride;
+    *out = njClip(((x3 + x2) >> 14) + 128);  out += stride;
+    *out = njClip(((x0 + x4) >> 14) + 128);  out += stride;
+    *out = njClip(((x8 + x6) >> 14) + 128);  out += stride;
+    *out = njClip(((x8 - x6) >> 14) + 128);  out += stride;
+    *out = njClip(((x0 - x4) >> 14) + 128);  out += stride;
+    *out = njClip(((x3 - x2) >> 14) + 128);  out += stride;
+    *out = njClip(((x7 - x1) >> 14) + 128);
+}
+
+#define njThrow(e) do { nj.error = e; return; } while (0)
+#define njCheckError() do { if (nj.error) return; } while (0)
+
+static int njShowBits(int bits) { // 能放得下大于32位的值么？
+    unsigned char newbyte;
+    if (!bits) return 0;
+    while (nj.bufbits < bits) { // 也就是说要buf的位数小于已经buf的位数的时候，就直接读出来？
+        if (nj.size <= 0) {
+            nj.buf = (nj.buf << 8) | 0xFF;
+            nj.bufbits += 8;
+            continue;
+        }
+        newbyte = *nj.pos++; // 数据指针是按字节
+        nj.size--;
+        nj.bufbits += 8;
+        nj.buf = (nj.buf << 8) | newbyte; // 高位最终会被覆盖掉，比如我要buf一个64位的值怎么办？
+        if (newbyte == 0xFF) {
+            if (nj.size) {
+                unsigned char marker = *nj.pos++;
+                nj.size--;
+                switch (marker) {
+                    case 0x00:
+                    case 0xFF:
+                        break;
+                    case 0xD9: nj.size = 0; break;
+                    default:
+                        if ((marker & 0xF8) != 0xD0)
+                            nj.error = NJ_SYNTAX_ERROR;
+                        else {
+                            nj.buf = (nj.buf << 8) | marker;
+                            nj.bufbits += 8;
+                        }
+                }
+            } else
+                nj.error = NJ_SYNTAX_ERROR;
+        }
+    }
+    return (nj.buf >> (nj.bufbits - bits)) & ((1 << bits) - 1);
+}
+
+NJ_INLINE void njSkipBits(int bits) {
+    if (nj.bufbits < bits)
+        (void) njShowBits(bits);
+    nj.bufbits -= bits;
+}
+
+NJ_INLINE int njGetBits(int bits) {
+    int res = njShowBits(bits);
+    njSkipBits(bits);
+    return res;
+}
+
+NJ_INLINE void njByteAlign(void) {
+    nj.bufbits &= 0xF8; // (1111 1000)8的倍数，不满8的部分丢弃
+}
+
+static void njSkip(int count) {
+    nj.pos += count; // 数据指针增加
+    nj.size -= count; // 总体数据大小减去count
+    nj.length -= count; // 当前marker长度减去count
+    if (nj.size < 0) nj.error = NJ_SYNTAX_ERROR;
+}
+
+NJ_INLINE unsigned short njDecode16(const unsigned char *pos) {
+    return (pos[0] << 8) | pos[1]; // 00000000 00001101
+}
+
+static void njDecodeLength(void) { // decode长度字段，这个方法调用一般都是已经进入到特定的marker之后
+    if (nj.size < 2) njThrow(NJ_SYNTAX_ERROR);
+    nj.length = njDecode16(nj.pos); // 该marker的长度(除去marker名字所占用的2个字节)
+    if (nj.length > nj.size) njThrow(NJ_SYNTAX_ERROR);
+    njSkip(2);
+}
+
+NJ_INLINE void njSkipMarker(void) {
+    njDecodeLength();
+    njSkip(nj.length);
+}
+
+NJ_INLINE void njDecodeSOF(void) { // 解析Start of Frame的时候就会把所需要的内存都分配好
+    int i, ssxmax = 0, ssymax = 0;
+    nj_component_t* c;
+    njDecodeLength(); // 解析长度并移动数据指针
+    if (nj.length < 9) njThrow(NJ_SYNTAX_ERROR);
+    if (nj.pos[0] != 8) njThrow(NJ_UNSUPPORTED); // 样本精度，一般都是8
+    nj.height = njDecode16(nj.pos + 1); // 图片高度/宽度
+    nj.width = njDecode16(nj.pos + 3);
+    nj.ncomp = nj.pos[5]; // 颜色分量数据，一般都是3
+    njSkip(6); // 之前共6个字节数据，所以移动数据指针6个字节
+    switch (nj.ncomp) { // 目前只支持1和3这两种
+        case 1:
+        case 3:
+            break;
+        default:
+            njThrow(NJ_UNSUPPORTED);
+    }
+    if (nj.length < (nj.ncomp * 3)) njThrow(NJ_SYNTAX_ERROR); // 数据量肯定是要大于颜色分量数 multiply 3，因为接着存颜色分量信息的每个结构占3个字节
+															  // 颜色分量ID占用1个字节，水平/垂直因子占用1个字节(高4位水平，低4位垂直)，量化表占用1个字节
+    for (i = 0, c = nj.comp;  i < nj.ncomp;  ++i, ++c) {
+        c->cid = nj.pos[0]; // 颜色分量ID
+        if (!(c->ssx = nj.pos[1] >> 4)) njThrow(NJ_SYNTAX_ERROR); // 高4位(水平因子)
+        if (c->ssx & (c->ssx - 1)) njThrow(NJ_UNSUPPORTED);  // non-power of two
+        if (!(c->ssy = nj.pos[1] & 15)) njThrow(NJ_SYNTAX_ERROR); // (00001111)低4位(垂直因子)
+        if (c->ssy & (c->ssy - 1)) njThrow(NJ_UNSUPPORTED);  // non-power of two
+        if ((c->qtsel = nj.pos[2]) & 0xFC) njThrow(NJ_SYNTAX_ERROR); // (11111101) 这里0xFC是用在这里干什么的？
+        njSkip(3); // 移动数据指针到下一个颜色分量
+        nj.qtused |= 1 << c->qtsel; // 这里是做什么用的？看不出来
+        if (c->ssx > ssxmax) ssxmax = c->ssx; // 记录最大水平因子
+        if (c->ssy > ssymax) ssymax = c->ssy; // 记录最大垂直因子
+    }
+    if (nj.ncomp == 1) { // 只有一种颜色分量的时候就简单啦
+        c = nj.comp;
+        c->ssx = c->ssy = ssxmax = ssymax = 1;
+    }
+    nj.mbsizex = ssxmax << 3; // MCU宽 是 水平采样因子最大值 multiply 8
+    nj.mbsizey = ssymax << 3; // MCU高 是 垂直采样因子最大值 multiply 8
+    nj.mbwidth = (nj.width + nj.mbsizex - 1) / nj.mbsizex; // 分子采用+ nj.mbsizex - 1就取到大于但是最接近(等于)宽度的值，
+														   // 并且这个值是MCU宽度整数倍 // 这里是水平方向MCU的个数
+    nj.mbheight = (nj.height + nj.mbsizey - 1) / nj.mbsizey; // 这里是垂直方向MCU的个数
+    for (i = 0, c = nj.comp;  i < nj.ncomp;  ++i, ++c) {
+        c->width = (nj.width * c->ssx + ssxmax - 1) / ssxmax; // 采样宽度？ 最大水平/垂直因子的值就是图片原来的值，否则就会根据因子做相应的减少
+        c->stride = (c->width + 7) & 0x7FFFFFF8; // (0111 1111 1111 1111 1111 1111 1111 1000) 做什么？以1234567结尾的都省略掉？
+												 // 变成8的整数
+												 // 补齐8位，注意前面有加7，所以总是不会比原来的少，比如原来是227，那么这里就会变成232
+												 // 这是按照数据单元计算的，所以不对
+
+        c->height = (nj.height * c->ssy + ssymax - 1) / ssymax;
+        c->stride = nj.mbwidth * nj.mbsizex * c->ssx / ssxmax; // 再计算一遍stride有什么用？前面计算的是错误的，没有考虑MCU宽度
+															   // 这里都已经是round过的了，所以直接计算
+
+        if (((c->width < 3) && (c->ssx != ssxmax)) || ((c->height < 3) && (c->ssy != ssymax))) njThrow(NJ_UNSUPPORTED);
+        if (!(c->pixels = njAllocMem(c->stride * (nj.mbheight * nj.mbsizey * c->ssy / ssymax)))) njThrow(NJ_OUT_OF_MEM); // 为分量分配内存
+																														 // 大小是所有MCU的
+																														 // 可能比图片实际
+																														 // 尺寸大
+    }
+    if (nj.ncomp == 3) { // 只有有3个颜色分量的时候才需要
+        nj.rgb = njAllocMem(nj.width * nj.height * nj.ncomp);
+        if (!nj.rgb) njThrow(NJ_OUT_OF_MEM);
+    }
+    njSkip(nj.length);
+}
+
+
+
+NJ_INLINE void njDecodeDHT(void) {
+    int codelen, currcnt, remain, spread, i, j;
+    nj_vlc_code_t *vlc;
+    static unsigned char counts[16]; // 码字
+    njDecodeLength();
+    while (nj.length >= 17) { // 码字的数量(16) + 类型和ID(1)
+        i = nj.pos[0]; // 类型和ID
+        if (i & 0xEC) njThrow(NJ_SYNTAX_ERROR); // (11101100)
+        if (i & 0x02) njThrow(NJ_UNSUPPORTED); // (00000010)
+        i = (i | (i >> 3)) & 3;  // combined DC/AC + tableid value
+								 // 直流0，直流1，交流0，交流1
+        for (codelen = 1;  codelen <= 16;  ++codelen) // 码字长度
+            counts[codelen - 1] = nj.pos[codelen]; // 读取码字 DHT 当中的16个字节 00 01 05 01 01 01 01 01 01 00 00 00 00 00 00 00
+        njSkip(17);
+
+        vlc = &nj.vlctab[i][0];
+        remain = spread = 65536;
+        for (codelen = 1;  codelen <= 16;  ++codelen) {
+            spread >>= 1; // 干什么？ // 65536 >> 16 = 1 每个category所包含的编码个数
+            currcnt = counts[codelen - 1];
+            if (!currcnt) continue; // 如果该位数没有码字
+            if (nj.length < currcnt) njThrow(NJ_SYNTAX_ERROR);
+            remain -= currcnt << (16 - codelen); // 干什么？ 计算当前size的码字占用多少VLC表的空间，得到剩下的空间
+            if (remain < 0) njThrow(NJ_SYNTAX_ERROR);
+            for (i = 0;  i < currcnt;  ++i) { // 码字个数，同样位数的码字可以有多个
+                register unsigned char code = nj.pos[i]; // 有多少个就，读多少个字节
+                for (j = spread;  j;  --j) { // 保存这么多个有什么作用？
+                    vlc->bits = (unsigned char) codelen; // 码字位数
+                    vlc->code = code; // 码字值(这个读取出来的到底是什么？00 01 02 03 04 05 06 07 08 09 0A 0B，是值，还是权重？)
+                    ++vlc;
+                }
+            }
+            njSkip(currcnt);
+        }
+        while (remain--) { // 16位都填充完成，剩下的就用0填(1位码字XX个，2位码字XX个，...)
+//			printf("i'm nothing vlc id %d\n", tblid);
+            vlc->bits = 0;
+            ++vlc;
+        }
+
+		// for debug
+//		printf("Huffman vlc id %d\n", tblid);
+//		njPrintHT(tblid);
+    }
+
+    if (nj.length) njThrow(NJ_SYNTAX_ERROR);
+}
+
+NJ_INLINE void njDecodeDQT(void) {
+    int i;
+    unsigned char *t;
+    njDecodeLength();
+    while (nj.length >= 65) {
+        i = nj.pos[0]; // QT信息，高4位为QT精度，低4位为QT号
+        if (i & 0xFC) njThrow(NJ_SYNTAX_ERROR); // (1111 1110)这个用来检测QT号码是否正确的吗？目前精度好像都为0，所以这么写？
+        nj.qtavail |= 1 << i; // XXX 直接通过这里转换为数量？
+        t = &nj.qtab[i][0];
+        for (i = 0;  i < 64;  ++i)
+            t[i] = nj.pos[i + 1]; // 读取到QT数组当中，但应该还是按照文件流当中的排列
+        njSkip(65);
+    }
+    if (nj.length) njThrow(NJ_SYNTAX_ERROR);
+}
+
+NJ_INLINE void njDecodeDRI(void) {
+    njDecodeLength();
+    if (nj.length < 2) njThrow(NJ_SYNTAX_ERROR);
+    nj.rstinterval = njDecode16(nj.pos);
+    njSkip(nj.length);
+}
+
+static int njGetVLC(nj_vlc_code_t* vlc, unsigned char* code) { // Variable Length Coding
+    int value = njShowBits(16); // 为什么是2个字节？ 这又是什么？ 或许是这里的Huffman编码的码字永远是少于16位的
+    int bits = vlc[value].bits;
+
+    if (!bits) { nj.error = NJ_SYNTAX_ERROR; return 0; }
+    njSkipBits(bits);
+    value = vlc[value].code;
+
+    if (code) *code = (unsigned char) value;
+    bits = value & 15; // 这个value必须是0~15之间？
+    if (!bits) {
+		return 0;
+	}
+    value = njGetBits(bits); // 如果这里需要读取的值的位数超过之前njShowBits剩余的值，这里会重新读取
+    if (value < (1 << (bits - 1)))
+        value += ((-1) << bits) + 1;
+
+    return value;
+}
+
+NJ_INLINE void njDecodeBlock(nj_component_t* c, unsigned char* out) { // 8 x 8
+    unsigned char code = 0;
+    int value, coef = 0;
+    njFillMem(nj.block, 0, sizeof(nj.block));
+	int dcvlcval = njGetVLC(&nj.vlctab[c->dctabsel][0], NULL);
+    c->dcpred += dcvlcval;
+    nj.block[0] = (c->dcpred) * nj.qtab[c->qtsel][0]; // DC // 这里是反量化？
+    do {
+        value = njGetVLC(&nj.vlctab[c->actabsel][0], &code); // DC 2/3
+        if (!code) break;  // EOB
+        if (!(code & 0x0F) && (code != 0xF0)) njThrow(NJ_SYNTAX_ERROR); // 这是什么字段？(难道是为了兼容这个过程中可以遇到0xF0这样的数据)
+        coef += (code >> 4) + 1; // coefficient 系数
+        if (coef > 63) njThrow(NJ_SYNTAX_ERROR);
+        nj.block[(int) njZZ[coef]] = value * nj.qtab[c->qtsel][coef]; // AC 这里是反量化？
+    } while (coef < 63);
+    for (coef = 0;  coef < 64;  coef += 8)
+        njRowIDCT(&nj.block[coef]); // 上面先Huffman解码/反量化，这里行(反DCT)
+    for (coef = 0;  coef < 8;  ++coef)
+        njColIDCT(&nj.block[coef], &out[coef], c->stride);
+}
+
+NJ_INLINE void njDecodeScan(void) {
+//	njPrintHT(0);
+//	njPrintHT(2);
+//	njPrintHT(1);
+//	njPrintHT(3);
+
+    int i, mbx, mby, sbx, sby;
+    int rstcount = nj.rstinterval, nextrst = 0;
+    nj_component_t* c;
+    njDecodeLength();
+    if (nj.length < (4 + 2 * nj.ncomp)) njThrow(NJ_SYNTAX_ERROR);
+    if (nj.pos[0] != nj.ncomp) njThrow(NJ_UNSUPPORTED);
+    njSkip(1); // 颜色分量数量
+    for (i = 0, c = nj.comp;  i < nj.ncomp;  ++i, ++c) {
+        if (nj.pos[0] != c->cid) njThrow(NJ_SYNTAX_ERROR); // 颜色分量ID
+        if (nj.pos[1] & 0xEE) njThrow(NJ_SYNTAX_ERROR);
+        c->dctabsel = nj.pos[1] >> 4; // 高4位为直流表DC Table
+        c->actabsel = (nj.pos[1] & 1) | 2; // 低4位为交流表AC Table(这里有做特殊处理，所以AC的表名不会和DC相同)
+
+
+
+        njSkip(2);
+    }
+    if (nj.pos[0] || (nj.pos[1] != 63) || nj.pos[2]) njThrow(NJ_UNSUPPORTED);
+    njSkip(nj.length); // 忽略3个字节 通常为 00 3F 00
+					   // 2 + 1 + 6 + 3为12字节，这个marker的长度刚好为12字节
+					   // 接下来都是编码过的图像数据
+    for (mbx = mby = 0;;) {
+        for (i = 0, c = nj.comp;  i < nj.ncomp;  ++i, ++c) // 每个分量都要decode
+            for (sby = 0;  sby < c->ssy;  ++sby) // 水平/垂直因子
+                for (sbx = 0;  sbx < c->ssx;  ++sbx) {
+                    njDecodeBlock(c, &c->pixels[((mby * c->ssy + sby) * c->stride + mbx * c->ssx + sbx) << 3]); // 读取原始编码过
+																												// 的图片数据到block中
+																												// 并反量化，反离散余弦变换
+                    njCheckError();
+                }
+        if (++mbx >= nj.mbwidth) { // 读完所有的MCU，到达最右就返回从下一行开始
+            mbx = 0;
+            if (++mby >= nj.mbheight) break; // 到达最底行的时候推出，decode结束
+        }
+        if (nj.rstinterval && !(--rstcount)) { // restart marker
+            njByteAlign();
+            i = njGetBits(16);
+            if (((i & 0xFFF8) != 0xFFD0) || ((i & 7) != nextrst)) njThrow(NJ_SYNTAX_ERROR);
+            nextrst = (nextrst + 1) & 7;
+            rstcount = nj.rstinterval;
+            for (i = 0;  i < 3;  ++i)
+                nj.comp[i].dcpred = 0;
+        }
+    }
+    nj.error = __NJ_FINISHED;
+}
+
+#if NJ_CHROMA_FILTER
+
+#define CF4A (-9)
+#define CF4B (111)
+#define CF4C (29)
+#define CF4D (-3)
+#define CF3A (28)
+#define CF3B (109)
+#define CF3C (-9)
+#define CF3X (104)
+#define CF3Y (27)
+#define CF3Z (-3)
+#define CF2A (139)
+#define CF2B (-11)
+#define CF(x) njClip(((x) + 64) >> 7)
+
+// 通常我们放大图片的时候就需要upsampling，缩小的时候就downsampling，通称为resampling
+// 这里Cb/Cr分量的会少些，所以需要upsampling
+
+NJ_INLINE void njUpsampleH(nj_component_t* c) {
+
+    const int xmax = c->width - 3;
+    unsigned char *out, *lin, *lout;
+    int x, y;
+    out = njAllocMem((c->width * c->height) << 1);
+    if (!out) njThrow(NJ_OUT_OF_MEM);
+    lin = c->pixels;
+    lout = out;
+    for (y = c->height;  y;  --y) {
+        lout[0] = CF(CF2A * lin[0] + CF2B * lin[1]);
+        lout[1] = CF(CF3X * lin[0] + CF3Y * lin[1] + CF3Z * lin[2]);
+        lout[2] = CF(CF3A * lin[0] + CF3B * lin[1] + CF3C * lin[2]);
+        for (x = 0;  x < xmax;  ++x) {
+            lout[(x << 1) + 3] = CF(CF4A * lin[x] + CF4B * lin[x + 1] + CF4C * lin[x + 2] + CF4D * lin[x + 3]);
+            lout[(x << 1) + 4] = CF(CF4D * lin[x] + CF4C * lin[x + 1] + CF4B * lin[x + 2] + CF4A * lin[x + 3]);
+        }
+        lin += c->stride;
+        lout += c->width << 1;
+        lout[-3] = CF(CF3A * lin[-1] + CF3B * lin[-2] + CF3C * lin[-3]);
+        lout[-2] = CF(CF3X * lin[-1] + CF3Y * lin[-2] + CF3Z * lin[-3]);
+        lout[-1] = CF(CF2A * lin[-1] + CF2B * lin[-2]);
+    }
+    c->width <<= 1;
+    c->stride = c->width;
+    njFreeMem(c->pixels);
+    c->pixels = out;
+}
+
+NJ_INLINE void njUpsampleV(nj_component_t* c) {
+
+    const int w = c->width, s1 = c->stride, s2 = s1 + s1;
+    unsigned char *out, *cin, *cout;
+    int x, y;
+    out = njAllocMem((c->width * c->height) << 1);
+    if (!out) njThrow(NJ_OUT_OF_MEM);
+    for (x = 0;  x < w;  ++x) {
+        cin = &c->pixels[x];
+        cout = &out[x];
+        *cout = CF(CF2A * cin[0] + CF2B * cin[s1]);  cout += w;
+        *cout = CF(CF3X * cin[0] + CF3Y * cin[s1] + CF3Z * cin[s2]);  cout += w;
+        *cout = CF(CF3A * cin[0] + CF3B * cin[s1] + CF3C * cin[s2]);  cout += w;
+        cin += s1;
+        for (y = c->height - 3;  y;  --y) {
+            *cout = CF(CF4A * cin[-s1] + CF4B * cin[0] + CF4C * cin[s1] + CF4D * cin[s2]);  cout += w;
+            *cout = CF(CF4D * cin[-s1] + CF4C * cin[0] + CF4B * cin[s1] + CF4A * cin[s2]);  cout += w;
+            cin += s1;
+        }
+        cin += s1;
+        *cout = CF(CF3A * cin[0] + CF3B * cin[-s1] + CF3C * cin[-s2]);  cout += w;
+        *cout = CF(CF3X * cin[0] + CF3Y * cin[-s1] + CF3Z * cin[-s2]);  cout += w;
+        *cout = CF(CF2A * cin[0] + CF2B * cin[-s1]);
+    }
+    c->height <<= 1;
+    c->stride = c->width;
+    njFreeMem(c->pixels);
+    c->pixels = out;
+}
+
+#else
+
+NJ_INLINE void njUpsample(nj_component_t* c) {
+
+    int x, y, xshift = 0, yshift = 0;
+    unsigned char *out, *lin, *lout;
+    while (c->width < nj.width) { c->width <<= 1; ++xshift; }
+    while (c->height < nj.height) { c->height <<= 1; ++yshift; }
+    out = njAllocMem(c->width * c->height); // 放大后的尺寸
+    if (!out) njThrow(NJ_OUT_OF_MEM);
+    lin = c->pixels;
+    lout = out;
+    for (y = 0;  y < c->height;  ++y) {
+        lin = &c->pixels[(y >> yshift) * c->stride];
+        for (x = 0;  x < c->width;  ++x)
+            lout[x] = lin[x >> xshift];
+        lout += c->width;
+    }
+    c->stride = c->width;
+    njFreeMem(c->pixels);
+    c->pixels = out;
+}
+
+#endif
+
+NJ_INLINE void njConvert() {
+    int i;
+    nj_component_t* c;
+    for (i = 0, c = nj.comp;  i < nj.ncomp;  ++i, ++c) { // 如果需要的话就upsampling
+        #if NJ_CHROMA_FILTER
+            while ((c->width < nj.width) || (c->height < nj.height)) {
+                if (c->width < nj.width) njUpsampleH(c);
+                njCheckError();
+                if (c->height < nj.height) njUpsampleV(c);
+                njCheckError();
+            }
+        #else
+            if ((c->width < nj.width) || (c->height < nj.height))
+                njUpsample(c);
+        #endif
+        if ((c->width < nj.width) || (c->height < nj.height)) njThrow(NJ_INTERNAL_ERR);
+    }
+    if (nj.ncomp == 3) { // SEE njGetImage()
+        // convert to RGB
+        int x, yy;
+        unsigned char *prgb = nj.rgb;
+        const unsigned char *py  = nj.comp[0].pixels;
+        const unsigned char *pcb = nj.comp[1].pixels;
+        const unsigned char *pcr = nj.comp[2].pixels;
+		// 多余的数据(编/解码是对齐用的)会被丢弃吗？
+        for (yy = nj.height;  yy;  --yy) { // 列
+            for (x = 0;  x < nj.width;  ++x) { // 行
+                register int y = py[x] << 8; // 这是为什么？ 色彩空间转换公式计算需要
+                register int cb = pcb[x] - 128; // YCbCr的Cb和Cr一般都是有符号数，但是在JPEG当中都是无符号数
+                register int cr = pcr[x] - 128;
+                *prgb++ = njClip((y            + 359 * cr + 128) >> 8); // 色彩空间转换，YCbCr到RGB
+                *prgb++ = njClip((y -  88 * cb - 183 * cr + 128) >> 8);
+                *prgb++ = njClip((y + 454 * cb            + 128) >> 8);
+            }
+            py += nj.comp[0].stride; // 移动YCbCr数据指针，每一行都是有stride的，所以当需要的数据都得到时，后面的就不管，直接丢弃，移动到下一行
+            pcb += nj.comp[1].stride;
+            pcr += nj.comp[2].stride;
+        }
+    } else if (nj.comp[0].width != nj.comp[0].stride) { // 如果宽度和stride都一样，什么都不用做
+        // grayscale -> only remove stride
+        unsigned char *pin = &nj.comp[0].pixels[nj.comp[0].stride];
+        unsigned char *pout = &nj.comp[0].pixels[nj.comp[0].width];
+        int y;
+        for (y = nj.comp[0].height - 1;  y;  --y) {
+            njCopyMem(pout, pin, nj.comp[0].width);
+            pin += nj.comp[0].stride;
+            pout += nj.comp[0].width;
+        }
+        nj.comp[0].stride = nj.comp[0].width;
+    }
+}
+
+void njInit(void) {
+    njFillMem(&nj, 0, sizeof(nj_context_t)); // 初始化nj_context_t
+}
+
+void njDone(void) {
+    int i;
+    for (i = 0;  i < 3;  ++i)
+        if (nj.comp[i].pixels) njFreeMem((void*) nj.comp[i].pixels);
+    if (nj.rgb) njFreeMem((void*) nj.rgb);
+    njInit();
+}
+
+nj_result_t njDecode(const void* jpeg, const int size) {
+    njDone();
+    nj.pos = (const unsigned char*) jpeg;
+    nj.size = size & 0x7FFFFFFF; // ？
+    if (nj.size < 2) return NJ_NO_JPEG;
+    if ((nj.pos[0] ^ 0xFF) | (nj.pos[1] ^ 0xD8)) return NJ_NO_JPEG; // 不以0xFFD8打头(为什么要用异或来判断？)
+    njSkip(2);
+    while (!nj.error) { // 有“错误”的时候离开
+        if ((nj.size < 2) || (nj.pos[0] != 0xFF)) return NJ_SYNTAX_ERROR; // 太小，或者不以0xFF打头
+        njSkip(2); // 移动到标签的后面(长度字段的前面)
+        switch (nj.pos[-1]) {
+            case 0xC0: njDecodeSOF();  break;
+            case 0xC4: njDecodeDHT();  break;
+            case 0xDB: njDecodeDQT();  break;
+            case 0xDD: njDecodeDRI();  break;
+            case 0xDA: njDecodeScan(); break;
+            case 0xFE: njSkipMarker(); break;
+            default:
+                if ((nj.pos[-1] & 0xF0) == 0xE0) // JPG0和APP0字段，目前都忽略
+                    njSkipMarker();
+                else
+                    return NJ_UNSUPPORTED;
+        }
+    }
+    if (nj.error != __NJ_FINISHED) return nj.error;
+    nj.error = NJ_OK;
+    njConvert();
+    return nj.error;
+}
+
+int njGetWidth(void)            { return nj.width; }
+int njGetHeight(void)           { return nj.height; }
+int njIsColor(void)             { return (nj.ncomp != 1); }
+unsigned char* njGetImage(void) { return (nj.ncomp == 1) ? nj.comp[0].pixels : nj.rgb; } // 一/三个分量
+int njGetImageSize(void)        { return nj.width * nj.height * nj.ncomp; }
+
+#endif // _NJ_INCLUDE_HEADER_ONLY

src/kernel/userland/nanojpeg.h

@@ -0,0 +1,10 @@
+// nanojpeg.h - Header for NanoJPEG decoder (freestanding kernel use)
+#ifndef NANOJPEG_H
+#define NANOJPEG_H
+
+// Include naojpeg.c in header-only mode to get the type/function declarations
+#define _NJ_INCLUDE_HEADER_ONLY
+#include "nanojpeg.c"
+#undef _NJ_INCLUDE_HEADER_ONLY
+
+#endif // NANOJPEG_H

src/kernel/userland/paint.c

@@ -0,0 +1,251 @@
+#include "libc/syscall.h"
+#include "libc/libui.h"
+#include "libc/stdlib.h"
+#include <stdbool.h>
+#include <stddef.h>
+#include <stdint.h>
+
+#define CANVAS_W 300
+#define CANVAS_H 200
+#define PAINT_MAGIC 0x544E5042 // 'BPNT'
+
+#define COLOR_BLACK         0xFF000000
+#define COLOR_WHITE         0xFFFFFFFF
+#define COLOR_RED           0xFFFF0000
+#define COLOR_APPLE_GREEN   0xFF4CD964
+#define COLOR_APPLE_BLUE    0xFF007AFF
+#define COLOR_APPLE_YELLOW  0xFFFFCC00
+
+#define COLOR_DARK_BG       0xFF121212
+#define COLOR_DARK_PANEL    0xFF202020
+#define COLOR_DARK_BORDER   0xFF404040
+#define COLOR_DARK_TEXT     0xFFE0E0E0
+
+static uint32_t *canvas_buffer = NULL;
+static uint32_t current_color = COLOR_BLACK;
+static int last_mx = -1;
+static int last_my = -1;
+static char current_file_path[256] = "/Desktop/drawing.pnt";
+
+static void paint_strcpy(char *dest, const char *src) {
+    while (*src) *dest++ = *src++;
+    *dest = 0;
+}
+
+static void debug_print(const char *msg) {
+    sys_write(1, msg, 0);
+    int i = 0;
+    while (msg[i]) i++;
+    sys_write(1, msg, i);
+    sys_write(1, "\n", 1);
+}
+
+static void paint_reset(void) {
+    if (canvas_buffer) {
+        for (int i = 0; i < CANVAS_W * CANVAS_H; i++) {
+            canvas_buffer[i] = COLOR_WHITE;
+        }
+    }
+}
+
+static void paint_paint(ui_window_t win) {
+    int canvas_x = 60;
+    int canvas_y = 30;
+    
+    // Canvas Area with dark background and rounded corners (draw first so it's behind everything)
+    ui_draw_rounded_rect_filled(win, canvas_x - 2, canvas_y - 2, CANVAS_W + 4, CANVAS_H + 4, 4, COLOR_DARK_BG);
+
+    // Toolbar area - dark mode
+    ui_draw_rounded_rect_filled(win, 10, 30, 40, 260 - 40, 6, COLOR_DARK_PANEL);
+    
+    // Color Palette with rounded corners
+    uint32_t colors[] = {COLOR_BLACK, COLOR_RED, COLOR_APPLE_GREEN, COLOR_APPLE_BLUE, COLOR_APPLE_YELLOW, COLOR_WHITE};
+    for (int i = 0; i < 6; i++) {
+        int cy = 40 + (i * 25);
+        ui_draw_rounded_rect_filled(win, 15, cy, 30, 20, 3, colors[i]);
+        
+        // Highlight selected color with border
+        if (current_color == colors[i]) {
+            // Note: libui might not have draw_rounded_rect (hollow), so we just draw four lines simulating it
+            // or we use ui_draw_rect for hollow border
+            ui_draw_rect(win, 13, cy - 2, 34, 1, COLOR_DARK_TEXT);
+            ui_draw_rect(win, 13, cy - 2 + 24, 34, 1, COLOR_DARK_TEXT);
+            ui_draw_rect(win, 13, cy - 2, 1, 24, COLOR_DARK_TEXT);
+            ui_draw_rect(win, 13 + 34, cy - 2, 1, 24, COLOR_DARK_TEXT);
+        }
+    }
+
+    // Toolbar Buttons - dark mode with rounded corners
+    ui_draw_rounded_rect_filled(win, 12, 260 - 65, 36, 20, 4, COLOR_DARK_BORDER);
+    ui_draw_string(win, 18, 260 - 58, "CLR", COLOR_DARK_TEXT);
+    
+    ui_draw_rounded_rect_filled(win, 12, 260 - 40, 36, 20, 4, COLOR_DARK_BORDER);
+    ui_draw_string(win, 18, 260 - 33, "SAV", COLOR_DARK_TEXT);
+
+    // Draw canvas content
+    if (canvas_buffer) {
+        for (int y = 0; y < CANVAS_H; y++) {
+            for (int x = 0; x < CANVAS_W; x++) {
+                uint32_t color = canvas_buffer[y * CANVAS_W + x];
+                ui_draw_rect(win, canvas_x + x, canvas_y + y, 1, 1, color);
+            }
+        }
+    }
+}
+
+static void paint_put_brush(ui_window_t win, int cx, int cy) {
+    if (!canvas_buffer) return;
+    for (int dy = 0; dy < 2; dy++) {
+        for (int dx = 0; dx < 2; dx++) {
+            int px = cx + dx;
+            int py = cy + dy;
+            if (px >= 0 && px < CANVAS_W && py >= 0 && py < CANVAS_H) {
+                canvas_buffer[py * CANVAS_W + px] = current_color;
+                ui_draw_rect(win, 60 + px, 30 + py, 1, 1, current_color);
+            }
+        }
+    }
+    ui_mark_dirty(win, 60 + cx, 30 + cy, 2, 2);
+}
+
+void paint_handle_mouse(ui_window_t win, int x, int y) {
+    int cx = x - 60;
+    int cy = y - 30;
+
+    if (cx < 0 || cx >= CANVAS_W || cy < 0 || cy >= CANVAS_H) {
+        last_mx = -1;
+        return;
+    }
+
+    if (last_mx == -1) {
+        paint_put_brush(win, cx, cy);
+    } else {
+        // Bresenham's line algorithm to fill gaps between points
+        int x0 = last_mx, y0 = last_my;
+        int x1 = cx, y1 = cy;
+        int dx = (x1 - x0 > 0) ? (x1 - x0) : (x0 - x1);
+        int dy = (y1 - y0 > 0) ? (y1 - y0) : (y0 - y1);
+        int sx = x0 < x1 ? 1 : -1;
+        int sy = y0 < y1 ? 1 : -1;
+        int err = dx - dy;
+
+        while (1) {
+            paint_put_brush(win, x0, y0);
+            if (x0 == x1 && y0 == y1) break;
+            int e2 = 2 * err;
+            if (e2 > -dy) { err -= dy; x0 += sx; }
+            if (e2 < dx) { err += dx; y0 += sy; }
+        }
+    }
+    last_mx = cx;
+    last_my = cy;
+}
+
+void paint_reset_last_pos(void) {
+    last_mx = -1;
+    last_my = -1;
+}
+
+// Simple window message dialog wrapper using syscall
+static void wm_show_message(const char *title, const char *msg) {
+    // Wait, userland doesn't have wm_show_message syscall available yet, or maybe it does? 
+    // We didn't add it or GUI_EVENT doesn't support it directly.
+    // For now we do nothing, or just open a small window.
+}
+
+static void paint_save(const char *path) {
+    int fd = sys_open(path, "w");
+    if (fd >= 0) {
+        uint32_t header[3] = {PAINT_MAGIC, CANVAS_W, CANVAS_H};
+        sys_write_fs(fd, (char*)header, sizeof(header));
+        sys_write_fs(fd, (char*)canvas_buffer, CANVAS_W * CANVAS_H * sizeof(uint32_t));
+        sys_close(fd);
+        wm_show_message("Paint", "Image saved.");
+    }
+}
+
+void paint_load(const char *path) {
+    paint_strcpy(current_file_path, path);
+    int fd = sys_open(path, "r");
+    if (fd >= 0) {
+        uint32_t header[3];
+        if (sys_read(fd, (char*)header, sizeof(header)) == sizeof(header)) {
+            if (header[0] == PAINT_MAGIC) {
+                sys_read(fd, (char*)canvas_buffer, CANVAS_W * CANVAS_H * sizeof(uint32_t));
+            }
+        }
+        sys_close(fd);
+    }
+}
+
+static void paint_click(ui_window_t win, int x, int y) {
+    // Check Buttons
+    if (x >= 12 && x < 48) {
+        if (y >= 260 - 65 && y < 260 - 45) {
+            paint_reset();
+            paint_paint(win);
+            ui_mark_dirty(win, 0, 0, 380, 260);
+            return;
+        }
+        if (y >= 260 - 40 && y < 260 - 20) {
+            paint_save(current_file_path);
+            return;
+        }
+    }
+
+    // Check Palette
+    if (x >= 15 && x < 45) {
+        for (int i = 0; i < 6; i++) {
+            int cy = 40 + (i * 25);
+            if (y >= cy && y < cy + 20) {
+                uint32_t colors[] = {COLOR_BLACK, COLOR_RED, COLOR_APPLE_GREEN, COLOR_APPLE_BLUE, COLOR_APPLE_YELLOW, COLOR_WHITE};
+                current_color = colors[i];
+                paint_paint(win);
+                ui_mark_dirty(win, 0, 0, 380, 260);
+                return;
+            }
+        }
+    }
+    paint_handle_mouse(win, x, y);
+}
+
+int main(int argc, char **argv) {
+    ui_window_t win = ui_window_create("Paint", 150, 100, 380, 260);
+    if (!win) return 1;
+
+    canvas_buffer = malloc(CANVAS_W * CANVAS_H * sizeof(uint32_t));
+    if (!canvas_buffer) return 1;
+
+    paint_reset();
+
+    if (argc > 1) {
+        paint_load(argv[1]);
+    }
+
+    gui_event_t ev;
+    while (1) {
+        if (ui_get_event(win, &ev)) {
+            if (ev.type == GUI_EVENT_PAINT) {
+                paint_paint(win);
+                ui_mark_dirty(win, 0, 0, 380, 260);
+            } else if (ev.type == GUI_EVENT_CLICK) {
+                paint_click(win, ev.arg1, ev.arg2);
+                paint_paint(win);
+                ui_mark_dirty(win, 0, 0, 380, 260);
+            } else if (ev.type == GUI_EVENT_MOUSE_DOWN) {
+                paint_handle_mouse(win, ev.arg1, ev.arg2);
+            } else if (ev.type == GUI_EVENT_MOUSE_UP) {
+                paint_reset_last_pos();
+            } else if (ev.type == GUI_EVENT_MOUSE_MOVE) {
+                if (ev.arg3 & 0x01) { // Left button down
+                    paint_handle_mouse(win, ev.arg1, ev.arg2);
+                } else {
+                    paint_reset_last_pos();
+                }
+            } else if (ev.type == GUI_EVENT_CLOSE) {
+                sys_exit(0);
+            }
+        }
+    }
+    return 0;
+}

src/kernel/userland/settings.c

@@ -0,0 +1,691 @@
+#include "libc/syscall.h"
+#include "libc/libui.h"
+#include <stddef.h>
+
+#define COLOR_COFFEE    0xFF6B4423
+#define COLOR_TEAL      0xFF008080
+#define COLOR_GREEN     0xFF008000
+#define COLOR_BLUE_BG   0xFF000080
+#define COLOR_PURPLE    0xFF800080
+#define COLOR_GREY      0xFF454545
+#define COLOR_BLACK     0xFF000000
+
+#define COLOR_DARK_PANEL  0xFF2D2D2D
+#define COLOR_DARK_TEXT   0xFFE0E0E0
+#define COLOR_DARK_BORDER 0xFF404040
+#define COLOR_DKGRAY      0xFFAAAAAA
+#define COLOR_DARK_BG     0xFF1E1E1E
+
+// Control panel state
+#define VIEW_MAIN 0
+#define VIEW_WALLPAPER 1
+#define VIEW_NETWORK 2
+#define VIEW_DESKTOP 3
+#define VIEW_MOUSE 4
+
+static int current_view = VIEW_MAIN;
+static char rgb_r[4] = "";
+static char rgb_g[4] = "";
+static char rgb_b[4] = "";
+static int focused_field = -1;
+static int input_cursor = 0;
+
+static char net_status[64] = "";
+
+// Pattern buffers (128x128)
+#define PATTERN_SIZE 128
+static uint32_t pattern_lumberjack[PATTERN_SIZE * PATTERN_SIZE];
+static uint32_t pattern_blue_diamond[PATTERN_SIZE * PATTERN_SIZE];
+
+#define WALLPAPER_THUMB_W 100
+#define WALLPAPER_THUMB_H 60
+static uint32_t moon_thumb[WALLPAPER_THUMB_W * WALLPAPER_THUMB_H];
+static uint32_t mtn_thumb[WALLPAPER_THUMB_W * WALLPAPER_THUMB_H];
+static _Bool moon_thumb_valid = 0;
+static _Bool mtn_thumb_valid = 0;
+
+static _Bool desktop_snap_to_grid = 1;
+static _Bool desktop_auto_align = 1;
+static int desktop_max_rows_per_col = 10;
+static int desktop_max_cols = 10;
+static int mouse_speed = 10;
+
+static void cli_itoa(int num, char *str) {
+    if (num == 0) {
+        str[0] = '0';
+        str[1] = '\0';
+        return;
+    }
+    int t = num;
+    int len = 0;
+    while (t > 0) { len++; t /= 10; }
+    str[len] = '\0';
+    for (int i = len - 1; i >= 0; i--) {
+        str[i] = (num % 10) + '0';
+        num /= 10;
+    }
+}
+
+static void generate_lumberjack_pattern(void) {
+    uint32_t red = 0xFFDC143C;
+    uint32_t dark_grey = 0xFF404040;
+    uint32_t black = 0xFF000000;
+    int scale = 5;
+    
+    for (int y = 0; y < PATTERN_SIZE; y++) {
+        for (int x = 0; x < PATTERN_SIZE; x++) {
+            int cell_x = (x / scale) % 3;
+            int cell_y = (y / scale) % 3;
+            uint32_t color;
+            if (cell_x == 1 && cell_y == 1) {
+                color = black;
+            } else if (cell_x == 1 || cell_y == 1) {
+                color = dark_grey;
+            } else {
+                color = red;
+            }
+            pattern_lumberjack[y * PATTERN_SIZE + x] = color;
+        }
+    }
+}
+
+static void generate_blue_diamond_pattern(void) {
+    uint32_t bg_color = 0xFFADD8E6;
+    uint32_t diamond_color = 0xFF0000CD;
+    
+    for (int y = 0; y < PATTERN_SIZE; y++) {
+        for (int x = 0; x < PATTERN_SIZE; x++) {
+            pattern_blue_diamond[y * PATTERN_SIZE + x] = bg_color;
+        }
+    }
+    for (int dy = -24; dy <= 24; dy++) {
+        for (int dx = -24; dx <= 24; dx++) {
+            int abs_dx = dx < 0 ? -dx : dx;
+            int abs_dy = dy < 0 ? -dy : dy;
+            if (abs_dx + abs_dy <= 24) {
+                int x1 = 32 + dx;
+                int y1 = 32 + dy;
+                if (x1 >= 0 && x1 < PATTERN_SIZE && y1 >= 0 && y1 < PATTERN_SIZE) {
+                    pattern_blue_diamond[y1 * PATTERN_SIZE + x1] = diamond_color;
+                }
+                int x2 = 96 + dx;
+                int y2 = 96 + dy;
+                if (x2 >= 0 && x2 < PATTERN_SIZE && y2 >= 0 && y2 < PATTERN_SIZE) {
+                    pattern_blue_diamond[y2 * PATTERN_SIZE + x2] = diamond_color;
+                }
+            }
+        }
+    }
+}
+
+static uint32_t parse_rgb_separate(const char *r, const char *g, const char *b) {
+    int rv = 0, gv = 0, bv = 0;
+    for (int i = 0; r[i] && i < 3; i++) {
+        if (r[i] >= '0' && r[i] <= '9') rv = rv * 10 + (r[i] - '0');
+    }
+    for (int i = 0; g[i] && i < 3; i++) {
+        if (g[i] >= '0' && g[i] <= '9') gv = gv * 10 + (g[i] - '0');
+    }
+    for (int i = 0; b[i] && i < 3; i++) {
+        if (b[i] >= '0' && b[i] <= '9') bv = bv * 10 + (b[i] - '0');
+    }
+    if (rv > 255) rv = 255;
+    if (gv > 255) gv = 255;
+    if (bv > 255) bv = 255;
+    return 0xFF000000 | (rv << 16) | (gv << 8) | bv;
+}
+
+static void control_panel_paint_main(ui_window_t win) {
+    int offset_x = 8;
+    int offset_y = 21;
+    int win_w = 350;
+    
+    int item_y = 15;
+    int item_h = 60;
+    int item_spacing = 10;
+    
+    // Wallpaper
+    ui_draw_rounded_rect_filled(win, offset_x, offset_y + item_y, win_w - 16, item_h, 8, COLOR_DARK_PANEL);
+    ui_draw_rect(win, offset_x + 12, offset_y + item_y + 8, 40, 40, 0xFF87CEEB);
+    ui_draw_rect(win, offset_x + 12, offset_y + item_y + 28, 40, 20, 0xFF90EE90);
+    ui_draw_rect(win, offset_x + 24, offset_y + item_y + 22, 3, 6, 0xFF654321);
+    ui_draw_rect(win, offset_x + 21, offset_y + item_y + 18, 9, 8, 0xFF228B22);
+    ui_draw_string(win, offset_x + 60, offset_y + item_y + 15, "Wallpaper", COLOR_DARK_TEXT);
+    ui_draw_string(win, offset_x + 60, offset_y + item_y + 35, "Choose wallpaper", COLOR_DKGRAY);
+    
+    // Network
+    item_y += item_h + item_spacing;
+    ui_draw_rounded_rect_filled(win, offset_x, offset_y + item_y, win_w - 16, item_h, 8, COLOR_DARK_PANEL);
+    ui_draw_rect(win, offset_x + 18, offset_y + item_y + 12, 24, 24, 0xFF4169E1);
+    ui_draw_rect(win, offset_x + 22, offset_y + item_y + 16, 16, 16, 0xFF87CEEB);
+    ui_draw_string(win, offset_x + 60, offset_y + item_y + 15, "Network", COLOR_DARK_TEXT);
+    ui_draw_string(win, offset_x + 60, offset_y + item_y + 35, "Internet and connectivity", COLOR_DKGRAY);
+    
+    // Desktop
+    item_y += item_h + item_spacing;
+    ui_draw_rounded_rect_filled(win, offset_x, offset_y + item_y, win_w - 16, item_h, 8, COLOR_DARK_PANEL);
+    ui_draw_rect(win, offset_x + 12, offset_y + item_y + 10, 36, 8, 0xFFE0C060);
+    ui_draw_rect(win, offset_x + 12, offset_y + item_y + 18, 36, 22, 0xFFD4A574);
+    ui_draw_string(win, offset_x + 60, offset_y + item_y + 15, "Desktop", COLOR_DARK_TEXT);
+    ui_draw_string(win, offset_x + 60, offset_y + item_y + 35, "Desktop alignment", COLOR_DKGRAY);
+    
+    // Mouse
+    item_y += item_h + item_spacing;
+    ui_draw_rounded_rect_filled(win, offset_x, offset_y + item_y, win_w - 16, item_h, 8, COLOR_DARK_PANEL);
+    ui_draw_rect(win, offset_x + 18, offset_y + item_y + 8, 20, 28, 0xFFD3D3D3);
+    ui_draw_rect(win, offset_x + 20, offset_y + item_y + 10, 16, 10, 0xFFB0B0B0);
+    ui_draw_string(win, offset_x + 60, offset_y + item_y + 15, "Mouse", COLOR_DARK_TEXT);
+    ui_draw_string(win, offset_x + 60, offset_y + item_y + 35, "Pointer settings", COLOR_DKGRAY);
+}
+
+static void control_panel_paint_wallpaper(ui_window_t win) {
+    int offset_x = 8;
+    int offset_y = 21;
+    
+    ui_draw_rounded_rect_filled(win, offset_x, offset_y + 5, 80, 25, 6, COLOR_DARK_PANEL);
+    ui_draw_string(win, offset_x + 10, offset_y + 13, "< Back", COLOR_DARK_TEXT);
+    
+    ui_draw_string(win, offset_x, offset_y + 40, "Presets:", COLOR_DARK_TEXT);
+    
+    int button_y = offset_y + 65;
+    int button_x = offset_x;
+    
+    // Colors
+    ui_draw_rounded_rect_filled(win, button_x, button_y, 91, 25, 6, COLOR_DARK_PANEL);
+    ui_draw_rect(win, button_x + 8, button_y + 6, 18, 13, COLOR_COFFEE);
+    ui_draw_string(win, button_x + 35, button_y + 8, "Coffee", COLOR_DARK_TEXT);
+    
+    ui_draw_rounded_rect_filled(win, button_x + 100, button_y, 91, 25, 6, COLOR_DARK_PANEL);
+    ui_draw_rect(win, button_x + 108, button_y + 6, 18, 13, COLOR_TEAL);
+    ui_draw_string(win, button_x + 135, button_y + 8, "Teal", COLOR_DARK_TEXT);
+    
+    ui_draw_rounded_rect_filled(win, button_x + 200, button_y, 91, 25, 6, COLOR_DARK_PANEL);
+    ui_draw_rect(win, button_x + 208, button_y + 6, 18, 13, COLOR_GREEN);
+    ui_draw_string(win, button_x + 235, button_y + 8, "Green", COLOR_DARK_TEXT);
+    
+    button_y += 35;
+    ui_draw_rounded_rect_filled(win, button_x, button_y, 91, 25, 6, COLOR_DARK_PANEL);
+    ui_draw_rect(win, button_x + 8, button_y + 6, 18, 13, COLOR_BLUE_BG);
+    ui_draw_string(win, button_x + 35, button_y + 8, "Blue", COLOR_DARK_TEXT);
+    
+    ui_draw_rounded_rect_filled(win, button_x + 100, button_y, 91, 25, 6, COLOR_DARK_PANEL);
+    ui_draw_rect(win, button_x + 108, button_y + 6, 18, 13, COLOR_PURPLE);
+    ui_draw_string(win, button_x + 132, button_y + 8, "Purple", COLOR_DARK_TEXT);
+    
+    ui_draw_rounded_rect_filled(win, button_x + 200, button_y, 91, 25, 6, COLOR_DARK_PANEL);
+    ui_draw_rect(win, button_x + 208, button_y + 6, 18, 13, COLOR_GREY);
+    ui_draw_string(win, button_x + 235, button_y + 8, "Grey", COLOR_DARK_TEXT);
+    
+    // Patterns
+    button_y += 40;
+    ui_draw_string(win, offset_x, button_y, "Patterns:", COLOR_DARK_TEXT);
+    
+    button_y += 20;
+    ui_draw_rounded_rect_filled(win, button_x, button_y, 132, 25, 6, COLOR_DARK_PANEL);
+    for (int py = 0; py < 10; py++) {
+        for (int px = 0; px < 12; px++) {
+            int cell_x = px % 3;
+            int cell_y = py % 3;
+            uint32_t color = (cell_x == 1 && cell_y == 1) ? 0xFF000000 : 
+                           (cell_x == 1 || cell_y == 1) ? 0xFF404040 : 0xFFDC143C;
+            ui_draw_rect(win, button_x + 8 + px, button_y + 7 + py, 1, 1, color);
+        }
+    }
+    ui_draw_string(win, button_x + 28, button_y + 8, "Lumberjack", COLOR_DARK_TEXT);
+    
+    ui_draw_rounded_rect_filled(win, button_x + 145, button_y, 132, 25, 6, COLOR_DARK_PANEL);
+    for (int py = 0; py < 8; py++) {
+        for (int px = 0; px < 10; px++) {
+            int cx = px - 5;
+            int cy = py - 4;
+            int abs_cx = cx < 0 ? -cx : cx;
+            int abs_cy = cy < 0 ? -cy : cy;
+            uint32_t color = (abs_cx + abs_cy <= 3) ? 0xFF0000CD : 0xFFADD8E6;
+            ui_draw_rect(win, button_x + 153 + px, button_y + 8 + py, 1, 1, color);
+        }
+    }
+    ui_draw_string(win, button_x + 165, button_y + 8, "Blue Diamond", COLOR_DARK_TEXT);
+    
+    // Custom color
+    button_y += 40;
+    ui_draw_string(win, offset_x, button_y, "Custom color:", COLOR_DARK_TEXT);
+    button_y += 20;
+    
+    ui_draw_string(win, button_x, button_y + 4, "R:", COLOR_DARK_TEXT);
+    ui_draw_rounded_rect_filled(win, button_x + 25, button_y, 50, 18, 4, COLOR_DARK_PANEL);
+    ui_draw_string(win, button_x + 30, button_y + 4, rgb_r, (focused_field == 0) ? 0xFFFF6B6B : COLOR_DARK_TEXT);
+    if (focused_field == 0) {
+        int cursor_x = button_x + 30 + input_cursor * 8;
+        ui_draw_rect(win, cursor_x, button_y + 4, 1, 9, 0xFFFF6B6B);
+    }
+    
+    ui_draw_string(win, button_x + 90, button_y + 4, "G:", COLOR_DARK_TEXT);
+    ui_draw_rounded_rect_filled(win, button_x + 115, button_y, 50, 18, 4, COLOR_DARK_PANEL);
+    ui_draw_string(win, button_x + 120, button_y + 4, rgb_g, (focused_field == 1) ? 0xFF90EE90 : COLOR_DARK_TEXT);
+    if (focused_field == 1) {
+        int cursor_x = button_x + 120 + input_cursor * 8;
+        ui_draw_rect(win, cursor_x, button_y + 4, 1, 9, 0xFF90EE90);
+    }
+    
+    ui_draw_string(win, button_x + 180, button_y + 4, "B:", COLOR_DARK_TEXT);
+    ui_draw_rounded_rect_filled(win, button_x + 205, button_y, 50, 18, 4, COLOR_DARK_PANEL);
+    ui_draw_string(win, button_x + 210, button_y + 4, rgb_b, (focused_field == 2) ? 0xFF87CEEB : COLOR_DARK_TEXT);
+    if (focused_field == 2) {
+        int cursor_x = button_x + 210 + input_cursor * 8;
+        ui_draw_rect(win, cursor_x, button_y + 4, 1, 9, 0xFF87CEEB);
+    }
+    
+    ui_draw_rounded_rect_filled(win, button_x, button_y + 25, 70, 25, 6, COLOR_DARK_PANEL);
+    ui_draw_string(win, button_x + 18, button_y + 33, "Apply", COLOR_DARK_TEXT);
+    
+    // Wallpapers section
+    button_y += 60;
+    ui_draw_string(win, offset_x, button_y, "Wallpapers:", COLOR_DARK_TEXT);
+    button_y += 20;
+    
+    ui_draw_rounded_rect_filled(win, button_x, button_y, WALLPAPER_THUMB_W + 8, WALLPAPER_THUMB_H + 24, 6, COLOR_DARK_PANEL);
+    if (moon_thumb_valid) {
+        for (int ty = 0; ty < WALLPAPER_THUMB_H; ty++) {
+            for (int tx = 0; tx < WALLPAPER_THUMB_W; tx++) {
+                ui_draw_rect(win, button_x + 4 + tx, button_y + 4 + ty, 1, 1, moon_thumb[ty * WALLPAPER_THUMB_W + tx]);
+            }
+        }
+    } else {
+        ui_draw_string(win, button_x + 20, button_y + 30, "Error", 0xFFFF4444);
+    }
+    ui_draw_string(win, button_x + 30, button_y + WALLPAPER_THUMB_H + 8, "Moon", COLOR_DARK_TEXT);
+    
+    int thumb2_x = button_x + WALLPAPER_THUMB_W + 20;
+    ui_draw_rounded_rect_filled(win, thumb2_x, button_y, WALLPAPER_THUMB_W + 8, WALLPAPER_THUMB_H + 24, 6, COLOR_DARK_PANEL);
+    if (mtn_thumb_valid) {
+        for (int ty = 0; ty < WALLPAPER_THUMB_H; ty++) {
+            for (int tx = 0; tx < WALLPAPER_THUMB_W; tx++) {
+                ui_draw_rect(win, thumb2_x + 4 + tx, button_y + 4 + ty, 1, 1, mtn_thumb[ty * WALLPAPER_THUMB_W + tx]);
+            }
+        }
+    } else {
+        ui_draw_string(win, thumb2_x + 20, button_y + 30, "Error", 0xFFFF4444);
+    }
+    ui_draw_string(win, thumb2_x + 16, button_y + WALLPAPER_THUMB_H + 8, "Mountain", COLOR_DARK_TEXT);
+}
+
+static void control_panel_paint_network(ui_window_t win) {
+    int offset_x = 8;
+    int offset_y = 21;
+    
+    ui_draw_rounded_rect_filled(win, offset_x, offset_y + 5, 80, 25, 6, COLOR_DARK_PANEL);
+    ui_draw_string(win, offset_x + 10, offset_y + 13, "< Back", COLOR_DARK_TEXT);
+    
+    ui_draw_string(win, offset_x, offset_y + 40, "Network:", COLOR_DARK_TEXT);
+    ui_draw_rounded_rect_filled(win, offset_x, offset_y + 55, 140, 25, 6, COLOR_DARK_PANEL);
+    ui_draw_string(win, offset_x + 30, offset_y + 63, "Init Network", COLOR_DARK_TEXT);
+    
+    if (net_status[0] != '\0') {
+        ui_draw_string(win, offset_x + 150, offset_y + 63, net_status, 0xFF90EE90);
+    }
+}
+
+static void control_panel_paint_desktop(ui_window_t win) {
+    int offset_x = 8;
+    int offset_y = 21;
+    
+    ui_draw_rounded_rect_filled(win, offset_x, offset_y + 5, 80, 25, 6, COLOR_DARK_PANEL);
+    ui_draw_string(win, offset_x + 10, offset_y + 13, "< Back", COLOR_DARK_TEXT);
+    ui_draw_string(win, offset_x, offset_y + 40, "Desktop Settings:", COLOR_DARK_TEXT);
+    
+    int section_y = offset_y + 65;
+    
+    ui_draw_rounded_rect_filled(win, offset_x, section_y, 16, 16, 3, COLOR_DARK_PANEL);
+    if (desktop_snap_to_grid) ui_draw_string(win, offset_x + 3, section_y + 1, "v", 0xFF90EE90);
+    ui_draw_string(win, offset_x + 25, section_y + 3, "Snap to Grid", COLOR_DARK_TEXT);
+    
+    section_y += 25;
+    ui_draw_rounded_rect_filled(win, offset_x, section_y, 16, 16, 3, COLOR_DARK_PANEL);
+    if (desktop_auto_align) ui_draw_string(win, offset_x + 3, section_y + 1, "v", 0xFF90EE90);
+    ui_draw_string(win, offset_x + 25, section_y + 3, "Auto Align Icons", COLOR_DARK_TEXT);
+    
+    section_y += 30;
+    ui_draw_string(win, offset_x, section_y + 3, "Apps per column:", COLOR_DARK_TEXT);
+    ui_draw_rounded_rect_filled(win, offset_x + 130, section_y, 20, 20, 4, COLOR_DARK_PANEL);
+    ui_draw_string(win, offset_x + 135, section_y + 4, "-", COLOR_DARK_TEXT);
+    
+    char num[4];
+    cli_itoa(desktop_max_rows_per_col, num);
+    ui_draw_string(win, offset_x + 160, section_y + 5, num, COLOR_DARK_TEXT);
+    
+    ui_draw_rounded_rect_filled(win, offset_x + 180, section_y, 20, 20, 4, COLOR_DARK_PANEL);
+    ui_draw_string(win, offset_x + 186, section_y + 4, "+", COLOR_DARK_TEXT);
+    
+    section_y += 30;
+    ui_draw_string(win, offset_x, section_y + 3, "Columns:", COLOR_DARK_TEXT);
+    ui_draw_rounded_rect_filled(win, offset_x + 130, section_y, 20, 20, 4, COLOR_DARK_PANEL);
+    ui_draw_string(win, offset_x + 135, section_y + 4, "-", COLOR_DARK_TEXT);
+    
+    char num_c[4];
+    cli_itoa(desktop_max_cols, num_c);
+    ui_draw_string(win, offset_x + 160, section_y + 5, num_c, COLOR_DARK_TEXT);
+    
+    ui_draw_rounded_rect_filled(win, offset_x + 180, section_y, 20, 20, 4, COLOR_DARK_PANEL);
+    ui_draw_string(win, offset_x + 186, section_y + 4, "+", COLOR_DARK_TEXT);
+}
+
+static void control_panel_paint_mouse(ui_window_t win) {
+    int offset_x = 8;
+    int offset_y = 21;
+    
+    ui_draw_rounded_rect_filled(win, offset_x, offset_y + 5, 80, 25, 6, COLOR_DARK_PANEL);
+    ui_draw_string(win, offset_x + 10, offset_y + 13, "< Back", COLOR_DARK_TEXT);
+    ui_draw_string(win, offset_x, offset_y + 40, "Mouse Settings:", COLOR_DARK_TEXT);
+    
+    int section_y = offset_y + 65;
+    ui_draw_string(win, offset_x, section_y, "Speed:", COLOR_DARK_TEXT);
+    
+    ui_draw_rounded_rect_filled(win, offset_x + 60, section_y + 8, 200, 8, 4, COLOR_DARK_PANEL);
+    
+    int knob_x = offset_x + 60 + (mouse_speed - 1) * 190 / 49;
+    ui_draw_rounded_rect_filled(win, knob_x, section_y + 2, 10, 14, 3, 0xFF4A90E2);
+    
+    ui_draw_string(win, offset_x + 270, section_y + 4, "x", COLOR_DARK_TEXT);
+    char speed_str[4];
+    cli_itoa(mouse_speed, speed_str);
+    ui_draw_string(win, offset_x + 280, section_y + 4, speed_str, COLOR_DARK_TEXT);
+}
+
+static void control_panel_paint(ui_window_t win) {
+    // Fill background
+    ui_draw_rect(win, 0, 20, 350, 480, COLOR_DARK_BG);
+
+    if (current_view == VIEW_MAIN) {
+        control_panel_paint_main(win);
+    } else if (current_view == VIEW_WALLPAPER) {
+        control_panel_paint_wallpaper(win);
+    } else if (current_view == VIEW_NETWORK) {
+        control_panel_paint_network(win);
+    } else if (current_view == VIEW_DESKTOP) {
+        control_panel_paint_desktop(win);
+    } else if (current_view == VIEW_MOUSE) {
+        control_panel_paint_mouse(win);
+    }
+}
+
+static void save_desktop_config(void) {
+    sys_system(4 /*SET_DESKTOP_PROP*/, 1, desktop_snap_to_grid, 0, 0);
+    sys_system(4, 2, desktop_auto_align, 0, 0);
+    sys_system(4, 3, desktop_max_rows_per_col, 0, 0);
+    sys_system(4, 4, desktop_max_cols, 0, 0);
+}
+
+static void save_mouse_config(void) {
+    sys_system(5 /*SET_MOUSE_SPEED*/, mouse_speed, 0, 0, 0);
+}
+
+static void fetch_kernel_state(void) {
+    desktop_snap_to_grid = sys_system(7 /*GET_DESKTOP_PROP*/, 1, 0, 0, 0);
+    desktop_auto_align = sys_system(7, 2, 0, 0, 0);
+    desktop_max_rows_per_col = sys_system(7, 3, 0, 0, 0);
+    desktop_max_cols = sys_system(7, 4, 0, 0, 0);
+    mouse_speed = sys_system(8 /*GET_MOUSE_SPEED*/, 0, 0, 0, 0);
+    
+    if (sys_system(9, 0, (uint64_t)moon_thumb, 0, 0) == 0) {
+        moon_thumb_valid = 1;
+    }
+    if (sys_system(9, 1, (uint64_t)mtn_thumb, 0, 0) == 0) {
+        mtn_thumb_valid = 1;
+    }
+}
+
+static void control_panel_handle_click(int x, int y) {
+    int win_w = 350;
+    
+    if (current_view == VIEW_MAIN) {
+        int offset_x = 8;
+        int offset_y = 21;
+        int item_h = 60;
+        int item_spacing = 10;
+        
+        int item_y = offset_y + 15;
+        if (x >= offset_x && x < win_w - 8 && y >= item_y && y < item_y + item_h) {
+            current_view = VIEW_WALLPAPER;
+            focused_field = -1;
+        }
+        item_y += item_h + item_spacing;
+        if (x >= offset_x && x < win_w - 8 && y >= item_y && y < item_y + item_h) {
+            current_view = VIEW_NETWORK;
+            focused_field = -1;
+        }
+        item_y += item_h + item_spacing;
+        if (x >= offset_x && x < win_w - 8 && y >= item_y && y < item_y + item_h) {
+            current_view = VIEW_DESKTOP;
+        }
+        item_y += item_h + item_spacing;
+        if (x >= offset_x && x < win_w - 8 && y >= item_y && y < item_y + item_h) {
+            current_view = VIEW_MOUSE;
+        }
+    } else if (current_view == VIEW_WALLPAPER) {
+        int offset_x = 8;
+        int offset_y = 21;
+        int button_y = offset_y + 65;
+        int button_x = offset_x;
+        
+        if (x >= offset_x && x < offset_x + 80 && y >= offset_y + 5 && y < offset_y + 30) {
+            current_view = VIEW_MAIN;
+            return;
+        }
+        
+        if (x >= button_x && x < button_x + 91 && y >= button_y && y < button_y + 25) {
+            sys_system(1, COLOR_COFFEE, 0, 0, 0);
+            return;
+        }
+        if (x >= button_x + 100 && x < button_x + 191 && y >= button_y && y < button_y + 25) {
+            sys_system(1, COLOR_TEAL, 0, 0, 0);
+            return;
+        }
+        if (x >= button_x + 200 && x < button_x + 291 && y >= button_y && y < button_y + 25) {
+            sys_system(1, COLOR_GREEN, 0, 0, 0);
+            return;
+        }
+        
+        button_y += 35;
+        if (x >= button_x && x < button_x + 91 && y >= button_y && y < button_y + 25) {
+            sys_system(1, COLOR_BLUE_BG, 0, 0, 0);
+            return;
+        }
+        if (x >= button_x + 100 && x < button_x + 191 && y >= button_y && y < button_y + 25) {
+            sys_system(1, COLOR_PURPLE, 0, 0, 0);
+            return;
+        }
+        if (x >= button_x + 200 && x < button_x + 291 && y >= button_y && y < button_y + 25) {
+            sys_system(1, COLOR_GREY, 0, 0, 0);
+            return;
+        }
+        
+        button_y += 60; // 40 + 20
+        if (x >= button_x && x < button_x + 132 && y >= button_y && y < button_y + 25) {
+            sys_system(2, (uint64_t)pattern_lumberjack, 0, 0, 0);
+            return;
+        }
+        if (x >= button_x + 145 && x < button_x + 277 && y >= button_y && y < button_y + 25) {
+            sys_system(2, (uint64_t)pattern_blue_diamond, 0, 0, 0);
+            return;
+        }
+        
+        button_y += 60;
+        if (x >= button_x + 25 && x < button_x + 75 && y >= button_y && y < button_y + 18) {
+            if (focused_field != 0) rgb_r[0] = 0;
+            focused_field = 0; input_cursor = 0; return;
+        }
+        if (x >= button_x + 115 && x < button_x + 165 && y >= button_y && y < button_y + 18) {
+            if (focused_field != 1) rgb_g[0] = 0;
+            focused_field = 1; input_cursor = 0; return;
+        }
+        if (x >= button_x + 205 && x < button_x + 255 && y >= button_y && y < button_y + 18) {
+            if (focused_field != 2) rgb_b[0] = 0;
+            focused_field = 2; input_cursor = 0; return;
+        }
+        
+        if (x >= button_x && x < button_x + 70 && y >= button_y + 25 && y < button_y + 50) {
+            uint32_t cust = parse_rgb_separate(rgb_r, rgb_g, rgb_b);
+            sys_system(1, cust, 0, 0, 0);
+            return;
+        }
+        
+        button_y += 80;
+        if (x >= button_x && x < button_x + WALLPAPER_THUMB_W + 8 && y >= button_y && y < button_y + WALLPAPER_THUMB_H + 24) {
+            sys_system(3, 0, 0, 0, 0);
+            return;
+        }
+        int thumb2_x = button_x + WALLPAPER_THUMB_W + 20;
+        if (x >= thumb2_x && x < thumb2_x + WALLPAPER_THUMB_W + 8 && y >= button_y && y < button_y + WALLPAPER_THUMB_H + 24) {
+            sys_system(3, 1, 0, 0, 0);
+            return;
+        }
+    } else if (current_view == VIEW_NETWORK) {
+        int offset_x = 8;
+        int offset_y = 21;
+        
+        if (x >= offset_x && x < offset_x + 80 && y >= offset_y + 5 && y < offset_y + 30) {
+            current_view = VIEW_MAIN;
+            focused_field = -1;
+            return;
+        }
+        
+        if (x >= offset_x && x < offset_x + 140 && y >= offset_y + 55 && y < offset_y + 80) {
+            if (sys_system(6, 0, 0, 0, 0) == 0) {
+                net_status[0] = 'I'; net_status[1] = 'n'; net_status[2] = 'i'; 
+                net_status[3] = 't'; net_status[4] = 'e'; net_status[5] = 'd'; net_status[6] = 0;
+            } else {
+                net_status[0] = 'F'; net_status[1] = 'a'; net_status[2] = 'i'; 
+                net_status[3] = 'l'; net_status[4] = 'e'; net_status[5] = 'd'; net_status[6] = 0;
+            }
+        }
+    } else if (current_view == VIEW_DESKTOP) {
+        int offset_x = 8;
+        int offset_y = 21;
+        
+        if (x >= offset_x && x < offset_x + 80 && y >= offset_y + 5 && y < offset_y + 30) {
+            current_view = VIEW_MAIN;
+            return;
+        }
+        
+        int section_y = offset_y + 65;
+        if (x >= offset_x && x < offset_x + 16 && y >= section_y && y < section_y + 16) {
+            desktop_snap_to_grid = !desktop_snap_to_grid;
+            if (!desktop_snap_to_grid) desktop_auto_align = 0;
+            save_desktop_config();
+            return;
+        }
+        
+        section_y += 25;
+        if (x >= offset_x && x < offset_x + 16 && y >= section_y && y < section_y + 16) {
+            desktop_auto_align = !desktop_auto_align;
+            if (desktop_auto_align) desktop_snap_to_grid = 1;
+            save_desktop_config();
+            return;
+        }
+        
+        section_y += 25;
+        if (x >= offset_x + 130 && x < offset_x + 150 && y >= section_y && y < section_y + 20) {
+            if (desktop_max_rows_per_col > 1) {
+                desktop_max_rows_per_col--;
+                save_desktop_config();
+            }
+        }
+        if (x >= offset_x + 180 && x < offset_x + 200 && y >= section_y && y < section_y + 20) {
+            if (desktop_max_rows_per_col < 15) desktop_max_rows_per_col++;
+            save_desktop_config();
+        }
+        
+        section_y += 25;
+        if (x >= offset_x + 130 && x < offset_x + 150 && y >= section_y && y < section_y + 20) {
+            if (desktop_max_cols > 1) {
+                desktop_max_cols--;
+                save_desktop_config();
+            }
+        }
+        if (x >= offset_x + 180 && x < offset_x + 200 && y >= section_y && y < section_y + 20) {
+            desktop_max_cols++;
+            save_desktop_config();
+        }
+    } else if (current_view == VIEW_MOUSE) {
+        int offset_x = 8;
+        int offset_y = 21;
+        
+        if (x >= offset_x && x < offset_x + 80 && y >= offset_y + 5 && y < offset_y + 30) {
+            current_view = VIEW_MAIN;
+            return;
+        }
+        
+        int section_y = offset_y + 65;
+        if (x >= offset_x + 60 && x <= offset_x + 260 && y >= section_y && y <= section_y + 20) {
+            int new_speed = 1 + (x - (offset_x + 60)) * 49 / 200;
+            if (new_speed < 1) new_speed = 1;
+            if (new_speed > 50) new_speed = 50;
+            mouse_speed = new_speed;
+            save_mouse_config();
+            return;
+        }
+    }
+}
+
+static void control_panel_handle_key(char c) {
+    if (focused_field < 0) return;
+    
+    if (current_view == VIEW_WALLPAPER) {
+        char *focused_buffer = NULL;
+        int max_len = 3;
+        
+        if (focused_field == 0) focused_buffer = rgb_r;
+        else if (focused_field == 1) focused_buffer = rgb_g;
+        else if (focused_field == 2) focused_buffer = rgb_b;
+        else return;
+        
+        if (c == '\b') {
+            if (input_cursor > 0) {
+                input_cursor--;
+                focused_buffer[input_cursor] = '\0';
+            }
+        } else if (c >= '0' && c <= '9') {
+            if (input_cursor < max_len) {
+                focused_buffer[input_cursor] = c;
+                input_cursor++;
+                focused_buffer[input_cursor] = '\0';
+            }
+        } else if (c == '\t') {
+            focused_field = (focused_field + 1) % 3;
+            input_cursor = 0;
+        }
+    }
+}
+
+int main(int argc, char **argv) {
+    (void)argc;
+    (void)argv;
+    ui_window_t win = ui_window_create("Settings", 200, 150, 350, 500);
+    if (!win) return 1;
+
+    generate_lumberjack_pattern();
+    generate_blue_diamond_pattern();
+    
+    fetch_kernel_state();
+    
+    gui_event_t ev;
+    while (1) {
+        if (ui_get_event(win, &ev)) {
+            if (ev.type == GUI_EVENT_PAINT) {
+                control_panel_paint(win);
+                ui_mark_dirty(win, 0, 0, 350, 500);
+            } else if (ev.type == GUI_EVENT_CLICK) {
+                control_panel_handle_click(ev.arg1, ev.arg2);
+                control_panel_paint(win);
+                ui_mark_dirty(win, 0, 0, 350, 500);
+            } else if (ev.type == GUI_EVENT_KEY) {
+                control_panel_handle_key((char)ev.arg1);
+                control_panel_paint(win);
+                ui_mark_dirty(win, 0, 0, 350, 500);
+            } else if (ev.type == GUI_EVENT_CLOSE) {
+                sys_exit(0);
+            }
+        }
+    }
+    return 0;
+}

src/kernel/userland/txtedit.c

@@ -1,11 +1,14 @@
-#include "editor.h"
-#include "graphics.h"
-#include "fat32.h"
-#include "wm.h"
-#include <stdbool.h>
+#include "libc/syscall.h"
+#include "libc/libui.h"
 #include <stddef.h>
 
-Window win_editor;
+#define COLOR_DARK_PANEL  0xFF202020
+#define COLOR_DARK_TEXT   0xFFE0E0E0
+#define COLOR_DARK_BORDER 0xFF404040
+#define COLOR_RED         0xFFFF4444
+#define COLOR_DARK_BG     0xFF121212
+#define COLOR_DKGRAY      0xFF808080
+#define COLOR_WHITE       0xFFFFFFFF
 
 #define EDITOR_MAX_LINES 128
 #define EDITOR_MAX_LINE_LEN 256
@@ -23,37 +26,18 @@ static int cursor_line = 0;
 static int cursor_col = 0;
 static int scroll_top = 0;
 static char open_filename[256] = "";
-static bool file_modified = false;
+static _Bool file_modified = 0;
 
-// === Helper Functions ===
-
-static size_t editor_strlen(const char *str) {
-    size_t len = 0;
-    while (str[len]) len++;
-    return len;
-}
+static int win_w = 700;
+static int win_h = 450;
 
 static void editor_strcpy(char *dest, const char *src) {
     while (*src) *dest++ = *src++;
     *dest = 0;
 }
 
-static int editor_strcmp(const char *s1, const char *s2) {
-    while (*s1 && (*s1 == *s2)) {
-        s1++;
-        s2++;
-    }
-    return *(const unsigned char*)s1 - *(const unsigned char*)s2;
-}
-
-// === Editor Logic ===
-
-// Forward declaration
-static void editor_ensure_cursor_visible(void);
-
 static void editor_clear_all(void) {
     for (int i = 0; i < EDITOR_MAX_LINES; i++) {
-        // Zero out entire buffer to prevent ghost text from previous file
         for (int j = 0; j < EDITOR_MAX_LINE_LEN; j++) {
             lines[i].content[j] = 0;
         }
@@ -64,37 +48,43 @@ static void editor_clear_all(void) {
     cursor_col = 0;
     scroll_top = 0;
     open_filename[0] = 0;
-    file_modified = false;
+    file_modified = 0;
+}
+
+static void editor_ensure_cursor_visible(void) {
+    int visible_lines = 22;
+    if (cursor_line < scroll_top) {
+        scroll_top = cursor_line;
+    }
+    if (cursor_line >= scroll_top + visible_lines) {
+        scroll_top = cursor_line - visible_lines + 1;
+    }
 }
 
 void editor_open_file(const char *filename) {
     editor_clear_all();
     editor_strcpy(open_filename, filename);
     
-    FAT32_FileHandle *fh = fat32_open(filename, "r");
-    if (!fh) {
-        // New file
-        file_modified = false;
+    int fd = sys_open(filename, "r");
+    if (fd < 0) {
+        file_modified = 0;
         return;
     }
     
-    // Read file content
-    char buffer[16384];
-    int bytes_read = fat32_read(fh, buffer, sizeof(buffer));
-    fat32_close(fh);
+    static char buffer[16384];
+    int bytes_read = sys_read(fd, buffer, sizeof(buffer));
+    sys_close(fd);
     
     if (bytes_read <= 0) {
-        file_modified = false;
+        file_modified = 0;
         return;
     }
     
-    // Parse into lines
     int line = 0;
     int col = 0;
     
     for (int i = 0; i < bytes_read && line < EDITOR_MAX_LINES; i++) {
         char ch = buffer[i];
-        
         if (ch == '\n') {
             lines[line].content[col] = 0;
             lines[line].length = col;
@@ -115,71 +105,54 @@ void editor_open_file(const char *filename) {
     }
     
     line_count = (line > 0) ? line : 1;
-    file_modified = false;
+    file_modified = 0;
 }
 
 static void editor_save_file(void) {
-    if (!open_filename[0]) {
-        // No filename set
-        return;
-    }
+    if (!open_filename[0]) return;
     
-    FAT32_FileHandle *fh = fat32_open(open_filename, "w");
-    if (!fh) {
-        return;
-    }
+    int fd = sys_open(open_filename, "w");
+    if (fd < 0) return;
     
-    // Write lines
     for (int i = 0; i < line_count; i++) {
-        fat32_write(fh, lines[i].content, lines[i].length);
-        fat32_write(fh, "\n", 1);
+        sys_write_fs(fd, lines[i].content, lines[i].length);
+        sys_write_fs(fd, "\n", 1);
+    }
+    sys_close(fd);
+    file_modified = 0;
 }
 
-    fat32_close(fh);
-    file_modified = false;
-}
-
-// Insert character at cursor position
 static void editor_insert_char(char ch) {
     if (cursor_line >= EDITOR_MAX_LINES) return;
-    
     EditorLine *line = &lines[cursor_line];
     
     if (ch == '\n') {
-        // Split line - shift all lines below down first
         if (line_count >= EDITOR_MAX_LINES) return;
-        
-        // Shift all lines from cursor_line+1 onwards down by one position
         for (int j = line_count; j > cursor_line; j--) {
             lines[j] = lines[j - 1];
         }
         line_count++;
         
-        // Clear the new line completely (zero entire buffer)
         for (int k = 0; k < EDITOR_MAX_LINE_LEN; k++) {
             lines[cursor_line + 1].content[k] = 0;
         }
         lines[cursor_line + 1].length = 0;
         
-        // Now split the current line at cursor position
         int current_len = lines[cursor_line].length;
         int new_len = current_len - cursor_col;
         
-        // Copy the second part to the new line
         for (int i = 0; i < new_len; i++) {
             lines[cursor_line + 1].content[i] = lines[cursor_line].content[cursor_col + i];
         }
         lines[cursor_line + 1].content[new_len] = 0;
         lines[cursor_line + 1].length = new_len;
         
-        // Truncate current line
         lines[cursor_line].content[cursor_col] = 0;
         lines[cursor_line].length = cursor_col;
         
         cursor_line++;
         cursor_col = 0;
     } else if (ch == '\b') {
-        // Backspace
         if (cursor_col > 0) {
             for (int i = cursor_col - 1; i < line->length; i++) {
                 line->content[i] = line->content[i + 1];
@@ -187,7 +160,6 @@ static void editor_insert_char(char ch) {
             line->length--;
             cursor_col--;
         } else if (cursor_line > 0) {
-            // Merge with previous line
             EditorLine *prev = &lines[cursor_line - 1];
             int merge_point = prev->length;
             
@@ -199,9 +171,8 @@ static void editor_insert_char(char ch) {
             prev->content[merge_point + i] = 0;
             prev->length = merge_point + i;
             
-            // Shift lines up
-            for (int i = cursor_line; i < line_count - 1; i++) {
-                lines[i] = lines[i + 1];
+            for (int j = cursor_line; j < line_count - 1; j++) {
+                lines[j] = lines[j + 1];
             }
             lines[line_count - 1].length = 0;
             lines[line_count - 1].content[0] = 0;
@@ -211,9 +182,7 @@ static void editor_insert_char(char ch) {
             line_count--;
         }
     } else if (ch >= 32 && ch <= 126) {
-        // Regular character
         if (cursor_col < EDITOR_MAX_LINE_LEN - 1) {
-            // Shift characters right
             for (int i = line->length; i > cursor_col; i--) {
                 line->content[i] = line->content[i - 1];
             }
@@ -222,60 +191,39 @@ static void editor_insert_char(char ch) {
             cursor_col++;
         }
     }
-    
-    file_modified = true;
+    file_modified = 1;
     editor_ensure_cursor_visible();
 }
 
-// Ensure cursor is visible by adjusting scroll position
-static void editor_ensure_cursor_visible(void) {
-    int visible_lines = 22;  // Allow ~24 lines to use available window space
+static void editor_paint(ui_window_t win) {
+    int offset_x = 4;
+    int offset_y = 24;
+    int content_width = win_w - 8;
+    int content_height = win_h - 28;
     
-    // Scroll up if cursor is above visible area
-    if (cursor_line < scroll_top) {
-        scroll_top = cursor_line;
-    }
+    // Top content bar
+    ui_draw_rounded_rect_filled(win, offset_x, offset_y, content_width, 25, 6, COLOR_DARK_PANEL);
+    ui_draw_string(win, offset_x + 10, offset_y + 6, "File", COLOR_DARK_TEXT);
+    ui_draw_string(win, offset_x + 55, offset_y + 6, open_filename, COLOR_DARK_TEXT);
     
-    // Scroll down if cursor is below visible area
-    if (cursor_line >= scroll_top + visible_lines) {
-        scroll_top = cursor_line - visible_lines + 1;
-    }
-}
-
-// === Paint Function ===
-
-static void editor_paint(Window *win) {
-    int offset_x = win->x + 4;
-    int offset_y = win->y + 24;
-    int content_width = win->w - 8;
-    int content_height = win->h - 28;
-    
-    // Top content bar (modern dark, rounded)
-    draw_rounded_rect_filled(offset_x, offset_y, content_width, 25, 6, COLOR_DARK_PANEL);
-    draw_string(offset_x + 10, offset_y + 6, "File", COLOR_DARK_TEXT);
-    draw_string(offset_x + 55, offset_y + 6, open_filename, COLOR_DARK_TEXT);
-    
-    // Save button (modern rounded)
+    // Save button
     int save_btn_x = offset_x + content_width - 80;
     int save_btn_y = offset_y + 3;
-    draw_rounded_rect_filled(save_btn_x, save_btn_y, 70, 20, 6, COLOR_DARK_BORDER);
-    draw_string(save_btn_x + 20, save_btn_y + 6, "Save", COLOR_DARK_TEXT);
+    ui_draw_rounded_rect_filled(win, save_btn_x, save_btn_y, 70, 20, 6, COLOR_DARK_BORDER);
+    ui_draw_string(win, save_btn_x + 20, save_btn_y + 6, "Save", COLOR_DARK_TEXT);
     
-    // Draw modification indicator
     if (file_modified) {
-        draw_string(offset_x + content_width - 200, offset_y + 5, "[Modified]", COLOR_RED);
+        ui_draw_string(win, offset_x + content_width - 200, offset_y + 5, "[Modified]", COLOR_RED);
     }
     
-    // Fill editor background - dark mode
-    draw_rect(win->x + 4, win->y + 54, win->w - 8, win->h - 58, COLOR_DARK_BG);
+    // Editor background
+    ui_draw_rect(win, 4, 54, win_w - 8, win_h - 58, COLOR_DARK_BG);
     
-    // Calculate available width for text (accounting for line numbers)
     int text_start_x = offset_x + 40;
     int available_width = content_width - 40;
     int max_chars_per_line = available_width / EDITOR_CHAR_WIDTH;
     if (max_chars_per_line < 1) max_chars_per_line = 1;
     
-    // Draw line numbers and content with word wrapping
     int display_line = 0;
     int visible_lines = (content_height - 55) / EDITOR_LINE_HEIGHT;
     int max_display_lines = visible_lines;
@@ -284,9 +232,7 @@ static void editor_paint(Window *win) {
     while (line_idx < line_count && display_line < max_display_lines) {
         int display_y = offset_y + 35 + display_line * EDITOR_LINE_HEIGHT;
         
-        // Only draw line number for first wrapped line of this editor line
         if (display_line == 0 || line_idx < line_count) {
-            // Draw line number
             char line_num_str[16];
             int temp = line_idx + 1;
             int str_len = 0;
@@ -298,7 +244,6 @@ static void editor_paint(Window *win) {
                     line_num_str[str_len++] = (temp % 10) + '0';
                     temp /= 10;
                 }
-                // Reverse
                 for (int j = 0; j < str_len / 2; j++) {
                     char t = line_num_str[j];
                     line_num_str[j] = line_num_str[str_len - 1 - j];
@@ -306,21 +251,19 @@ static void editor_paint(Window *win) {
                 }
             }
             line_num_str[str_len] = 0;
-            draw_string(offset_x + 4, display_y, line_num_str, COLOR_DKGRAY);
+            ui_draw_string(win, offset_x + 4, display_y, line_num_str, COLOR_DKGRAY);
         }
         
-        // Word-based text wrapping for this line
         const char *text = lines[line_idx].content;
         int text_len = lines[line_idx].length;
         int char_idx = 0;
         int local_display_line = 0;
-        bool first_pass = true;
+        _Bool first_pass = 1;
         
         while ((char_idx < text_len || (text_len == 0 && first_pass)) && display_line < max_display_lines) {
-            first_pass = false;
+            first_pass = 0;
             int current_display_y = offset_y + 35 + display_line * EDITOR_LINE_HEIGHT;
             
-            // Extract segment (up to max_chars_per_line)
             char segment[256];
             int segment_len = 0;
             int segment_start = char_idx;
@@ -330,7 +273,6 @@ static void editor_paint(Window *win) {
             }
             segment[segment_len] = 0;
             
-            // Word-based wrapping: find last space if we didn't reach end
             if (char_idx < text_len && segment_len > 0) {
                 int last_space = -1;
                 for (int i = segment_len - 1; i >= 0; i--) {
@@ -339,51 +281,44 @@ static void editor_paint(Window *win) {
                         break;
                     }
                 }
-                
                 if (last_space > 0) {
                     segment_len = last_space;
                     segment[segment_len] = 0;
                     char_idx = segment_start + last_space + 1;
-                    // Skip additional spaces
                     while (char_idx < text_len && text[char_idx] == ' ') {
                         char_idx++;
                     }
                 }
             }
             
-            // Draw the text segment
             if (segment_len > 0) {
-                draw_string(text_start_x, current_display_y, segment, COLOR_DARK_TEXT);
+                ui_draw_string(win, text_start_x, current_display_y, segment, COLOR_DARK_TEXT);
             }
             
-            // Draw cursor if on this line and wrapped segment
             if (line_idx == cursor_line) {
                 int segment_end = segment_start + segment_len;
-                bool draw_cursor = false;
+                _Bool draw_cursor = 0;
                 if (cursor_col >= segment_start && cursor_col < segment_end) {
-                    draw_cursor = true;
+                    draw_cursor = 1;
                 } else if (cursor_col == text_len && segment_end == text_len) {
-                    draw_cursor = true;
+                    draw_cursor = 1;
                 }
                 if (draw_cursor) {
                     int cursor_x = text_start_x + ((cursor_col - segment_start) * EDITOR_CHAR_WIDTH);
-                    draw_rect(cursor_x, current_display_y, 2, 10, COLOR_WHITE);
+                    ui_draw_rect(win, cursor_x, current_display_y, 2, 10, COLOR_WHITE);
                 }
             }
             
             display_line++;
             local_display_line++;
-            
             if (char_idx >= text_len) break;
         }
-        
         line_idx++;
     }
     
-    // Status bar at bottom (modern dark, rounded)
     int status_y = offset_y + content_height - 20;
-    draw_rounded_rect_filled(offset_x, status_y, content_width, 20, 6, COLOR_DARK_PANEL);
-    draw_string(offset_x + 10, status_y + 5, "Line: ", COLOR_DARK_TEXT);
+    ui_draw_rounded_rect_filled(win, offset_x, status_y, content_width, 20, 6, COLOR_DARK_PANEL);
+    ui_draw_string(win, offset_x + 10, status_y + 5, "Line: ", COLOR_DARK_TEXT);
     
     char line_str[32];
     int temp = cursor_line + 1;
@@ -399,8 +334,8 @@ static void editor_paint(Window *win) {
     }
     line_str[idx] = 0;
     
-    draw_string(offset_x + 60, status_y + 5, line_str, COLOR_DARK_TEXT);
-    draw_string(offset_x + 100, status_y + 5, "  Col: ", COLOR_DARK_TEXT);
+    ui_draw_string(win, offset_x + 60, status_y + 5, line_str, COLOR_DARK_TEXT);
+    ui_draw_string(win, offset_x + 100, status_y + 5, "  Col: ", COLOR_DARK_TEXT);
     
     char col_str[32];
     temp = cursor_col + 1;
@@ -416,100 +351,81 @@ static void editor_paint(Window *win) {
     }
     col_str[idx] = 0;
     
-    draw_string(offset_x + 170, status_y + 5, col_str, COLOR_DARK_TEXT);
+    ui_draw_string(win, offset_x + 170, status_y + 5, col_str, COLOR_DARK_TEXT);
 }
 
-// === Key Handler ===
-
-static void editor_handle_key(Window *win, char c) {
-    // Arrow keys - UP
-    if (c == 17) {
+static void editor_handle_key(char c) {
+    if (c == 17) { // UP
         if (cursor_line > 0) {
             cursor_line--;
-            if (cursor_col > (int)lines[cursor_line].length) {
-                cursor_col = lines[cursor_line].length;
+            if (cursor_col > lines[cursor_line].length) cursor_col = lines[cursor_line].length;
+            if (cursor_line < scroll_top) scroll_top = cursor_line;
         }
-            if (cursor_line < scroll_top) {
-                scroll_top = cursor_line;
-            }
-        }
-        return;
-    }
-    
-    // Arrow keys - DOWN
-    if (c == 18) {
+    } else if (c == 18) { // DOWN
         if (cursor_line < line_count - 1) {
             cursor_line++;
-            if (cursor_col > (int)lines[cursor_line].length) {
-                cursor_col = lines[cursor_line].length;
-            }
+            if (cursor_col > lines[cursor_line].length) cursor_col = lines[cursor_line].length;
             int visible_lines = 20;
-            if (cursor_line >= scroll_top + visible_lines) {
-                scroll_top = cursor_line - visible_lines + 1;
+            if (cursor_line >= scroll_top + visible_lines) scroll_top = cursor_line - visible_lines + 1;
         }
-        }
-        return;
-    }
-    
-    // Arrow keys - LEFT
-    if (c == 19) {
+    } else if (c == 19) { // LEFT
         if (cursor_col > 0) {
             cursor_col--;
         } else if (cursor_line > 0) {
             cursor_line--;
             cursor_col = lines[cursor_line].length;
         }
-        return;
-    }
-    
-    // Arrow keys - RIGHT
-    if (c == 20) {
-        if (cursor_col < (int)lines[cursor_line].length) {
+    } else if (c == 20) { // RIGHT
+        if (cursor_col < lines[cursor_line].length) {
             cursor_col++;
         } else if (cursor_line < line_count - 1) {
             cursor_line++;
             cursor_col = 0;
         }
-        return;
-    }
-    
-    // Regular character input
+    } else {
         editor_insert_char(c);
     }
+}
 
-// === Click Handler ===
-
-static void editor_handle_click(Window *win, int x, int y) {
-    // x and y are relative to window origin
-    int content_width = win->w - 8;
-    
-    // Check save button - position is at (4 + content_width - 80, 24 + 3) = (4 + w - 8 - 80, 27)
-    // Button dimensions: 70 wide, 20 tall
+static void editor_handle_click(int x, int y) {
+    int content_width = win_w - 8;
     int button_x = 4 + content_width - 80;
     int button_y = 24 + 3;
     
-    if (x >= button_x && x < button_x + 70 &&
-        y >= button_y && y < button_y + 20) {
+    if (x >= button_x && x < button_x + 70 && y >= button_y && y < button_y + 20) {
         editor_save_file();
-        return;
     }
 }
 
-// === Initialization ===
-
-void editor_init(void) {
-    win_editor.title = "Text Editor";
-    win_editor.x = 100;
-    win_editor.y = 150;
-    win_editor.w = 700;
-    win_editor.h = 450;
-    win_editor.visible = false;
-    win_editor.focused = false;
-    win_editor.z_index = 0;
-    win_editor.paint = editor_paint;
-    win_editor.handle_key = editor_handle_key;
-    win_editor.handle_click = editor_handle_click;
-    win_editor.handle_right_click = NULL;
+int main(int argc, char **argv) {
+    ui_window_t win = ui_window_create("Text Editor", 100, 150, win_w, win_h);
+    if (!win) return 1;
 
     editor_clear_all();
+    if (argc > 1) {
+        editor_open_file(argv[1]);
+    } else {
+        editor_strcpy(open_filename, "untitled.txt");
+    }
+
+    gui_event_t ev;
+    while (1) {
+        if (ui_get_event(win, &ev)) {
+            if (ev.type == GUI_EVENT_PAINT) {
+                editor_paint(win);
+                ui_mark_dirty(win, 0, 0, win_w, win_h);
+            } else if (ev.type == GUI_EVENT_CLICK) {
+                editor_handle_click(ev.arg1, ev.arg2);
+                editor_paint(win);
+                ui_mark_dirty(win, 0, 0, win_w, win_h);
+            } else if (ev.type == GUI_EVENT_KEY) {
+                editor_handle_key((char)ev.arg1);
+                editor_paint(win);
+                ui_mark_dirty(win, 0, 0, win_w, win_h);
+            } else if (ev.type == GUI_EVENT_CLOSE) {
+                sys_exit(0);
+            }
+        }
+    }
+    return 0;
 }

src/kernel/userland/viewer.c

@@ -0,0 +1,226 @@
+#include "nanojpeg.h"
+#include "libc/syscall.h"
+#include "libc/libui.h"
+#include "libc/stdlib.h"
+#include <stdbool.h>
+#include <stddef.h>
+#include <stdint.h>
+
+#define VIEWER_MAX_W 800
+#define VIEWER_MAX_H 600
+
+static uint32_t *viewer_pixels = NULL;
+static int viewer_img_w = 0;
+static int viewer_img_h = 0;
+static char viewer_title[64] = "Viewer";
+static bool viewer_has_image = false;
+static char viewer_file_path[256];
+
+static int win_w = 500;
+static int win_h = 400;
+
+static void viewer_strcpy(char *dst, const char *src) {
+    while (*src) *dst++ = *src++;
+    *dst = 0;
+}
+
+static int viewer_strlen(const char *s) {
+    int len = 0;
+    while (s[len]) len++;
+    return len;
+}
+
+static void viewer_scale_rgb_to_argb(const unsigned char *rgb, int src_w, int src_h,
+                                     uint32_t *dst, int dst_w, int dst_h) {
+    for (int y = 0; y < dst_h; y++) {
+        int src_y = y * src_h / dst_h;
+        if (src_y >= src_h) src_y = src_h - 1;
+        for (int x = 0; x < dst_w; x++) {
+            int src_x = x * src_w / dst_w;
+            if (src_x >= src_w) src_x = src_w - 1;
+            int idx = (src_y * src_w + src_x) * 3;
+            unsigned char r = rgb[idx];
+            unsigned char g = rgb[idx + 1];
+            unsigned char b = rgb[idx + 2];
+            dst[y * dst_w + x] = 0xFF000000 | ((uint32_t)r << 16) | ((uint32_t)g << 8) | b;
+        }
+    }
+}
+
+static void viewer_paint(ui_window_t win) {
+    int cx = 4;
+    int cy = 24;
+    int cw = win_w - 8;
+    int ch = win_h - 28;
+
+    ui_draw_rect(win, cx, cy, cw, ch, 0xFF1A1A1A);
+
+    if (!viewer_has_image) {
+        ui_draw_string(win, cx + 20, cy + ch / 2, "No image loaded", 0xFF888888);
+        return;
+    }
+
+    int disp_w = viewer_img_w;
+    int disp_h = viewer_img_h;
+
+    if (disp_w > cw - 8) {
+        disp_h = disp_h * (cw - 8) / disp_w;
+        disp_w = cw - 8;
+    }
+    if (disp_h > ch - 40) {
+        disp_w = disp_w * (ch - 40) / disp_h;
+        disp_h = ch - 40;
+    }
+
+    int ox = cx + (cw - disp_w) / 2;
+    int oy = cy + (ch - disp_h - 30) / 2;
+
+    for (int y = 0; y < disp_h; y++) {
+        int src_y = y * viewer_img_h / disp_h;
+        if (src_y >= viewer_img_h) src_y = viewer_img_h - 1;
+        for (int x = 0; x < disp_w; x++) {
+            int src_x = x * viewer_img_w / disp_w;
+            if (src_x >= viewer_img_w) src_x = viewer_img_w - 1;
+            uint32_t pixel = viewer_pixels[src_y * viewer_img_w + src_x];
+            ui_draw_rect(win, ox + x, oy + y, 1, 1, pixel);
+        }
+    }
+
+    int btn_w = 160;
+    int btn_h = 22;
+    int btn_x = cx + (cw - btn_w) / 2;
+    int btn_y = win_h - 30;
+    ui_draw_rounded_rect_filled(win, btn_x, btn_y, btn_w, btn_h, 6, 0xFF2D2D2D);
+    ui_draw_string(win, btn_x + 10, btn_y + 6, "Set as Wallpaper", 0xFFF0F0F0);
+}
+
+static void viewer_handle_click(ui_window_t win, int x, int y) {
+    if (!viewer_has_image) return;
+
+    int cx = 4;
+    int cw = win_w - 8;
+    int btn_w = 160;
+    int btn_x = cx + (cw - btn_w) / 2;
+    int btn_y = win_h - 30;
+    
+    if (x >= btn_x && x < btn_x + btn_w && y >= btn_y && y < btn_y + 22) {
+        // SYSTEM_CMD_SET_WALLPAPER is 3 based on syscall.c code
+        sys_system(3, (uint64_t)viewer_file_path, 0, 0, 0);
+    }
+}
+
+void viewer_open_file(const char *path) {
+    int fd = sys_open(path, "r");
+    if (fd < 0) return;
+
+    // We can't use stat yet, so read chunks until EOF
+    // Alternatively, use a large buffer if sys_read handles large chunks.
+    int alloc_size = 2 * 1024 * 1024;
+    unsigned char *buf = malloc(alloc_size);
+    if (!buf) {
+        sys_close(fd);
+        return;
+    }
+
+    int total_read = 0;
+    while (total_read < alloc_size) {
+        int chunk = sys_read(fd, (char*)buf + total_read, alloc_size - total_read);
+        if (chunk <= 0) break;
+        total_read += chunk;
+    }
+    sys_close(fd);
+
+    if (total_read <= 0) {
+        free(buf);
+        return;
+    }
+
+    njInit();
+    nj_result_t result = njDecode(buf, total_read);
+    if (result != NJ_OK) {
+        njDone();
+        free(buf);
+        return;
+    }
+
+    int img_w = njGetWidth();
+    int img_h = njGetHeight();
+    unsigned char *rgb = njGetImage();
+
+    if (!rgb || img_w <= 0 || img_h <= 0) {
+        njDone();
+        free(buf);
+        return;
+    }
+
+    int fit_w = img_w;
+    int fit_h = img_h;
+    if (fit_w > VIEWER_MAX_W) {
+        fit_h = fit_h * VIEWER_MAX_W / fit_w;
+        fit_w = VIEWER_MAX_W;
+    }
+    if (fit_h > VIEWER_MAX_H) {
+        fit_w = fit_w * VIEWER_MAX_H / fit_h;
+        fit_h = VIEWER_MAX_H;
+    }
+
+    viewer_pixels = malloc(fit_w * fit_h * sizeof(uint32_t));
+    if (viewer_pixels) {
+        viewer_scale_rgb_to_argb(rgb, img_w, img_h, viewer_pixels, fit_w, fit_h);
+        viewer_img_w = fit_w;
+        viewer_img_h = fit_h;
+        viewer_has_image = true;
+    }
+
+    njDone();
+    free(buf);
+
+    viewer_strcpy(viewer_file_path, path);
+
+    const char *fname = path;
+    int plen = viewer_strlen(path);
+    for (int i = plen - 1; i >= 0; i--) {
+        if (path[i] == '/') {
+            fname = &path[i + 1];
+            break;
+        }
+    }
+    
+    viewer_title[0] = 'V'; viewer_title[1] = 'i'; viewer_title[2] = 'e';
+    viewer_title[3] = 'w'; viewer_title[4] = 'e'; viewer_title[5] = 'r';
+    viewer_title[6] = ' '; viewer_title[7] = '-'; viewer_title[8] = ' ';
+    int ti = 9;
+    for (int i = 0; fname[i] && ti < 60; i++) {
+        viewer_title[ti++] = fname[i];
+    }
+    viewer_title[ti] = 0;
+
+    win_w = fit_w + 16;
+    if (win_w < 200) win_w = 200;
+    win_h = fit_h + 64;
+    if (win_h < 100) win_h = 100;
+}
+
+int main(int argc, char **argv) {
+    if (argc > 1) {
+        viewer_open_file(argv[1]);
+    }
+
+    ui_window_t win = ui_window_create(viewer_title, 100, 50, win_w, win_h);
+    if (!win) return 1;
+
+    gui_event_t ev;
+    while (1) {
+        if (ui_get_event(win, &ev)) {
+            if (ev.type == GUI_EVENT_PAINT) {
+                viewer_paint(win);
+                ui_mark_dirty(win, 0, 0, win_w, win_h);
+            } else if (ev.type == GUI_EVENT_CLICK) {
+                viewer_handle_click(win, ev.arg1, ev.arg2);
+            } else if (ev.type == GUI_EVENT_CLOSE) {
+                sys_exit(0);
+            }
+        }
+    }
+    return 0;
+}

src/kernel/viewer.c

@@ -1,332 +0,0 @@
-// viewer.c - Image Viewer app for BoredOS
-// Opens .jpg files and displays the decoded image in a window
-
-#include "viewer.h"
-#include "nanojpeg.h"
-#include "graphics.h"
-#include "fat32.h"
-#include "memory_manager.h"
-#include "wallpaper.h"
-#include "io.h"
-#include <stddef.h>
-
-Window win_viewer;
-
-// Viewer state
-#define VIEWER_MAX_W 800
-#define VIEWER_MAX_H 600
-static uint32_t viewer_pixels[VIEWER_MAX_W * VIEWER_MAX_H];
-static int viewer_img_w = 0;
-static int viewer_img_h = 0;
-static char viewer_title[64] = "Viewer";
-static bool viewer_has_image = false;
-
-// Deferred open: click handler stores path, main loop decodes
-static char viewer_pending_path[256];
-static volatile bool viewer_open_pending = false;
-
-// Store the file path for "Set as Wallpaper"
-static char viewer_file_path[256];
-
-// String helpers
-static int viewer_strlen(const char *s) {
-    int len = 0;
-    while (s[len]) len++;
-    return len;
-}
-
-static void viewer_strcpy(char *dst, const char *src) {
-    while (*src) *dst++ = *src++;
-    *dst = 0;
-}
-
-// Simple nearest-neighbor scale from decoded RGB to ARGB pixel buffer
-static void viewer_scale_rgb_to_argb(const unsigned char *rgb, int src_w, int src_h,
-                                     uint32_t *dst, int dst_w, int dst_h) {
-    for (int y = 0; y < dst_h; y++) {
-        int src_y = y * src_h / dst_h;
-        if (src_y >= src_h) src_y = src_h - 1;
-        for (int x = 0; x < dst_w; x++) {
-            int src_x = x * src_w / dst_w;
-            if (src_x >= src_w) src_x = src_w - 1;
-            int idx = (src_y * src_w + src_x) * 3;
-            unsigned char r = rgb[idx];
-            unsigned char g = rgb[idx + 1];
-            unsigned char b = rgb[idx + 2];
-            dst[y * dst_w + x] = 0xFF000000 | ((uint32_t)r << 16) | ((uint32_t)g << 8) | b;
-        }
-    }
-}
-
-static void viewer_paint(Window *win) {
-    int cx = win->x + 4;
-    int cy = win->y + 24;
-    int cw = win->w - 8;
-    int ch = win->h - 28;
-
-    draw_rect(cx, cy, cw, ch, 0xFF1A1A1A);
-
-    if (!viewer_has_image) {
-        draw_string(cx + 20, cy + ch / 2, "No image loaded", 0xFF888888);
-        return;
-    }
-
-    // Calculate display size (fit within window, keep aspect ratio)
-    int disp_w = viewer_img_w;
-    int disp_h = viewer_img_h;
-
-    if (disp_w > cw - 8) {
-        disp_h = disp_h * (cw - 8) / disp_w;
-        disp_w = cw - 8;
-    }
-    if (disp_h > ch - 40) {
-        disp_w = disp_w * (ch - 40) / disp_h;
-        disp_h = ch - 40;
-    }
-
-    // Center in window
-    int ox = cx + (cw - disp_w) / 2;
-    int oy = cy + (ch - disp_h - 30) / 2;
-
-    // Draw the image pixel by pixel (nearest-neighbor from stored buffer)
-    for (int y = 0; y < disp_h; y++) {
-        int src_y = y * viewer_img_h / disp_h;
-        if (src_y >= viewer_img_h) src_y = viewer_img_h - 1;
-        for (int x = 0; x < disp_w; x++) {
-            int src_x = x * viewer_img_w / disp_w;
-            if (src_x >= viewer_img_w) src_x = viewer_img_w - 1;
-            uint32_t pixel = viewer_pixels[src_y * viewer_img_w + src_x];
-            put_pixel(ox + x, oy + y, pixel);
-        }
-    }
-
-    // Draw "Set as Wallpaper" button at the bottom
-    int btn_w = 160;
-    int btn_h = 22;
-    int btn_x = cx + (cw - btn_w) / 2;
-    int btn_y = win->y + win->h - 30;
-    draw_rounded_rect_filled(btn_x, btn_y, btn_w, btn_h, 6, 0xFF2D2D2D);
-    draw_string(btn_x + 10, btn_y + 6, "Set as Wallpaper", 0xFFF0F0F0);
-}
-
-static void viewer_handle_click(Window *win, int x, int y) {
-    if (!viewer_has_image) return;
-
-    int cx = 4;
-    int cw = win->w - 8;
-
-    // Check "Set as Wallpaper" button
-    int btn_w = 160;
-    int btn_x = cx + (cw - btn_w) / 2;
-    int btn_y = win->h - 30;
-    if (x >= btn_x && x < btn_x + btn_w && y >= btn_y && y < btn_y + 22) {
-        // Queue wallpaper change from file (deferred to main loop)
-        wallpaper_request_set_from_file(viewer_file_path);
-    }
-}
-
-static void viewer_handle_key(Window *win, char c) {
-    (void)win;
-    (void)c;
-}
-
-// Simple serial output for debugging
-static void v_serial_char(char c) {
-    while (!(inb(0x3F8 + 5) & 0x20));
-    outb(0x3F8, c);
-}
-static void v_serial_str(const char *s) { while (*s) v_serial_char(*s++); }
-static void v_serial_num(int n) {
-    if (n < 0) { v_serial_char('-'); n = -n; }
-    if (n >= 10) v_serial_num(n / 10);
-    v_serial_char('0' + (n % 10));
-}
-
-// Called from interrupt context - just queue the path for later processing
-void viewer_open_file(const char *path) {
-    v_serial_str("[VIEWER] open_file queued: ");
-    v_serial_str(path);
-    v_serial_str("\n");
-    viewer_strcpy(viewer_pending_path, path);
-    viewer_open_pending = true;
-}
-
-// Process deferred viewer open (called from main loop, NOT interrupt context)
-void viewer_process_pending(void) {
-    if (!viewer_open_pending) return;
-    viewer_open_pending = false;
-
-    const char *path = viewer_pending_path;
-    v_serial_str("[VIEWER] process_pending: ");
-    v_serial_str(path);
-    v_serial_str("\n");
-
-    FAT32_FileHandle *fh = fat32_open(path, "r");
-    if (!fh) {
-        v_serial_str("[VIEWER] fat32_open FAILED\n");
-        return;
-    }
-
-    uint32_t file_size = fh->size;
-    v_serial_str("[VIEWER] file_size=");
-    v_serial_num((int)file_size);
-    v_serial_str("\n");
-
-    if (file_size == 0 || file_size > 2 * 1024 * 1024) {
-        v_serial_str("[VIEWER] file too big or empty\n");
-        fat32_close(fh);
-        return;
-    }
-
-    unsigned char *buf = (unsigned char*)kmalloc(file_size);
-    if (!buf) {
-        v_serial_str("[VIEWER] kmalloc FAILED\n");
-        fat32_close(fh);
-        return;
-    }
-
-    int total_read = 0;
-    while (total_read < (int)file_size) {
-        int chunk = fat32_read(fh, buf + total_read, (int)file_size - total_read);
-        if (chunk <= 0) break;
-        total_read += chunk;
-    }
-    fat32_close(fh);
-
-    v_serial_str("[VIEWER] read ");
-    v_serial_num(total_read);
-    v_serial_str(" bytes\n");
-
-    if (total_read <= 0) {
-        kfree(buf);
-        return;
-    }
-
-    // Decode JPEG (now running in main loop, safe context)
-    njInit();
-    nj_result_t result = njDecode(buf, total_read);
-    v_serial_str("[VIEWER] njDecode returned: ");
-    v_serial_num((int)result);
-    v_serial_str("\n");
-
-    if (result != NJ_OK) {
-        njDone();
-        kfree(buf);
-        return;
-    }
-
-    int img_w = njGetWidth();
-    int img_h = njGetHeight();
-    unsigned char *rgb = njGetImage();
-
-    v_serial_str("[VIEWER] decoded ");
-    v_serial_num(img_w);
-    v_serial_str("x");
-    v_serial_num(img_h);
-    v_serial_str("\n");
-
-    if (!rgb || img_w <= 0 || img_h <= 0) {
-        njDone();
-        kfree(buf);
-        return;
-    }
-
-    // Scale to fit viewer buffer
-    int fit_w = img_w;
-    int fit_h = img_h;
-    if (fit_w > VIEWER_MAX_W) {
-        fit_h = fit_h * VIEWER_MAX_W / fit_w;
-        fit_w = VIEWER_MAX_W;
-    }
-    if (fit_h > VIEWER_MAX_H) {
-        fit_w = fit_w * VIEWER_MAX_H / fit_h;
-        fit_h = VIEWER_MAX_H;
-    }
-
-    viewer_scale_rgb_to_argb(rgb, img_w, img_h, viewer_pixels, fit_w, fit_h);
-    viewer_img_w = fit_w;
-    viewer_img_h = fit_h;
-    viewer_has_image = true;
-
-    njDone();
-    kfree(buf);
-
-    // Store the file path for "Set as Wallpaper"
-    viewer_strcpy(viewer_file_path, path);
-
-    // Update title - extract filename from path
-    const char *fname = path;
-    int plen = viewer_strlen(path);
-    for (int i = plen - 1; i >= 0; i--) {
-        if (path[i] == '/') {
-            fname = &path[i + 1];
-            break;
-        }
-    }
-    viewer_title[0] = 'V'; viewer_title[1] = 'i'; viewer_title[2] = 'e';
-    viewer_title[3] = 'w'; viewer_title[4] = 'e'; viewer_title[5] = 'r';
-    viewer_title[6] = ' '; viewer_title[7] = '-'; viewer_title[8] = ' ';
-    int ti = 9;
-    for (int i = 0; fname[i] && ti < 60; i++) {
-        viewer_title[ti++] = fname[i];
-    }
-    viewer_title[ti] = 0;
-
-    // Resize window to fit image
-    win_viewer.w = fit_w + 16;
-    if (win_viewer.w < 200) win_viewer.w = 200;
-    win_viewer.h = fit_h + 64;
-    if (win_viewer.h < 100) win_viewer.h = 100;
-
-    // Reset position to ensure visibility
-    win_viewer.x = 100;
-    win_viewer.y = 50;
-
-    v_serial_str("[VIEWER] window: x=");
-    v_serial_num(win_viewer.x);
-    v_serial_str(" y=");
-    v_serial_num(win_viewer.y);
-    v_serial_str(" w=");
-    v_serial_num(win_viewer.w);
-    v_serial_str(" h=");
-    v_serial_num(win_viewer.h);
-    v_serial_str(" fit=");
-    v_serial_num(fit_w);
-    v_serial_str("x");
-    v_serial_num(fit_h);
-    v_serial_str("\n");
-
-    // Show and bring to front
-    win_viewer.visible = true;
-    wm_bring_to_front(&win_viewer);
-
-    v_serial_str("[VIEWER] z_index=");
-    v_serial_num(win_viewer.z_index);
-    v_serial_str(" visible=");
-    v_serial_num(win_viewer.visible);
-    v_serial_str(" focused=");
-    v_serial_num(win_viewer.focused);
-    v_serial_str("\n");
-    v_serial_str("[VIEWER] window shown!\n");
-}
-
-void viewer_init(void) {
-    win_viewer.title = viewer_title;
-    viewer_title[0] = 'V'; viewer_title[1] = 'i'; viewer_title[2] = 'e';
-    viewer_title[3] = 'w'; viewer_title[4] = 'e'; viewer_title[5] = 'r';
-    viewer_title[6] = 0;
-    win_viewer.x = 100;
-    win_viewer.y = 50;
-    win_viewer.w = 500;
-    win_viewer.h = 400;
-    win_viewer.visible = false;
-    win_viewer.paint = viewer_paint;
-    win_viewer.handle_click = viewer_handle_click;
-    win_viewer.handle_key = viewer_handle_key;
-    win_viewer.handle_right_click = NULL;
-    win_viewer.data = NULL;
-    // Window is registered directly in wm_init's all_windows array
-    v_serial_str("[VIEWER] init done, win_viewer paint=");
-    v_serial_num(win_viewer.paint != NULL);
-    v_serial_str("\n");
-}

src/kernel/viewer.h

@@ -1,13 +0,0 @@
-// viewer.h - Image Viewer app for BoredOS
-#ifndef VIEWER_H
-#define VIEWER_H
-
-#include "wm.h"
-
-extern Window win_viewer;
-
-void viewer_init(void);
-void viewer_open_file(const char *path);        // Safe from interrupt context (deferred)
-void viewer_process_pending(void);              // Call from main loop only
-
-#endif // VIEWER_H

src/kernel/wm.c

@@ -3,22 +3,16 @@
 #include "io.h"
 #include "cmd.h"
 #include "process.h"
+#include "syscall.h"
 #include "cli_apps/cli_utils.h"
 #include "explorer.h"
-#include "editor.h"
-#include "markdown.h"
 #include <stdbool.h>
 #include <stddef.h>
-
-#include "viewer.h"
 #include "wallpaper.h"
-#include "control_panel.h"
 #include "about.h"
-#include "minesweeper.h"
 #include "fat32.h"
 #include "nanojpeg.h"
 #include "memory_manager.h"
-#include "paint.h"
 #include "disk.h"
 
 extern void serial_write(const char *str);
@@ -152,7 +146,7 @@ static void refresh_desktop_icons(void) {
         // Find if this icon still exists in the file list
         int found_idx = -1;
         for (int j = 0; j < file_count; j++) {
-            if (!file_processed[j] && str_eq(desktop_icons[i].name, files[j].name) == 0) {
+            if (!file_processed[j] && str_eq(desktop_icons[i].name, files[j].name) != 0) {
                 found_idx = j;
                 break;
             }
@@ -529,7 +523,7 @@ static int thumb_cache_next = 0; // Round-robin eviction
 
 static uint32_t* thumb_cache_lookup(const char *path) {
     for (int i = 0; i < THUMB_CACHE_SIZE; i++) {
-        if (thumb_cache[i].valid && str_eq(thumb_cache[i].path, path) == 0) {
+        if (thumb_cache[i].valid && str_eq(thumb_cache[i].path, path) != 0) {
             return thumb_cache[i].pixels;
         }
     }
@@ -538,7 +532,7 @@ static uint32_t* thumb_cache_lookup(const char *path) {
 
 static bool thumb_cache_is_failed(const char *path) {
     for (int i = 0; i < THUMB_CACHE_SIZE; i++) {
-        if (thumb_cache[i].failed && str_eq(thumb_cache[i].path, path) == 0) {
+        if (thumb_cache[i].failed && str_eq(thumb_cache[i].path, path) != 0) {
             return true;
         }
     }
@@ -619,10 +613,10 @@ void draw_image_icon(int x, int y, const char *label) {
     
     uint32_t *thumb = NULL;
     // Fast path: check hardcoded wallpaper names
-    if (str_eq(label, "moon.jpg") == 0) thumb = wallpaper_get_thumb(0);
-    else if (str_eq(label, "mountain.jpg") == 0) thumb = wallpaper_get_thumb(1);
-    else if (str_eq(label, "moon") == 0) thumb = wallpaper_get_thumb(0);
-    else if (str_eq(label, "mountain") == 0) thumb = wallpaper_get_thumb(1);
+    if (str_eq(label, "moon.jpg") != 0) thumb = wallpaper_get_thumb(0);
+    else if (str_eq(label, "mountain.jpg") != 0) thumb = wallpaper_get_thumb(1);
+    else if (str_eq(label, "moon") != 0) thumb = wallpaper_get_thumb(0);
+    else if (str_eq(label, "mountain") != 0) thumb = wallpaper_get_thumb(1);
     
     if (!thumb) {
         if (str_ends_with(label, "moon.jpg")) thumb = wallpaper_get_thumb(0);
@@ -658,7 +652,7 @@ void draw_image_icon(int x, int y, const char *label) {
         // Draw thumbnail into icon - handle both 100x60 wallpaper thumbs and 48x48 dynamic thumbs
         bool is_wallpaper_thumb = false;
         if (str_ends_with(label, "moon.jpg") || str_ends_with(label, "mountain.jpg") ||
-            str_eq(label, "moon") == 0 || str_eq(label, "mountain") == 0) {
+            str_eq(label, "moon") != 0 || str_eq(label, "mountain") != 0) {
             is_wallpaper_thumb = true;
         }
         int dst_w = 44, dst_h = 44;
@@ -1567,7 +1561,9 @@ void wm_handle_click(int x, int y) {
         if (item == 0) {  // About
             wm_bring_to_front(&win_about);
         } else if (item == 1) {  // Settings
-            wm_bring_to_front(&win_control_panel);
+            Window *existing = wm_find_window_by_title("Settings");
+            if (existing) wm_bring_to_front(existing);
+            else process_create_elf("/bin/settings.elf", NULL);
         } else if (item == 2) {  // Shutdown
             cli_cmd_shutdown(NULL);
         } else if (item == 3) {  // Restart
@@ -1608,10 +1604,6 @@ void wm_handle_click(int x, int y) {
             // Reset window state on close
             if (topmost == &win_explorer) {
                 explorer_reset();
-            } else if (topmost == &win_control_panel) {
-                control_panel_reset();
-            } else if (topmost == &win_paint) {
-                paint_reset();
             }
         } else if (y < topmost->y + 30) {
             // Dragging the title bar
@@ -1729,11 +1721,6 @@ void wm_handle_right_click(int x, int y) {
         // Mouse Down
         drag_start_x = mx;
         drag_start_y = my;
-        
-        if (win_paint.focused && win_paint.visible) {
-            paint_reset_last_pos();
-        }
-
         // Check Dock for app clicks (bottom of screen, floating)
         int dock_h = 60;
         int dock_y = sh - dock_h - 6;  // Float above bottom
@@ -1763,11 +1750,6 @@ void wm_handle_right_click(int x, int y) {
         }
     } else if (right && !prev_right) {
         wm_handle_right_click(mx, my);
-    } else if (left && win_paint.focused && win_paint.visible && !is_dragging) {
-        int rel_x = mx - win_paint.x;
-        int rel_y = my - win_paint.y;
-        paint_handle_mouse(rel_x, rel_y);
-        force_redraw = true;
     } else if (left && is_dragging && drag_window) {
         drag_window->x = mx - drag_offset_x;
         drag_window->y = my - drag_offset_y;
@@ -1855,7 +1837,9 @@ void wm_handle_right_click(int x, int y) {
                     process_create_elf("/bin/notepad.elf", NULL);
                 }
             } else if (str_starts_with(start_menu_pending_app, "Editor")) {
-                wm_bring_to_front(&win_editor);
+                Window *existing = wm_find_window_by_title("Txtedit");
+                if (existing) wm_bring_to_front(existing);
+                else process_create_elf("/bin/txtedit.elf", NULL);
             } else if (str_starts_with(start_menu_pending_app, "Terminal")) {
                 cmd_reset(); wm_bring_to_front(&win_cmd);
             } else if (str_starts_with(start_menu_pending_app, "Calculator")) {
@@ -1866,11 +1850,17 @@ void wm_handle_right_click(int x, int y) {
                     process_create_elf("/bin/calculator.elf", NULL);
                 }
             } else if (str_starts_with(start_menu_pending_app, "Minesweeper")) {
-                wm_bring_to_front(&win_minesweeper);
+                Window *existing = wm_find_window_by_title("Minesweeper");
+                if (existing) wm_bring_to_front(existing);
+                else process_create_elf("/bin/minesweeper.elf", NULL);
             } else if (str_starts_with(start_menu_pending_app, "Settings")) {
-                wm_bring_to_front(&win_control_panel);
+                Window *existing = wm_find_window_by_title("Settings");
+                if (existing) wm_bring_to_front(existing);
+                else process_create_elf("/bin/settings.elf", NULL);
             } else if (str_starts_with(start_menu_pending_app, "Paint")) {
-                wm_bring_to_front(&win_paint);
+                Window *existing = wm_find_window_by_title("Paint");
+                if (existing) wm_bring_to_front(existing);
+                else process_create_elf("/bin/paint.elf", NULL);
             } else if (str_starts_with(start_menu_pending_app, "About")) {
                 wm_bring_to_front(&win_about);
             } else if (str_starts_with(start_menu_pending_app, "Shutdown")) {
@@ -1896,9 +1886,9 @@ void wm_handle_right_click(int x, int y) {
                     } else if (str_ends_with(icon->name, "Calculator.shortcut")) {
                         process_create_elf("/bin/calculator.elf", NULL); handled = true;
                     } else if (str_ends_with(icon->name, "Minesweeper.shortcut")) {
-                        wm_bring_to_front(&win_minesweeper); handled = true;
+                        process_create_elf("/bin/minesweeper.elf", NULL); handled = true;
                     } else if (str_ends_with(icon->name, "Settings.shortcut")) {
-                        wm_bring_to_front(&win_control_panel); handled = true;
+                        process_create_elf("/bin/settings.elf", NULL); handled = true;
                     } else if (str_ends_with(icon->name, "Terminal.shortcut")) {
                         wm_bring_to_front(&win_cmd); handled = true;
                     } else if (str_ends_with(icon->name, "About.shortcut")) {
@@ -1908,7 +1898,7 @@ void wm_handle_right_click(int x, int y) {
                     } else if (str_ends_with(icon->name, "Recycle Bin.shortcut")) {
                         explorer_open_directory("/RecycleBin"); handled = true;
                     } else if (str_ends_with(icon->name, "Paint.shortcut")) {
-                        wm_bring_to_front(&win_paint); handled = true;
+                        process_create_elf("/bin/paint.elf", NULL); handled = true;
                     }
                     
                     if (!handled) {
@@ -1927,8 +1917,7 @@ void wm_handle_right_click(int x, int y) {
                                     if (fat32_is_directory(buf)) {
                                         explorer_open_directory(buf);
                                     } else {
-                                        editor_open_file(buf);
-                                        wm_bring_to_front(&win_editor);
+                                        process_create_elf("/bin/txtedit.elf", buf);
                                     }
                                     pending_desktop_icon_click = -1;
                                     force_redraw = true;
@@ -1948,16 +1937,13 @@ void wm_handle_right_click(int x, int y) {
                     if (str_ends_with(icon->name, ".elf")) {
                         process_create_elf(path, NULL);
                     } else if (str_ends_with(icon->name, ".pnt")) {
-                        paint_load(path);
-                        wm_bring_to_front(&win_paint);
+                        process_create_elf("/bin/paint.elf", path);
                     } else if (str_ends_with(icon->name, ".md")) {
-                        markdown_open_file(path);
-                        wm_bring_to_front(&win_markdown);
+                        process_create_elf("/bin/markdown.elf", path);
                     } else if (str_ends_with(icon->name, ".jpg") || str_ends_with(icon->name, ".JPG")) {
-                        viewer_open_file(path);
+                        process_create_elf("/bin/viewer.elf", path);
                     } else {
-                        editor_open_file(path);
-                        wm_bring_to_front(&win_editor);
+                        process_create_elf("/bin/txtedit.elf", path);
                     }
                 }
             }
@@ -2008,7 +1994,7 @@ void wm_handle_right_click(int x, int y) {
                         if (from_desktop) {
                             char path[128] = "/Desktop/";
                             int p=9; int n=0; while(desktop_icons[i].name[n]) path[p++] = desktop_icons[i].name[n++]; path[p]=0;
-                            if (str_eq(path, drag_file_path) == 0) continue;
+                            if (str_eq(path, drag_file_path) != 0) continue;
                         }
 
                         if (rect_contains(desktop_icons[i].x + 20, desktop_icons[i].y, 40, 40, mx, my)) {
@@ -2051,7 +2037,7 @@ void wm_handle_right_click(int x, int y) {
                         if (desktop_auto_align && !msg_box_visible) {
                             int new_idx = -1;
                             for(int i=0; i<desktop_icon_count; i++) {
-                                if (str_eq(desktop_icons[i].name, filename) == 0) {
+                                if (str_eq(desktop_icons[i].name, filename) != 0) {
                                     new_idx = i;
                                     break;
                                 }
@@ -2075,7 +2061,7 @@ void wm_handle_right_click(int x, int y) {
                             }
                         } else if (!desktop_auto_align && !msg_box_visible) {
                             for(int i=0; i<desktop_icon_count; i++) {
-                                if (str_eq(desktop_icons[i].name, filename) == 0) {
+                                if (str_eq(desktop_icons[i].name, filename) != 0) {
                                     desktop_icons[i].x = mx - 20;
                                     desktop_icons[i].y = my - 20;
                                     if (desktop_snap_to_grid) {
@@ -2096,7 +2082,7 @@ void wm_handle_right_click(int x, int y) {
                         for(int i=0; i<desktop_icon_count; i++) {
                             char path[128] = "/Desktop/";
                             int p=9; int n=0; while(desktop_icons[i].name[n]) path[p++] = desktop_icons[i].name[n++]; path[p]=0;
-                            if (str_eq(path, drag_file_path) == 0) {
+                            if (str_eq(path, drag_file_path) != 0) {
                                 dragged_idx = i;
                                 break;
                             }
@@ -2173,6 +2159,61 @@ void wm_handle_right_click(int x, int y) {
         force_redraw = true;
     }
     
+    // Send mouse events to userland windows
+    if (left && !prev_left) {
+        // Left button pressed - send MOUSE_DOWN event to topmost window
+        Window *topmost = NULL;
+        int topmost_z = -1;
+        for (int w = 0; w < window_count; w++) {
+            Window *win = all_windows[w];
+            if (win->visible && rect_contains(win->x, win->y, win->w, win->h, mx, my)) {
+                if (win->z_index > topmost_z) {
+                    topmost = win;
+                    topmost_z = win->z_index;
+                }
+            }
+        }
+        if (topmost && topmost->data) {
+            syscall_send_mouse_down_event(topmost, mx - topmost->x, my - topmost->y);
+        }
+    }
+    
+    if (!left && prev_left) {
+        // Left button released - send MOUSE_UP event to topmost window
+        Window *topmost = NULL;
+        int topmost_z = -1;
+        for (int w = 0; w < window_count; w++) {
+            Window *win = all_windows[w];
+            if (win->visible && rect_contains(win->x, win->y, win->w, win->h, mx, my)) {
+                if (win->z_index > topmost_z) {
+                    topmost = win;
+                    topmost_z = win->z_index;
+                }
+            }
+        }
+        if (topmost && topmost->data) {
+            syscall_send_mouse_up_event(topmost, mx - topmost->x, my - topmost->y);
+        }
+    }
+    
+    if (dx != 0 || dy != 0) {
+        // Mouse moved - send MOUSE_MOVE event to topmost window
+        Window *topmost = NULL;
+        int topmost_z = -1;
+        for (int w = 0; w < window_count; w++) {
+            Window *win = all_windows[w];
+            if (win->visible && rect_contains(win->x, win->y, win->w, win->h, mx, my)) {
+                if (win->z_index > topmost_z) {
+                    topmost = win;
+                    topmost_z = win->z_index;
+                }
+            }
+        }
+        if (topmost && topmost->data) {
+            syscall_send_mouse_move_event(topmost, mx - topmost->x, my - topmost->y, buttons);
+        }
+    }
+    
     prev_left = left;
     prev_right = right;
     
@@ -2290,13 +2331,7 @@ void wm_init(void) {
 
     cmd_init();
     explorer_init();
-    editor_init();
-    markdown_init();
-    control_panel_init();
     about_init();
-    minesweeper_init();
-    paint_init();
-    viewer_init();
     wallpaper_init();
     
     refresh_desktop_icons();
@@ -2304,24 +2339,12 @@ void wm_init(void) {
     // Initialize z-indices
     win_cmd.z_index = 0;
     win_explorer.z_index = 1;
-    win_editor.z_index = 2;
-    win_markdown.z_index = 3;
-    win_control_panel.z_index = 4;
-    win_about.z_index = 5;
-    win_minesweeper.z_index = 6;
-    win_paint.z_index = 7;
-    win_viewer.z_index = 8;
+    win_about.z_index = 2;
     
     all_windows[0] = &win_cmd;
     all_windows[1] = &win_explorer;
-    all_windows[2] = &win_editor;
-    all_windows[3] = &win_markdown;
-    all_windows[4] = &win_control_panel;
-    all_windows[5] = &win_about;
-    all_windows[6] = &win_minesweeper;
-    all_windows[7] = &win_paint;
-    all_windows[8] = &win_viewer;
-    window_count = 9;
+    all_windows[2] = &win_about;
+    window_count = 3;
     
     // Only show Explorer on desktop (initially hidden)
     win_explorer.visible = false;
@@ -2330,11 +2353,7 @@ void wm_init(void) {
     
     // Rest are hidden initially
     win_cmd.visible = false;
-    win_editor.visible = false;
-    win_markdown.visible = false;
-    win_control_panel.visible = false;
     win_about.visible = false;
-    win_minesweeper.visible = false;
     
     force_redraw = true;
 }