perf: optimize graphics rendering and implement caching

src/userland/gui/settings.c

@@ -415,6 +415,23 @@ static void decode_wallpapers_task(void *arg) {
         wp->name[(nl-4 < 63) ? nl-4 : 63] = 0;
 
         // Load and generate thumbnail
+        char cache_path[256];
+        int cp = 0;
+        char *cpref = "/Library/Caches/Thumbnails/";
+        while (cpref[cp]) { cache_path[cp] = cpref[cp]; cp++; }
+        int cn = 0;
+        while (info[i].name[cn]) { cache_path[cp+cn] = info[i].name[cn]; cn++; }
+        char *csuf = ".bin";
+        int cs = 0;
+        while (csuf[cs]) { cache_path[cp+cn+cs] = csuf[cs]; cs++; }
+        cache_path[cp+cn+cs] = 0;
+
+        int cfd = sys_open(cache_path, "r");
+        if (cfd >= 0) {
+            sys_read(cfd, wp->thumb, WALLPAPER_THUMB_W * WALLPAPER_THUMB_H * 4);
+            sys_close(cfd);
+            wp->valid = 1;
+        } else {
             int fd = sys_open(wp->path, "r");
             if (fd >= 0) {
                 int size = sys_seek(fd, 0, 2); // SEEK_END
@@ -429,12 +446,22 @@ static void decode_wallpapers_task(void *arg) {
                                 scale_rgba_to_argb(img, img_w, img_h, wp->thumb, WALLPAPER_THUMB_W, WALLPAPER_THUMB_H);
                                 wp->valid = 1;
                                 stbi_image_free(img);
+
+                                // Save to cache
+                                sys_mkdir("/Library/Caches");
+                                sys_mkdir("/Library/Caches/Thumbnails");
+                                int swfd = sys_open(cache_path, "w");
+                                if (swfd >= 0) {
+                                    sys_write_fs(swfd, wp->thumb, WALLPAPER_THUMB_W * WALLPAPER_THUMB_H * 4);
+                                    sys_close(swfd);
                                 }
-                        free(buf); // Release memory
+                            }
+                            free(buf);
                         }
                 }
                 sys_close(fd);
             }
+        }
 
         wallpaper_count++;
     }
@@ -624,11 +651,7 @@ static void control_panel_paint_wallpaper(ui_window_t win) {
         
         widget_button_draw(&settings_ctx, &btn_wp_thumbs[i]);
         if (wallpapers[i].valid) {
-            for (int py = 0; py < WALLPAPER_THUMB_H; py++) {
+            ui_draw_image(win, button_x + tx + 4, button_y + ty + 4, WALLPAPER_THUMB_W, WALLPAPER_THUMB_H, wallpapers[i].thumb);
-                for (int px = 0; px < WALLPAPER_THUMB_W; px++) {
-                    ui_draw_rect(win, button_x + tx + 4 + px, button_y + ty + 4 + py, 1, 1, wallpapers[i].thumb[py * WALLPAPER_THUMB_W + px]);
-                }
-            }
         }
         ui_draw_string(win, button_x + tx + 8, button_y + ty + WALLPAPER_THUMB_H + 8, wallpapers[i].name, 0xFFFFFFFF);
     }

src/wm/wallpaper.c

@@ -20,6 +20,53 @@ static volatile const char *pending_wallpaper_path = NULL;
 static char pending_path_buf[256];
 
 #define WALLPAPER_CONF_PATH "/Library/BWM/Wallpaper/wallpaper"
+#define WALLPAPER_CACHE_PATH "/Library/Caches/Wallpaper.bin"
+
+static void wallpaper_save_cache(void) {
+    if (!wp_pixels || wp_width <= 0 || wp_height <= 0) return;
+    fat32_mkdir("/Library/Caches");
+    FAT32_FileHandle *fh = fat32_open(WALLPAPER_CACHE_PATH, "w");
+    if (fh && fh->valid) {
+        uint32_t w = (uint32_t)wp_width;
+        uint32_t h = (uint32_t)wp_height;
+        fat32_write(fh, &w, 4);
+        fat32_write(fh, &h, 4);
+        fat32_write(fh, wp_pixels, w * h * 4);
+        fat32_close(fh);
+    }
+}
+
+static int wallpaper_load_cache(void) {
+    if (!fat32_exists(WALLPAPER_CACHE_PATH)) return 0;
+    FAT32_FileHandle *fh = fat32_open(WALLPAPER_CACHE_PATH, "r");
+    if (!fh || !fh->valid) return 0;
+    
+    uint32_t w, h;
+    fat32_read(fh, &w, 4);
+    fat32_read(fh, &h, 4);
+    
+    if (w != (uint32_t)get_screen_width() || h != (uint32_t)get_screen_height()) {
+        fat32_close(fh);
+        return 0;
+    }
+    
+    if (!wp_pixels) {
+        wp_pixels = (uint32_t*)kmalloc(MAX_WP_WIDTH * MAX_WP_HEIGHT * sizeof(uint32_t));
+        if (!wp_pixels) { fat32_close(fh); return 0; }
+    }
+    
+    uint32_t total_size = w * h * 4;
+    uint32_t bytes_read = fat32_read(fh, wp_pixels, total_size);
+    fat32_close(fh);
+    
+    if (bytes_read == total_size) {
+        wp_width = (int)w;
+        wp_height = (int)h;
+        graphics_set_bg_image(wp_pixels, wp_width, wp_height);
+        return 1;
+    }
+    return 0;
+}
 
 // Simple nearest-neighbor scale from decoded RGBA to ARGB pixel buffer
 static void scale_rgba_to_argb(const unsigned char *rgba, int src_w, int src_h,
@@ -72,6 +119,7 @@ static int decode_and_set_wallpaper(const unsigned char *jpg_data, unsigned int
     stbi_image_free(rgba);
 
     graphics_set_bg_image(wp_pixels, wp_width, wp_height);
+    wallpaper_save_cache();
     return 1;
 }
 
@@ -190,6 +238,9 @@ int wallpaper_get_width(void) { return wp_width; }
 int wallpaper_get_height(void) { return wp_height; }
 
 void wallpaper_init(void) {
+    if (wallpaper_load_cache()) {
+        serial_str("[WALLPAPER] Loaded from cache\n");
+    } else {
         wallpaper_load_setting();
         
         if (pending_wallpaper_path == NULL) {
@@ -200,3 +251,4 @@ void wallpaper_init(void) {
             }
         }
     }
+}