NEW: math.h/libmath.c

This commit is contained in:
boreddevnl 2026-04-03 23:28:29 +02:00
parent c330382436
commit fca67f68a9
3 changed files with 239 additions and 117 deletions

View file

@ -7,6 +7,7 @@
#include "../../wm/libwidget.h" #include "../../wm/libwidget.h"
#include <stdbool.h> #include <stdbool.h>
#include "stdlib.h" #include "stdlib.h"
#include "math.h"
// External syscalls from libc // External syscalls from libc
extern void sys_parallel_run(void (*fn)(void*), void **args, int count); extern void sys_parallel_run(void (*fn)(void*), void **args, int count);
@ -49,83 +50,7 @@ static int32_t *graph_zb = NULL; // Z-Buffer for 3D depth testing
#define MODE_3D 1 #define MODE_3D 1
static const double MY_PI = 3.14159265358979323846; // Math functions provided by libc/math.h (sin, cos, tan, sqrt, log, exp, pow, fabs, fmod, M_PI)
static double my_fabs(double x) { return x < 0 ? -x : x; }
static double my_fmod(double x, double y) {
if (y == 0) return 0;
return x - (int)(x / y) * y;
}
static double my_sin(double x) {
x = my_fmod(x, 2 * MY_PI);
if (x > MY_PI) x -= 2 * MY_PI;
if (x < -MY_PI) x += 2 * MY_PI;
double x2 = x * x, term = x, sum = x;
for (int i = 1; i <= 8; i++) {
term *= -x2 / ((2*i) * (2*i + 1));
sum += term;
}
return sum;
}
static double my_cos(double x) { return my_sin(x + MY_PI / 2); }
static double my_tan(double x) {
double c = my_cos(x);
if (my_fabs(c) < 1e-10) return 1e15;
return my_sin(x) / c;
}
static double my_sqrt(double x) {
if (x <= 0) return 0;
double g = x * 0.5;
for (int i = 0; i < 25; i++) g = (g + x / g) * 0.5;
return g;
}
static double my_ln(double x) {
if (x <= 0) return -1e30;
int e = 0;
while (x > 2) { x /= 2; e++; }
while (x < 0.5) { x *= 2; e--; }
double t = (x - 1) / (x + 1), t2 = t * t, sum = t, term = t;
for (int i = 1; i <= 20; i++) { term *= t2; sum += term / (2*i + 1); }
return 2 * sum + e * 0.693147180559945;
}
static double my_exp(double x) {
if (x > 700) return 1e300;
if (x < -700) return 0;
int k = (int)(x / 0.693147180559945);
if (x < 0 && k * 0.693147180559945 > x) k--;
double r = x - k * 0.693147180559945;
double sum = 1, term = 1;
for (int i = 1; i <= 20; i++) { term *= r / i; sum += term; }
double result = sum;
if (k >= 0) { for (int i = 0; i < k; i++) result *= 2; }
else { for (int i = 0; i < -k; i++) result /= 2; }
return result;
}
static double my_pow_int(double b, int e) {
if (e == 0) return 1;
if (e < 0) return 1.0 / my_pow_int(b, -e);
double r = 1;
while (e > 0) { if (e & 1) r *= b; b *= b; e >>= 1; }
return r;
}
static double my_pow(double b, double e) {
if (b == 0) return 0;
if (e == 0) return 1;
int ie = (int)e;
if ((double)ie == e) return my_pow_int(b, ie);
if (b < 0) return 0;
return my_exp(e * my_ln(b));
}
// ================= // =================
// Expression Parser // Expression Parser
@ -210,7 +135,7 @@ static int tokenize(const char *input, Token *tokens) {
else if (strcmp(buf, "abs") == 0) tokens[count].type = TOK_FN_ABS; else if (strcmp(buf, "abs") == 0) tokens[count].type = TOK_FN_ABS;
else if (strcmp(buf, "log") == 0) tokens[count].type = TOK_FN_LOG; else if (strcmp(buf, "log") == 0) tokens[count].type = TOK_FN_LOG;
else if (strcmp(buf, "pi") == 0 || strcmp(buf, "PI") == 0) { else if (strcmp(buf, "pi") == 0 || strcmp(buf, "PI") == 0) {
tokens[count].type = TOK_NUM; tokens[count].value = MY_PI; tokens[count].type = TOK_NUM; tokens[count].value = M_PI;
} else { tokens[count].type = TOK_NUM; tokens[count].value = 0; } } else { tokens[count].type = TOK_NUM; tokens[count].value = 0; }
count++; count++;
} else { } else {
@ -331,22 +256,22 @@ static double eval_ast(ASTNode *n, int idx, double x, double y, double z) {
case NODE_MUL: return eval_ast(n, nd->left, x, y, z) * eval_ast(n, nd->right, x, y, z); case NODE_MUL: return eval_ast(n, nd->left, x, y, z) * eval_ast(n, nd->right, x, y, z);
case NODE_DIV: { case NODE_DIV: {
double d = eval_ast(n, nd->right, x, y, z); double d = eval_ast(n, nd->right, x, y, z);
return my_fabs(d) < 1e-15 ? 1e15 : eval_ast(n, nd->left, x, y, z) / d; return fabs(d) < 1e-15 ? 1e15 : eval_ast(n, nd->left, x, y, z) / d;
} }
case NODE_POW: { case NODE_POW: {
double b = eval_ast(n, nd->left, x, y, z); double b = eval_ast(n, nd->left, x, y, z);
double e = eval_ast(n, nd->right, x, y, z); double e = eval_ast(n, nd->right, x, y, z);
if (e == 2.0) return b * b; if (e == 2.0) return b * b;
if (e == 3.0) return b * b * b; if (e == 3.0) return b * b * b;
return my_pow(b, e); return pow(b, e);
} }
case NODE_NEG: return -eval_ast(n, nd->left, x, y, z); case NODE_NEG: return -eval_ast(n, nd->left, x, y, z);
case NODE_SIN: return my_sin(eval_ast(n, nd->left, x, y, z)); case NODE_SIN: return sin(eval_ast(n, nd->left, x, y, z));
case NODE_COS: return my_cos(eval_ast(n, nd->left, x, y, z)); case NODE_COS: return cos(eval_ast(n, nd->left, x, y, z));
case NODE_TAN: return my_tan(eval_ast(n, nd->left, x, y, z)); case NODE_TAN: return tan(eval_ast(n, nd->left, x, y, z));
case NODE_SQRT: return my_sqrt(eval_ast(n, nd->left, x, y, z)); case NODE_SQRT: return sqrt(eval_ast(n, nd->left, x, y, z));
case NODE_ABS: return my_fabs(eval_ast(n, nd->left, x, y, z)); case NODE_ABS: return fabs(eval_ast(n, nd->left, x, y, z));
case NODE_LOG: return my_ln(eval_ast(n, nd->left, x, y, z)); case NODE_LOG: return log(eval_ast(n, nd->left, x, y, z));
} }
return 0; return 0;
} }
@ -397,22 +322,22 @@ static double run_bc(Instruction *bc, int len, double x, double y, double z) {
case OP_MUL: { double b = stack[--sp]; double a = stack[--sp]; stack[sp++] = a * b; break; } case OP_MUL: { double b = stack[--sp]; double a = stack[--sp]; stack[sp++] = a * b; break; }
case OP_DIV: { case OP_DIV: {
double b = stack[--sp]; double a = stack[--sp]; double b = stack[--sp]; double a = stack[--sp];
stack[sp++] = (my_fabs(b) < 1e-15) ? 1e15 : a / b; break; stack[sp++] = (fabs(b) < 1e-15) ? 1e15 : a / b; break;
} }
case OP_POW: { case OP_POW: {
double b = stack[--sp]; double a = stack[--sp]; double b = stack[--sp]; double a = stack[--sp];
if (b == 2.0) stack[sp++] = a * a; if (b == 2.0) stack[sp++] = a * a;
else if (b == 3.0) stack[sp++] = a * a * a; else if (b == 3.0) stack[sp++] = a * a * a;
else stack[sp++] = my_pow(a, b); else stack[sp++] = pow(a, b);
break; break;
} }
case OP_NEG: stack[sp-1] = -stack[sp-1]; break; case OP_NEG: stack[sp-1] = -stack[sp-1]; break;
case OP_SIN: stack[sp-1] = my_sin(stack[sp-1]); break; case OP_SIN: stack[sp-1] = sin(stack[sp-1]); break;
case OP_COS: stack[sp-1] = my_cos(stack[sp-1]); break; case OP_COS: stack[sp-1] = cos(stack[sp-1]); break;
case OP_TAN: stack[sp-1] = my_tan(stack[sp-1]); break; case OP_TAN: stack[sp-1] = tan(stack[sp-1]); break;
case OP_SQRT: stack[sp-1] = my_sqrt(stack[sp-1]); break; case OP_SQRT: stack[sp-1] = sqrt(stack[sp-1]); break;
case OP_ABS: stack[sp-1] = my_fabs(stack[sp-1]); break; case OP_ABS: stack[sp-1] = fabs(stack[sp-1]); break;
case OP_LOG: stack[sp-1] = my_ln(stack[sp-1]); break; case OP_LOG: stack[sp-1] = log(stack[sp-1]); break;
} }
} }
return sp > 0 ? stack[sp-1] : 0; return sp > 0 ? stack[sp-1] : 0;
@ -537,7 +462,7 @@ static void gfb_pixel_z(int x, int y, int z, uint32_t c) {
static void gfb_line(int x0, int y0, int x1, int y1, uint32_t c) { static void gfb_line(int x0, int y0, int x1, int y1, uint32_t c) {
int dx = my_fabs((double)(x1 - x0)), dy = my_fabs((double)(y1 - y0)); int dx = fabs((double)(x1 - x0)), dy = fabs((double)(y1 - y0));
int sx = x0 < x1 ? 1 : -1, sy = y0 < y1 ? 1 : -1; int sx = x0 < x1 ? 1 : -1, sy = y0 < y1 ? 1 : -1;
int err = dx - dy; int err = dx - dy;
for (int i = 0; i < 2000; i++) { for (int i = 0; i < 2000; i++) {
@ -550,7 +475,7 @@ static void gfb_line(int x0, int y0, int x1, int y1, uint32_t c) {
} }
static void gfb_line_z(int x0, int y0, int z0, int x1, int y1, int z1, uint32_t c) { static void gfb_line_z(int x0, int y0, int z0, int x1, int y1, int z1, uint32_t c) {
int dx = my_fabs((double)(x1 - x0)), dy = my_fabs((double)(y1 - y0)); int dx = fabs((double)(x1 - x0)), dy = fabs((double)(y1 - y0));
int sx = x0 < x1 ? 1 : -1, sy = y0 < y1 ? 1 : -1; int sx = x0 < x1 ? 1 : -1, sy = y0 < y1 ? 1 : -1;
int err = dx - dy; int err = dx - dy;
int steps = (dx > dy ? dx : dy); int steps = (dx > dy ? dx : dy);
@ -613,7 +538,7 @@ static uint32_t color_by_height(double z, double zmin, double zmax) {
} }
static uint32_t apply_shading(uint32_t color, double nx, double ny, double nz) { static uint32_t apply_shading(uint32_t color, double nx, double ny, double nz) {
double len = my_sqrt(nx*nx + ny*ny + nz*nz); double len = sqrt(nx*nx + ny*ny + nz*nz);
if (len > 1e-9) { nx /= len; ny /= len; nz /= len; } if (len > 1e-9) { nx /= len; ny /= len; nz /= len; }
else { nx = 0; ny = 1; nz = 0; } else { nx = 0; ny = 1; nz = 0; }
@ -811,16 +736,16 @@ static void autofit_2d_view(void) {
for (int px = 0; px < graph_w; px += 2) { for (int px = 0; px < graph_w; px += 2) {
double wx = world_x_2d(px); double wx = world_x_2d(px);
double wy = eval_rhs_only(wx, 0, 0); double wy = eval_rhs_only(wx, 0, 0);
if (wy == wy && my_fabs(wy) < 1e10) { if (wy == wy && fabs(wy) < 1e10) {
if (wy < y_min_data) y_min_data = wy; if (wy < y_min_data) y_min_data = wy;
if (wy > y_max_data) y_max_data = wy; if (wy > y_max_data) y_max_data = wy;
found = true; found = true;
} }
} }
if (found) { if (found) {
if (y_min_data * y_max_data <= 0 || my_fabs(y_min_data) < (y_max_data - y_min_data) * 0.5) { if (y_min_data * y_max_data <= 0 || fabs(y_min_data) < (y_max_data - y_min_data) * 0.5) {
double max_abs = my_fabs(y_min_data); double max_abs = fabs(y_min_data);
if (my_fabs(y_max_data) > max_abs) max_abs = my_fabs(y_max_data); if (fabs(y_max_data) > max_abs) max_abs = fabs(y_max_data);
double pad = max_abs * 0.15; double pad = max_abs * 0.15;
if (pad < 0.5) pad = 0.5; if (pad < 0.5) pad = 0.5;
view_y_min = -(max_abs + pad); view_y_min = -(max_abs + pad);
@ -838,13 +763,13 @@ static void autofit_2d_view(void) {
if (current_y_range < target_y_range) { if (current_y_range < target_y_range) {
double cy = (view_y_min + view_y_max) / 2.0; double cy = (view_y_min + view_y_max) / 2.0;
if (my_fabs(cy) < current_y_range * 0.1) cy = 0; if (fabs(cy) < current_y_range * 0.1) cy = 0;
view_y_min = cy - target_y_range / 2.0; view_y_min = cy - target_y_range / 2.0;
view_y_max = cy + target_y_range / 2.0; view_y_max = cy + target_y_range / 2.0;
} else { } else {
double target_x_range = current_y_range * (double)graph_w / (double)graph_h; double target_x_range = current_y_range * (double)graph_w / (double)graph_h;
double cx = (view_x_min + view_x_max) / 2.0; double cx = (view_x_min + view_x_max) / 2.0;
if (my_fabs(cx) < x_range * 0.1) cx = 0; if (fabs(cx) < x_range * 0.1) cx = 0;
view_x_min = cx - target_x_range / 2.0; view_x_min = cx - target_x_range / 2.0;
view_x_max = cx + target_x_range / 2.0; view_x_max = cx + target_x_range / 2.0;
} }
@ -893,9 +818,9 @@ static void render_2d_explicit(void) {
for (int px = 0; px < graph_w; px++) { for (int px = 0; px < graph_w; px++) {
double wx = world_x_2d(px); double wx = world_x_2d(px);
double wy = eval_rhs_only(wx, 0, 0); double wy = eval_rhs_only(wx, 0, 0);
if (wy != wy || my_fabs(wy) > 1e10) { prev_valid = false; continue; } if (wy != wy || fabs(wy) > 1e10) { prev_valid = false; continue; }
int sy = screen_y_2d(wy); int sy = screen_y_2d(wy);
if (prev_valid && my_fabs((double)(sy - prev_sy)) < graph_h) { if (prev_valid && fabs((double)(sy - prev_sy)) < graph_h) {
gfb_line(prev_sx, prev_sy, px, sy, COLOR_CURVE); gfb_line(prev_sx, prev_sy, px, sy, COLOR_CURVE);
} }
prev_sx = px; prev_sy = sy; prev_valid = true; prev_sx = px; prev_sy = sy; prev_valid = true;
@ -980,7 +905,7 @@ static void eval_3d_explicit_job(void *arg) {
surf_y_3d[j][i] = wy; surf_y_3d[j][i] = wy;
surf[j][i].count = 0; surf[j][i].count = 0;
if (my_fabs(wz) > 1e10 || wz != wz) { if (fabs(wz) > 1e10 || wz != wz) {
// Invalid value // Invalid value
return; return;
} }
@ -997,7 +922,7 @@ static void eval_3d_explicit_job(void *arg) {
double nx = -dfx; double nx = -dfx;
double ny = -dfy; double ny = -dfy;
double nz = 1.0; double nz = 1.0;
double len = my_sqrt(nx*nx + ny*ny + nz*nz); double len = sqrt(nx*nx + ny*ny + nz*nz);
if (len > 1e-9) { nx /= len; ny /= len; nz /= len; } if (len > 1e-9) { nx /= len; ny /= len; nz /= len; }
else { nx = 0; ny = 0; nz = 1; } else { nx = 0; ny = 0; nz = 1; }
@ -1031,7 +956,7 @@ static void eval_3d_implicit_job(void *arg) {
double cur_f = eval_implicit(wx, wy, zz); double cur_f = eval_implicit(wx, wy, zz);
if ((prev_f > 0) != (cur_f > 0)) { if ((prev_f > 0) != (cur_f > 0)) {
if (my_fabs(prev_f) < 1e10 && my_fabs(cur_f) < 1e10) { if (fabs(prev_f) < 1e10 && fabs(cur_f) < 1e10) {
double za = zz - z_step, zb = zz; double za = zz - z_step, zb = zz;
double fa = prev_f, fb = cur_f; double fa = prev_f, fb = cur_f;
@ -1070,7 +995,7 @@ static void eval_3d_implicit_job(void *arg) {
double nx = eval_implicit(wx+eps, wy, wz) - eval_implicit(wx-eps, wy, wz); double nx = eval_implicit(wx+eps, wy, wz) - eval_implicit(wx-eps, wy, wz);
double ny = eval_implicit(wx, wy+eps, wz) - eval_implicit(wx, wy-eps, wz); double ny = eval_implicit(wx, wy+eps, wz) - eval_implicit(wx, wy-eps, wz);
double nz = eval_implicit(wx, wy, wz+eps) - eval_implicit(wx, wy, wz-eps); double nz = eval_implicit(wx, wy, wz+eps) - eval_implicit(wx, wy, wz-eps);
double d = my_sqrt(nx*nx + ny*ny + nz*nz); double d = sqrt(nx*nx + ny*ny + nz*nz);
if (d > 1e-12) { nx /= d; ny /= d; nz /= d; } if (d > 1e-12) { nx /= d; ny /= d; nz /= d; }
else { nx = 0; ny = 1; nz = 0; } else { nx = 0; ny = 1; nz = 0; }
@ -1126,7 +1051,7 @@ static void render_3d_draw_job(void *arg) {
float avg_nz = surf[j][i].nz[s] + surf[j][i+1].nz[s] + surf[j+1][i].nz[s] + surf[j+1][i+1].nz[s]; float avg_nz = surf[j][i].nz[s] + surf[j][i+1].nz[s] + surf[j+1][i].nz[s] + surf[j+1][i+1].nz[s];
avg_nx *= 0.25f; avg_ny *= 0.25f; avg_nz *= 0.25f; avg_nx *= 0.25f; avg_ny *= 0.25f; avg_nz *= 0.25f;
float nlen = (float)my_sqrt(avg_nx*avg_nx + avg_ny*avg_ny + avg_nz*avg_nz); float nlen = (float)sqrt(avg_nx*avg_nx + avg_ny*avg_ny + avg_nz*avg_nz);
if (nlen > 1e-9) { avg_nx /= nlen; avg_ny /= nlen; avg_nz /= nlen; } if (nlen > 1e-9) { avg_nx /= nlen; avg_ny /= nlen; avg_nz /= nlen; }
else { avg_nx = 0; avg_ny = 0; avg_nz = 1; } else { avg_nx = 0; avg_ny = 0; avg_nz = 1; }
@ -1166,7 +1091,7 @@ static void render_3d_draw_job(void *arg) {
double wx = surf_x[j][i], wy = surf_y_3d[j][i]; double wx = surf_x[j][i], wy = surf_y_3d[j][i];
double gnx = eval_implicit(wx + eps, wy, mid_z) - eval_implicit(wx - eps, wy, mid_z); double gnx = eval_implicit(wx + eps, wy, mid_z) - eval_implicit(wx - eps, wy, mid_z);
double gny = eval_implicit(wx, wy + eps, mid_z) - eval_implicit(wx, wy - eps, mid_z); double gny = eval_implicit(wx, wy + eps, mid_z) - eval_implicit(wx, wy - eps, mid_z);
double dmag = my_sqrt(gnx*gnx + gny*gny); double dmag = sqrt(gnx*gnx + gny*gny);
if (dmag > 1e-12) { gnx /= dmag; gny /= dmag; } if (dmag > 1e-12) { gnx /= dmag; gny /= dmag; }
else { gnx = 0; gny = 1; } else { gnx = 0; gny = 1; }
@ -1398,9 +1323,9 @@ static void render_graph(void) {
for (int px = 0; px < graph_w; px++) { for (int px = 0; px < graph_w; px++) {
double wx = world_x_2d(px); double wx = world_x_2d(px);
double wy = eval_rhs_only(wx, 0, 0); double wy = eval_rhs_only(wx, 0, 0);
if (wy != wy || my_fabs(wy) > 1e10) { prev_valid = false; continue; } if (wy != wy || fabs(wy) > 1e10) { prev_valid = false; continue; }
int sy = screen_y_2d(wy); int sy = screen_y_2d(wy);
if (prev_valid && my_fabs((double)(sy - prev_sy)) < graph_h) if (prev_valid && fabs((double)(sy - prev_sy)) < graph_h)
gfb_line(prev_sx, prev_sy, px, sy, COLOR_CURVE); gfb_line(prev_sx, prev_sy, px, sy, COLOR_CURVE);
prev_sx = px; prev_sy = sy; prev_valid = true; prev_sx = px; prev_sy = sy; prev_valid = true;
} }
@ -1425,7 +1350,7 @@ static void render_graph(void) {
double x_start = (int)(view_x_min / x_step) * x_step; double x_start = (int)(view_x_min / x_step) * x_step;
int safety = 0; int safety = 0;
for (double wx = x_start - x_step; wx <= view_x_max + x_step && safety < 100; wx += x_step, safety++) { for (double wx = x_start - x_step; wx <= view_x_max + x_step && safety < 100; wx += x_step, safety++) {
if (my_fabs(wx) < x_step * 0.1) continue; // Skip zero if (fabs(wx) < x_step * 0.1) continue; // Skip zero
int sx = screen_x_2d(wx); int sx = screen_x_2d(wx);
if (sx > 20 && sx < graph_w - 40) { if (sx > 20 && sx < graph_w - 40) {
char buf[32]; double_to_str(wx, buf); char buf[32]; double_to_str(wx, buf);
@ -1440,7 +1365,7 @@ static void render_graph(void) {
double y_start = (int)(view_y_min / y_step) * y_step; double y_start = (int)(view_y_min / y_step) * y_step;
safety = 0; safety = 0;
for (double wy = y_start - y_step; wy <= view_y_max + y_step && safety < 100; wy += y_step, safety++) { for (double wy = y_start - y_step; wy <= view_y_max + y_step && safety < 100; wy += y_step, safety++) {
if (my_fabs(wy) < y_step * 0.1) continue; // Skip zero if (fabs(wy) < y_step * 0.1) continue; // Skip zero
int sy = screen_y_2d(wy); int sy = screen_y_2d(wy);
if (sy > 20 && sy < graph_h - 20) { if (sy > 20 && sy < graph_h - 20) {
char buf[32]; double_to_str(wy, buf); char buf[32]; double_to_str(wy, buf);
@ -1460,8 +1385,8 @@ static void render_graph(void) {
// Paint // Paint
// ===== // =====
static void paint_all(void) { static void paint_all(void) {
rot_cx = my_cos(rot_x); rot_sx = my_sin(rot_x); rot_cx = cos(rot_x); rot_sx = sin(rot_x);
rot_cy = my_cos(rot_y); rot_sy = my_sin(rot_y); rot_cy = cos(rot_y); rot_sy = sin(rot_y);
ui_draw_rect(win_graph, 0, 0, win_w, TOOLBAR_H, COLOR_TOOLBAR_BG); ui_draw_rect(win_graph, 0, 0, win_w, TOOLBAR_H, COLOR_TOOLBAR_BG);
widget_textbox_draw(&wctx, &tb_equation); widget_textbox_draw(&wctx, &tb_equation);

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// Copyright (c) 2023-2026 Chris (boreddevnl)
// This software is released under the GNU General Public License v3.0. See LICENSE file for details.
// This header needs to maintain in any file it is present in, as per the GPL license terms.
#include "math.h"
static double _pow_int(double b, int e) {
if (e == 0) return 1.0;
if (e < 0) { return 1.0 / _pow_int(b, -e); }
double r = 1.0;
while (e > 0) {
if (e & 1) r *= b;
b *= b;
e >>= 1;
}
return r;
}
double fabs(double x) {
return x < 0.0 ? -x : x;
}
double fmod(double x, double y) {
if (y == 0.0) return 0.0;
return x - (int)(x / y) * y;
}
double floor(double x) {
int i = (int)x;
return (x < 0.0 && (double)i != x) ? (double)(i - 1) : (double)i;
}
double ceil(double x) {
int i = (int)x;
return (x > 0.0 && (double)i != x) ? (double)(i + 1) : (double)i;
}
double sin(double x) {
x = fmod(x, 2.0 * M_PI);
if (x > M_PI) x -= 2.0 * M_PI;
if (x < -M_PI) x += 2.0 * M_PI;
double x2 = x * x;
double term = x;
double sum = x;
for (int i = 1; i <= 8; i++) {
term *= -x2 / ((2*i) * (2*i + 1));
sum += term;
}
return sum;
}
double cos(double x) {
return sin(x + M_PI / 2.0);
}
double tan(double x) {
double c = cos(x);
if (fabs(c) < 1e-10) return 1e15;
return sin(x) / c;
}
double sqrt(double x) {
if (x <= 0.0) return 0.0;
double g = x * 0.5;
for (int i = 0; i < 25; i++) {
g = (g + x / g) * 0.5;
}
return g;
}
double log(double x) {
if (x <= 0.0) return -1e30;
int e = 0;
while (x > 2.0) { x /= 2.0; e++; }
while (x < 0.5) { x *= 2.0; e--; }
double t = (x - 1.0) / (x + 1.0);
double t2 = t * t;
double sum = t, term = t;
for (int i = 1; i <= 20; i++) {
term *= t2;
sum += term / (2*i + 1);
}
return 2.0 * sum + e * M_LN2;
}
double log2(double x) {
// log2(x) = ln(x) / ln(2)
return log(x) / M_LN2;
}
double log10(double x) {
return log(x) / 2.302585092994046;
}
double exp(double x) {
if (x > 700.0) return 1e300;
if (x < -700.0) return 0.0;
int k = (int)(x / M_LN2);
if (x < 0.0 && (double)k * M_LN2 > x) k--;
double r = x - (double)k * M_LN2;
double sum = 1.0, term = 1.0;
for (int i = 1; i <= 20; i++) {
term *= r / (double)i;
sum += term;
}
double result = sum;
if (k >= 0) { for (int i = 0; i < k; i++) result *= 2.0; }
else { for (int i = 0; i < -k; i++) result /= 2.0; }
return result;
}
double pow(double base, double exponent) {
if (base == 0.0) return 0.0;
if (exponent == 0.0) return 1.0;
int ie = (int)exponent;
if ((double)ie == exponent) return _pow_int(base, ie);
if (base < 0.0) return 0.0;
return exp(exponent * log(base));
}
double sinh(double x) {
double ep = exp(x);
double em = exp(-x);
return (ep - em) * 0.5;
}
double cosh(double x) {
double ep = exp(x);
double em = exp(-x);
return (ep + em) * 0.5;
}
double tanh(double x) {
double e2 = exp(2.0 * x);
return (e2 - 1.0) / (e2 + 1.0);
}
double hypot(double x, double y) {
return sqrt(x*x + y*y);
}
double fmin(double a, double b) {
return a < b ? a : b;
}
double fmax(double a, double b) {
return a > b ? a : b;
}
double fclamp(double x, double lo, double hi) {
if (x < lo) return lo;
if (x > hi) return hi;
return x;
}

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// Copyright (c) 2023-2026 Chris (boreddevnl)
// This software is released under the GNU General Public License v3.0. See LICENSE file for details.
// This header needs to maintain in any file it is present in, as per the GPL license terms.
#ifndef MATH_H
#define MATH_H
#define M_PI 3.14159265358979323846
#define M_E 2.71828182845904523536
#define M_LN2 0.69314718055994530942
#define M_SQRT2 1.41421356237309504880
#define HUGE_VAL (1e300 * 1e300)
double fabs(double x);
double fmod(double x, double y);
double floor(double x);
double ceil(double x);
double sin(double x);
double cos(double x);
double tan(double x);
double sqrt(double x);
double log(double x);
double log2(double x);
double log10(double x);
double exp(double x);
double pow(double base, double exponent);
double sinh(double x);
double cosh(double x);
double tanh(double x);
double hypot(double x, double y);
double fmin(double a, double b);
double fmax(double a, double b);
double fclamp(double x, double lo, double hi);
#endif /* MATH_H */