Peak 0.4.0 and Draw

1 files changed, 224 insertions, 0 deletions

diff --git a/Draw/draw.h b/Draw/draw.h
new file mode 100644
index 0000000..fded875
--- /dev/null
+++ b/Draw/draw.h
@@ -0,0 +1,224 @@
+/* ===========================================================================
+ * DRAW - software raster into an RGBA32 buffer - see LICENCE at end of file.
+ * =========================================================================== */
+
+#ifndef DRAW_H
+#define DRAW_H
+
+#include <stdint.h>
+#include <string.h>
+#include <stdlib.h>
+#include <math.h>
+
+typedef struct Draw {
+    uint32_t *px;
+    int w, h;
+    int cx, cy, cw, ch;
+} Draw;
+
+#define DRAW__MIN(a, b) ((a) < (b) ? (a) : (b))
+#define DRAW__MAX(a, b) ((a) > (b) ? (a) : (b))
+
+static inline void
+draw_begin(Draw *d, uint32_t *px, int w, int h)
+{
+    d->px = px;
+    d->w = w;
+    d->h = h;
+    d->cx = 0;
+    d->cy = 0;
+    d->cw = w;
+    d->ch = h;
+}
+
+static inline void
+draw_clip(Draw *d, int x, int y, int w, int h)
+{
+    d->cx = x;
+    d->cy = y;
+    d->cw = w;
+    d->ch = h;
+}
+
+static inline void
+draw_clip_reset(Draw *d)
+{
+    d->cx = 0;
+    d->cy = 0;
+    d->cw = d->w;
+    d->ch = d->h;
+}
+
+static inline void
+draw_pixel(Draw *d, int x, int y, uint32_t color)
+{
+    if (x < d->cx || x >= d->cx + d->cw || y < d->cy || y >= d->cy + d->ch) return;
+    if (x < 0 || x >= d->w || y < 0 || y >= d->h) return;
+    d->px[y * d->w + x] = color;
+}
+
+static inline uint32_t
+draw__lerp(uint32_t c0, uint32_t c1, float t)
+{
+    if (t <= 0.0f) return c0;
+    if (t >= 1.0f) return c1;
+    uint32_t a0 = (c0 >> 24) & 0xFF, a1 = (c1 >> 24) & 0xFF;
+    uint32_t r0 = (c0 >> 16) & 0xFF, r1 = (c1 >> 16) & 0xFF;
+    uint32_t g0 = (c0 >> 8)  & 0xFF, g1 = (c1 >> 8)  & 0xFF;
+    uint32_t b0 = c0 & 0xFF,         b1 = c1 & 0xFF;
+    uint32_t a = (uint32_t)(a0 + t * ((float)a1 - (float)a0));
+    uint32_t r = (uint32_t)(r0 + t * ((float)r1 - (float)r0));
+    uint32_t g = (uint32_t)(g0 + t * ((float)g1 - (float)g0));
+    uint32_t b = (uint32_t)(b0 + t * ((float)b1 - (float)b0));
+    return (a << 24) | (r << 16) | (g << 8) | b;
+}
+
+static inline float
+draw__cross(float ax, float ay, float bx, float by, float cx, float cy)
+{
+    return (cx - ax) * (by - ay) - (cy - ay) * (bx - ax);
+}
+
+static inline void
+draw_blit(Draw *d, int x, int y, const uint32_t *src, int sw, int sh)
+{
+    for (int row = 0; row < sh; ++row) {
+        int ty = y + row;
+        if (ty < d->cy || ty >= d->cy + d->ch || ty < 0 || ty >= d->h) continue;
+        int x0 = DRAW__MAX(x, d->cx);
+        int x1 = DRAW__MIN(x + sw, d->cx + d->cw);
+        if (x0 >= x1) continue;
+        memcpy(&d->px[ty * d->w + x0], &src[row * sw + (x0 - x)], (size_t)(x1 - x0) * sizeof(uint32_t));
+    }
+}
+
+static inline void
+draw_rect(Draw *d, int x, int y, int w, int h, uint32_t color)
+{
+    int x0 = DRAW__MAX(x, d->cx);
+    int y0 = DRAW__MAX(y, d->cy);
+    int x1 = DRAW__MIN(x + w, d->cx + d->cw);
+    int y1 = DRAW__MIN(y + h, d->cy + d->ch);
+    for (int py = y0; py < y1; ++py) {
+        if (py < 0 || py >= d->h) continue;
+        for (int px = x0; px < x1; ++px) {
+            if (px < 0 || px >= d->w) continue;
+            d->px[py * d->w + px] = color;
+        }
+    }
+}
+
+static inline void
+draw_rect_gradient(Draw *d, int x, int y, int w, int h, uint32_t c0, uint32_t c1, uint32_t c2, uint32_t c3)
+{
+    for (int ry = 0; ry < h; ++ry) {
+        float ty = (h > 1) ? (float)ry / (float)(h - 1) : 0.0f;
+        uint32_t left  = draw__lerp(c0, c3, ty);
+        uint32_t right = draw__lerp(c1, c2, ty);
+        for (int rx = 0; rx < w; ++rx) {
+            float tx = (w > 1) ? (float)rx / (float)(w - 1) : 0.0f;
+            draw_pixel(d, x + rx, y + ry, draw__lerp(left, right, tx));
+        }
+    }
+}
+
+static inline void
+draw_tri(Draw *d, int x0, int y0, int x1, int y1, int x2, int y2, uint32_t c0, uint32_t c1, uint32_t c2)
+{
+    int min_x = DRAW__MIN(x0, DRAW__MIN(x1, x2));
+    int max_x = DRAW__MAX(x0, DRAW__MAX(x1, x2));
+    int min_y = DRAW__MIN(y0, DRAW__MIN(y1, y2));
+    int max_y = DRAW__MAX(y0, DRAW__MAX(y1, y2));
+    float area = draw__cross((float)x0, (float)y0, (float)x1, (float)y1, (float)x2, (float)y2);
+    if (area == 0.0f) return;
+    int solid = (c0 == c1 && c1 == c2);
+    for (int y = min_y; y <= max_y; ++y) {
+        for (int x = min_x; x <= max_x; ++x) {
+            float w0 = draw__cross((float)x1, (float)y1, (float)x2, (float)y2, (float)x, (float)y);
+            float w1 = draw__cross((float)x2, (float)y2, (float)x0, (float)y0, (float)x, (float)y);
+            float w2 = draw__cross((float)x0, (float)y0, (float)x1, (float)y1, (float)x, (float)y);
+            if ((w0 >= 0 && w1 >= 0 && w2 >= 0) || (w0 <= 0 && w1 <= 0 && w2 <= 0)) {
+                uint32_t c = c0;
+                if (!solid) {
+                    w0 /= area;
+                    w1 /= area;
+                    w2 /= area;
+                    c = draw__lerp(c0, c1, w1 / (w0 + w1 + 1e-6f));
+                    c = draw__lerp(c, c2, w2);
+                }
+                draw_pixel(d, x, y, c);
+            }
+        }
+    }
+}
+
+static inline void
+draw_line(Draw *d, int x0, int y0, int x1, int y1, int width, uint32_t c0, uint32_t c1)
+{
+    float total = 0.0f;
+    int grad = (c0 != c1);
+    if (grad) total = sqrtf((float)((x1 - x0) * (x1 - x0) + (y1 - y0) * (y1 - y0)));
+    int dx = abs(x1 - x0), sx = x0 < x1 ? 1 : -1;
+    int dy = -abs(y1 - y0), sy = y0 < y1 ? 1 : -1;
+    int err = dx + dy;
+    int ox0 = x0, oy0 = y0;
+    int hw = width / 2;
+    for (;;) {
+        uint32_t c = c0;
+        if (grad) {
+            float cd = sqrtf((float)((x0 - ox0) * (x0 - ox0) + (y0 - oy0) * (y0 - oy0)));
+            c = draw__lerp(c0, c1, total > 0.0f ? cd / total : 0.0f);
+        }
+        for (int ox = -hw; ox <= hw; ++ox)
+            for (int oy = -hw; oy <= hw; ++oy)
+                draw_pixel(d, x0 + ox, y0 + oy, c);
+        if (x0 == x1 && y0 == y1) break;
+        int e2 = 2 * err;
+        if (e2 >= dy) { err += dy; x0 += sx; }
+        if (e2 <= dx) { err += dx; y0 += sy; }
+    }
+}
+
+#endif /* DRAW_H */
+
+/*
+------------------------------------------------------------------------------
+This software is available under 2 licenses -- choose whichever you prefer.
+------------------------------------------------------------------------------
+ALTERNATIVE A - MIT License
+Copyright (c) 2026 Vasco Alves
+Permission is hereby granted, free of charge, to any person obtaining a copy of
+this software and associated documentation files (the "Software"), to deal in
+the Software without restriction, including without limitation the rights to
+use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
+of the Software, and to permit persons to whom the Software is furnished to do
+so, subject to the following conditions:
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
+------------------------------------------------------------------------------
+ALTERNATIVE B - Public Domain (www.unlicense.org)
+This is free and unencumbered software released into the public domain.
+Anyone is free to copy, modify, publish, use, compile, sell, or distribute this
+software, either in source code form or as a compiled binary, for any purpose,
+commercial or non-commercial, and by any means.
+In jurisdictions that recognize copyright laws, the author or authors of this
+software dedicate any and all copyright interest in the software to the public
+domain. We make this dedication for the benefit of the public at large and to
+the detriment of our heirs and successors. We intend this dedication to be an
+overt act of relinquishment in perpetuity of all present and future rights to
+this software under copyright law.
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+------------------------------------------------------------------------------
+*/