WIP: debugging stuff

src/renderer.c

@@ -126,6 +126,33 @@ void ren_free_coverage(RenCoverageImage *coverage) {
   free(coverage);
 }
 
+void debug_bitmap_draw_rect(RenImage *image, GlyphBitmapInfo *glyph) {
+  const int subpixel = 3;
+  const int x0 = glyph->x0, x1 = glyph->x1;
+  const int y0 = glyph->y0, y1 = glyph->y1;
+  const int w = image->width;
+  RenColor *c = image->pixels + y0 * w;
+  for (int x = x0 * subpixel; x < x1 * subpixel; x++) {
+    c[x].g = c[x].g >> 1;
+    c[x].b = c[x].b >> 1;
+  }
+  c = image->pixels + x1 * subpixel;
+  for (int y = y0; y < y1; y++) {
+    c[y * w].g = c[y * w].g >> 1;
+    c[y * w].b = c[y * w].b >> 1;
+  }
+  c = image->pixels + y1 * w;
+  for (int x = x0 * subpixel; x < x1 * subpixel; x++) {
+    c[x].g = c[x].g >> 1;
+    c[x].b = c[x].b >> 1;
+  }
+  c = image->pixels + x0 * subpixel;
+  for (int y = y0 + 1; y < y1; y++) {
+    c[y * w].g = c[y * w].g >> 1;
+    c[y * w].b = c[y * w].b >> 1;
+  }
+}
+
 static GlyphSet* load_glyphset(RenFont *font, int idx) {
   GlyphSet *set = check_alloc(calloc(1, sizeof(GlyphSet)));
 
@@ -149,6 +176,32 @@ retry:
     goto retry;
   }
 
+  static int debug_image_index = 1;
+  if (idx == 0) {
+  // DEBUG CODE
+  RenImage *debug_cov_image = ren_new_image(width * subpixel_scale, height);
+  for (int h = 0; h < height; h++) {
+    RenColor *d = debug_cov_image->pixels + h * width * subpixel_scale;
+    uint8_t *s = set->coverage->pixels + h * subpixel_scale * width;
+    for (int w = 0; w < width * subpixel_scale; w++) {
+      uint8_t cover = s[w];
+      d[w] = (RenColor) {.b = 0xff - cover, .g = 0xff - cover, .r = 0xff - cover, .a = 0xff};
+    }
+  }
+  for (int i = 0; i < 256; i++) {
+    debug_bitmap_draw_rect(debug_cov_image, &set->glyphs[i]);
+  }
+  SDL_Surface *surface = SDL_CreateRGBSurfaceWithFormatFrom(
+      debug_cov_image->pixels,
+      width * subpixel_scale, height, 32, width * subpixel_scale * 4,
+      SDL_PIXELFORMAT_RGBA32);
+  char img_filename[64];
+  sprintf(img_filename, "agg-glyphset-%03d.bmp", debug_image_index);
+  SDL_SaveBMP(surface, img_filename);
+  SDL_FreeSurface(surface);
+  ren_free_image(debug_cov_image);
+  debug_image_index++;
+  }
   /* adjust glyph's xadvance */
   for (int i = 0; i < 256; i++) {
     set->glyphs[i].xadvance = floor(set->glyphs[i].xadvance + 0.5);