1 files changed, 5 insertions(+), 23 deletions(-)

M image-viewer/src/image.c

@@ 94,7 94,8 @@ double get_scale_factor(uint16_t w, uint16_t h, image_region_t display_region) {
 static void image_write_downscale(image_t *image, display_t *display,
                                   image_region_t region, image_region_t display_region, double scale_factor) {
   float downscale_factor = 1 / scale_factor;
-  uint16_t avg_pixels = downscale_factor;
+  const downscale_precision = 10000;
+  uint32_t downscale_factor_i = downscale_factor * downscale_precision;
   uint16_t w = region.width, h = region.height;
   uint16_t sw = (uint16_t)(scale_factor * w), sh = (uint16_t)(scale_factor * h);
 


@@ 103,33 104,14 @@ static void image_write_downscale(image_t *image, display_t *display,
     avg_range++;
   }
 
-  uint32_t avg_count = avg_pixels * avg_pixels;
-  uint32_t downhalf = downscale_factor / 2;
-
   uint16_t beg_x = (display_region.width - sw) / 2 + display_region.x;
   uint16_t beg_y = (display_region.height - sh) / 2 + display_region.y;
 
   for (int y = 0; y < sh; y++) {
     for (int x = 0; x < sw; x++) {
-      uint16_t px = (uint16_t)(downscale_factor * (x + 0.5f)) + region.x;
-      uint16_t py = (uint16_t)(downscale_factor * (y + 0.5f)) + region.y;
-      raw_pixel_t result = {.red = 0, .green = 0, .blue = 0};
-
-      for (int avg_x = 0; avg_x < avg_pixels; avg_x++) {
-        for (int avg_y = 0; avg_y < avg_pixels; avg_y++) {
-          display_pixel_t pixel = image_get_pixel(image, px + avg_x - downhalf, py + avg_y - downhalf);
-
-          result.red += pixel.fields.r;
-          result.green += pixel.fields.g;
-          result.blue += pixel.fields.b;
-        }
-      }
-
-      result.red /= avg_count;
-      result.green /= avg_count;
-      result.blue /= avg_count;
-
-      display_pixel_t result_display = {.fields = {.r = result.red, .g = result.green, .b = result.blue}};
+      uint16_t px = ((uint64_t)(downscale_factor_i * (2*x + 1)))/(downscale_precision * 2) + region.x;
+      uint16_t py = ((uint64_t)(downscale_factor_i * (2*y + 1)))/(downscale_precision * 2) + region.y;
+      display_pixel_t result_display = image_get_pixel(image, px, py);
       display_set_pixel(display, x + beg_x, y + beg_y, result_display);
     }
   }