fix: distance_field_generator now takes the ball_radius as input parameter instead of hardcoded offset

assets/shaders/distance_field.fs

@@ -23,7 +23,7 @@ float getBallInfluence(vec2 pos, vec2 center, float radius) {
 
 float getShapeInfluence(vec2 pos) {
     vec2 uv = pos / resolution;
-    uv.y = 1 - uv.y + 0.045; // invert y and offset to match with wallpaper texture
+    uv.y = 1.0 - uv.y;
     
     if (any(lessThan(uv, vec2(0.0))) || any(greaterThan(uv, vec2(1.0)))) {
         return 0.0;

src/distance_field_generator.c

@@ -7,7 +7,7 @@ static bool is_inside_shape(Color pixel) {
     return pixel.r == 255 && pixel.g == 255 && pixel.b == 255;
 }
 
-static Image generate_distance_field(Image input_texture, int search_radius) {
+static Image generate_distance_field(Image input_texture, int search_radius, int offset_y) {
     int width = input_texture.width;
     int height = input_texture.height;
 
@@ -25,7 +25,10 @@ static Image generate_distance_field(Image input_texture, int search_radius) {
 
         for (int x = 0; x < width; x += 1) {
             int index = y * width + x;
-            bool is_inside = is_inside_shape(input_pixels[index]);
+            int src_y = y + offset_y;
+            bool is_inside = (src_y >= 0 && src_y < height)
+                ? is_inside_shape(input_pixels[src_y * width + x])
+                : false;
 
             float min_distance_sq = search_radius * search_radius;
             bool found_boundary = false;
@@ -33,7 +36,7 @@ static Image generate_distance_field(Image input_texture, int search_radius) {
             for (int dy = -search_radius; dy <= search_radius; dy += 1) {
                 for (int dx = -search_radius; dx <= search_radius; dx += 1) {
                     int sample_x = x + dx;
-                    int sample_y = y + dy;
+                    int sample_y = y + dy + offset_y;
 
                     if (sample_x < 0 || sample_x >= width || sample_y < 0 || sample_y >= height) continue;
 
@@ -74,13 +77,15 @@ static Image generate_distance_field(Image input_texture, int search_radius) {
 int main(int argc, char *argv[])
 {
     if (argc < 3) {
-        TraceLog(LOG_ERROR, "Usage: %s <input_image> <output_image> [search_radius]", argv[0]);
+        TraceLog(LOG_ERROR, "Usage: %s <input_image> <output_image> [search_radius] [ball_radius]", argv[0]);
         return 1;
     }
 
     const char *input_path = argv[1];
     const char *output_path = argv[2];
     int search_radius = (argc >= 4) ? atoi(argv[3]) : 100;
+    int ball_radius   = (argc >= 5) ? atoi(argv[4]) : 0;
+    int offset_y      = ball_radius / 2;
 
     Image input_image = LoadImage(input_path);
     if (input_image.data == NULL) {
@@ -88,7 +93,7 @@ int main(int argc, char *argv[])
         return 1;
     }
 
-    Image distance_field_image = generate_distance_field(input_image, search_radius);
+    Image distance_field_image = generate_distance_field(input_image, search_radius, offset_y);
     if (!ExportImage(distance_field_image, output_path)) {
         TraceLog(LOG_ERROR, "Failed to save output image '%s'", output_path);
         UnloadImage(input_image);