1 files changed, 32 insertions, 27 deletions

diff --git a/source/blender/gpu/shaders/sculpt_paint/sculpt_paint_image_comp.glsl b/source/blender/gpu/shaders/sculpt_paint/sculpt_paint_image_comp.glsl
index 86c90de2d90..f4af1509233 100644
--- a/source/blender/gpu/shaders/sculpt_paint/sculpt_paint_image_comp.glsl
+++ b/source/blender/gpu/shaders/sculpt_paint/sculpt_paint_image_comp.glsl
@@ -20,9 +20,6 @@ void main()
 {
   PackedPixelRow row = pixel_row_buf[gl_GlobalInvocationID.x + pixel_row_offset];
   TrianglePaintInput triangle = paint_input[PIXEL_ROW_PRIM_INDEX(row)];
-  PaintTileData paint_tile;
-  ivec3 image_coord = paint_tile_coord_from_udim(
-      1001, PIXEL_ROW_START_IMAGE_COORD(row), paint_tile);
 
   uint row_len = PIXEL_ROW_LEN(row);
 
@@ -34,34 +31,42 @@ void main()
   vec3 delta;
   SCULPT_get_row_pos_and_delta(co1, co2, co3, triangle, row, pos, delta);
 
-  for (int x = 0; x < row_len; x++) {
-    /* TODO: Do clipping test. */
-    vec4 color;
-    bool color_read = false;
+  int x = 0;
+  while (x < row_len) {
+    PaintTileData paint_tile;
+    ivec3 image_coord = paint_tile_coord_from_udim(
+        1001, PIXEL_ROW_START_IMAGE_COORD(row) + int2(x, 0), paint_tile);
+    bool in_use = false;
+    for (; x < row_len && image_coord.x < SUB_TILE_SIZE; x++, image_coord.x++, pos += delta) {
+      /* TODO: Do clipping test. */
+      vec4 color;
+      bool color_read = false;
 
-    for (int step_index = paint_step_range[0]; step_index < paint_step_range[1]; step_index++) {
-      PaintStepData step_data = paint_step_buf[step_index];
-
-      float distance;
-      bool test_result = SCULPT_brush_test(paint_brush_buf.test, step_data, pos, distance);
-      if (test_result) {
-        if (!color_read) {
-          color = imageLoad(paint_tiles_img, image_coord);
-          color_read = true;
+      for (int step_index = paint_step_range[0]; step_index < paint_step_range[1]; step_index++) {
+        PaintStepData step_data = paint_step_buf[step_index];
+        float distance;
+        bool test_result = SCULPT_brush_test(paint_brush_buf.test, step_data, pos, distance);
+        if (test_result) {
+          if (!color_read) {
+            color = imageLoad(paint_tiles_img, image_coord);
+            color_read = true;
+            in_use = true;
+          }
+          // TODO: blend with color...
+          float factor = SCULPT_hardness_factor(distance, step_data.hardness, step_data.radius);
+          float curve_factor = SCULPT_curve_strength(factor, paint_brush_buf.falloff_shape);
+          vec4 final_paint_color = SCULPT_blend_color(
+              color, paint_brush_buf.color * curve_factor * step_data.strength);
+          final_paint_color *= paint_brush_buf.alpha;
+          color = SCULPT_blend_color(color, final_paint_color);
         }
-        // TODO: blend with color...
-        float factor = SCULPT_hardness_factor(distance, step_data.hardness, step_data.radius);
-        float curve_factor = SCULPT_curve_strength(factor, paint_brush_buf.falloff_shape);
-        vec4 final_paint_color = SCULPT_blend_color(
-            color, paint_brush_buf.color * curve_factor * step_data.strength);
-        final_paint_color *= paint_brush_buf.alpha;
-        color = SCULPT_blend_color(color, final_paint_color);
+      }
+      if (color_read) {
+        imageStore(paint_tiles_img, image_coord, color);
       }
     }
-    if (color_read) {
-      imageStore(paint_tiles_img, image_coord, color);
+    if (in_use) {
+      paint_tile_mark_used(paint_tile);
     }
-    image_coord.x += 1;
-    pos += delta;
   }
 }
\ No newline at end of file