Re-add culling
diff --git a/vello_shaders/shader/fine.wgsl b/vello_shaders/shader/fine.wgsl
index 4ed20e4..77b2f7d 100644
--- a/vello_shaders/shader/fine.wgsl
+++ b/vello_shaders/shader/fine.wgsl
@@ -1162,23 +1162,26 @@
let image = read_image(cmd_ix);
let atlas_max = image.atlas_offset + image.extents - vec2(1.0);
for (var i = 0u; i < PIXELS_PER_THREAD; i += 1u) {
- let my_xy = vec2(xy.x + f32(i), xy.y);
- let atlas_uv = image.matrx.xy * my_xy.x + image.matrx.zw * my_xy.y + image.xlat + image.atlas_offset - vec2(0.5);
- // This currently only implements the Pad extend mode
- // TODO: Support repeat and reflect
- // TODO: If the image couldn't be added to the atlas (i.e. was too big), this isn't robust
- let atlas_uv_clamped = clamp(atlas_uv, image.atlas_offset, atlas_max);
- // We know that the floor and ceil are within the atlas area because atlas_max and
- // atlas_offset are integers
- let uv_quad = vec4(floor(atlas_uv_clamped), ceil(atlas_uv_clamped));
- let uv_frac = fract(atlas_uv);
- let a = premul_alpha(textureLoad(image_atlas, vec2<i32>(uv_quad.xy), 0));
- let b = premul_alpha(textureLoad(image_atlas, vec2<i32>(uv_quad.xw), 0));
- let c = premul_alpha(textureLoad(image_atlas, vec2<i32>(uv_quad.zy), 0));
- let d = premul_alpha(textureLoad(image_atlas, vec2<i32>(uv_quad.zw), 0));
- let fg_rgba = mix(mix(a, b, uv_frac.y), mix(c, d, uv_frac.y), uv_frac.x);
- let fg_i = fg_rgba * area[i];
- rgba[i] = rgba[i] * (1.0 - fg_i.a) + fg_i;
+ // We only need to load from the textures if the value will be used.
+ if area[i] != 0.0 {
+ let my_xy = vec2(xy.x + f32(i), xy.y);
+ let atlas_uv = image.matrx.xy * my_xy.x + image.matrx.zw * my_xy.y + image.xlat + image.atlas_offset - vec2(0.5);
+ // This currently only implements the Pad extend mode
+ // TODO: Support repeat and reflect
+ // TODO: If the image couldn't be added to the atlas (i.e. was too big), this isn't robust
+ let atlas_uv_clamped = clamp(atlas_uv, image.atlas_offset, atlas_max);
+ // We know that the floor and ceil are within the atlas area because atlas_max and
+ // atlas_offset are integers
+ let uv_quad = vec4(floor(atlas_uv_clamped), ceil(atlas_uv_clamped));
+ let uv_frac = fract(atlas_uv);
+ let a = premul_alpha(textureLoad(image_atlas, vec2<i32>(uv_quad.xy), 0));
+ let b = premul_alpha(textureLoad(image_atlas, vec2<i32>(uv_quad.xw), 0));
+ let c = premul_alpha(textureLoad(image_atlas, vec2<i32>(uv_quad.zy), 0));
+ let d = premul_alpha(textureLoad(image_atlas, vec2<i32>(uv_quad.zw), 0));
+ let fg_rgba = mix(mix(a, b, uv_frac.y), mix(c, d, uv_frac.y), uv_frac.x);
+ let fg_i = fg_rgba * area[i];
+ rgba[i] = rgba[i] * (1.0 - fg_i.a) + fg_i;
+ }
}
cmd_ix += 2u;
}
