1 files changed, 81 insertions, 0 deletions
diff --git a/gfx/wr/webrender/res/brush_linear_gradient.glsl b/gfx/wr/webrender/res/brush_linear_gradient.glsl
new file mode 100644
index 0000000000..5d2b92cb6c
--- /dev/null
+++ b/gfx/wr/webrender/res/brush_linear_gradient.glsl
@@ -0,0 +1,81 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#define VECS_PER_SPECIFIC_BRUSH 2
+
+#include shared,prim_shared,brush,gradient_shared
+
+flat varying vec2 v_start_point;
+flat varying vec2 v_scale_dir;
+
+#ifdef WR_VERTEX_SHADER
+
+struct Gradient {
+    vec4 start_end_point;
+    int extend_mode;
+    vec2 stretch_size;
+};
+
+Gradient fetch_gradient(int address) {
+    vec4 data[2] = fetch_from_gpu_cache_2(address);
+    return Gradient(
+        data[0],
+        int(data[1].x),
+        data[1].yz
+    );
+}
+
+void brush_vs(
+    VertexInfo vi,
+    int prim_address,
+    RectWithSize local_rect,
+    RectWithSize segment_rect,
+    ivec4 prim_user_data,
+    int specific_resource_address,
+    mat4 transform,
+    PictureTask pic_task,
+    int brush_flags,
+    vec4 texel_rect
+) {
+    Gradient gradient = fetch_gradient(prim_address);
+
+    write_gradient_vertex(
+        vi,
+        local_rect,
+        segment_rect,
+        prim_user_data,
+        brush_flags,
+        texel_rect,
+        gradient.extend_mode,
+        gradient.stretch_size
+    );
+
+    vec2 start_point = gradient.start_end_point.xy;
+    vec2 end_point = gradient.start_end_point.zw;
+    vec2 dir = end_point - start_point;
+
+    v_start_point = start_point;
+    v_scale_dir = dir / dot(dir, dir);
+
+    // Normalize UV and offsets to 0..1 scale.
+    v_start_point /= v_repeated_size;
+    v_scale_dir *= v_repeated_size;
+}
+#endif
+
+#ifdef WR_FRAGMENT_SHADER
+Fragment brush_fs() {
+    vec2 pos = compute_gradient_pos();
+
+    float offset = dot(pos - v_start_point, v_scale_dir);
+
+    vec4 color = sample_gradient(offset);
+
+#ifdef WR_FEATURE_ALPHA_PASS
+    color *= init_transform_fs(v_local_pos);
+#endif
+
+    return Fragment(color);
+}
+#endif