1 files changed, 68 insertions, 0 deletions
diff --git a/gfx/wr/webrender/res/cs_linear_gradient.glsl b/gfx/wr/webrender/res/cs_linear_gradient.glsl
new file mode 100644
index 0000000000..b1aff899a6
--- /dev/null
+++ b/gfx/wr/webrender/res/cs_linear_gradient.glsl
@@ -0,0 +1,68 @@
+/* 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/. */
+
+#include shared,rect,render_task,gpu_cache,gpu_buffer,gradient
+
+varying highp vec2 v_pos;
+
+flat varying mediump vec2 v_scale_dir;
+
+// Start offset. Packed in to a vector to work around bug 1630356.
+flat varying highp vec2 v_start_offset;
+
+#ifdef WR_VERTEX_SHADER
+
+#define EXTEND_MODE_REPEAT 1
+
+PER_INSTANCE in vec4 aTaskRect;
+PER_INSTANCE in vec2 aStartPoint;
+PER_INSTANCE in vec2 aEndPoint;
+PER_INSTANCE in vec2 aScale;
+PER_INSTANCE in int aExtendMode;
+PER_INSTANCE in int aGradientStopsAddress;
+
+void main(void) {
+    vec2 pos = mix(aTaskRect.xy, aTaskRect.zw, aPosition.xy);
+    gl_Position = uTransform * vec4(pos, 0.0, 1.0);
+
+    v_pos = aPosition.xy * aScale;
+
+    vec2 dir = aEndPoint - aStartPoint;
+
+    // Normalize UV and offsets to 0..1 scale.
+    v_scale_dir = dir / dot(dir, dir);
+    v_start_offset.x = dot(aStartPoint, v_scale_dir);
+
+    v_scale_dir *= (aTaskRect.zw - aTaskRect.xy);
+
+    v_gradient_repeat.x = float(aExtendMode == EXTEND_MODE_REPEAT);
+    v_gradient_address.x = aGradientStopsAddress;
+}
+#endif
+
+
+#ifdef WR_FRAGMENT_SHADER
+
+void main(void) {
+    // Project position onto a direction vector to compute offset.
+    float offset = dot(v_pos, v_scale_dir) - v_start_offset.x;
+
+    oFragColor = sample_gradient(offset);
+}
+
+
+#ifdef SWGL_DRAW_SPAN
+void swgl_drawSpanRGBA8() {
+    int address = swgl_validateGradient(sGpuBuffer, get_gpu_buffer_uv(v_gradient_address.x), int(GRADIENT_ENTRIES + 2.0));
+    if (address < 0) {
+        return;
+    }
+
+    swgl_commitLinearGradientRGBA8(sGpuBuffer, address, GRADIENT_ENTRIES, false, v_gradient_repeat.x != 0.0,
+                                   v_pos, v_scale_dir, v_start_offset.x);
+}
+#endif
+
+
+#endif