1 files changed, 71 insertions, 0 deletions
diff --git a/gfx/wr/webrender/res/cs_radial_gradient.glsl b/gfx/wr/webrender/res/cs_radial_gradient.glsl
new file mode 100644
index 0000000000..16ffe06376
--- /dev/null
+++ b/gfx/wr/webrender/res/cs_radial_gradient.glsl
@@ -0,0 +1,71 @@
+/* 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;
+
+// Start radius. Packed in to a vector to work around bug 1630356.
+flat varying highp vec2 v_start_radius;
+
+#ifdef WR_VERTEX_SHADER
+
+#define EXTEND_MODE_REPEAT 1
+
+PER_INSTANCE in vec4 aTaskRect;
+PER_INSTANCE in vec2 aCenter;
+PER_INSTANCE in vec2 aScale;
+PER_INSTANCE in float aStartRadius;
+PER_INSTANCE in float aEndRadius;
+PER_INSTANCE in float aXYRatio;
+PER_INSTANCE in int aExtendMode;
+PER_INSTANCE in int aGradientStopsAddress;
+
+void main(void) {
+    // Store 1/rd where rd = end_radius - start_radius
+    // If rd = 0, we can't get its reciprocal. Instead, just use a zero scale.
+    float rd = aEndRadius - aStartRadius;
+    float radius_scale = rd != 0.0 ? 1.0 / rd : 0.0;
+
+    vec2 pos = mix(aTaskRect.xy, aTaskRect.zw, aPosition.xy);
+    gl_Position = uTransform * vec4(pos, 0.0, 1.0);
+
+    v_start_radius.x = aStartRadius * radius_scale;
+
+    // Transform all coordinates by the y scale so the
+    // fragment shader can work with circles
+
+    // v_pos is in a coordinate space relative to the task rect
+    // (so it is independent of the task origin).
+    v_pos = ((aTaskRect.zw - aTaskRect.xy) * aPosition.xy * aScale - aCenter) * radius_scale;
+    v_pos.y *= aXYRatio;
+
+    v_gradient_repeat.x = float(aExtendMode == EXTEND_MODE_REPEAT);
+    v_gradient_address.x = aGradientStopsAddress;
+}
+#endif
+
+
+#ifdef WR_FRAGMENT_SHADER
+
+void main(void) {
+    // Solve for t in length(pd) = v_start_radius + t * rd
+    float offset = length(v_pos) - v_start_radius.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_commitRadialGradientRGBA8(sGpuBuffer, address, GRADIENT_ENTRIES, v_gradient_repeat.x != 0.0,
+                                   v_pos, v_start_radius.x);
+}
+#endif
+
+#endif