1 files changed, 67 insertions, 0 deletions
diff --git a/gfx/wr/webrender/res/cs_conic_gradient.glsl b/gfx/wr/webrender/res/cs_conic_gradient.glsl
new file mode 100644
index 0000000000..551fc8a90b
--- /dev/null
+++ b/gfx/wr/webrender/res/cs_conic_gradient.glsl
@@ -0,0 +1,67 @@
+/* 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
+
+#define PI                  3.141592653589793
+
+varying highp vec2 v_pos;
+
+flat varying highp vec2 v_center;
+
+// x: start offset, y: offset scale, z: angle
+// Packed in to a vector to work around bug 1630356.
+flat varying highp vec3 v_start_offset_offset_scale_angle_vec;
+#define v_start_offset v_start_offset_offset_scale_angle_vec.x
+#define v_offset_scale v_start_offset_offset_scale_angle_vec.y
+#define v_angle v_start_offset_offset_scale_angle_vec.z
+
+#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 aStartOffset;
+PER_INSTANCE in float aEndOffset;
+PER_INSTANCE in float aAngle;
+PER_INSTANCE in int aExtendMode;
+PER_INSTANCE in int aGradientStopsAddress;
+
+void main(void) {
+    // Store 1/d where d = end_offset - start_offset
+    // If d = 0, we can't get its reciprocal. Instead, just use a zero scale.
+    float d = aEndOffset - aStartOffset;
+    v_offset_scale = d != 0.0 ? 1.0 / d : 0.0;
+
+    vec2 pos = mix(aTaskRect.xy, aTaskRect.zw, aPosition.xy);
+    gl_Position = uTransform * vec4(pos, 0.0, 1.0);
+
+    v_angle = PI / 2.0 - aAngle;
+    v_start_offset = aStartOffset * v_offset_scale;
+
+    // v_pos and v_center are in a coordinate space relative to the task rect
+    // (so they are independent of the task origin).
+    v_center = aCenter * v_offset_scale;
+    v_pos = (aTaskRect.zw - aTaskRect.xy) * aPosition.xy * v_offset_scale * aScale;
+
+    v_gradient_repeat.x = float(aExtendMode == EXTEND_MODE_REPEAT);
+    v_gradient_address.x = aGradientStopsAddress;
+}
+#endif
+
+
+#ifdef WR_FRAGMENT_SHADER
+
+void main(void) {
+    // Use inverse trig to find the angle offset from the relative position.
+    vec2 current_dir = v_pos - v_center;
+    float current_angle = atan(current_dir.y, current_dir.x) + v_angle;
+    float offset = fract(current_angle / (2.0 * PI)) * v_offset_scale - v_start_offset;
+
+    oFragColor = sample_gradient(offset);
+}
+
+#endif