1 files changed, 102 insertions, 0 deletions
diff --git a/gfx/wr/webrender/res/render_task.glsl b/gfx/wr/webrender/res/render_task.glsl
new file mode 100644
index 0000000000..cd9aea402c
--- /dev/null
+++ b/gfx/wr/webrender/res/render_task.glsl
@@ -0,0 +1,102 @@
+/* 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/. */
+
+
+#ifdef WR_VERTEX_SHADER
+#define VECS_PER_RENDER_TASK        2U
+
+uniform HIGHP_SAMPLER_FLOAT sampler2D sRenderTasks;
+
+struct RenderTaskData {
+    RectWithEndpoint task_rect;
+    vec4 user_data;
+};
+
+// See RenderTaskData in render_task.rs
+RenderTaskData fetch_render_task_data(int index) {
+    ivec2 uv = get_fetch_uv(index, VECS_PER_RENDER_TASK);
+
+    vec4 texel0 = TEXEL_FETCH(sRenderTasks, uv, 0, ivec2(0, 0));
+    vec4 texel1 = TEXEL_FETCH(sRenderTasks, uv, 0, ivec2(1, 0));
+
+    RectWithEndpoint task_rect = RectWithEndpoint(
+        texel0.xy,
+        texel0.zw
+    );
+
+    RenderTaskData data = RenderTaskData(
+        task_rect,
+        texel1
+    );
+
+    return data;
+}
+
+RectWithEndpoint fetch_render_task_rect(int index) {
+    ivec2 uv = get_fetch_uv(index, VECS_PER_RENDER_TASK);
+
+    vec4 texel0 = TEXEL_FETCH(sRenderTasks, uv, 0, ivec2(0, 0));
+    vec4 texel1 = TEXEL_FETCH(sRenderTasks, uv, 0, ivec2(1, 0));
+
+    RectWithEndpoint task_rect = RectWithEndpoint(
+        texel0.xy,
+        texel0.zw
+    );
+
+    return task_rect;
+}
+
+#define PIC_TYPE_IMAGE          1
+#define PIC_TYPE_TEXT_SHADOW    2
+
+/*
+ The dynamic picture that this brush exists on. Right now, it
+ contains minimal information. In the future, it will describe
+ the transform mode of primitives on this picture, among other things.
+ */
+struct PictureTask {
+    RectWithEndpoint task_rect;
+    float device_pixel_scale;
+    vec2 content_origin;
+};
+
+PictureTask fetch_picture_task(int address) {
+    RenderTaskData task_data = fetch_render_task_data(address);
+
+    PictureTask task = PictureTask(
+        task_data.task_rect,
+        task_data.user_data.x,
+        task_data.user_data.yz
+    );
+
+    return task;
+}
+
+#define CLIP_TASK_EMPTY 0x7FFF
+
+struct ClipArea {
+    RectWithEndpoint task_rect;
+    float device_pixel_scale;
+    vec2 screen_origin;
+};
+
+ClipArea fetch_clip_area(int index) {
+    ClipArea area;
+
+    if (index >= CLIP_TASK_EMPTY) {
+        area.task_rect = RectWithEndpoint(vec2(0.0), vec2(0.0));
+        area.device_pixel_scale = 0.0;
+        area.screen_origin = vec2(0.0);
+    } else {
+        RenderTaskData task_data = fetch_render_task_data(index);
+
+        area.task_rect = task_data.task_rect;
+        area.device_pixel_scale = task_data.user_data.x;
+        area.screen_origin = task_data.user_data.yz;
+    }
+
+    return area;
+}
+
+#endif //WR_VERTEX_SHADER