Add comments, rename things, remove unused code

webrender/res/brush.glsl

@@ -37,7 +37,7 @@ void main(void) {
                           VECS_PER_SPECIFIC_BRUSH +
                           segment_index * VECS_PER_SEGMENT;
 
-    vec4[2] segment_data = fetch_from_resource_cache_2(segment_address);
+    vec4[2] segment_data = fetch_from_gpu_cache_2(segment_address);
     RectWithSize local_segment_rect = RectWithSize(segment_data[0].xy, segment_data[0].zw);
 
     VertexInfo vi;

webrender/res/brush_blend.glsl

@@ -101,8 +101,8 @@ void brush_vs(
         }
         case 10: {
             // Color Matrix
-            vec4 mat_data[3] = fetch_from_resource_cache_3(user_data.z);
-            vec4 offset_data = fetch_from_resource_cache_1(user_data.z + 4);
+            vec4 mat_data[3] = fetch_from_gpu_cache_3(user_data.z);
+            vec4 offset_data = fetch_from_gpu_cache_1(user_data.z + 4);
             vColorMat = mat3(mat_data[0].xyz, mat_data[1].xyz, mat_data[2].xyz);
             vColorOffset = offset_data.rgb;
             break;

webrender/res/brush_image.glsl

@@ -33,7 +33,7 @@ struct ImageBrushData {
 };
 
 ImageBrushData fetch_image_data(int address) {
-    vec4[3] raw_data = fetch_from_resource_cache_3(address);
+    vec4[3] raw_data = fetch_from_gpu_cache_3(address);
     ImageBrushData data = ImageBrushData(
         raw_data[0],
         raw_data[1],

webrender/res/brush_linear_gradient.glsl

@@ -32,7 +32,7 @@ struct Gradient {
 };
 
 Gradient fetch_gradient(int address) {
-    vec4 data[2] = fetch_from_resource_cache_2(address);
+    vec4 data[2] = fetch_from_gpu_cache_2(address);
     return Gradient(
         data[0],
         int(data[1].x),

webrender/res/brush_mix_blend.glsl

@@ -24,7 +24,7 @@ void brush_vs(
     vec4 unused
 ) {
     vec2 snapped_device_pos = snap_device_pos(vi);
-    vec2 texture_size = vec2(textureSize(sCacheRGBA8, 0));
+    vec2 texture_size = vec2(textureSize(sPrevPassColor, 0));
     vOp = user_data.x;
 
     PictureTask src_task = fetch_picture_task(user_data.z);
@@ -200,8 +200,8 @@ const int MixBlendMode_Color       = 14;
 const int MixBlendMode_Luminosity  = 15;
 
 Fragment brush_fs() {
-    vec4 Cb = textureLod(sCacheRGBA8, vBackdropUv, 0.0);
-    vec4 Cs = textureLod(sCacheRGBA8, vSrcUv, 0.0);
+    vec4 Cb = textureLod(sPrevPassColor, vBackdropUv, 0.0);
+    vec4 Cs = textureLod(sPrevPassColor, vSrcUv, 0.0);
 
     if (Cb.a == 0.0) {
         return Fragment(Cs);

webrender/res/brush_radial_gradient.glsl

@@ -31,7 +31,7 @@ struct RadialGradient {
 };
 
 RadialGradient fetch_radial_gradient(int address) {
-    vec4 data[2] = fetch_from_resource_cache_2(address);
+    vec4 data[2] = fetch_from_gpu_cache_2(address);
     return RadialGradient(
         data[0],
         data[1].x,

webrender/res/brush_solid.glsl

@@ -19,7 +19,7 @@ struct SolidBrush {
 };
 
 SolidBrush fetch_solid_primitive(int address) {
-    vec4 data = fetch_from_resource_cache_1(address);
+    vec4 data = fetch_from_gpu_cache_1(address);
     return SolidBrush(data);
 }
 

webrender/res/brush_yuv_image.glsl

@@ -77,7 +77,7 @@ struct YuvPrimitive {
 };
 
 YuvPrimitive fetch_yuv_primitive(int address) {
-    vec4 data = fetch_from_resource_cache_1(address);
+    vec4 data = fetch_from_gpu_cache_1(address);
     return YuvPrimitive(data.x);
 }
 

webrender/res/clip_shared.glsl

@@ -2,7 +2,7 @@
  * 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 rect,render_task,resource_cache,snap,transform
+#include rect,render_task,gpu_cache,snap,transform
 
 #ifdef WR_VERTEX_SHADER
 

webrender/res/cs_blur.glsl

@@ -46,9 +46,9 @@ void main(void) {
     RectWithSize target_rect = blur_task.common_data.task_rect;
 
 #if defined WR_FEATURE_COLOR_TARGET
-    vec2 texture_size = vec2(textureSize(sCacheRGBA8, 0).xy);
+    vec2 texture_size = vec2(textureSize(sPrevPassColor, 0).xy);
 #else
-    vec2 texture_size = vec2(textureSize(sCacheA8, 0).xy);
+    vec2 texture_size = vec2(textureSize(sPrevPassAlpha, 0).xy);
 #endif
     vUv.z = src_task.texture_layer_index;
     vSigma = blur_task.blur_radius;
@@ -89,10 +89,10 @@ void main(void) {
 
 #if defined WR_FEATURE_COLOR_TARGET
 #define SAMPLE_TYPE vec4
-#define SAMPLE_TEXTURE(uv)  texture(sCacheRGBA8, uv)
+#define SAMPLE_TEXTURE(uv)  texture(sPrevPassColor, uv)
 #else
 #define SAMPLE_TYPE float
-#define SAMPLE_TEXTURE(uv)  texture(sCacheA8, uv).r
+#define SAMPLE_TEXTURE(uv)  texture(sPrevPassAlpha, uv).r
 #endif
 
 // TODO(gw): Write a fast path blur that handles smaller blur radii

webrender/res/cs_clip_box_shadow.glsl

@@ -26,7 +26,7 @@ struct BoxShadowData {
 };
 
 BoxShadowData fetch_data(ivec2 address) {
-    vec4 data[3] = fetch_from_resource_cache_3_direct(address);
+    vec4 data[3] = fetch_from_gpu_cache_3_direct(address);
     RectWithSize dest_rect = RectWithSize(data[2].xy, data[2].zw);
     BoxShadowData bs_data = BoxShadowData(
         data[0].xy,

webrender/res/cs_clip_image.glsl

@@ -17,7 +17,7 @@ struct ImageMaskData {
 };
 
 ImageMaskData fetch_mask_data(ivec2 address) {
-    vec4 data = fetch_from_resource_cache_1_direct(address);
+    vec4 data = fetch_from_gpu_cache_1_direct(address);
     RectWithSize local_rect = RectWithSize(data.xy, data.zw);
     ImageMaskData mask_data = ImageMaskData(local_rect);
     return mask_data;

webrender/res/cs_clip_line.glsl

@@ -28,7 +28,7 @@ struct LineDecorationData {
 };
 
 LineDecorationData fetch_data(ivec2 address) {
-    vec4 data[2] = fetch_from_resource_cache_2_direct(address);
+    vec4 data[2] = fetch_from_gpu_cache_2_direct(address);
     RectWithSize local_rect = RectWithSize(data[0].xy, data[0].zw);
     LineDecorationData line_data = LineDecorationData(
         local_rect,

webrender/res/cs_clip_rectangle.glsl

@@ -18,7 +18,7 @@ struct ClipRect {
 };
 
 ClipRect fetch_clip_rect(ivec2 address) {
-    vec4 data[2] = fetch_from_resource_cache_2_direct(address);
+    vec4 data[2] = fetch_from_gpu_cache_2_direct(address);
     ClipRect rect = ClipRect(RectWithSize(data[0].xy, data[0].zw), data[1]);
     return rect;
 }
@@ -32,7 +32,7 @@ struct ClipCorner {
 // miscompilations with a macOS 10.12 Intel driver.
 ClipCorner fetch_clip_corner(ivec2 address, float index) {
     address += ivec2(2 + 2 * int(index), 0);
-    vec4 data[2] = fetch_from_resource_cache_2_direct(address);
+    vec4 data[2] = fetch_from_gpu_cache_2_direct(address);
     ClipCorner corner = ClipCorner(RectWithSize(data[0].xy, data[0].zw), data[1]);
     return corner;
 }

webrender/res/cs_scale.glsl

@@ -32,9 +32,9 @@ void main(void) {
     RectWithSize target_rect = scale_task.common_data.task_rect;
 
 #if defined WR_FEATURE_COLOR_TARGET
-    vec2 texture_size = vec2(textureSize(sCacheRGBA8, 0).xy);
+    vec2 texture_size = vec2(textureSize(sPrevPassColor, 0).xy);
 #else
-    vec2 texture_size = vec2(textureSize(sCacheA8, 0).xy);
+    vec2 texture_size = vec2(textureSize(sPrevPassAlpha, 0).xy);
 #endif
 
     vUv.z = src_task.texture_layer_index;
@@ -54,10 +54,10 @@ void main(void) {
 
 #if defined WR_FEATURE_COLOR_TARGET
 #define SAMPLE_TYPE vec4
-#define SAMPLE_TEXTURE(uv)  texture(sCacheRGBA8, uv)
+#define SAMPLE_TEXTURE(uv)  texture(sPrevPassColor, uv)
 #else
 #define SAMPLE_TYPE float
-#define SAMPLE_TEXTURE(uv)  texture(sCacheA8, uv).r
+#define SAMPLE_TEXTURE(uv)  texture(sPrevPassAlpha, uv).r
 #endif
 
 void main(void) {

webrender/res/gpu_cache.glsl

@@ -0,0 +1,137 @@
+/* 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/. */
+
+uniform HIGHP_SAMPLER_FLOAT sampler2D sGpuCache;
+
+#define VECS_PER_IMAGE_RESOURCE     2
+
+// TODO(gw): This is here temporarily while we have
+//           both GPU store and cache. When the GPU
+//           store code is removed, we can change the
+//           PrimitiveInstance instance structure to
+//           use 2x unsigned shorts as vertex attributes
+//           instead of an int, and encode the UV directly
+//           in the vertices.
+ivec2 get_gpu_cache_uv(int address) {
+    return ivec2(uint(address) % WR_MAX_VERTEX_TEXTURE_WIDTH,
+                 uint(address) / WR_MAX_VERTEX_TEXTURE_WIDTH);
+}
+
+vec4[2] fetch_from_gpu_cache_2_direct(ivec2 address) {
+    return vec4[2](
+        TEXEL_FETCH(sGpuCache, address, 0, ivec2(0, 0)),
+        TEXEL_FETCH(sGpuCache, address, 0, ivec2(1, 0))
+    );
+}
+
+vec4[2] fetch_from_gpu_cache_2(int address) {
+    ivec2 uv = get_gpu_cache_uv(address);
+    return vec4[2](
+        TEXEL_FETCH(sGpuCache, uv, 0, ivec2(0, 0)),
+        TEXEL_FETCH(sGpuCache, uv, 0, ivec2(1, 0))
+    );
+}
+
+#ifdef WR_VERTEX_SHADER
+
+vec4[8] fetch_from_gpu_cache_8(int address) {
+    ivec2 uv = get_gpu_cache_uv(address);
+    return vec4[8](
+        TEXEL_FETCH(sGpuCache, uv, 0, ivec2(0, 0)),
+        TEXEL_FETCH(sGpuCache, uv, 0, ivec2(1, 0)),
+        TEXEL_FETCH(sGpuCache, uv, 0, ivec2(2, 0)),
+        TEXEL_FETCH(sGpuCache, uv, 0, ivec2(3, 0)),
+        TEXEL_FETCH(sGpuCache, uv, 0, ivec2(4, 0)),
+        TEXEL_FETCH(sGpuCache, uv, 0, ivec2(5, 0)),
+        TEXEL_FETCH(sGpuCache, uv, 0, ivec2(6, 0)),
+        TEXEL_FETCH(sGpuCache, uv, 0, ivec2(7, 0))
+    );
+}
+
+vec4[3] fetch_from_gpu_cache_3(int address) {
+    ivec2 uv = get_gpu_cache_uv(address);
+    return vec4[3](
+        TEXEL_FETCH(sGpuCache, uv, 0, ivec2(0, 0)),
+        TEXEL_FETCH(sGpuCache, uv, 0, ivec2(1, 0)),
+        TEXEL_FETCH(sGpuCache, uv, 0, ivec2(2, 0))
+    );
+}
+
+vec4[3] fetch_from_gpu_cache_3_direct(ivec2 address) {
+    return vec4[3](
+        TEXEL_FETCH(sGpuCache, address, 0, ivec2(0, 0)),
+        TEXEL_FETCH(sGpuCache, address, 0, ivec2(1, 0)),
+        TEXEL_FETCH(sGpuCache, address, 0, ivec2(2, 0))
+    );
+}
+
+vec4[4] fetch_from_gpu_cache_4_direct(ivec2 address) {
+    return vec4[4](
+        TEXEL_FETCH(sGpuCache, address, 0, ivec2(0, 0)),
+        TEXEL_FETCH(sGpuCache, address, 0, ivec2(1, 0)),
+        TEXEL_FETCH(sGpuCache, address, 0, ivec2(2, 0)),
+        TEXEL_FETCH(sGpuCache, address, 0, ivec2(3, 0))
+    );
+}
+
+vec4[4] fetch_from_gpu_cache_4(int address) {
+    ivec2 uv = get_gpu_cache_uv(address);
+    return vec4[4](
+        TEXEL_FETCH(sGpuCache, uv, 0, ivec2(0, 0)),
+        TEXEL_FETCH(sGpuCache, uv, 0, ivec2(1, 0)),
+        TEXEL_FETCH(sGpuCache, uv, 0, ivec2(2, 0)),
+        TEXEL_FETCH(sGpuCache, uv, 0, ivec2(3, 0))
+    );
+}
+
+vec4 fetch_from_gpu_cache_1_direct(ivec2 address) {
+    return texelFetch(sGpuCache, address, 0);
+}
+
+vec4 fetch_from_gpu_cache_1(int address) {
+    ivec2 uv = get_gpu_cache_uv(address);
+    return texelFetch(sGpuCache, uv, 0);
+}
+
+//TODO: image resource is too specific for this module
+
+struct ImageResource {
+    RectWithEndpoint uv_rect;
+    float layer;
+    vec3 user_data;
+};
+
+ImageResource fetch_image_resource(int address) {
+    //Note: number of blocks has to match `renderer::BLOCKS_PER_UV_RECT`
+    vec4 data[2] = fetch_from_gpu_cache_2(address);
+    RectWithEndpoint uv_rect = RectWithEndpoint(data[0].xy, data[0].zw);
+    return ImageResource(uv_rect, data[1].x, data[1].yzw);
+}
+
+ImageResource fetch_image_resource_direct(ivec2 address) {
+    vec4 data[2] = fetch_from_gpu_cache_2_direct(address);
+    RectWithEndpoint uv_rect = RectWithEndpoint(data[0].xy, data[0].zw);
+    return ImageResource(uv_rect, data[1].x, data[1].yzw);
+}
+
+// Fetch optional extra data for a texture cache resource. This can contain
+// a polygon defining a UV rect within the texture cache resource.
+struct ImageResourceExtra {
+    vec2 st_tl;
+    vec2 st_tr;
+    vec2 st_bl;
+    vec2 st_br;
+};
+
+ImageResourceExtra fetch_image_resource_extra(int address) {
+    vec4 data[2] = fetch_from_gpu_cache_2(address + VECS_PER_IMAGE_RESOURCE);
+    return ImageResourceExtra(
+        data[0].xy,
+        data[0].zw,
+        data[1].xy,
+        data[1].zw
+    );
+}
+
+#endif //WR_VERTEX_SHADER

webrender/res/prim_shared.glsl

@@ -2,7 +2,7 @@
  * 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 rect,render_task,resource_cache,snap,transform
+#include rect,render_task,gpu_cache,snap,transform
 
 #define EXTEND_MODE_CLAMP  0
 #define EXTEND_MODE_REPEAT 1
@@ -15,11 +15,8 @@
 #define RASTER_LOCAL            0
 #define RASTER_SCREEN           1
 
-uniform sampler2DArray sCacheA8;
-uniform sampler2DArray sCacheRGBA8;
-
-// An A8 target for standalone tasks that is available to all passes.
-uniform sampler2DArray sSharedCacheA8;
+uniform sampler2DArray sPrevPassAlpha;
+uniform sampler2DArray sPrevPassColor;
 
 vec2 clamp_rect(vec2 pt, RectWithSize rect) {
     return clamp(pt, rect.p0, rect.p0 + rect.size);
@@ -254,7 +251,7 @@ float do_clip() {
     // is still interpolated and becomes a subject of precision-caused
     // fluctuations, see https://bugzilla.mozilla.org/show_bug.cgi?id=1491911
     ivec3 tc = ivec3(mask_uv, vClipMaskUv.z + 0.5);
-    return texelFetch(sCacheA8, tc, 0).r;
+    return texelFetch(sPrevPassAlpha, tc, 0).r;
 }
 
 #ifdef WR_FEATURE_DITHERING
@@ -297,7 +294,7 @@ vec4 sample_gradient(int address, float offset, float gradient_repeat) {
     lut_offset = clamp(lut_offset, 0, 2 * (GRADIENT_ENTRIES + 1));
 
     // Fetch the start and end color.
-    vec4 texels[2] = fetch_from_resource_cache_2(address + lut_offset);
+    vec4 texels[2] = fetch_from_gpu_cache_2(address + lut_offset);
 
     // Finally interpolate and apply dithering
     return dither(mix(texels[0], texels[1], fract(x)));