Auto merge of #523 - glennw:resource-list-2, r=pcwalton

Remove ResourceList structure and usage.

Previously, a resource list would be built at the start of the
frame. This would allow glyphs missing from the texture cache
to be rasterized.

However, sometimes (e.g. with subpixel antialiasing) it's not possible
to know right at the start of the frame exactly what needs to be
rasterized yet.

Instead, we now allow the resource cache to add requests during
the prepare_prim_for_render() stage. Primitives that request
resources are marked as needing a resolve operation. This allows
primitives that request resources to update their UV coords etc
before batching occurs (since texture IDs for resources must be
known before batching can occur).

This also lays most of the groundwork for running the resource
cache rasterizer as a separate thread in the future. This will be
used to ensure that if too many glyphs are requested in one frame,
WR can continue running without blocking, using older glyphs and
then re-render the scene when newer, high resolution glyphs are
available.

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webrender/res/clip_shared.glsl

@@ -16,7 +16,8 @@ void write_clip(ClipInfo clip) {
                        clip.bottom_right.outer_inner_radius.x,
                        clip.bottom_left.outer_inner_radius.x);
     //TODO: interpolate the final mask UV
-    vClipMaskUvRect = clip.mask_info.uv_rect;
+    vec2 texture_size = textureSize(sMask, 0);
+    vClipMaskUvRect = clip.mask_info.uv_rect / texture_size.xyxy;
     vClipMaskLocalRect = clip.mask_info.local_rect; //TODO: transform
 }
 #endif

webrender/res/prim_shared.glsl

@@ -594,7 +594,6 @@ struct Image {
     vec4 st_rect;                        // Location of the image texture in the texture atlas.
     vec4 stretch_size_and_tile_spacing;  // Size of the actual image and amount of space between
                                          //     tiled instances of this image.
-    bool has_pixel_coords;
 };
 
 Image fetch_image(int index) {
@@ -605,9 +604,6 @@ Image fetch_image(int index) {
     image.st_rect = texelFetchOffset(sData32, uv, 0, ivec2(0, 0));
     image.stretch_size_and_tile_spacing = texelFetchOffset(sData32, uv, 0, ivec2(1, 0));
 
-    image.has_pixel_coords = image.st_rect.z < 0.0;
-    image.st_rect.z = abs(image.st_rect.z);
-
     return image;
 }
 

webrender/res/ps_image.vs.glsl

@@ -23,14 +23,9 @@ void main(void) {
 #endif
 
     // vUv will contain how many times this image has wrapped around the image size.
-    vec2 st0 = image.st_rect.xy;
-    vec2 st1 = image.st_rect.zw;
-
-    if (image.has_pixel_coords) {
-        vec2 texture_size = vec2(textureSize(sDiffuse, 0));
-        st0 /= texture_size;
-        st1 /= texture_size;
-    }
+    vec2 texture_size = vec2(textureSize(sDiffuse, 0));
+    vec2 st0 = image.st_rect.xy / texture_size;
+    vec2 st1 = image.st_rect.zw / texture_size;
 
     vTextureSize = st1 - st0;
     vTextureOffset = st0;

webrender/res/shared.glsl

@@ -25,7 +25,6 @@
     #define varying in
 
     // Uniform inputs
-    uniform sampler2D sMask;
 
     // Fragment shader outputs
     out vec4 oFragColor;
@@ -35,6 +34,7 @@
 // Shared shader uniforms
 //======================================================================================
 uniform sampler2D sDiffuse;
+uniform sampler2D sMask;
 
 //======================================================================================
 // Interpolator definitions

webrender/src/internal_types.rs

@@ -475,24 +475,6 @@ pub struct PolygonPosColorUv {
     pub vertices: Vec<WorkVertex>,
 }
 
-#[derive(PartialEq, Eq, Hash)]
-pub struct Glyph {
-    pub size: Au,
-    pub blur_radius: Au,
-    pub index: u32,
-}
-
-impl Glyph {
-    #[inline]
-    pub fn new(size: Au, blur_radius: Au, index: u32) -> Glyph {
-        Glyph {
-            size: size,
-            blur_radius: blur_radius,
-            index: index,
-        }
-    }
-}
-
 #[derive(Debug, Clone)]
 #[repr(C)]
 pub struct PackedVertexForTextureCacheUpdate {

webrender/src/lib.rs

@@ -63,7 +63,6 @@ mod profiler;
 mod record;
 mod render_backend;
 mod resource_cache;
-mod resource_list;
 mod scene;
 mod spring;
 mod texture_cache;

webrender/src/platform/macos/font.rs

@@ -121,14 +121,18 @@ impl FontContext {
                                 size: Au,
                                 character: u32,
                                 device_pixel_ratio: f32) -> Option<GlyphDimensions> {
-        self.get_ct_font(font_key, size, device_pixel_ratio).map(|ref ct_font| {
+        self.get_ct_font(font_key, size, device_pixel_ratio).and_then(|ref ct_font| {
             let glyph = character as CGGlyph;
             let metrics = get_glyph_metrics(ct_font, glyph);
-            GlyphDimensions {
-                left: metrics.rasterized_left,
-                top: metrics.rasterized_ascent,
-                width: metrics.rasterized_width as u32,
-                height: metrics.rasterized_height as u32,
+            if metrics.rasterized_width == 0 || metrics.rasterized_height == 0 {
+                None
+            } else {
+                Some(GlyphDimensions {
+                    left: metrics.rasterized_left,
+                    top: metrics.rasterized_ascent,
+                    width: metrics.rasterized_width as u32,
+                    height: metrics.rasterized_height as u32,
+                })
             }
         })
     }

webrender/src/platform/unix/font.rs

@@ -115,13 +115,17 @@ impl FontContext {
                                 size: Au,
                                 character: u32,
                                 device_pixel_ratio: f32) -> Option<GlyphDimensions> {
-        self.load_glyph(font_key, size, character, device_pixel_ratio).map(|slot| {
+        self.load_glyph(font_key, size, character, device_pixel_ratio).and_then(|slot| {
             let metrics = unsafe { &(*slot).metrics };
-            GlyphDimensions {
-                left: (metrics.horiBearingX >> 6) as i32,
-                top: (metrics.horiBearingY >> 6) as i32,
-                width: (metrics.width >> 6) as u32,
-                height: (metrics.height >> 6) as u32,
+            if metrics.width == 0 || metrics.height == 0 {
+                None
+            } else {
+                Some(GlyphDimensions {
+                    left: (metrics.horiBearingX >> 6) as i32,
+                    top: (metrics.horiBearingY >> 6) as i32,
+                    width: (metrics.width >> 6) as u32,
+                    height: (metrics.height >> 6) as u32,
+                })
             }
         })
     }