Fixup commit for gradient banding work

webrender/res/prim_shared.glsl

@@ -762,7 +762,7 @@ float do_clip() {
 vec4 dither(vec4 color) {
     const int matrix_mask = 7;
 
-    ivec2 pos = ivec2(gl_FragCoord) & ivec2(matrix_mask);
+    ivec2 pos = ivec2(gl_FragCoord.xy) & ivec2(matrix_mask);
     float noise_factor = 4.0 / 255.0;
     float noise = texelFetch(sDither, pos, 0).r * noise_factor;
     return color + vec4(noise, noise, noise, 0);

webrender/res/ps_angle_gradient.fs.glsl

@@ -12,9 +12,9 @@ void main(void) {
     float x = mix(clamp(vOffset, 0.0, 1.0), fract(vOffset), vGradientRepeat) * 0.5 * texture_size.x;
 
     x = 2.0 * floor(x) + 0.5 + fract(x);
-    float y = vGradientIndex + 1.0 / 256.0;
 
     // Use linear filtering to mix in the low bits (vGradientIndex + 1) with the high
     // bits (vGradientIndex)
+    float y = vGradientIndex * 2.0 + 0.5 + 1.0 / 256.0;
     oFragColor = dither(texture(sGradients, vec2(x, y) / texture_size));
 }

webrender/res/ps_angle_gradient.vs.glsl

@@ -27,7 +27,7 @@ void main(void) {
     vOffset = dot(vi.local_pos - start_point, dir) / dot(dir, dir);
 
     // V coordinate of gradient row in lookup texture.
-    vGradientIndex = float(prim.sub_index) * 2.0 + 0.5;
+    vGradientIndex = float(prim.sub_index);
 
     // Whether to repeat the gradient instead of clamping.
     vGradientRepeat = float(int(gradient.extend_mode.x) == EXTEND_MODE_REPEAT);

webrender/res/ps_radial_gradient.fs.glsl

@@ -54,6 +54,6 @@ void main(void) {
 
     // Use linear filtering to mix in the low bits (vGradientIndex + 1) with the high
     // bits (vGradientIndex)
-    float y = vGradientIndex + 1.0 / 256.0;
+    float y = vGradientIndex * 2.0 + 0.5 + 1.0 / 256.0;
     oFragColor = dither(texture(sGradients, vec2(x, y) / texture_size));
 }

webrender/res/ps_radial_gradient.vs.glsl

@@ -27,7 +27,7 @@ void main(void) {
     vEndRadius = gradient.start_end_radius_extend_mode.y;
 
     // V coordinate of gradient row in lookup texture.
-    vGradientIndex = float(prim.sub_index) * 2.0 + 0.5;
+    vGradientIndex = float(prim.sub_index);
 
     // Whether to repeat the gradient instead of clamping.
     vGradientRepeat = float(int(gradient.start_end_radius_extend_mode.z) == EXTEND_MODE_REPEAT);

webrender/src/device.rs

@@ -1717,7 +1717,7 @@ impl Device {
             }
             ImageFormat::RGB8 => (gl::RGB, 3, data),
             ImageFormat::RGBA8 => (get_gl_format_bgra(self.gl()), 4, data),
-            ImageFormat::Invalid | ImageFormat::RGBA16 | ImageFormat::RGBAF32 => unreachable!(),
+            ImageFormat::Invalid | ImageFormat::RGBAF32 => unreachable!(),
         };
 
         let row_length = match stride {
@@ -2103,7 +2103,6 @@ fn gl_texture_formats_for_image_format(gl: &gl::Gl, format: ImageFormat) -> (gl:
                 }
             }
         }
-        ImageFormat::RGBA16 => (gl::RGBA16UI as gl::GLint, gl::RGBA_INTEGER),
         ImageFormat::RGBAF32 => (gl::RGBA32F as gl::GLint, gl::RGBA),
         ImageFormat::Invalid => unreachable!(),
     }
@@ -2112,7 +2111,6 @@ fn gl_texture_formats_for_image_format(gl: &gl::Gl, format: ImageFormat) -> (gl:
 fn gl_type_for_texture_format(format: ImageFormat) -> gl::GLuint {
     match format {
         ImageFormat::RGBAF32 => gl::FLOAT,
-        ImageFormat::RGBA16 => gl::UNSIGNED_SHORT,
         _ => gl::UNSIGNED_BYTE,
     }
 }

webrender/src/gpu_store.rs

@@ -30,7 +30,6 @@ pub trait GpuStoreLayout {
     fn texel_size() -> usize {
         match Self::image_format() {
             ImageFormat::RGBA8 => 4,
-            ImageFormat::RGBA16 => 8,
             ImageFormat::RGBAF32 => 16,
             _ => unreachable!(),
         }

webrender/src/internal_types.rs

@@ -316,20 +316,19 @@ pub struct PackedTexel {
 
 impl PackedTexel {
     pub fn high_bytes(color: &ColorF) -> PackedTexel {
-        PackedTexel {
-            b: (0.5 + color.b * COLOR_FLOAT_TO_FIXED).floor() as u8,
-            g: (0.5 + color.g * COLOR_FLOAT_TO_FIXED).floor() as u8,
-            r: (0.5 + color.r * COLOR_FLOAT_TO_FIXED).floor() as u8,
-            a: (0.5 + color.a * COLOR_FLOAT_TO_FIXED).floor() as u8,
-        }
+        Self::extract_bytes(color, COLOR_FLOAT_TO_FIXED)
     }
 
     pub fn low_bytes(color: &ColorF) -> PackedTexel {
+        Self::extract_bytes(color, COLOR_FLOAT_TO_FIXED_WIDE)
+    }
+
+    fn extract_bytes(color: &ColorF, multiplier: f32) -> PackedTexel {
         PackedTexel {
-            b: ((0.5 + color.b * COLOR_FLOAT_TO_FIXED_WIDE).floor() as u16 & 0xff) as u8,
-            g: ((0.5 + color.g * COLOR_FLOAT_TO_FIXED_WIDE).floor() as u16 & 0xff) as u8,
-            r: ((0.5 + color.r * COLOR_FLOAT_TO_FIXED_WIDE).floor() as u16 & 0xff) as u8,
-            a: ((0.5 + color.a * COLOR_FLOAT_TO_FIXED_WIDE).floor() as u16 & 0xff) as u8,
+            b: ((0.5 + color.b * multiplier).floor() as u32 & 0xff) as u8,
+            g: ((0.5 + color.g * multiplier).floor() as u32 & 0xff) as u8,
+            r: ((0.5 + color.r * multiplier).floor() as u32 & 0xff) as u8,
+            a: ((0.5 + color.a * multiplier).floor() as u32 & 0xff) as u8,
         }
     }
 }

webrender/src/prim_store.rs

@@ -277,7 +277,7 @@ pub struct GradientDataEntry {
 // first the entry index is calculated to determine which two colors to interpolate between, then
 // the offset within that entry bucket is used to interpolate between the two colors in that entry.
 // This layout preserves hard stops, as the end color for a given entry can differ from the start
-// color for the following entry, despite them being adjacent. Colors are stored within in RGBA16
+// color for the following entry, despite them being adjacent. Colors are stored within in BGRA8
 // format for texture upload.
 pub struct GradientData {
     pub colors_high: [GradientDataEntry; GRADIENT_DATA_RESOLUTION],

webrender/src/texture_cache.rs

@@ -607,7 +607,7 @@ impl TextureCache {
             ImageFormat::A8 => (&mut self.arena.pages_a8, &mut profile.pages_a8),
             ImageFormat::RGBA8 => (&mut self.arena.pages_rgba8, &mut profile.pages_rgba8),
             ImageFormat::RGB8 => (&mut self.arena.pages_rgb8, &mut profile.pages_rgb8),
-            ImageFormat::Invalid | ImageFormat::RGBA16 | ImageFormat::RGBAF32 => unreachable!(),
+            ImageFormat::Invalid | ImageFormat::RGBAF32 => unreachable!(),
         };
 
         // TODO(gw): Handle this sensibly (support failing to render items that can't fit?)

webrender_traits/src/image.rs

@@ -28,7 +28,6 @@ pub enum ImageFormat {
     RGB8     = 2,
     RGBA8    = 3,
     RGBAF32  = 4,
-    RGBA16   = 5,
 }
 
 impl ImageFormat {
@@ -37,7 +36,6 @@ impl ImageFormat {
             ImageFormat::A8 => Some(1),
             ImageFormat::RGB8 => Some(3),
             ImageFormat::RGBA8 => Some(4),
-            ImageFormat::RGBA16 => Some(8),
             ImageFormat::RGBAF32 => Some(16),
             ImageFormat::Invalid => None,
         }

wrench/benchmarks/aligned-gradient.yaml

@@ -59,4 +59,4 @@ root:
       start: [ 0, -2000 ]
       end: [ 0, 4000 ]
       stops: [ 0.0, red, 1.0, green ]
-      repeat: false
+      repeat: false

wrench/benchmarks/radial-gradient.yaml

@@ -56,4 +56,4 @@ root:
       end-center: [ 990, 540 ]
       end-radius: 8000
       stops: [ 0.0, black, 1.0, white ]
-      repeat: false
+      repeat: false

wrench/benchmarks/unaligned-gradient.yaml

@@ -59,4 +59,4 @@ root:
       start: [ 0, -2000 ]
       end: [ 1, 4000 ]
       stops: [ 0.0, red, 1.0, green ]
-      repeat: false
+      repeat: false

wrench/src/wrench.rs

@@ -429,7 +429,7 @@ fn is_image_opaque(format: ImageFormat, bytes: &[u8]) -> bool {
         }
         ImageFormat::RGB8 => true,
         ImageFormat::A8 => false,
-        ImageFormat::Invalid | ImageFormat::RGBA16 | ImageFormat::RGBAF32 => unreachable!(),
+        ImageFormat::Invalid | ImageFormat::RGBAF32 => unreachable!(),
     }
 }