1 files changed, 13 insertions, 70 deletions

diff --git a/src/gpu/effects/GrDitherEffect.fp b/src/gpu/effects/GrDitherEffect.fp
index 937efae264..1c35b38cd2 100644
--- a/src/gpu/effects/GrDitherEffect.fp
+++ b/src/gpu/effects/GrDitherEffect.fp
@@ -1,74 +1,17 @@
-// This controls the range of values added to color channels
-layout(key) in int rangeType;
-
-@make {
-    static sk_sp<GrFragmentProcessor> Make(GrPixelConfig dstConfig) {
-        int rangeType;
-        switch (dstConfig) {
-            case kGray_8_GrPixelConfig:
-            case kRGBA_8888_GrPixelConfig:
-            case kBGRA_8888_GrPixelConfig:
-            case kSRGBA_8888_GrPixelConfig:
-            case kSBGRA_8888_GrPixelConfig:
-                rangeType = 0;
-                break;
-            case kRGB_565_GrPixelConfig:
-                rangeType = 1;
-                break;
-            case kRGBA_4444_GrPixelConfig:
-                rangeType = 2;
-                break;
-            case kUnknown_GrPixelConfig:
-            case kAlpha_half_GrPixelConfig:
-            case kRGBA_8888_sint_GrPixelConfig:
-            case kRGBA_float_GrPixelConfig:
-            case kRG_float_GrPixelConfig:
-            case kRGBA_half_GrPixelConfig:
-            case kAlpha_8_GrPixelConfig:
-                return nullptr;
-        }
-        return sk_sp<GrFragmentProcessor>(new GrDitherEffect(rangeType));
-    }
-}
-
 void main() {
-    float value;
-    float range;
-    @switch (rangeType) {
-        case 0:
-            range = 1.0 / 255.0;
-            break;
-        case 1:
-            range = 1.0 / 63.0;
-            break;
-        default:
-            // Experimentally this looks better than the expected value of 1/15.
-            range = 0.125 / 15.0;
-            break;
-    }
-    @if (sk_Caps.integerSupport) {
-        // This ordered-dither code is lifted from the cpu backend.
-        int x = int(sk_FragCoord.x);
-        int y = int(sk_FragCoord.y);
-        uint m = (y & 1) << 5 | (x & 1) << 4 |
-                 (y & 2) << 2 | (x & 2) << 1 |
-                 (y & 4) >> 1 | (x & 4) >> 2;
-        value = float(m) * 1.0 / 64.0 - 63.0 / 128.0;
-    } else {
-        // Generate a random number based on the fragment position. For this
-        // random number generator, we use the "GLSL rand" function
-        // that seems to be floating around on the internet. It works under
-        // the assumption that sin(<big number>) oscillates with high frequency
-        // and sampling it will generate "randomness". Since we're using this
-        // for rendering and not cryptography it should be OK.
-        value = fract(sin(dot(sk_FragCoord.xy, vec2(12.9898, 78.233))) * 43758.5453) - .5;
-    }
-    // For each color channel, add the random offset to the channel value and then clamp
-    // between 0 and alpha to keep the color premultiplied.
-    sk_OutColor = vec4(clamp(sk_InColor.rgb + value * range, 0, sk_InColor.a), sk_InColor.a);
+    // Generate a random number based on the fragment position. For this
+    // random number generator, we use the "GLSL rand" function
+    // that seems to be floating around on the internet. It works under
+    // the assumption that sin(<big number>) oscillates with high frequency
+    // and sampling it will generate "randomness". Since we're using this
+    // for rendering and not cryptography it should be OK.
+
+    // For each channel c, add the random offset to the pixel to either bump
+    // it up or let it remain constant during quantization.
+    float r = fract(sin(dot(sk_FragCoord.xy, vec2(12.9898, 78.233))) * 43758.5453) - .5;
+    sk_OutColor = clamp(1 / 255.0 * vec4(r) + sk_InColor, 0, 1);
 }
 
 @test(testData) {
-    float range = testData->fRandom->nextRangeF(0.001f, 0.05f);
-    return sk_sp<GrFragmentProcessor>(new GrDitherEffect(range));
-}
+    return GrDitherEffect::Make();
+}
\ No newline at end of file