diff options
| author |  Brian Salomon <bsalomon@google.com> | 2017-07-17 16:44:32 -0400 |
|---|---|---|
| committer |  Skia Commit-Bot <skia-commit-bot@chromium.org> | 2017-07-18 12:40:16 +0000 |
| commit | cda20154b611c33b8fc8abf1f01d888166e19dcb (patch) | |
| tree | d482dd7f4728d321b3700cc1132b0f025699c473 /src/gpu | |
| parent | 0aa492d0f47d7becbd87c582a61591bdf2d17fa7 (diff) | |
Make dither range symmetric about 0
Change-Id: I0c2eec60beb665c7dca9b9fddc00ac112a1ff2e1
Reviewed-on: https://skia-review.googlesource.com/24121
Reviewed-by: Robert Phillips <robertphillips@google.com>
Commit-Queue: Brian Salomon <bsalomon@google.com>
Diffstat (limited to 'src/gpu')
| -rw-r--r-- | src/gpu/effects/GrDitherEffect.cpp | 2 | ||||
| -rw-r--r-- | src/gpu/effects/GrDitherEffect.fp | 4 |
2 files changed, 3 insertions, 3 deletions
diff --git a/src/gpu/effects/GrDitherEffect.cpp b/src/gpu/effects/GrDitherEffect.cpp index 370e0eedd1..052ed4e36d 100644 --- a/src/gpu/effects/GrDitherEffect.cpp +++ b/src/gpu/effects/GrDitherEffect.cpp @@ -23,7 +23,7 @@ public: GrGLSLFPFragmentBuilder* fragBuilder = args.fFragBuilder; const GrDitherEffect& _outer = args.fFp.cast<GrDitherEffect>(); (void) _outer; - fragBuilder->codeAppendf("float r = fract(sin(dot(sk_FragCoord.xy, vec2(12.989800000000001, 78.233000000000004))) * 43758.545299999998);\n%s = clamp(0.0039215686274509803 * vec4(r) + %s, 0.0, 1.0);\n", args.fOutputColor, args.fInputColor ? args.fInputColor : "vec4(1)"); + fragBuilder->codeAppendf("float r = fract(sin(dot(sk_FragCoord.xy, vec2(12.989800000000001, 78.233000000000004))) * 43758.545299999998) - 0.5;\n%s = clamp(0.0039215686274509803 * vec4(r) + %s, 0.0, 1.0);\n", args.fOutputColor, args.fInputColor ? args.fInputColor : "vec4(1)"); } private: void onSetData(const GrGLSLProgramDataManager& pdman, const GrFragmentProcessor& _proc) override { diff --git a/src/gpu/effects/GrDitherEffect.fp b/src/gpu/effects/GrDitherEffect.fp index 77ff009113..1c35b38cd2 100644 --- a/src/gpu/effects/GrDitherEffect.fp +++ b/src/gpu/effects/GrDitherEffect.fp @@ -8,8 +8,8 @@ void main() { // 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); - sk_OutColor = clamp(1.0 / 255.0 * vec4(r) + sk_InColor, 0, 1); + 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) { |