commit ab8ce1a5ae0a0c87cb127634b9bdb94f3a17cec8
author Brian Osman <brianosman@google.com> Wed Apr 19 16:08:30 2017 -0400
committer Skia Commit-Bot <skia-commit-bot@chromium.org> Tue May 09 18:55:24 2017 +0000
tree e5f84361490be98a8f6a09a4a932987adc130fa7
parent 13dddce65fd87a8175a209a49f35615735a2886a

Fixed distance field interpolation for gamma correct rendering

Bug: skia:
Change-Id: I9037decfeb9b2ab673434bb3c4b7f55aca186d68
Reviewed-on: https://skia-review.googlesource.com/13872
Reviewed-by: Jim Van Verth <jvanverth@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>

src/gpu/effects/GrDistanceFieldGeoProc.cpp

diff --git a/src/gpu/effects/GrDistanceFieldGeoProc.cpp b/src/gpu/effects/GrDistanceFieldGeoProc.cpp
index 5ad2ef2..96d322f 100644
--- a/src/gpu/effects/GrDistanceFieldGeoProc.cpp
+++ b/src/gpu/effects/GrDistanceFieldGeoProc.cpp
@@ -163,7 +163,7 @@
         // mapped linearly to coverage, so use a linear step:
         if (isGammaCorrect) {
             fragBuilder->codeAppend(
-                "float val = clamp(distance + afwidth / (2.0 * afwidth), 0.0, 1.0);");
+                "float val = clamp((distance + afwidth) / (2.0 * afwidth), 0.0, 1.0);");
         } else {
             fragBuilder->codeAppend("float val = smoothstep(-afwidth, afwidth, distance);");
         }
@@ -419,7 +419,7 @@
         // mapped linearly to coverage, so use a linear step:
         if (isGammaCorrect) {
             fragBuilder->codeAppend(
-                "float val = clamp(distance + afwidth / (2.0 * afwidth), 0.0, 1.0);");
+                "float val = clamp((distance + afwidth) / (2.0 * afwidth), 0.0, 1.0);");
         } else {
             fragBuilder->codeAppend("float val = smoothstep(-afwidth, afwidth, distance);");
         }
@@ -713,7 +713,7 @@
         // mapped linearly to coverage, so use a linear step:
         if (isGammaCorrect) {
             fragBuilder->codeAppend("vec4 val = "
-                "vec4(clamp(distance + vec3(afwidth) / vec3(2.0 * afwidth), 0.0, 1.0), 1.0);");
+                "vec4(clamp((distance + vec3(afwidth)) / vec3(2.0 * afwidth), 0.0, 1.0), 1.0);");
         } else {
             fragBuilder->codeAppend(
                 "vec4 val = vec4(smoothstep(vec3(-afwidth), vec3(afwidth), distance), 1.0);");