commit 5a9a9b8d5bd9f2833cd4f346d916d6be5ee736e0
author Ethan Nicholas <ethannicholas@google.com> Fri Sep 20 12:59:22 2019 -0400
committer Skia Commit-Bot <skia-commit-bot@chromium.org> Fri Sep 20 16:59:58 2019 +0000
tree c0a1eba2c92c9e82508450465399a58cd840908c
parent 6934d75b55384b4aab391ec0bfdf772529e8e2de

Revert "added support for SkSL unpremul function"

This reverts commit ffdc3e668061cff14ea55ba087e9105f2ff219fc.

Reason for revert: breaking Chrome roll

Original change's description:
> added support for SkSL unpremul function
> 
> Change-Id: I970f1ad0dd0859448c874498fe02342f8abc3aa3
> Reviewed-on: https://skia-review.googlesource.com/c/skia/+/242897
> Reviewed-by: Brian Salomon <bsalomon@google.com>
> Commit-Queue: Ethan Nicholas <ethannicholas@google.com>

TBR=bsalomon@google.com,brianosman@google.com,ethannicholas@google.com

Change-Id: I72dacea82b1f4ea2aa6cd600122a4810657aa32e
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/243117
Reviewed-by: Ethan Nicholas <ethannicholas@google.com>
Commit-Queue: Ethan Nicholas <ethannicholas@google.com>

src/gpu/glsl/GrGLSLShaderBuilder.cpp

diff --git a/src/gpu/glsl/GrGLSLShaderBuilder.cpp b/src/gpu/glsl/GrGLSLShaderBuilder.cpp
index a75479d..a87d591 100644
--- a/src/gpu/glsl/GrGLSLShaderBuilder.cpp
+++ b/src/gpu/glsl/GrGLSLShaderBuilder.cpp
@@ -159,7 +159,8 @@
         const GrShaderVar gColorXformArgs[] = { GrShaderVar("color", kHalf4_GrSLType) };
         SkString body;
         if (colorXformHelper->applyUnpremul()) {
-            body.append("color = unpremul(color);");
+            body.append("half nonZeroAlpha = max(color.a, 0.0001);");
+            body.append("color = half4(color.rgb / nonZeroAlpha, nonZeroAlpha);");
         }
         if (colorXformHelper->applySrcTF()) {
             body.appendf("color.r = %s(color.r);", srcTFFuncName.c_str());