commit 33aa2c7b5c351c17a11ce2bf7d7cd70a3d86cecc
author Brian Osman <brianosman@google.com> Wed Apr 05 09:26:15 2017 -0400
committer Skia Commit-Bot <skia-commit-bot@chromium.org> Wed Apr 05 14:00:50 2017 +0000
tree 6fbc30a47986750570d00026ddb3c89a0c3a55df
parent bf17eecf46b246d354b926aacc41e9ea882df49d

Allow FPs to elevate default precision for the entire fragment program

Currently, GrConfigConversionEffect is able to round-trip on many
mobile GPUs because it uses highp for all intermediate variables
(including the texture fetch result). Separating the texture sample
into a different processor breaks that.

This is a blunt instrument, not to be used lightly.

This reverts commit dffe9827b18444d1426859d9035f9f0087201f44.

Bug: skia:
Change-Id: I940af3256c47e6672a008d516db9e55669672ca3
Reviewed-on: https://skia-review.googlesource.com/11345
Reviewed-by: Brian Salomon <bsalomon@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>

src/gpu/glsl/GrGLSLFragmentShaderBuilder.cpp

diff --git a/src/gpu/glsl/GrGLSLFragmentShaderBuilder.cpp b/src/gpu/glsl/GrGLSLFragmentShaderBuilder.cpp
index a1f5173..484bd78 100644
--- a/src/gpu/glsl/GrGLSLFragmentShaderBuilder.cpp
+++ b/src/gpu/glsl/GrGLSLFragmentShaderBuilder.cpp
@@ -85,7 +85,8 @@
     , fCustomColorOutputIndex(-1)
     , fHasSecondaryOutput(false)
     , fUsedSampleOffsetArrays(0)
-    , fHasInitializedSampleMask(false) {
+    , fHasInitializedSampleMask(false)
+    , fDefaultPrecision(kMedium_GrSLPrecision) {
     fSubstageIndices.push_back(0);
 #ifdef SK_DEBUG
     fUsedProcessorFeatures = GrProcessor::kNone_RequiredFeatures;
@@ -178,6 +179,10 @@
     fHasInitializedSampleMask = true;
 }
 
+void GrGLSLFragmentShaderBuilder::elevateDefaultPrecision(GrSLPrecision precision) {
+    fDefaultPrecision = SkTMax(fDefaultPrecision, precision);
+}
+
 const char* GrGLSLFragmentShaderBuilder::dstColor() {
     SkDEBUGCODE(fHasReadDstColor = true;)
 
@@ -279,7 +284,7 @@
 
 void GrGLSLFragmentShaderBuilder::onFinalize() {
     fProgramBuilder->varyingHandler()->getFragDecls(&this->inputs(), &this->outputs());
-    GrGLSLAppendDefaultFloatPrecisionDeclaration(kDefault_GrSLPrecision,
+    GrGLSLAppendDefaultFloatPrecisionDeclaration(fDefaultPrecision,
                                                  *fProgramBuilder->shaderCaps(),
                                                  &this->precisionQualifier());
     if (fUsedSampleOffsetArrays & (1 << kSkiaDevice_Coordinates)) {