commit 7b046312edd9219ba8e66c255f5347c000b69ee1
author Chris Dalton <csmartdalton@google.com> Fri Feb 02 11:06:30 2018 -0700
committer Skia Commit-Bot <skia-commit-bot@chromium.org> Fri Feb 02 18:43:29 2018 +0000
tree 1119465d75682b9d5952e30695033d1105a24c93
parent 7a9263906c677c0fa5636521e3cc58ba60837720

ccpr: Don't use flat interpolation when it is slow

Bug: skia:
Change-Id: I1bc087187541183fdbaa5f2b93e8b8d287ac8ef8
Reviewed-on: https://skia-review.googlesource.com/102100
Commit-Queue: Chris Dalton <csmartdalton@google.com>
Reviewed-by: Jim Van Verth <jvanverth@google.com>
Reviewed-by: Brian Salomon <bsalomon@google.com>

src/gpu/glsl/GrGLSLVarying.cpp

diff --git a/src/gpu/glsl/GrGLSLVarying.cpp b/src/gpu/glsl/GrGLSLVarying.cpp
index 5a57613..c5cef34 100644
--- a/src/gpu/glsl/GrGLSLVarying.cpp
+++ b/src/gpu/glsl/GrGLSLVarying.cpp
@@ -10,36 +10,44 @@
 #include "glsl/GrGLSLProgramBuilder.h"
 
 void GrGLSLVaryingHandler::addPassThroughAttribute(const GrGeometryProcessor::Attribute* input,
-                                                   const char* output) {
-    GrSLType type = GrVertexAttribTypeToSLType(input->fType);
-    GrGLSLVarying v(type);
-    this->addVarying(input->fName, &v);
-    this->writePassThroughAttribute(input, output, v);
-}
-
-void GrGLSLVaryingHandler::addFlatPassThroughAttribute(const GrGeometryProcessor::Attribute* input,
-                                                       const char* output) {
-    GrSLType type = GrVertexAttribTypeToSLType(input->fType);
-    GrGLSLVarying v(type);
-    this->addFlatVarying(input->fName, &v);
-    this->writePassThroughAttribute(input, output, v);
-}
-
-void GrGLSLVaryingHandler::writePassThroughAttribute(const GrGeometryProcessor::Attribute* input,
-                                                     const char* output, const GrGLSLVarying& v) {
+                                                   const char* output,
+                                                   Interpolation interpolation) {
     SkASSERT(!fProgramBuilder->primitiveProcessor().willUseGeoShader());
+    GrSLType type = GrVertexAttribTypeToSLType(input->fType);
+    GrGLSLVarying v(type);
+    this->addVarying(input->fName, &v, interpolation);
     fProgramBuilder->fVS.codeAppendf("%s = %s;", v.vsOut(), input->fName);
     fProgramBuilder->fFS.codeAppendf("%s = %s;", output, v.fsIn());
 }
 
-void GrGLSLVaryingHandler::internalAddVarying(const char* name, GrGLSLVarying* varying, bool flat) {
+static bool use_flat_interpolation(GrGLSLVaryingHandler::Interpolation interpolation,
+                                   const GrShaderCaps& shaderCaps) {
+    switch (interpolation) {
+        using Interpolation = GrGLSLVaryingHandler::Interpolation;
+        case Interpolation::kInterpolated:
+            return false;
+        case Interpolation::kCanBeFlat:
+            SkASSERT(!shaderCaps.preferFlatInterpolation() ||
+                     shaderCaps.flatInterpolationSupport());
+            return shaderCaps.preferFlatInterpolation();
+        case Interpolation::kMustBeFlat:
+            SkASSERT(shaderCaps.flatInterpolationSupport());
+            return true;
+    }
+    SK_ABORT("Invalid interpolation");
+    return false;
+}
+
+void GrGLSLVaryingHandler::addVarying(const char* name, GrGLSLVarying* varying,
+                                      Interpolation interpolation) {
+    SkASSERT(GrSLTypeIsFloatType(varying->type()) || Interpolation::kMustBeFlat == interpolation);
     bool willUseGeoShader = fProgramBuilder->primitiveProcessor().willUseGeoShader();
     VaryingInfo& v = fVaryings.push_back();
 
     SkASSERT(varying);
     SkASSERT(kVoid_GrSLType != varying->fType);
     v.fType = varying->fType;
-    v.fIsFlat = flat;
+    v.fIsFlat = use_flat_interpolation(interpolation, *fProgramBuilder->shaderCaps());
     fProgramBuilder->nameVariable(&v.fVsOut, 'v', name);
     v.fVisibility = kNone_GrShaderFlags;
     if (varying->isInVertexShader()) {