Use noperspective interpolation for 2D draws

src/gpu/GrPathProcessor.cpp

 /*
 * Copyright 2013 Google Inc.
 *
 * Use of this source code is governed by a BSD-style license that can be
 * found in the LICENSE file.
 */
 
 #include "GrPathProcessor.h"
 
 #include "gl/GrGLGpu.h"
 #include "glsl/GrGLSLCaps.h"
 #include "glsl/GrGLSLFragmentShaderBuilder.h"
 #include "glsl/GrGLSLProcessorTypes.h"
 #include "glsl/GrGLSLUniformHandler.h"
 #include "glsl/GrGLSLVarying.h"
 
 class GrGLPathProcessor : public GrGLSLPrimitiveProcessor {
 public:
     GrGLPathProcessor() : fColor(GrColor_ILLEGAL) {}
 
     static void GenKey(const GrPathProcessor& pathProc,
                        const GrGLSLCaps&,
                        GrProcessorKeyBuilder* b) {
         b->add32(SkToInt(pathProc.overrides().readsColor()) |
-                 SkToInt(pathProc.overrides().readsCoverage()) << 16);
+                 (SkToInt(pathProc.overrides().readsCoverage()) << 1) |
+                 (SkToInt(pathProc.viewMatrix().hasPerspective()) << 2));
     }
 
     void emitCode(EmitArgs& args) override {
         GrGLSLFragmentBuilder* fragBuilder = args.fFragBuilder;
         const GrPathProcessor& pathProc = args.fGP.cast<GrPathProcessor>();
 
+        if (!pathProc.viewMatrix().hasPerspective()) {
+            args.fVaryingHandler->setNoPerspective();
+        }
+
         // emit transforms
         this->emitTransforms(args.fVaryingHandler, args.fTransformsIn, args.fTransformsOut);
 
         // Setup uniform color
         if (pathProc.overrides().readsColor()) {
             const char* stagedLocalVarName;
             fColorUniform = args.fUniformHandler->addUniform(kFragment_GrShaderFlag,
                                                              kVec4f_GrSLType,
                                                              kDefault_GrSLPrecision,
                                                              "Color",
@@ skipping 88 matching lines @@
 
 void GrPathProcessor::getGLSLProcessorKey(const GrGLSLCaps& caps,
                                           GrProcessorKeyBuilder* b) const {
     GrGLPathProcessor::GenKey(*this, caps, b);
 }
 
 GrGLSLPrimitiveProcessor* GrPathProcessor::createGLSLInstance(const GrGLSLCaps& caps) const {
     SkASSERT(caps.pathRenderingSupport());
     return new GrGLPathProcessor();
 }