added constant folding & branch elimination to skslc

src/gpu/glsl/GrGLSLShaderBuilder.cpp

 /*
  * Copyright 2014 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "GrShaderVar.h"
 #include "GrShaderCaps.h"
 #include "GrSwizzle.h"
@@ skipping 54 matching lines @@
     if (swizzle != GrSwizzle::RGBA()) {
         out->appendf(".%s", swizzle.c_str());
     }
 }
 
 void GrGLSLShaderBuilder::appendTextureLookup(SkString* out,
                                               SamplerHandle samplerHandle,
                                               const char* coordName,
                                               GrSLType varyingType) const {
     const GrShaderVar& sampler = fProgramBuilder->samplerVariable(samplerHandle);
-    GrSLType samplerType = sampler.getType();
-    if (samplerType == kTexture2DRectSampler_GrSLType) {
-        if (varyingType == kVec2f_GrSLType) {
-            out->appendf("texture(%s, textureSize(%s) * %s)",
-                         sampler.c_str(), sampler.c_str(), coordName);
-        } else {
-            out->appendf("texture(%s, vec3(textureSize(%s) * %s.xy, %s.z))",
-                         sampler.c_str(), sampler.c_str(), coordName, coordName);
-        }
-    } else {
-        out->appendf("texture(%s, %s)", sampler.c_str(), coordName);
-    }
+    out->appendf("texture(%s, %s)", sampler.c_str(), coordName);
     append_texture_swizzle(out, fProgramBuilder->samplerSwizzle(samplerHandle));
 }
 
 void GrGLSLShaderBuilder::appendTextureLookup(SamplerHandle samplerHandle,
                                               const char* coordName,
                                               GrSLType varyingType,
                                               GrGLSLColorSpaceXformHelper* colorXformHelper) {
     if (colorXformHelper && colorXformHelper->isValid()) {
         // With a color gamut transform, we need to wrap the lookup in another function call
         SkString lookup;
@@ skipping 139 matching lines @@
     // append the 'footer' to code
     this->code().append("}");
 
     for (int i = 0; i <= fCodeIndex; i++) {
         fCompilerStrings[i] = fShaderStrings[i].c_str();
         fCompilerStringLengths[i] = (int)fShaderStrings[i].size();
     }
 
     fFinalized = true;
 }