Implement GL support for buffer textures

src/gpu/glsl/GrGLSLShaderBuilder.h

 /*
  * Copyright 2014 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef GrGLSLShaderBuilder_DEFINED
 #define GrGLSLShaderBuilder_DEFINED
 
@@ skipping 31 matching lines @@
 
     /** Does the work of appendTextureLookup and modulates the result by modulation. The result is
         always a vec4. modulation and the swizzle specified by GrGLSLTextureSampler must both be
         vec4 or float. If modulation is "" or nullptr it this function acts as though
         appendTextureLookup were called. */
     void appendTextureLookupAndModulate(const char* modulation,
                                         const GrGLSLTextureSampler&,
                                         const char* coordName,
                                         GrSLType coordType = kVec2f_GrSLType);
 
+    void appendTextureLookup(const GrGLSLTextureSampler& sampler, const GrGLSLShaderVar& coord) {
+        this->appendTextureLookup(sampler, coord.getName().c_str(), coord.getType());
+    }
+
+    void appendTextureLookupAndModulate(const char* modulation,
+                                        const GrGLSLTextureSampler& sampler,
+                                        const GrGLSLShaderVar& coord) {
+        this->appendTextureLookupAndModulate(modulation, sampler, coord.getName().c_str(),
+                                             coord.getType());
+    }
+
     /**
     * Adds a #define directive to the top of the shader.
     */
     void define(const char* macro, const char* replacement) {
         this->definitions().appendf("#define %s %s\n", macro, replacement);
     }
 
     void define(const char* macro, int replacement) {
         this->definitions().appendf("#define %s %i\n", macro, replacement);
     }
@@ skipping 71 matching lines @@
     void appendDecls(const VarArray& vars, SkString* out) const;
 
     /**
      * Features that should only be enabled internally by the builders.
      */
     enum GLSLPrivateFeature {
         kFragCoordConventions_GLSLPrivateFeature,
         kBlendEquationAdvanced_GLSLPrivateFeature,
         kBlendFuncExtended_GLSLPrivateFeature,
         kExternalTexture_GLSLPrivateFeature,
+        kBufferTexture_GLSLPrivateFeature,
         kFramebufferFetch_GLSLPrivateFeature,
         kNoPerspectiveInterpolation_GLSLPrivateFeature,
         kSampleVariables_GLSLPrivateFeature,
         kSampleMaskOverrideCoverage_GLSLPrivateFeature,
         kLastGLSLPrivateFeature = kSampleMaskOverrideCoverage_GLSLPrivateFeature
     };
 
     /*
      * A general function which enables an extension in a shader if the feature bit is not present
      *
@@ skipping 67 matching lines @@
     int fCodeIndex;
     bool fFinalized;
 
     friend class GrGLSLProgramBuilder;
     friend class GrGLProgramBuilder;
     friend class GrGLSLVaryingHandler; // to access noperspective interpolation feature.
     friend class GrGLPathProgramBuilder; // to access fInputs.
     friend class GrVkProgramBuilder;
 };
 #endif