Add caps and GL API for buffer texture

src/gpu/glsl/GrGLSLCaps.h

 /*
  * Copyright 2012 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 
 #ifndef GrGLSLCaps_DEFINED
 #define GrGLSLCaps_DEFINED
@@ skipping 48 matching lines @@
     bool noperspectiveInterpolationSupport() const { return fNoPerspectiveInterpolationSupport; }
 
     bool multisampleInterpolationSupport() const { return fMultisampleInterpolationSupport; }
 
     bool sampleVariablesSupport() const { return fSampleVariablesSupport; }
 
     bool sampleMaskOverrideCoverageSupport() const { return fSampleMaskOverrideCoverageSupport; }
 
     bool externalTextureSupport() const { return fExternalTextureSupport; }
 
+    bool bufferTextureSupport() const { return fBufferTextureSupport; }
+
     AdvBlendEqInteraction advBlendEqInteraction() const { return fAdvBlendEqInteraction; }
 
     bool mustEnableAdvBlendEqs() const {
         return fAdvBlendEqInteraction >= kGeneralEnable_AdvBlendEqInteraction;
     }
 
     bool mustEnableSpecificAdvBlendEqs() const {
         return fAdvBlendEqInteraction == kSpecificEnables_AdvBlendEqInteraction;
     }
     
@@ skipping 32 matching lines @@
     // source blending is supported.
     const char* secondaryOutputExtensionString() const {
         return fSecondaryOutputExtensionString;
     }
 
     const char* externalTextureExtensionString() const {
         SkASSERT(this->externalTextureSupport());
         return fExternalTextureExtensionString;
     }
 
+    const char* bufferTextureExtensionString() const {
+        SkASSERT(this->bufferTextureSupport());
+        return fBufferTextureExtensionString;
+    }
+
     const char* noperspectiveInterpolationExtensionString() const {
         SkASSERT(this->noperspectiveInterpolationSupport());
         return fNoPerspectiveInterpolationExtensionString;
     }
 
     const char* multisampleInterpolationExtensionString() const {
         SkASSERT(this->multisampleInterpolationSupport());
         return fMultisampleInterpolationExtensionString;
     }
 
@@ skipping 41 matching lines @@
     bool fFBFetchNeedsCustomOutput : 1;
     bool fBindlessTextureSupport : 1;
     bool fUsesPrecisionModifiers : 1;
     bool fCanUseAnyFunctionInShader : 1;
     bool fFlatInterpolationSupport : 1;
     bool fNoPerspectiveInterpolationSupport : 1;
     bool fMultisampleInterpolationSupport : 1;
     bool fSampleVariablesSupport : 1;
     bool fSampleMaskOverrideCoverageSupport : 1;
     bool fExternalTextureSupport : 1;
+    bool fBufferTextureSupport : 1;
 
     // Used for specific driver bug work arounds
     bool fCanUseMinAndAbsTogether : 1;
     bool fMustForceNegatedAtanParamToFloat : 1;
 
     const char* fVersionDeclString;
 
     const char* fShaderDerivativeExtensionString;
     const char* fFragCoordConventionsExtensionString;
     const char* fSecondaryOutputExtensionString;
     const char* fExternalTextureExtensionString;
+    const char* fBufferTextureExtensionString;
     const char* fNoPerspectiveInterpolationExtensionString;
     const char* fMultisampleInterpolationExtensionString;
     const char* fSampleVariablesExtensionString;
 
     const char* fFBFetchColorName;
     const char* fFBFetchExtensionString;
 
     uint8_t fMaxVertexSamplers;
     uint8_t fMaxGeometrySamplers;
     uint8_t fMaxFragmentSamplers;
     uint8_t fMaxCombinedSamplers;
 
     AdvBlendEqInteraction fAdvBlendEqInteraction;
 
     GrSwizzle fConfigTextureSwizzle[kGrPixelConfigCnt];
     GrSwizzle fConfigOutputSwizzle[kGrPixelConfigCnt];
 
     friend class GrGLCaps;  // For initialization.
     friend class GrVkCaps;
 
     typedef GrShaderCaps INHERITED;
 };
 
 #endif