Create swizzle table inside of glsl caps

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 64 matching lines @@
     bool forceHighPrecisionNDSTransform() const { return fForceHighPrecisionNDSTransform; }
 
     // Returns the string of an extension that must be enabled in the shader to support
     // derivatives. If nullptr is returned then no extension needs to be enabled. Before calling
     // this function, the caller should check that shaderDerivativeSupport exists.
     const char* shaderDerivativeExtensionString() const {
         SkASSERT(this->shaderDerivativeSupport());
         return fShaderDerivativeExtensionString;
     }
 
+    bool mustSwizzleInShader() const { return fMustSwizzleInShader; }
+
+    /**
+     * Returns a string which represents how to map from an internal GLFormat to a given
+     * GrPixelConfig. A draw side swizzle will then use this mapping to correctly set components.
+     */
+    const char* getSwizzleMap(GrPixelConfig config) const { return fConfigSwizzle[config]; }

[bsalomon, 2015/11/03 14:45:51]

Maybe change the last sentence to something like "mustSwizzleInShader()
determines whether this swizzle is applied in generated shader code or using
sampler state in the 3D API."?

[egdaniel, 2015/11/03 15:23:56]

Done.

+
     GrGLSLGeneration generation() const { return fGLSLGeneration; }
 
     /**
     * Returns a string containing the caps info.
     */
     SkString dump() const override;
 
 private:
+    void onApplyOptionsOverrides(const GrContextOptions& options) override;
+
     GrGLSLGeneration fGLSLGeneration;
     
     bool fDropsTileOnZeroDivide : 1;
     bool fFBFetchSupport : 1;
     bool fFBFetchNeedsCustomOutput : 1;
     bool fBindlessTextureSupport : 1;
     bool fUsesPrecisionModifiers : 1;
     bool fCanUseAnyFunctionInShader : 1;
     bool fForceHighPrecisionNDSTransform : 1;
 
     const char* fVersionDeclString;
 
     const char* fShaderDerivativeExtensionString;
 
     const char* fFBFetchColorName;
     const char* fFBFetchExtensionString;
 
     AdvBlendEqInteraction fAdvBlendEqInteraction;
 
+    bool        fMustSwizzleInShader;
+    const char* fConfigSwizzle[kGrPixelConfigCnt];
+
     friend class GrGLCaps;  // For initialization.
 
     typedef GrShaderCaps INHERITED;
 };
 
 
 #endif