Add gl_SampleMask functionality to fragment builders

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 40 matching lines @@
     const char* fbFetchColorName() const { return fFBFetchColorName; }
 
     const char* fbFetchExtensionString() const { return fFBFetchExtensionString; }
 
     bool dropsTileOnZeroDivide() const { return fDropsTileOnZeroDivide; }
 
     bool flatInterpolationSupport() const { return fFlatInterpolationSupport; }
 
     bool noperspectiveInterpolationSupport() const { return fNoPerspectiveInterpolationSupport; }
 
+    bool sampleVariablesSupport() const { return fSampleVariablesSupport; }
+
+    bool sampleMaskOverrideCoverageSupport() const { return fSampleMaskOverrideCoverageSupport; }
+
     AdvBlendEqInteraction advBlendEqInteraction() const { return fAdvBlendEqInteraction; }
 
     bool mustEnableAdvBlendEqs() const {
         return fAdvBlendEqInteraction >= kGeneralEnable_AdvBlendEqInteraction;
     }
 
     bool mustEnableSpecificAdvBlendEqs() const {
         return fAdvBlendEqInteraction == kSpecificEnables_AdvBlendEqInteraction;
     }
     
@@ skipping 10 matching lines @@
 
     bool mustForceNegatedAtanParamToFloat() const { return fMustForceNegatedAtanParamToFloat; }
 
     // 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;
     }
-    
+
     // Returns the string of an extension that will do all necessary coord transfomations needed
     // when reading the fragment position. If such an extension does not exisits, this function
     // returns a nullptr, and all transforms of the frag position must be done manually in the
     // shader.
     const char* fragCoordConventionsExtensionString() const {
         return fFragCoordConventionsExtensionString;
     }
 
     // This returns the name of an extension that must be enabled in the shader, if such a thing is
     // required in order to use a secondary output in the shader. This returns a nullptr if no such
     // extension is required. However, the return value of this function does not say whether dual
     // source blending is supported.
     const char* secondaryOutputExtensionString() const {
         return fSecondaryOutputExtensionString;
     }
 
     const char* externalTextureExtensionString() const {
         return fExternalTextureExtensionString;
     }
 
     const char* noperspectiveInterpolationExtensionString() const {
         SkASSERT(this->noperspectiveInterpolationSupport());
         return fNoPerspectiveInterpolationExtensionString;
     }
 
+    const char* sampleVariablesExtensionString() const {
+        SkASSERT(this->sampleVariablesSupport());
+        return fSampleVariablesExtensionString;
+    }
+
     /**
      * Given a texture's config, this determines what swizzle must be appended to accesses to the
      * texture in generated shader code. Swizzling may be implemented in texture parameters or a
      * sampler rather than in the shader. In this case the returned swizzle will always be "rgba".
      */
     const GrSwizzle& configTextureSwizzle(GrPixelConfig config) const {
         return fConfigTextureSwizzle[config];
     }
 
     /** Swizzle that should occur on the fragment shader outputs for a given config. */
@@ skipping 14 matching lines @@
     GrGLSLGeneration fGLSLGeneration;
     
     bool fDropsTileOnZeroDivide : 1;
     bool fFBFetchSupport : 1;
     bool fFBFetchNeedsCustomOutput : 1;
     bool fBindlessTextureSupport : 1;
     bool fUsesPrecisionModifiers : 1;
     bool fCanUseAnyFunctionInShader : 1;
     bool fFlatInterpolationSupport : 1;
     bool fNoPerspectiveInterpolationSupport : 1;
+    bool fSampleVariablesSupport : 1;
+    bool fSampleMaskOverrideCoverageSupport : 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* fNoPerspectiveInterpolationExtensionString;
+    const char* fSampleVariablesExtensionString;
 
     const char* fFBFetchColorName;
     const char* fFBFetchExtensionString;
 
     AdvBlendEqInteraction fAdvBlendEqInteraction;
 
     GrSwizzle fConfigTextureSwizzle[kGrPixelConfigCnt];
     GrSwizzle fConfigOutputSwizzle[kGrPixelConfigCnt];
 
     friend class GrGLCaps;  // For initialization.
     friend class GrVkCaps;
 
     typedef GrShaderCaps INHERITED;
 };
 
 #endif