1 /* 2 * Copyright 2012 Google Inc. 3 * 4 * Use of this source code is governed by a BSD-style license that can be 5 * found in the LICENSE file. 6 */ 7 8 9 #ifndef GrGLSLCaps_DEFINED 10 #define GrGLSLCaps_DEFINED 11 12 #include "GrCaps.h" 13 #include "GrGLSL.h" 14 #include "GrSwizzle.h" 15 16 class GrGLSLCaps : public GrShaderCaps { 17 public: 18 19 20 /** 21 * Indicates how GLSL must interact with advanced blend equations. The KHR extension requires 22 * special layout qualifiers in the fragment shader. 23 */ 24 enum AdvBlendEqInteraction { 25 kNotSupported_AdvBlendEqInteraction, //<! No _blend_equation_advanced extension 26 kAutomatic_AdvBlendEqInteraction, //<! No interaction required 27 kGeneralEnable_AdvBlendEqInteraction, //<! layout(blend_support_all_equations) out 28 kSpecificEnables_AdvBlendEqInteraction, //<! Specific layout qualifiers per equation 29 30 kLast_AdvBlendEqInteraction = kSpecificEnables_AdvBlendEqInteraction 31 }; 32 33 /** 34 * Initializes the GrGLSLCaps to a default set of features 35 */ 36 GrGLSLCaps(const GrContextOptions&); 37 38 /** 39 * Some helper functions for encapsulating various extensions to read FB Buffer on openglES 40 * 41 * TODO(joshualitt) On desktop opengl 4.2+ we can achieve something similar to this effect 42 */ 43 bool fbFetchSupport() const { return fFBFetchSupport; } 44 45 bool fbFetchNeedsCustomOutput() const { return fFBFetchNeedsCustomOutput; } 46 47 bool bindlessTextureSupport() const { return fBindlessTextureSupport; } 48 49 const char* versionDeclString() const { return fVersionDeclString; } 50 51 const char* fbFetchColorName() const { return fFBFetchColorName; } 52 53 const char* fbFetchExtensionString() const { return fFBFetchExtensionString; } 54 55 bool dropsTileOnZeroDivide() const { return fDropsTileOnZeroDivide; } 56 57 bool flatInterpolationSupport() const { return fFlatInterpolationSupport; } 58 59 bool noperspectiveInterpolationSupport() const { return fNoPerspectiveInterpolationSupport; } 60 61 bool sampleVariablesSupport() const { return fSampleVariablesSupport; } 62 63 bool sampleMaskOverrideCoverageSupport() const { return fSampleMaskOverrideCoverageSupport; } 64 65 AdvBlendEqInteraction advBlendEqInteraction() const { return fAdvBlendEqInteraction; } 66 67 bool mustEnableAdvBlendEqs() const { 68 return fAdvBlendEqInteraction >= kGeneralEnable_AdvBlendEqInteraction; 69 } 70 71 bool mustEnableSpecificAdvBlendEqs() const { 72 return fAdvBlendEqInteraction == kSpecificEnables_AdvBlendEqInteraction; 73 } 74 75 bool mustDeclareFragmentShaderOutput() const { 76 return fGLSLGeneration > k110_GrGLSLGeneration; 77 } 78 79 bool usesPrecisionModifiers() const { return fUsesPrecisionModifiers; } 80 81 // Returns whether we can use the glsl funciton any() in our shader code. 82 bool canUseAnyFunctionInShader() const { return fCanUseAnyFunctionInShader; } 83 84 bool canUseMinAndAbsTogether() const { return fCanUseMinAndAbsTogether; } 85 86 bool mustForceNegatedAtanParamToFloat() const { return fMustForceNegatedAtanParamToFloat; } 87 88 // Returns the string of an extension that must be enabled in the shader to support 89 // derivatives. If nullptr is returned then no extension needs to be enabled. Before calling 90 // this function, the caller should check that shaderDerivativeSupport exists. 91 const char* shaderDerivativeExtensionString() const { 92 SkASSERT(this->shaderDerivativeSupport()); 93 return fShaderDerivativeExtensionString; 94 } 95 96 // Returns the string of an extension that will do all necessary coord transfomations needed 97 // when reading the fragment position. If such an extension does not exisits, this function 98 // returns a nullptr, and all transforms of the frag position must be done manually in the 99 // shader. 100 const char* fragCoordConventionsExtensionString() const { 101 return fFragCoordConventionsExtensionString; 102 } 103 104 // This returns the name of an extension that must be enabled in the shader, if such a thing is 105 // required in order to use a secondary output in the shader. This returns a nullptr if no such 106 // extension is required. However, the return value of this function does not say whether dual 107 // source blending is supported. 108 const char* secondaryOutputExtensionString() const { 109 return fSecondaryOutputExtensionString; 110 } 111 112 const char* externalTextureExtensionString() const { 113 return fExternalTextureExtensionString; 114 } 115 116 const char* noperspectiveInterpolationExtensionString() const { 117 SkASSERT(this->noperspectiveInterpolationSupport()); 118 return fNoPerspectiveInterpolationExtensionString; 119 } 120 121 const char* sampleVariablesExtensionString() const { 122 SkASSERT(this->sampleVariablesSupport()); 123 return fSampleVariablesExtensionString; 124 } 125 126 /** 127 * Given a texture's config, this determines what swizzle must be appended to accesses to the 128 * texture in generated shader code. Swizzling may be implemented in texture parameters or a 129 * sampler rather than in the shader. In this case the returned swizzle will always be "rgba". 130 */ 131 const GrSwizzle& configTextureSwizzle(GrPixelConfig config) const { 132 return fConfigTextureSwizzle[config]; 133 } 134 135 /** Swizzle that should occur on the fragment shader outputs for a given config. */ 136 const GrSwizzle& configOutputSwizzle(GrPixelConfig config) const { 137 return fConfigOutputSwizzle[config]; 138 } 139 140 GrGLSLGeneration generation() const { return fGLSLGeneration; } 141 142 /** 143 * Returns a string containing the caps info. 144 */ 145 SkString dump() const override; 146 147 private: 148 void onApplyOptionsOverrides(const GrContextOptions& options) override; 149 150 GrGLSLGeneration fGLSLGeneration; 151 152 bool fDropsTileOnZeroDivide : 1; 153 bool fFBFetchSupport : 1; 154 bool fFBFetchNeedsCustomOutput : 1; 155 bool fBindlessTextureSupport : 1; 156 bool fUsesPrecisionModifiers : 1; 157 bool fCanUseAnyFunctionInShader : 1; 158 bool fFlatInterpolationSupport : 1; 159 bool fNoPerspectiveInterpolationSupport : 1; 160 bool fSampleVariablesSupport : 1; 161 bool fSampleMaskOverrideCoverageSupport : 1; 162 163 // Used for specific driver bug work arounds 164 bool fCanUseMinAndAbsTogether : 1; 165 bool fMustForceNegatedAtanParamToFloat : 1; 166 167 const char* fVersionDeclString; 168 169 const char* fShaderDerivativeExtensionString; 170 const char* fFragCoordConventionsExtensionString; 171 const char* fSecondaryOutputExtensionString; 172 const char* fExternalTextureExtensionString; 173 const char* fNoPerspectiveInterpolationExtensionString; 174 const char* fSampleVariablesExtensionString; 175 176 const char* fFBFetchColorName; 177 const char* fFBFetchExtensionString; 178 179 AdvBlendEqInteraction fAdvBlendEqInteraction; 180 181 GrSwizzle fConfigTextureSwizzle[kGrPixelConfigCnt]; 182 GrSwizzle fConfigOutputSwizzle[kGrPixelConfigCnt]; 183 184 friend class GrGLCaps; // For initialization. 185 friend class GrVkCaps; 186 187 typedef GrShaderCaps INHERITED; 188 }; 189 190 #endif 191
