diff -r 000000000000 -r 6474c204b198 gfx/skia/trunk/src/gpu/gl/GrGLShaderBuilder.h --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/gfx/skia/trunk/src/gpu/gl/GrGLShaderBuilder.h Wed Dec 31 06:09:35 2014 +0100 @@ -0,0 +1,475 @@ +/* + * 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 GrGLShaderBuilder_DEFINED +#define GrGLShaderBuilder_DEFINED + +#include "GrAllocator.h" +#include "GrBackendEffectFactory.h" +#include "GrColor.h" +#include "GrEffect.h" +#include "SkTypes.h" +#include "gl/GrGLProgramEffects.h" +#include "gl/GrGLSL.h" +#include "gl/GrGLUniformManager.h" + +#include + +class GrGLContextInfo; +class GrEffectStage; +class GrGLProgramDesc; + +/** + Contains all the incremental state of a shader as it is being built,as well as helpers to + manipulate that state. +*/ +class GrGLShaderBuilder { +public: + typedef GrTAllocator VarArray; + typedef GrBackendEffectFactory::EffectKey EffectKey; + typedef GrGLProgramEffects::TextureSampler TextureSampler; + typedef GrGLProgramEffects::TransformedCoordsArray TransformedCoordsArray; + typedef GrGLUniformManager::BuilderUniform BuilderUniform; + + enum ShaderVisibility { + kVertex_Visibility = 0x1, + kGeometry_Visibility = 0x2, + kFragment_Visibility = 0x4, + }; + + GrGLShaderBuilder(GrGpuGL*, GrGLUniformManager&, const GrGLProgramDesc&); + virtual ~GrGLShaderBuilder() {} + + /** + * Use of these features may require a GLSL extension to be enabled. Shaders may not compile + * if code is added that uses one of these features without calling enableFeature() + */ + enum GLSLFeature { + kStandardDerivatives_GLSLFeature = 0, + + kLastGLSLFeature = kStandardDerivatives_GLSLFeature + }; + + /** + * If the feature is supported then true is returned and any necessary #extension declarations + * are added to the shaders. If the feature is not supported then false will be returned. + */ + bool enableFeature(GLSLFeature); + + /** + * Called by GrGLEffects to add code the fragment shader. + */ + void fsCodeAppendf(const char format[], ...) SK_PRINTF_LIKE(2, 3) { + va_list args; + va_start(args, format); + fFSCode.appendVAList(format, args); + va_end(args); + } + + void fsCodeAppend(const char* str) { fFSCode.append(str); } + + /** Appends a 2D texture sample with projection if necessary. coordType must either be Vec2f or + Vec3f. The latter is interpreted as projective texture coords. The vec length and swizzle + order of the result depends on the GrTextureAccess associated with the TextureSampler. */ + void appendTextureLookup(SkString* out, + const TextureSampler&, + const char* coordName, + GrSLType coordType = kVec2f_GrSLType) const; + + /** Version of above that appends the result to the fragment shader code instead.*/ + void fsAppendTextureLookup(const TextureSampler&, + const char* coordName, + GrSLType coordType = kVec2f_GrSLType); + + + /** Does the work of appendTextureLookup and modulates the result by modulation. The result is + always a vec4. modulation and the swizzle specified by TextureSampler must both be vec4 or + float. If modulation is "" or NULL it this function acts as though appendTextureLookup were + called. */ + void fsAppendTextureLookupAndModulate(const char* modulation, + const TextureSampler&, + const char* coordName, + GrSLType coordType = kVec2f_GrSLType); + + /** Emits a helper function outside of main() in the fragment shader. */ + void fsEmitFunction(GrSLType returnType, + const char* name, + int argCnt, + const GrGLShaderVar* args, + const char* body, + SkString* outName); + + typedef uint8_t DstReadKey; + typedef uint8_t FragPosKey; + + /** Returns a key for adding code to read the copy-of-dst color in service of effects that + require reading the dst. It must not return 0 because 0 indicates that there is no dst + copy read at all (in which case this function should not be called). */ + static DstReadKey KeyForDstRead(const GrTexture* dstCopy, const GrGLCaps&); + + /** Returns a key for reading the fragment location. This should only be called if there is an + effect that will requires the fragment position. If the fragment position is not required, + the key is 0. */ + static FragPosKey KeyForFragmentPosition(const GrRenderTarget* dst, const GrGLCaps&); + + /** If texture swizzling is available using tex parameters then it is preferred over mangling + the generated shader code. This potentially allows greater reuse of cached shaders. */ + static const GrGLenum* GetTexParamSwizzle(GrPixelConfig config, const GrGLCaps& caps); + + /** Add a uniform variable to the current program, that has visibility in one or more shaders. + visibility is a bitfield of ShaderVisibility values indicating from which shaders the + uniform should be accessible. At least one bit must be set. Geometry shader uniforms are not + supported at this time. The actual uniform name will be mangled. If outName is not NULL then + it will refer to the final uniform name after return. Use the addUniformArray variant to add + an array of uniforms. + */ + GrGLUniformManager::UniformHandle addUniform(uint32_t visibility, + GrSLType type, + const char* name, + const char** outName = NULL) { + return this->addUniformArray(visibility, type, name, GrGLShaderVar::kNonArray, outName); + } + GrGLUniformManager::UniformHandle addUniformArray(uint32_t visibility, + GrSLType type, + const char* name, + int arrayCount, + const char** outName = NULL); + + const GrGLShaderVar& getUniformVariable(GrGLUniformManager::UniformHandle u) const { + return fUniformManager.getBuilderUniform(fUniforms, u).fVariable; + } + + /** + * Shortcut for getUniformVariable(u).c_str() + */ + const char* getUniformCStr(GrGLUniformManager::UniformHandle u) const { + return this->getUniformVariable(u).c_str(); + } + + /** + * This returns a variable name to access the 2D, perspective correct version of the coords in + * the fragment shader. If the coordinates at index are 3-dimensional, it immediately emits a + * perspective divide into the fragment shader (xy / z) to convert them to 2D. + */ + SkString ensureFSCoords2D(const TransformedCoordsArray&, int index); + + /** Returns a variable name that represents the position of the fragment in the FS. The position + is in device space (e.g. 0,0 is the top left and pixel centers are at half-integers). */ + const char* fragmentPosition(); + + /** Returns the color of the destination pixel. This may be NULL if no effect advertised + that it will read the destination. */ + const char* dstColor(); + + /** + * Interfaces used by GrGLProgram. + */ + const GrGLSLExpr4& getInputColor() const { + return fInputColor; + } + const GrGLSLExpr4& getInputCoverage() const { + return fInputCoverage; + } + + /** + * Adds code for effects and returns a GrGLProgramEffects* object. The caller is responsible for + * deleting it when finished. effectStages contains the effects to add. effectKeys[i] is the key + * generated from effectStages[i]. inOutFSColor specifies the input color to the first stage and + * is updated to be the output color of the last stage. + * The handles to texture samplers for effectStage[i] are added to + * effectSamplerHandles[i]. + */ + virtual GrGLProgramEffects* createAndEmitEffects(const GrEffectStage* effectStages[], + const EffectKey effectKeys[], + int effectCnt, + GrGLSLExpr4* inOutFSColor) = 0; + + const char* getColorOutputName() const; + const char* enableSecondaryOutput(); + + GrGLUniformManager::UniformHandle getRTHeightUniform() const { return fRTHeightUniform; } + GrGLUniformManager::UniformHandle getDstCopyTopLeftUniform() const { + return fDstCopyTopLeftUniform; + } + GrGLUniformManager::UniformHandle getDstCopyScaleUniform() const { + return fDstCopyScaleUniform; + } + GrGLUniformManager::UniformHandle getColorUniform() const { return fColorUniform; } + GrGLUniformManager::UniformHandle getCoverageUniform() const { return fCoverageUniform; } + GrGLUniformManager::UniformHandle getDstCopySamplerUniform() const { + return fDstCopySamplerUniform; + } + + bool finish(GrGLuint* outProgramId); + + const GrGLContextInfo& ctxInfo() const; + + /** + * Helper for begining and ending a block in the fragment code. TODO: Make GrGLShaderBuilder + * aware of all blocks and turn single \t's into the correct number of tabs (or spaces) so that + * our shaders print pretty without effect writers tracking indentation. + */ + class FSBlock { + public: + FSBlock(GrGLShaderBuilder* builder) : fBuilder(builder) { + SkASSERT(NULL != builder); + fBuilder->fsCodeAppend("\t{\n"); + } + + ~FSBlock() { + fBuilder->fsCodeAppend("\t}\n"); + } + private: + GrGLShaderBuilder* fBuilder; + }; + +protected: + GrGpuGL* gpu() const { return fGpu; } + + void setInputColor(const GrGLSLExpr4& inputColor) { fInputColor = inputColor; } + void setInputCoverage(const GrGLSLExpr4& inputCoverage) { fInputCoverage = inputCoverage; } + + /** Add input/output variable declarations (i.e. 'varying') to the fragment shader. */ + GrGLShaderVar& fsInputAppend() { return fFSInputs.push_back(); } + + // Generates a name for a variable. The generated string will be name prefixed by the prefix + // char (unless the prefix is '\0'). It also mangles the name to be stage-specific if we're + // generating stage code. + void nameVariable(SkString* out, char prefix, const char* name); + + // Helper for emitEffects(). + void createAndEmitEffects(GrGLProgramEffectsBuilder*, + const GrEffectStage* effectStages[], + const EffectKey effectKeys[], + int effectCnt, + GrGLSLExpr4* inOutFSColor); + + virtual bool compileAndAttachShaders(GrGLuint programId, SkTDArray* shaderIds) const; + virtual void bindProgramLocations(GrGLuint programId) const; + + void appendDecls(const VarArray&, SkString*) const; + void appendUniformDecls(ShaderVisibility, SkString*) const; + +private: + class CodeStage : public SkNoncopyable { + public: + CodeStage() : fNextIndex(0), fCurrentIndex(-1), fEffectStage(NULL) {} + + bool inStageCode() const { + this->validate(); + return NULL != fEffectStage; + } + + const GrEffectStage* effectStage() const { + this->validate(); + return fEffectStage; + } + + int stageIndex() const { + this->validate(); + return fCurrentIndex; + } + + class AutoStageRestore : public SkNoncopyable { + public: + AutoStageRestore(CodeStage* codeStage, const GrEffectStage* newStage) { + SkASSERT(NULL != codeStage); + fSavedIndex = codeStage->fCurrentIndex; + fSavedEffectStage = codeStage->fEffectStage; + + if (NULL == newStage) { + codeStage->fCurrentIndex = -1; + } else { + codeStage->fCurrentIndex = codeStage->fNextIndex++; + } + codeStage->fEffectStage = newStage; + + fCodeStage = codeStage; + } + ~AutoStageRestore() { + fCodeStage->fCurrentIndex = fSavedIndex; + fCodeStage->fEffectStage = fSavedEffectStage; + } + private: + CodeStage* fCodeStage; + int fSavedIndex; + const GrEffectStage* fSavedEffectStage; + }; + private: + void validate() const { SkASSERT((NULL == fEffectStage) == (-1 == fCurrentIndex)); } + int fNextIndex; + int fCurrentIndex; + const GrEffectStage* fEffectStage; + } fCodeStage; + + /** + * Features that should only be enabled by GrGLShaderBuilder itself. + */ + enum GLSLPrivateFeature { + kFragCoordConventions_GLSLPrivateFeature = kLastGLSLFeature + 1, + kEXTShaderFramebufferFetch_GLSLPrivateFeature, + kNVShaderFramebufferFetch_GLSLPrivateFeature, + }; + bool enablePrivateFeature(GLSLPrivateFeature); + + // If we ever have VS/GS features we can expand this to take a bitmask of ShaderVisibility and + // track the enables separately for each shader. + void addFSFeature(uint32_t featureBit, const char* extensionName); + + // Interpretation of DstReadKey when generating code + enum { + kNoDstRead_DstReadKey = 0, + kYesDstRead_DstReadKeyBit = 0x1, // Set if we do a dst-copy-read. + kUseAlphaConfig_DstReadKeyBit = 0x2, // Set if dst-copy config is alpha only. + kTopLeftOrigin_DstReadKeyBit = 0x4, // Set if dst-copy origin is top-left. + }; + + enum { + kNoFragPosRead_FragPosKey = 0, // The fragment positition will not be needed. + kTopLeftFragPosRead_FragPosKey = 0x1,// Read frag pos relative to top-left. + kBottomLeftFragPosRead_FragPosKey = 0x2,// Read frag pos relative to bottom-left. + }; + + GrGpuGL* fGpu; + GrGLUniformManager& fUniformManager; + uint32_t fFSFeaturesAddedMask; + SkString fFSFunctions; + SkString fFSExtensions; + VarArray fFSInputs; + VarArray fFSOutputs; + GrGLUniformManager::BuilderUniformArray fUniforms; + + SkString fFSCode; + + bool fSetupFragPosition; + GrGLUniformManager::UniformHandle fDstCopySamplerUniform; + + GrGLSLExpr4 fInputColor; + GrGLSLExpr4 fInputCoverage; + + bool fHasCustomColorOutput; + bool fHasSecondaryOutput; + + GrGLUniformManager::UniformHandle fRTHeightUniform; + GrGLUniformManager::UniformHandle fDstCopyTopLeftUniform; + GrGLUniformManager::UniformHandle fDstCopyScaleUniform; + GrGLUniformManager::UniformHandle fColorUniform; + GrGLUniformManager::UniformHandle fCoverageUniform; + + bool fTopLeftFragPosRead; +}; + +//////////////////////////////////////////////////////////////////////////////// + +class GrGLFullShaderBuilder : public GrGLShaderBuilder { +public: + GrGLFullShaderBuilder(GrGpuGL*, GrGLUniformManager&, const GrGLProgramDesc&); + + /** + * Called by GrGLEffects to add code to one of the shaders. + */ + void vsCodeAppendf(const char format[], ...) SK_PRINTF_LIKE(2, 3) { + va_list args; + va_start(args, format); + fVSCode.appendVAList(format, args); + va_end(args); + } + + void vsCodeAppend(const char* str) { fVSCode.append(str); } + + /** Add a vertex attribute to the current program that is passed in from the vertex data. + Returns false if the attribute was already there, true otherwise. */ + bool addAttribute(GrSLType type, const char* name); + + /** Add a varying variable to the current program to pass values between vertex and fragment + shaders. If the last two parameters are non-NULL, they are filled in with the name + generated. */ + void addVarying(GrSLType type, + const char* name, + const char** vsOutName = NULL, + const char** fsInName = NULL); + + /** Returns a vertex attribute that represents the vertex position in the VS. This is the + pre-matrix position and is commonly used by effects to compute texture coords via a matrix. + */ + const GrGLShaderVar& positionAttribute() const { return *fPositionVar; } + + /** Returns a vertex attribute that represents the local coords in the VS. This may be the same + as positionAttribute() or it may not be. It depends upon whether the rendering code + specified explicit local coords or not in the GrDrawState. */ + const GrGLShaderVar& localCoordsAttribute() const { return *fLocalCoordsVar; } + + /** + * Are explicit local coordinates provided as input to the vertex shader. + */ + bool hasExplicitLocalCoords() const { return (fLocalCoordsVar != fPositionVar); } + + bool addEffectAttribute(int attributeIndex, GrSLType type, const SkString& name); + const SkString* getEffectAttributeName(int attributeIndex) const; + + virtual GrGLProgramEffects* createAndEmitEffects( + const GrEffectStage* effectStages[], + const EffectKey effectKeys[], + int effectCnt, + GrGLSLExpr4* inOutFSColor) SK_OVERRIDE; + + GrGLUniformManager::UniformHandle getViewMatrixUniform() const { + return fViewMatrixUniform; + } + +protected: + virtual bool compileAndAttachShaders(GrGLuint programId, SkTDArray* shaderIds) const SK_OVERRIDE; + virtual void bindProgramLocations(GrGLuint programId) const SK_OVERRIDE; + +private: + const GrGLProgramDesc& fDesc; + VarArray fVSAttrs; + VarArray fVSOutputs; + VarArray fGSInputs; + VarArray fGSOutputs; + + SkString fVSCode; + + struct AttributePair { + void set(int index, const SkString& name) { + fIndex = index; fName = name; + } + int fIndex; + SkString fName; + }; + SkSTArray<10, AttributePair, true> fEffectAttributes; + + GrGLUniformManager::UniformHandle fViewMatrixUniform; + + GrGLShaderVar* fPositionVar; + GrGLShaderVar* fLocalCoordsVar; + + typedef GrGLShaderBuilder INHERITED; +}; + +//////////////////////////////////////////////////////////////////////////////// + +class GrGLFragmentOnlyShaderBuilder : public GrGLShaderBuilder { +public: + GrGLFragmentOnlyShaderBuilder(GrGpuGL*, GrGLUniformManager&, const GrGLProgramDesc&); + + int getNumTexCoordSets() const { return fNumTexCoordSets; } + int addTexCoordSets(int count); + + virtual GrGLProgramEffects* createAndEmitEffects( + const GrEffectStage* effectStages[], + const EffectKey effectKeys[], + int effectCnt, + GrGLSLExpr4* inOutFSColor) SK_OVERRIDE; + +private: + int fNumTexCoordSets; + + typedef GrGLShaderBuilder INHERITED; +}; + +#endif