| /* |
| * 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 "GrCustomStage.h" |
| #include "gl/GrGLShaderVar.h" |
| #include "gl/GrGLSL.h" |
| #include "gl/GrGLUniformManager.h" |
| |
| class GrGLContextInfo; |
| |
| /** |
| Contains all the incremental state of a shader as it is being built,as well as helpers to |
| manipulate that state. |
| */ |
| class GrGLShaderBuilder { |
| public: |
| /** |
| * Used by GrGLProgramStages to add texture reads to their shader code. |
| */ |
| class TextureSampler { |
| public: |
| TextureSampler() |
| : fTextureAccess(NULL) |
| , fSamplerUniform(GrGLUniformManager::kInvalidUniformHandle) {} |
| |
| TextureSampler(const TextureSampler& other) { *this = other; } |
| |
| TextureSampler& operator= (const TextureSampler& other) { |
| GrAssert(NULL == fTextureAccess); |
| GrAssert(GrGLUniformManager::kInvalidUniformHandle == fSamplerUniform); |
| |
| fTextureAccess = other.fTextureAccess; |
| fSamplerUniform = other.fSamplerUniform; |
| return *this; |
| } |
| |
| const GrTextureAccess* textureAccess() const { return fTextureAccess; } |
| |
| private: |
| void init(GrGLShaderBuilder* builder, const GrTextureAccess* access) { |
| GrAssert(NULL == fTextureAccess); |
| GrAssert(GrGLUniformManager::kInvalidUniformHandle == fSamplerUniform); |
| |
| GrAssert(NULL != builder); |
| GrAssert(NULL != access); |
| fSamplerUniform = builder->addUniform(GrGLShaderBuilder::kFragment_ShaderType, |
| kSampler2D_GrSLType, |
| "Sampler"); |
| GrAssert(GrGLUniformManager::kInvalidUniformHandle != fSamplerUniform); |
| |
| fTextureAccess = access; |
| } |
| |
| const GrTextureAccess* fTextureAccess; |
| GrGLUniformManager::UniformHandle fSamplerUniform; |
| |
| friend class GrGLShaderBuilder; // to access fSamplerUniform |
| friend class GrGLProgram; // to construct these and access fSamplerUniform. |
| }; |
| |
| typedef SkTArray<TextureSampler> TextureSamplerArray; |
| |
| enum ShaderType { |
| kVertex_ShaderType = 0x1, |
| kGeometry_ShaderType = 0x2, |
| kFragment_ShaderType = 0x4, |
| }; |
| |
| GrGLShaderBuilder(const GrGLContextInfo&, GrGLUniformManager&); |
| |
| /** Determines whether we should use texture2D() or texture2Dproj(), and if an explicit divide |
| is required for the sample coordinates, creates the new variable and emits the code to |
| initialize it. This should only be called by GrGLProgram.*/ |
| void setupTextureAccess(const char* varyingFSName, GrSLType varyingType); |
| |
| /** Appends a texture sample with projection if necessary; if coordName is not |
| specified, uses fSampleCoords. 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 = NULL, |
| GrSLType coordType = kVec2f_GrSLType) const; |
| |
| /** 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 appendTextureLookupAndModulate(SkString* out, |
| const char* modulation, |
| const TextureSampler&, |
| const char* coordName = NULL, |
| GrSLType coordType = kVec2f_GrSLType) const; |
| |
| /** Gets the name of the default texture coords which are always kVec2f */ |
| const char* defaultTexCoordsName() const { return fDefaultTexCoordsName.c_str(); } |
| |
| /* Returns true if the texture matrix from which the default texture coords are computed has |
| perspective. */ |
| bool defaultTextureMatrixIsPerspective() const { |
| return fTexCoordVaryingType == kVec3f_GrSLType; |
| } |
| |
| /** Emits a helper function outside of main(). Currently ShaderType must be |
| kFragment_ShaderType. */ |
| void emitFunction(ShaderType shader, |
| GrSLType returnType, |
| const char* name, |
| int argCnt, |
| const GrGLShaderVar* args, |
| const char* body, |
| SkString* outName); |
| |
| /** Generates a StageKey for the shader code based on the texture access parameters and the |
| capabilities of the GL context. This is useful for keying the shader programs that may |
| have multiple representations, based on the type/format of textures used. */ |
| static GrCustomStage::StageKey KeyForTextureAccess(const GrTextureAccess& access, |
| const GrGLCaps& caps); |
| |
| /** 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 visibilty in one or more shaders. |
| visibility is a bitfield of ShaderType 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) const; |
| |
| /** |
| * Shorcut for getUniformVariable(u).c_str() |
| */ |
| const char* getUniformCStr(GrGLUniformManager::UniformHandle u) const { |
| return this->getUniformVariable(u).c_str(); |
| } |
| |
| /** 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); |
| |
| /** Called after building is complete to get the final shader string. */ |
| void getShader(ShaderType, SkString*) const; |
| |
| /** |
| * TODO: Make this do all the compiling, linking, etc. Hide from the custom stages |
| */ |
| void finished(GrGLuint programID); |
| |
| /** |
| * Sets the current stage (used to make variable names unique). |
| * TODO: Hide from the custom stages |
| */ |
| void setCurrentStage(int stage) { fCurrentStage = stage; } |
| void setNonStage() { fCurrentStage = kNonStageIdx; } |
| |
| private: |
| |
| typedef GrTAllocator<GrGLShaderVar> VarArray; |
| |
| void appendDecls(const VarArray&, SkString*) const; |
| void appendUniformDecls(ShaderType, SkString*) const; |
| |
| typedef GrGLUniformManager::BuilderUniform BuilderUniform; |
| GrGLUniformManager::BuilderUniformArray fUniforms; |
| |
| // TODO: Everything below here private. |
| public: |
| |
| SkString fHeader; // VS+FS, GLSL version, etc |
| VarArray fVSAttrs; |
| VarArray fVSOutputs; |
| VarArray fGSInputs; |
| VarArray fGSOutputs; |
| VarArray fFSInputs; |
| SkString fGSHeader; // layout qualifiers specific to GS |
| VarArray fFSOutputs; |
| SkString fVSCode; |
| SkString fGSCode; |
| SkString fFSCode; |
| bool fUsesGS; |
| |
| private: |
| enum { |
| kNonStageIdx = -1, |
| }; |
| |
| const GrGLContextInfo& fContext; |
| GrGLUniformManager& fUniformManager; |
| int fCurrentStage; |
| SkString fFSFunctions; |
| |
| /// Per-stage settings - only valid while we're inside GrGLProgram::genStageCode(). |
| //@{ |
| GrSLType fTexCoordVaryingType; // the type, either Vec2f or Vec3f, of the coords passed |
| // as a varying from the VS to the FS. |
| SkString fDefaultTexCoordsName; // the name of the default 2D coords value. |
| //@} |
| |
| }; |
| |
| #endif |