Home | History | Annotate | Download | only in glsl 
      1 /*
      2  * Copyright 2013 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 #ifndef GrGLSLPrimitiveProcessor_DEFINED
      9 #define GrGLSLPrimitiveProcessor_DEFINED
     10 
     11 #include "GrFragmentProcessor.h"
     12 #include "GrPrimitiveProcessor.h"
     13 #include "glsl/GrGLSLProgramDataManager.h"
     14 #include "glsl/GrGLSLUniformHandler.h"
     15 
     16 class GrPrimitiveProcessor;
     17 class GrGLSLFPFragmentBuilder;
     18 class GrGLSLGeometryBuilder;
     19 class GrGLSLGPBuilder;
     20 class GrGLSLVaryingHandler;
     21 class GrGLSLVertexBuilder;
     22 class GrShaderCaps;
     23 
     24 class GrGLSLPrimitiveProcessor {
     25 public:
     26     using FPCoordTransformIter = GrFragmentProcessor::CoordTransformIter;
     27 
     28     virtual ~GrGLSLPrimitiveProcessor() {}
     29 
     30     using UniformHandle      = GrGLSLProgramDataManager::UniformHandle;
     31     using SamplerHandle      = GrGLSLUniformHandler::SamplerHandle;
     32 
     33     /**
     34      * This class provides access to the GrCoordTransforms across all GrFragmentProcessors in a
     35      * GrPipeline. It is also used by the primitive processor to specify the fragment shader
     36      * variable that will hold the transformed coords for each GrCoordTransform. It is required that
     37      * the primitive processor iterate over each coord transform and insert a shader var result for
     38      * each. The GrGLSLFragmentProcessors will reference these variables in their fragment code.
     39      */
     40     class FPCoordTransformHandler : public SkNoncopyable {
     41     public:
     42         FPCoordTransformHandler(const GrPipeline& pipeline,
     43                                 SkTArray<GrShaderVar>* transformedCoordVars)
     44                 : fIter(pipeline)
     45                 , fTransformedCoordVars(transformedCoordVars) {}
     46 
     47         ~FPCoordTransformHandler() { SkASSERT(!this->nextCoordTransform());}
     48 
     49         const GrCoordTransform* nextCoordTransform();
     50 
     51         // 'args' are constructor params to GrShaderVar.
     52         template<typename... Args>
     53         void specifyCoordsForCurrCoordTransform(Args&&... args) {
     54             SkASSERT(!fAddedCoord);
     55             fTransformedCoordVars->emplace_back(std::forward<Args>(args)...);
     56             SkDEBUGCODE(fAddedCoord = true;)
     57         }
     58 
     59     private:
     60         GrFragmentProcessor::CoordTransformIter fIter;
     61         SkDEBUGCODE(bool                        fAddedCoord = false;)
     62         SkDEBUGCODE(const GrCoordTransform*     fCurr = nullptr;)
     63         SkTArray<GrShaderVar>*                  fTransformedCoordVars;
     64     };
     65 
     66     struct EmitArgs {
     67         EmitArgs(GrGLSLVertexBuilder* vertBuilder,
     68                  GrGLSLGeometryBuilder* geomBuilder,
     69                  GrGLSLFPFragmentBuilder* fragBuilder,
     70                  GrGLSLVaryingHandler* varyingHandler,
     71                  GrGLSLUniformHandler* uniformHandler,
     72                  const GrShaderCaps* caps,
     73                  const GrPrimitiveProcessor& gp,
     74                  const char* outputColor,
     75                  const char* outputCoverage,
     76                  const char* rtAdjustName,
     77                  const SamplerHandle* texSamplers,
     78                  FPCoordTransformHandler* transformHandler)
     79             : fVertBuilder(vertBuilder)
     80             , fGeomBuilder(geomBuilder)
     81             , fFragBuilder(fragBuilder)
     82             , fVaryingHandler(varyingHandler)
     83             , fUniformHandler(uniformHandler)
     84             , fShaderCaps(caps)
     85             , fGP(gp)
     86             , fOutputColor(outputColor)
     87             , fOutputCoverage(outputCoverage)
     88             , fRTAdjustName(rtAdjustName)
     89             , fTexSamplers(texSamplers)
     90             , fFPCoordTransformHandler(transformHandler) {}
     91         GrGLSLVertexBuilder* fVertBuilder;
     92         GrGLSLGeometryBuilder* fGeomBuilder;
     93         GrGLSLFPFragmentBuilder* fFragBuilder;
     94         GrGLSLVaryingHandler* fVaryingHandler;
     95         GrGLSLUniformHandler* fUniformHandler;
     96         const GrShaderCaps* fShaderCaps;
     97         const GrPrimitiveProcessor& fGP;
     98         const char* fOutputColor;
     99         const char* fOutputCoverage;
    100         const char* fRTAdjustName;
    101         const SamplerHandle* fTexSamplers;
    102         FPCoordTransformHandler* fFPCoordTransformHandler;
    103     };
    104 
    105     /**
    106      * This is similar to emitCode() in the base class, except it takes a full shader builder.
    107      * This allows the effect subclass to emit vertex code.
    108      */
    109     virtual void emitCode(EmitArgs&) = 0;
    110 
    111     /**
    112      * A GrGLSLPrimitiveProcessor instance can be reused with any GrGLSLPrimitiveProcessor that
    113      * produces the same stage key; this function reads data from a GrGLSLPrimitiveProcessor and
    114      * uploads any uniform variables required  by the shaders created in emitCode(). The
    115      * GrPrimitiveProcessor parameter is guaranteed to be of the same type and to have an
    116      * identical processor key as the GrPrimitiveProcessor that created this
    117      * GrGLSLPrimitiveProcessor.
    118      * The subclass may use the transform iterator to perform any setup required for the particular
    119      * set of fp transform matrices, such as uploading via uniforms. The iterator will iterate over
    120      * the transforms in the same order as the TransformHandler passed to emitCode.
    121      */
    122     virtual void setData(const GrGLSLProgramDataManager&, const GrPrimitiveProcessor&,
    123                          FPCoordTransformIter&&) = 0;
    124 
    125     static SkMatrix GetTransformMatrix(const SkMatrix& localMatrix, const GrCoordTransform&);
    126 
    127 protected:
    128     void setupUniformColor(GrGLSLFPFragmentBuilder* fragBuilder,
    129                            GrGLSLUniformHandler* uniformHandler,
    130                            const char* outputName,
    131                            UniformHandle* colorUniform);
    132 };
    133 
    134 #endif
    135