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      1 /*
      2  * Copyright 2015 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 GrGLSLUniformHandler_DEFINED
      9 #define GrGLSLUniformHandler_DEFINED
     10 
     11 #include "GrGLSLProgramDataManager.h"
     12 #include "GrShaderVar.h"
     13 #include "GrSwizzle.h"
     14 
     15 // variable names beginning with this prefix will not be mangled
     16 #define GR_NO_MANGLE_PREFIX "sk_"
     17 
     18 class GrGLSLProgramBuilder;
     19 class GrSamplerState;
     20 class GrTexture;
     21 
     22 // Handles for program uniforms (other than per-effect uniforms)
     23 struct GrGLSLBuiltinUniformHandles {
     24     GrGLSLProgramDataManager::UniformHandle fRTAdjustmentUni;
     25     // Render target width, used to implement sk_Width
     26     GrGLSLProgramDataManager::UniformHandle fRTWidthUni;
     27     // Render target height, used to implement sk_Height and to calculate sk_FragCoord when
     28     // origin_upper_left is not supported.
     29     GrGLSLProgramDataManager::UniformHandle fRTHeightUni;
     30 };
     31 
     32 class GrGLSLUniformHandler {
     33 public:
     34     virtual ~GrGLSLUniformHandler() {}
     35 
     36     using UniformHandle = GrGLSLProgramDataManager::UniformHandle;
     37 
     38     GR_DEFINE_RESOURCE_HANDLE_CLASS(SamplerHandle);
     39 
     40     /** Add a uniform variable to the current program, that has visibility in one or more shaders.
     41         visibility is a bitfield of GrShaderFlag values indicating from which shaders the uniform
     42         should be accessible. At least one bit must be set. Geometry shader uniforms are not
     43         supported at this time. The actual uniform name will be mangled. If outName is not nullptr
     44         then it will refer to the final uniform name after return. Use the addUniformArray variant
     45         to add an array of uniforms. */
     46     UniformHandle addUniform(uint32_t visibility,
     47                              GrSLType type,
     48                              GrSLPrecision precision,
     49                              const char* name,
     50                              const char** outName = nullptr) {
     51         SkASSERT(!GrSLTypeIsCombinedSamplerType(type));
     52         return this->addUniformArray(visibility, type, precision, name, 0, outName);
     53     }
     54 
     55     UniformHandle addUniform(uint32_t visibility,
     56                              GrSLType type,
     57                              const char* name,
     58                              const char** outName = nullptr) {
     59         return this->addUniform(visibility, type, kDefault_GrSLPrecision, name, outName);
     60     }
     61 
     62     UniformHandle addUniformArray(uint32_t visibility,
     63                                   GrSLType type,
     64                                   GrSLPrecision precision,
     65                                   const char* name,
     66                                   int arrayCount,
     67                                   const char** outName = nullptr) {
     68         SkASSERT(!GrSLTypeIsCombinedSamplerType(type));
     69         bool mangle = strncmp(name, GR_NO_MANGLE_PREFIX, strlen(GR_NO_MANGLE_PREFIX));
     70         return this->internalAddUniformArray(visibility, type, precision, name, mangle, arrayCount,
     71                                              outName);
     72     }
     73 
     74     UniformHandle addUniformArray(uint32_t visibility,
     75                                   GrSLType type,
     76                                   const char* name,
     77                                   int arrayCount,
     78                                   const char** outName = nullptr) {
     79         SkASSERT(!GrSLTypeIsCombinedSamplerType(type));
     80         bool mangle = strncmp(name, GR_NO_MANGLE_PREFIX, strlen(GR_NO_MANGLE_PREFIX));
     81         return this->internalAddUniformArray(visibility, type, kDefault_GrSLPrecision, name, mangle,
     82                                              arrayCount, outName);
     83     }
     84 
     85     virtual const GrShaderVar& getUniformVariable(UniformHandle u) const = 0;
     86 
     87     /**
     88      * Shortcut for getUniformVariable(u).c_str()
     89      */
     90     virtual const char* getUniformCStr(UniformHandle u) const = 0;
     91 
     92 protected:
     93     explicit GrGLSLUniformHandler(GrGLSLProgramBuilder* program) : fProgramBuilder(program) {}
     94 
     95     // This is not owned by the class
     96     GrGLSLProgramBuilder* fProgramBuilder;
     97 
     98 private:
     99     virtual const GrShaderVar& samplerVariable(SamplerHandle) const = 0;
    100     virtual GrSwizzle samplerSwizzle(SamplerHandle) const = 0;
    101 
    102     virtual SamplerHandle addSampler(const GrTexture*, const GrSamplerState&, const char* name,
    103                                      const GrShaderCaps*) = 0;
    104 
    105     virtual UniformHandle internalAddUniformArray(uint32_t visibility,
    106                                                   GrSLType type,
    107                                                   GrSLPrecision precision,
    108                                                   const char* name,
    109                                                   bool mangleName,
    110                                                   int arrayCount,
    111                                                   const char** outName) = 0;
    112 
    113     virtual void appendUniformDecls(GrShaderFlags visibility, SkString*) const = 0;
    114 
    115     friend class GrGLSLProgramBuilder;
    116 };
    117 
    118 #endif
    119