src/gpu/GrSpirvUniformHandler.h

/*
 * Copyright 2019 Google Inc.
 *
 * Use of this source code is governed by a BSD-style license that can be
 * found in the LICENSE file.
 */

#ifndef GrSpirvUniformHandler_DEFINED
#define GrSpirvUniformHandler_DEFINED

#include "src/gpu/GrTAllocator.h"
#include "src/gpu/glsl/GrGLSLUniformHandler.h"

/*
 * This class can be used for basic spir-v uniform handling. It will make a single uniform buffer
 * for all the uniforms and will be placed in the first set and binding. Textures and samplers are
 * placed in the second set and kept as separate objects. They are interleaved as sampler texture
 * pairs with each object in the next binding slot.
 */
class GrSpirvUniformHandler : public GrGLSLUniformHandler {
public:
    static const int kUniformsPerBlock = 8;

    const GrShaderVar& getUniformVariable(UniformHandle u) const override;
    const char* getUniformCStr(UniformHandle u) const override;

    struct SpirvUniformInfo : public UniformInfo {
        int fUBOOffset;
    };
    typedef GrTAllocator<SpirvUniformInfo> UniformInfoArray;
    enum {
        kUniformBinding = 0,
        kUniformDescriptorSet = 0,
        kSamplerTextureDescriptorSet = 1,
    };
    uint32_t getRTHeightOffset() const;

    int numUniforms() const override {
        return fUniforms.count();
    }

    UniformInfo& uniform(int idx) override {
        return fUniforms.item(idx);
    }

private:
    explicit GrSpirvUniformHandler(GrGLSLProgramBuilder* program);

    SamplerHandle addSampler(const GrBackendFormat&, GrSamplerState, const GrSwizzle&,
                             const char* name, const GrShaderCaps*) override;
    const char* samplerVariable(SamplerHandle handle) const override;
    GrSwizzle samplerSwizzle(SamplerHandle handle) const override;
    void appendUniformDecls(GrShaderFlags visibility, SkString*) const override;
    UniformHandle internalAddUniformArray(const GrFragmentProcessor* owner,
                                          uint32_t visibility,
                                          GrSLType type,
                                          const char* name,
                                          bool mangleName,
                                          int arrayCount,
                                          const char** outName) override;

    UniformInfoArray    fUniforms;
    UniformInfoArray    fSamplers;
    UniformInfoArray    fTextures;
    SkTArray<GrSwizzle> fSamplerSwizzles;
    SkTArray<SkString>  fSamplerReferences;

    uint32_t fCurrentUBOOffset = 0;
    uint32_t fRTHeightOffset = 0;

    friend class GrD3DPipelineStateBuilder;
    friend class GrDawnProgramBuilder;

    typedef GrGLSLUniformHandler INHERITED;
};

#endif