src/dawn/native/opengl/PipelineGL.h

// Copyright 2017 The Dawn & Tint Authors
//
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//    this list of conditions and the following disclaimer in the documentation
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#ifndef SRC_DAWN_NATIVE_OPENGL_PIPELINEGL_H_
#define SRC_DAWN_NATIVE_OPENGL_PIPELINEGL_H_

#include <utility>
#include <vector>

#include "dawn/native/Pipeline.h"

#include "include/tint/tint.h"

#include "dawn/native/PerStage.h"
#include "dawn/native/opengl/BindingPoint.h"
#include "dawn/native/opengl/opengl_platform.h"

namespace dawn::native {
struct ProgrammableStage;
}  // namespace dawn::native

namespace dawn::native::opengl {

struct OpenGLFunctions;
class PipelineLayout;
class Sampler;
class Buffer;
class TextureView;

class PipelineGL {
  public:
    PipelineGL();
    ~PipelineGL();

    // For each unit a sampler is bound to we need to know if we should use filtering or not
    // because int and uint texture are only complete without filtering.
    struct SamplerUnit {
        GLuint unit;
        bool shouldUseFiltering;
    };
    const std::vector<SamplerUnit>& GetTextureUnitsForSampler(GLuint index) const;
    const std::vector<GLuint>& GetTextureUnitsForTextureView(GLuint index) const;
    GLuint GetProgramHandle() const;

    const Buffer* GetInternalUniformBuffer() const;
    const BindingPointToFunctionAndOffset& GetBindingPointBuiltinDataInfo() const;

  protected:
    void ApplyNow(const OpenGLFunctions& gl);
    MaybeError InitializeBase(const OpenGLFunctions& gl,
                              const PipelineLayout* layout,
                              const PerStage<ProgrammableStage>& stages,
                              bool usesInstanceIndex,
                              bool usesFragDepth);
    void DeleteProgram(const OpenGLFunctions& gl);

  private:
    GLuint mProgram;
    std::vector<std::vector<SamplerUnit>> mUnitsForSamplers;
    std::vector<std::vector<GLuint>> mUnitsForTextures;
    std::vector<GLuint> mPlaceholderSamplerUnits;
    // TODO(enga): This could live on the Device, or elsewhere, but currently it makes Device
    // destruction complex as it requires the sampler to be destroyed before the sampler cache.
    Ref<Sampler> mPlaceholderSampler;

    // Maintain an internal uniform buffer to store extra information needed by shader emulation.
    GLuint mInternalUniformBufferBinding;
    bool mNeedsTextureBuiltinUniformBuffer;
    Ref<Buffer> mTextureBuiltinsBuffer;

    // Reflect info from tint: a map from texture binding point to extra data need to push into the
    // internal uniform buffer.
    BindingPointToFunctionAndOffset mBindingPointEmulatedBuiltins;
};

}  // namespace dawn::native::opengl

#endif  // SRC_DAWN_NATIVE_OPENGL_PIPELINEGL_H_