fullscreenShader.h

//
// Copyright 2018 Pixar
//
// Licensed under the terms set forth in the LICENSE.txt file available at
// https://openusd.org/license.
//
#ifndef PXR_IMAGING_HDX_FULLSCREENSHADER_H
#define PXR_IMAGING_HDX_FULLSCREENSHADER_H
 
#include "pxr/pxr.h"
 
#include "pxr/imaging/hdx/api.h"
#include "pxr/imaging/hdx/effectsShader.h"
 
#include "pxr/imaging/hgi/buffer.h"
#include "pxr/imaging/hgi/graphicsPipeline.h"
#include "pxr/imaging/hgi/shaderProgram.h"
#include "pxr/imaging/hgi/texture.h"
 
#include "pxr/base/gf/vec4i.h"
 
#include "pxr/base/tf/token.h"
 
#include <map>
#include <vector>
 
PXR_NAMESPACE_OPEN_SCOPE
 
class Hgi;
class HioGlslfx;
 
class HdxFullscreenShader : public HdxEffectsShader
{
public:
    HDX_API
    HdxFullscreenShader(Hgi* hgi, const std::string& debugName);
 
    HDX_API
    ~HdxFullscreenShader() override;
 
    HDX_API
    void SetProgram(
        const TfToken& glslfxPath,
        const TfToken& shaderName,
        HgiShaderFunctionDesc& fragDesc);
 
    HDX_API
    void SetProgram(
        const HgiShaderFunctionDesc& fragDesc);
 
    HDX_API
    void BindBuffers(HgiBufferHandleVector const& buffers);
 
    HDX_API
    void BindTextures(
        HgiTextureHandleVector const& textures,
        HgiSamplerHandleVector const& samplers = HgiSamplerHandleVector());
 
    HDX_API
    void SetDepthState(HgiDepthStencilState const& state);
 
    HDX_API
    void SetBlendState(
        bool enableBlending,
        HgiBlendFactor srcColorBlendFactor,
        HgiBlendFactor dstColorBlendFactor,
        HgiBlendOp colorBlendOp,
        HgiBlendFactor srcAlphaBlendFactor,
        HgiBlendFactor dstAlphaBlendFactor,
        HgiBlendOp alphaBlendOp);
 
    HDX_API
    void SetClearState(
        GfVec4f clearColor,
        GfVec4f clearDepth);
 
    HDX_API
    void SetShaderConstants(
        uint32_t byteSize,
        const void* data);
 
    HDX_API
    void Draw(HgiTextureHandle const& colorDst,
              HgiTextureHandle const& depthDst);
 
    HDX_API
    void Draw(HgiTextureHandle const& colorDst,
              HgiTextureHandle const& colorResolveDst,
              HgiTextureHandle const& depthDst,
              HgiTextureHandle const& depthResolveDst,
              GfVec4i const& viewport);
 
private:
    HdxFullscreenShader() = delete;
    HdxFullscreenShader(const HdxFullscreenShader&) = delete;
    HdxFullscreenShader& operator=(const HdxFullscreenShader&) = delete;
 
    // Utility function to create buffer resources.
    void _CreateBufferResources();
 
    // Utility to set resource bindings.
    void _SetResourceBindings();
 
    // Utility to create default vertex buffer descriptor.
    void _SetVertexBufferDescriptor();
 
    // Utility to create and get the default texture sampler.
    HgiSamplerHandle _GetDefaultSampler();
 
    // Utility to set the default program.
    void _SetDefaultProgram(bool writeDepth);
 
    // Internal draw method
    void _Draw(
        HgiTextureHandle const& colorDst,
        HgiTextureHandle const& colorResolveDst,
        HgiTextureHandle const& depthDst,
        HgiTextureHandle const& depthResolveDst,
        GfVec4i const &viewport);
 
    void _RecordDrawCmds() override;
 
    // Print shader compile errors.
    void _PrintCompileErrors();
 
    HgiTextureHandleVector _textures;
    HgiSamplerHandleVector _samplers;
    HgiBufferHandleVector _buffers;
 
    TfToken _glslfxPath;
    TfToken _shaderName;
 
    HgiBufferHandle _indexBuffer;
    HgiBufferHandle _vertexBuffer;
    HgiShaderProgramHandle _shaderProgram;
    HgiSamplerHandle _defaultSampler;
 
    HgiDepthStencilState _depthStencilState;
 
    HgiAttachmentDesc _colorAttachment;
    HgiAttachmentDesc _depthAttachment;
};
 
PXR_NAMESPACE_CLOSE_SCOPE
 
#endif // PXR_IMAGING_HDX_FULLSCREENSHADER_H