boundingBoxTask.h

//
// Copyright 2022 Pixar
//
// Licensed under the terms set forth in the LICENSE.txt file available at
// https://openusd.org/license.
//
#ifndef HDX_BOUNDINGBOX_TASK_H
#define HDX_BOUNDINGBOX_TASK_H
 
#include "pxr/pxr.h"
 
#include "pxr/base/gf/matrix4f.h"
 
#include "pxr/imaging/hdx/api.h"
#include "pxr/imaging/hdx/task.h"
#include "pxr/imaging/hdx/tokens.h"
 
#include "pxr/imaging/hd/camera.h"
 
#include "pxr/imaging/hgi/attachmentDesc.h"
#include "pxr/imaging/hgi/buffer.h"
#include "pxr/imaging/hgi/graphicsCmds.h"
#include "pxr/imaging/hgi/graphicsPipeline.h"
#include "pxr/imaging/hgi/resourceBindings.h"
#include "pxr/imaging/hgi/shaderProgram.h"
#include "pxr/imaging/hgi/texture.h"
 
#include "pxr/usd/sdf/path.h"
 
PXR_NAMESPACE_OPEN_SCOPE
 
class HdStRenderPassState;
 
struct HdxBoundingBoxTaskParams
{
    using BBoxVector = std::vector<GfBBox3d>;
 
    HDX_API
    HdxBoundingBoxTaskParams()
        : aovName()
        , bboxes()
        , color(1)
        , dashSize(3)
        {}
 
    TfToken aovName;
 
    // Data provided by the application
    BBoxVector bboxes;
    GfVec4f color;
    float dashSize;
};
 
class HdxBoundingBoxTask : public HdxTask
{
public:
    using TaskParams = HdxBoundingBoxTaskParams;
 
    HDX_API
    HdxBoundingBoxTask(HdSceneDelegate* delegate, const SdfPath& id);
 
    HDX_API
    ~HdxBoundingBoxTask() override;
 
    HDX_API
    void Prepare(HdTaskContext* ctx,
                 HdRenderIndex* renderIndex) override;
 
    HDX_API
    void Execute(HdTaskContext* ctx) override;
 
protected:
    HDX_API
    void _Sync(HdSceneDelegate* delegate,
               HdTaskContext* ctx,
               HdDirtyBits* dirtyBits) override;
 
private:
    HdxBoundingBoxTask() = delete;
    HdxBoundingBoxTask(const HdxBoundingBoxTask&) = delete;
    HdxBoundingBoxTask &operator =(const HdxBoundingBoxTask&) = delete;
 
    // Utility function to create the shader for drawing dashed lines.
    bool _CreateShaderResources();
 
    // Utility function to create buffer resources.
    bool _CreateBufferResources();
 
    // Utility to create resource bindings
    bool _CreateResourceBindings();
 
    // Utility to create a pipeline.
    bool _CreatePipeline(
        const HgiTextureHandle& colorTexture,
        const HgiTextureHandle& depthTexture);
 
    // Utility to get the view and projection matrix from the camera.
    GfMatrix4d _ComputeViewProjectionMatrix(
        const HdStRenderPassState& hdStRenderPassState) const;
 
    // Utility to set the shader constants for drawing.
    void _UpdateShaderConstants(
        HgiGraphicsCmds* gfxCmds,
        const GfVec4i& gfxViewport,
        const HdStRenderPassState& hdStRenderPassState);
 
    // Create and submit the draw commands.
    void _DrawBBoxes(
        const HgiTextureHandle& colorTexture,
        const HgiTextureHandle& depthTexture,
        const HdStRenderPassState& hdStRenderPassState);
 
    // Destroy shader program and the shader functions it holds.
    void _DestroyShaderProgram();
 
    // Print shader compile errors.
    void _PrintCompileErrors();
 
    HgiAttachmentDesc _colorAttachment;
    HgiAttachmentDesc _depthAttachment;
 
    HgiBufferHandle _vertexBuffer;
    size_t _maxTransforms;
    HgiBufferHandle _transformsBuffer;
    HgiShaderProgramHandle _shaderProgram;
    HgiResourceBindingsHandle _resourceBindings;
    HgiGraphicsPipelineHandle _pipeline;
 
    HdxBoundingBoxTaskParams _params;
};
 
// VtValue requirements
HDX_API
std::ostream& operator<<(std::ostream& out, const HdxBoundingBoxTaskParams& pv);
HDX_API
bool operator==(const HdxBoundingBoxTaskParams& lhs,
                const HdxBoundingBoxTaskParams& rhs);
HDX_API
bool operator!=(const HdxBoundingBoxTaskParams& lhs,
                const HdxBoundingBoxTaskParams& rhs);
 
PXR_NAMESPACE_CLOSE_SCOPE
 
#endif