viewImageBlitOverride/viewImageBlitOverride.h

#ifndef viewImageBlitOverride_h_
#define viewImageBlitOverride_h_

//-
// Copyright 2012 Autodesk, Inc.  All rights reserved.
//
// Use of this software is subject to the terms of the Autodesk license agreement
// provided at the time of installation or download, or which otherwise
// accompanies this software in either electronic or hard copy form.
//+


#include <maya/MString.h>
#include <maya/MTextureManager.h>
#include <maya/MShaderManager.h>

//
// Sample plugin which will blit an image as the scene and rely on
// Maya's internal rendering for the UI only
// 
namespace viewImageBlitOverride
{
class RenderOverride : public MHWRender::MRenderOverride
{
public:
    RenderOverride( const MString & name );
    ~RenderOverride() override;
    MHWRender::DrawAPI supportedDrawAPIs() const override;

    MStatus setup( const MString & destination ) override;
    bool startOperationIterator() override;
    MHWRender::MRenderOperation * renderOperation() override;
    bool nextRenderOperation() override;
    MStatus cleanup() override;

    MString uiName() const override
    {
        return mUIName;
    }
    
    // Global override instance
    static RenderOverride* sViewImageBlitOverrideInstance;

protected:
    bool updateTextures(MHWRender::MRenderer *theRenderer,
                        MHWRender::MTextureManager* textureManager);

    // UI name 
    MString mUIName;

    // Operations + names
    MHWRender::MRenderOperation* mOperations[4];
    MString mOperationNames[3];

    // Texture(s) used for the quad render
    MHWRender::MTextureDescription mColorTextureDesc;
    MHWRender::MTextureDescription mDepthTextureDesc;
    MHWRender::MTextureAssignment mColorTexture;
    MHWRender::MTextureAssignment mDepthTexture;

    int mCurrentOperation;

    // Options
    bool mLoadImagesFromDisk;
};

//
// Image blit used to perform the 'scene render'
//
class SceneBlit : public MHWRender::MQuadRender
{
public:
    SceneBlit(const MString &name);
    ~SceneBlit() override;

    const MHWRender::MShaderInstance * shader() override;
    MHWRender::MClearOperation & clearOperation() override;
    const MHWRender::MDepthStencilState *depthStencilStateOverride() override;

    inline void setColorTexture( const MHWRender::MTextureAssignment &val )
    {
        mColorTexture.texture = val.texture;
        mColorTextureChanged = true;
    }
    inline void setDepthTexture( const MHWRender::MTextureAssignment &val )
    {
        mDepthTexture.texture = val.texture;
        mDepthTextureChanged = true;
    }

protected:
    // Shader to use for the quad render
    MHWRender::MShaderInstance *mShaderInstance;
    // Texture(s) used for the quad render. Not owned by operation.
    MHWRender::MTextureAssignment mColorTexture;
    MHWRender::MTextureAssignment mDepthTexture;
    bool mColorTextureChanged;
    bool mDepthTextureChanged;

    const MHWRender::MDepthStencilState *mDepthStencilState;
};

//
// UI pass
//
class UIDraw : MHWRender::MSceneRender
{
public:
    UIDraw(const MString& name);
    ~UIDraw() override;

    MHWRender::MSceneRender::MSceneFilterOption     renderFilterOverride() override;
    MUint64                                         getObjectTypeExclusions() override;
    MHWRender::MClearOperation &                    clearOperation() override;
};


} //namespace

#endif