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/M3dView.h>
#include <maya/MViewport2Renderer.h>
#include <maya/MShaderManager.h>
#include <maya/MTextureManager.h>
#include <maya/MUiMessage.h>
#include <maya/MStateManager.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 );
    virtual ~RenderOverride();
    virtual MHWRender::DrawAPI supportedDrawAPIs() const;

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

    virtual MString uiName() const
    {
        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();

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

    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();

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


} //namespace

#endif