viewCallbackTest/viewCallbackTest.cpp

//-
// ==========================================================================
// Copyright 1995,2006,2008 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.
// ==========================================================================
//+

// DESCRIPTION:
// 
// Produces the command "viewCallbackTest". 
//
// This plug-in installs the pre and post rendering callbacks of MUiMessage.
// As a simple demonstration, a modelling view can be inverted or shaded based on depth.
// In the depth shaded mode, the closer objects are lighter in color. Below is some
// sample MEL for using this plug-in once it is loaded.
//
//  // Invert mode
//  viewCallbackTest -bo "invert" `getPanel -withFocus`;
//  // Depth mode
//  viewCallbackTest -bo "showDepth" `getPanel -withFocus`;
//
// Note that the screen does not refresh right after the plug-in execution.
//

#include <stdio.h>

#define OPENMAYA_EXPORT

#include <maya/MIOStream.h>
#include <maya/MGlobal.h>
#include <maya/MString.h>
#include <maya/MStringArray.h>
#include <maya/MEventMessage.h>
#include <maya/MUiMessage.h>
#include <maya/MFnPlugin.h>

#include <maya/MPxCommand.h>
#include <maya/MSyntax.h>
#include <maya/MArgDatabase.h>
#include <maya/MArgList.h>

#include <maya/M3dView.h>
#include <maya/MPoint.h>
#include <maya/MImage.h>

#include <stdio.h>

// Static pointer to the current refreshCompute per panel so we can delete
// it if the plug-in is unloaded.
//
class refreshCompute;
static refreshCompute* currentRefreshCompute[4] = { 0, 0, 0, 0 };

// Possible buffer operations supported
enum MbufferOperation {
    kInvertColorBuffer,
    kDrawDepthBuffer
};

//
// Command class declaration
//
class viewCallbackTest : public MPxCommand
{
public:
    viewCallbackTest();
                    ~viewCallbackTest() override; 

    MStatus                 doIt( const MArgList& args ) override;

    static MSyntax          newSyntax();
    static void*            creator();

private:
    MStatus                 parseArgs( const MArgList& args );

    // Name of panel to monitor
    MString                 mPanelName;
    MbufferOperation        mBufferOperation;
};

//
// Refresh computation class implementation
//
class refreshCompute
{
public:
    refreshCompute(const MString &panelName, MbufferOperation bufferOperation);
    ~refreshCompute();

    const MString &panelName() const { return mPanelName; }
    void setPanelName(const MString &panelName) { mPanelName = panelName; }

    MbufferOperation bufferOperation() const { return mBufferOperation; }
    void setBufferOperation(const MbufferOperation operation) { mBufferOperation = operation; }

    void clearCallbacks();

protected:
    static void             deleteCB(const MString& panelName, void * data);
    static void             preRenderCB(const MString& panelName, void * data);
    static void             postRenderCB(const MString& panelName, void * data);

    MCallbackId             mDeleteId;
    MCallbackId             mPreRenderId;
    MCallbackId             mPostRenderId;

    MString                 mPanelName;
    MbufferOperation        mBufferOperation;
};


//
// Command class implementation
//

// Constructor
//
viewCallbackTest::viewCallbackTest()
{
    mPanelName = MString("");
    mBufferOperation = kInvertColorBuffer;
}

// Destructor
//
viewCallbackTest::~viewCallbackTest()
{
    // Do nothing
}

// creator
//
void* viewCallbackTest::creator()
{
    return (void *) (new viewCallbackTest);
}

// newSyntax
//
// Buffer operation = -bo/-bufferOperation <string> = (invert | showDepth)
const char *bufferOperationShortName = "-bo";
const char *bufferOperationLongName = "-bufferOperation";
#define _NUMBER_BUFFER_OPERATIONS_ 2
const MString bufferOperationStrings[_NUMBER_BUFFER_OPERATIONS_ ] = 
        { MString("invert"), MString("showDepth") };
const MbufferOperation bufferOperations[_NUMBER_BUFFER_OPERATIONS_] = 
        { kInvertColorBuffer, kDrawDepthBuffer };

MSyntax viewCallbackTest::newSyntax()
{
    MSyntax syntax;

    syntax.addFlag(bufferOperationShortName, bufferOperationLongName, MSyntax::kString);

    // Name of model panel to monitor
    //
    syntax.addArg(MSyntax::kString);

    return syntax;
}

// parseArgs
//
MStatus viewCallbackTest::parseArgs(const MArgList& args)
{
    MStatus         status;
    MArgDatabase    argData(syntax(), args);

    // Buffer operation argument variables
    mBufferOperation = kInvertColorBuffer;
    MString operationString;

    MString         arg;
    for ( unsigned int i = 0; i < args.length(); i++ ) 
    {
        arg = args.asString( i, &status );
        if (!status)              
            continue;

        if ( arg == MString(bufferOperationShortName) || arg == MString(bufferOperationLongName) ) 
        {
            if (i == args.length()-1) {
                arg += ": must specify a buffer operation.";
                displayError(arg);
                return MS::kFailure;
            }
            i++;
            args.get(i, operationString );

            bool validOperation = false;
            for (unsigned int k=0; k<_NUMBER_BUFFER_OPERATIONS_; k++)
            {
                if (bufferOperationStrings[i] == operationString)
                {
                    mBufferOperation = bufferOperations[k];
                    validOperation = true;
                }
            }
            if (!validOperation)
                status.perror("Invalid operation specified. Using invert by default.");
        }
    }

    // Read off the panel name
    status = argData.getCommandArgument(0, mPanelName);
    if (!status)
    {
        status.perror("No panel name specified as command argument");
        return status;
    }
    return MS::kSuccess;
}

// doIt
//
MStatus viewCallbackTest::doIt(const MArgList& args)
{
    MStatus status;

    status = parseArgs(args);
    if (!status)
    {
        return status;
    }

    try
    {
        // Only allow one computation per panel at this time.
        refreshCompute *foundComputePtr = 0;
        unsigned int i;
        for (i=0; i<4; i++)
        {
            if (currentRefreshCompute[i] && 
                (currentRefreshCompute[i])->panelName() == mPanelName)
            {
                foundComputePtr = currentRefreshCompute[i];
            }
        }

        // If alread exists, just change the operator if it differs.
        if (foundComputePtr)
        {
            foundComputePtr->setBufferOperation( mBufferOperation);
        }
        else
        {
            for (i=0; i<4; i++)
            {
                if (!currentRefreshCompute[i])
                {
                    currentRefreshCompute[i] = new refreshCompute(mPanelName, mBufferOperation);
                    break;
                }
            }
        }
    }
    catch(MStatus status)
    {
        return status;
    }
    catch(...)
    {
        throw;
    }

    return status;
}

//
// refreshCompute implementation
//
refreshCompute::refreshCompute(const MString &panelName, 
                               MbufferOperation postBufferOperation)
{
    MStatus status;

    // Set panel name and operator for post rendering
    mPanelName = panelName;
    mBufferOperation = postBufferOperation;

    // Add the callbacks
    //
    mDeleteId
        = MUiMessage::add3dViewDestroyMsgCallback(panelName,
                                           &refreshCompute::deleteCB,
                                           (void *) this, &status);
    if (mDeleteId == 0)
        status.perror(MString("Could not attach view deletion callback to panel ") +
                      panelName);

    mPreRenderId
        = MUiMessage::add3dViewPreRenderMsgCallback(panelName,
                                          &refreshCompute::preRenderCB,
                                          (void *) this, &status);
    if (mPreRenderId == 0)
        status.perror(MString("Could not attach view prerender callback to panel ") +
                panelName);

    mPostRenderId
        = MUiMessage::add3dViewPostRenderMsgCallback(panelName,
                                           &refreshCompute::postRenderCB,
                                           (void *) this, &status);
    if (mPostRenderId == 0)
        status.perror(MString("Could not attach view postrender callback to panel ") +
                      panelName);
}

// Clear all callbacks for this compute
void refreshCompute::clearCallbacks()
{   
    if (mDeleteId)
        MMessage::removeCallback(mDeleteId);

    if (mPreRenderId)
        MMessage::removeCallback(mPreRenderId);

    if (mPostRenderId)
        MMessage::removeCallback(mPostRenderId);
}

refreshCompute::~refreshCompute()
{
    clearCallbacks();

    // Reset any global pointer pointing to this compute
    for (unsigned int i=0; i<4; i++)
    {
        if (currentRefreshCompute[i] && 
            (currentRefreshCompute[i])->panelName() == mPanelName)
        {
            currentRefreshCompute[i] = 0;
        }
    }
}

// Delete callback
//
void refreshCompute::deleteCB(const MString& panelName, void * data)
{
    refreshCompute *pf = (refreshCompute *) data;

    cout<<"In delete view callback for view "<<panelName.asChar()
        <<". Remove all callbacks."<<endl;

    // Delete callback.
    delete pf;
}

// Pre-render callback
//
void refreshCompute::preRenderCB(const MString& panelName, void * data)
{
    refreshCompute *thisCompute = (refreshCompute *) data;
    if (!thisCompute)
        return;

    M3dView view;
    MStatus status = M3dView::getM3dViewFromModelPanel(panelName, view);
    if (status != MS::kSuccess)
        return;

    int width = 0, height = 0;
    width = view.portWidth( &status );
    if (status != MS::kSuccess || (width < 2))
        return;
    height = view.portHeight( &status );
    if (status != MS::kSuccess || (height < 2))
        return;

    unsigned int vx,vy,vwidth,vheight;
    vx = 0;
    vy = 0;
    vwidth = width / 2;
    vheight = height / 2;
    status = view.pushViewport (vx, vy, vwidth, vheight);

    if (thisCompute->mBufferOperation != kDrawDepthBuffer)
    {
        M3dView view;
        MStatus status = M3dView::getM3dViewFromModelPanel(panelName, view);
        MPoint origin;
        status = view.drawText( MString("Pre render callback: ") + panelName, origin );
    }

    view.popViewport();
}

// Post-render callback
//
void refreshCompute::postRenderCB(const MString& panelName, void * data)
{   
    refreshCompute *thisCompute = (refreshCompute *) data;
    if (!thisCompute)
        return;

    // Get the view if any for the panel
    M3dView view;
    MStatus status = M3dView::getM3dViewFromModelPanel(panelName, view);
    if (status != MS::kSuccess)
        return;

    if (thisCompute->mBufferOperation == kDrawDepthBuffer)
    {
        int width = 0, height = 0;
        width = view.portWidth( &status ) / 2 ;
        if (status != MS::kSuccess || (width < 2))
            return;
        height = view.portHeight( &status ) / 2 ;
        if (status != MS::kSuccess || (height < 2))
            return;

        unsigned int numPixels = width * height;

        float *depthPixels = new float[numPixels];
        if (!depthPixels)
            return;

        unsigned char *colorPixels = new unsigned char[numPixels * 4];
        if (!colorPixels)
        {
            delete [] depthPixels;
            delete [] colorPixels;
            return;
        }

        // Read into a float buffer
        status = view.readDepthMap( 0,0, width, height, (unsigned char *)depthPixels, M3dView::kDepth_Float );

        if (status != MS::kSuccess)
        {
            delete [] depthPixels;
            delete [] colorPixels;
            return;
        }

        // Find depth range and remap normalized depth range (-1 to 1) into 0...255
        // for color.
        float *dPtr = depthPixels;
        unsigned int i = 0;

        float zmin = 100.0f; // *dPtr;
        float zmax = -100.0f; // *dPtr;
        for(i=0; i<numPixels; i++)
        {
            float val = *dPtr; // * 2.0f - 1.0f;
            if(val < zmin) {
                zmin = *dPtr;
            }
            if(val > zmax) {
                zmax = *dPtr;
            }
            dPtr++;
        }
        float zrange = zmax - zmin;
        //printf("depth values = (%g, %g). Range = %g\n", zmin, zmax, zrange);

        unsigned char *cPtr = colorPixels;

        dPtr = depthPixels;
        for(i=0; i < numPixels; i++)
        {
            float val = *dPtr; // * 2.0f - 1.0f;
            //unsigned char depth = (unsigned char)(255.0f * (( (*dPtr)-zmin) / zrange) + zmin );
            unsigned char depth = (unsigned char)(255.0f * (( (val)-zmin) / zrange) );
            //unsigned char depth = (unsigned char)(255.0f * val);
            *cPtr = depth; cPtr++;
            *cPtr = depth; cPtr++;
            *cPtr = depth; cPtr++;
            *cPtr = 0xff;   
            cPtr++;
            dPtr++;
        }

        MImage image;
        image.setPixels( colorPixels, width, height );

        // Uncomment next line to test writing buffer to file.
        //image.writeToFile( "C:\\temp\\dumpDepth.iff" );

        // Write all pixels back. The origin of the image (lower left)
        // is used 
        status = view.writeColorBuffer( image, 5, 5 );

        if (depthPixels)
            delete [] depthPixels;
        if (colorPixels)
            delete [] colorPixels;
    }

    // Do a simple color invert operation on all pixels
    //
    else if (thisCompute->mBufferOperation == kInvertColorBuffer)
    {
        // Optional to read as RGBA. Note that this will be slower
        // since we must swizzle the bytes around from the default
        // BGRA format.
        bool readAsRGBA = true;

        // Read the RGB values from the color buffer
        MImage image;
        status = view.readColorBuffer( image, readAsRGBA );
        if (status != MS::kSuccess)
            return;

        status = view.writeColorBuffer( image, 5, 5 );

        unsigned char *pixelPtr = (unsigned char*)image.pixels();
        if (pixelPtr)
        {
            unsigned int width, height;
            image.getSize( width, height );

            MImage image2;
            image2.create( width, height );
            unsigned char *pixelPtr2 = (unsigned char*)image2.pixels();

            unsigned int numPixels = width * height;
            for (unsigned int i=0; i < numPixels; i++)
            {
                *pixelPtr2 = (255 - *pixelPtr); 
                pixelPtr2++; pixelPtr++;
                *pixelPtr2 = (255 - *pixelPtr); 
                pixelPtr2++; pixelPtr++;
                *pixelPtr2 = (255 - *pixelPtr); 
                pixelPtr2++; pixelPtr++;
                *pixelPtr2 = 255;   
                pixelPtr2++; pixelPtr++;
            }

            // Write all pixels back. The origin of the image (lower left)
            // is used 
            status = view.writeColorBuffer( image2, 5, short(5+height/2) );
        }
    }
}

//
// Plug-in functions
//

MStatus initializePlugin( MObject obj )
{ 
    MStatus   status;
    MFnPlugin plugin( obj, PLUGIN_COMPANY, "6.5", "Any");

    // Register the command so we can actually do some work
    //
    status = plugin.registerCommand("viewCallbackTest",
                                    viewCallbackTest::creator,
                                    viewCallbackTest::newSyntax);

    if (!status)
    {
        status.perror("registerCommand");
    }

    return status;
}

MStatus uninitializePlugin( MObject obj)
{
    MStatus   status;
    MFnPlugin plugin( obj );

    // Remove all computation class + callbacks
    for (unsigned int i=0; i<4; i++)
    {
        delete currentRefreshCompute[i];
        currentRefreshCompute[i] = 0;
    }

    // Deregister the command
    //
    status = plugin.deregisterCommand("viewCallbackTest");

    if (!status)
    {
        status.perror("deregisterCommand");
    }

    return status;
}