helix2Cmd.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.
// ==========================================================================
//+

//
// This example takes a curve and changes it into a helix.
//

#include <maya/MIOStream.h>
#include <math.h>

#include <maya/MFnPlugin.h>
#include <maya/MFnNurbsCurve.h>
#include <maya/MPointArray.h>
#include <maya/MDoubleArray.h>
#include <maya/MPoint.h>
#include <maya/MSelectionList.h>
#include <maya/MItSelectionList.h>
#include <maya/MItCurveCV.h>
#include <maya/MGlobal.h>
#include <maya/MDagPath.h>
#include <maya/MString.h>
#include <maya/MPxCommand.h>
#include <maya/MArgList.h>

class helix2 : public MPxCommand
{

public:
                                helix2();
        virtual         ~helix2();

        MStatus         doIt( const MArgList& );
        MStatus         redoIt();
        MStatus         undoIt();
        bool            isUndoable() const;

        static          void* creator();

private:
        MDagPath        fDagPath;
        MObject         fComponent;
        MPointArray     fCVs;
        double          radius;
        double          pitch;
};

MStatus helix2::doIt( const MArgList& args )
{
        MStatus status;

        // Parse the arguments.
        for ( unsigned i = 0; i < args.length(); i++ ) {
                if ( MString( "-p" ) == args.asString( i, &status )
                                && MS::kSuccess == status)
                {
                        double tmp = args.asDouble( ++i, &status );
                        if ( MS::kSuccess == status )
                                pitch = tmp;
                }
                else if ( MString( "-r" ) == args.asString( i, &status )
                                && MS::kSuccess == status)
                {
                        double tmp = args.asDouble( ++i, &status );
                        if ( MS::kSuccess == status )
                                radius = tmp;
                } else {
                        MString msg = "Invalid flag: ";
                        msg += args.asString( i );
                        displayError( msg );
                        return MS::kFailure;
                }
        }

        // Get the first selected curve from the selection list.
        MSelectionList slist;
        MGlobal::getActiveSelectionList( slist );

        MItSelectionList        list( slist, MFn::kNurbsCurve, &status );
        if (MS::kSuccess != status) {
                cerr << "doIt: could not create selection list iterator\n";
                return status;
        }

        if (list.isDone()) {
                cerr << "doIt: no curve has been selected\n";
                return MS::kFailure;
        }

        list.getDagPath( fDagPath, fComponent );

        return redoIt();
}

MStatus helix2::redoIt()
{
        unsigned                i, numCVs;
        MStatus                 status;
        MFnNurbsCurve   curveFn( fDagPath );

        numCVs = curveFn.numCVs();
        status = curveFn.getCVs( fCVs );
        if ( MS::kSuccess != status )
        {
                cerr << "redoIt: could not get cvs status: " << status << endl;
                return MS::kFailure;
        }

        MPointArray             points(fCVs);
        for (i = 0; i < numCVs; i++)
                points[i] = MPoint( radius * cos( (double)i ),
                                                        pitch * (double)i,
                                                        radius * sin( (double)i ) );
        status = curveFn.setCVs( points );
        if ( MS::kSuccess != status )
        {
                cerr << "redoIt: could not setCVs status: " << status << endl;
                fCVs.clear();
                return status;
        }

        status == curveFn.updateCurve();
        if ( MS::kSuccess != status )
        {
                cerr << "redoIt: updateCurve() failed status: " << status << endl;
                return status;
        }

        return MS::kSuccess;
}

MStatus helix2::undoIt()
{
        MStatus         status;

        MFnNurbsCurve   curveFn( fDagPath );
        status = curveFn.setCVs( fCVs );
        if ( MS::kSuccess != status)
        {
                cerr << "undoIt: array length is " << fCVs.length()
                     << "bad status: " << status << endl;
                return status;
        }

        status = curveFn.updateCurve();
        if ( MS::kSuccess != status )
        {
                cerr << "undoIt: updateCurve() failed status: " << status << endl;
                return status;
        }

        fCVs.clear();
        return MS::kSuccess;
}

void* helix2::creator()
{
        return new helix2();
}

helix2::helix2()
        : radius( 4.0 ),
          pitch( 0.5 ),
          fComponent()
{}

helix2::~helix2()
{
        fCVs.clear();
        // Note that we do nothing with fComponent which is owned by Maya.
}

bool helix2::isUndoable() const
{
        return true;
}

MStatus initializePlugin( MObject obj )
{ 
        MStatus   status;
        MFnPlugin plugin( obj, PLUGIN_COMPANY, "3.0", "Any");

        status = plugin.registerCommand( "helix2", helix2::creator );
        if (!status) {
                status.perror("registerCommand");
                return status;
        }

        return status;
}

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

        status = plugin.deregisterCommand( "helix2" );
        if (!status) {
                status.perror("deregisterCommand");
                return status;
        }

        return status;
}