sweptEmitter.h

//-
// ==========================================================================
// 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.
// ==========================================================================
//+

#include <maya/MIOStream.h>
#include <maya/MTime.h>
#include <maya/MVector.h>
#include <maya/MObject.h>
#include <maya/MPlug.h>
#include <maya/MDataBlock.h>
#include <maya/MFnPlugin.h>
#include <maya/MPxEmitterNode.h>


class MIntArray;
class MVectorArray;
class MFnArrayAttrsData;

#define McheckErr(stat, msg)            \
        if ( MS::kSuccess != stat )             \
        {                                                               \
                cerr << msg;                            \
                return MS::kFailure;            \
        }

class sweptEmitter: public MPxEmitterNode
{
public:
        sweptEmitter();
        virtual ~sweptEmitter();

        static void             *creator();
        static MStatus  initialize();
        virtual MStatus compute( const MPlug& plug, MDataBlock& block );
        static MTypeId  id;


private:

        void    emit( const MVectorArray &inPosAry, const MVectorArray &inVelAry,
                                        const MIntArray &countAry, double dt, double speed,
                                        double inheritFactor, MVector dirV,
                                        MVectorArray &outPos, MVectorArray &outVel );

        MVector useRotation ( MVector &direction );

        MStatus emitCountPerPoint( const MPlug& plug, MDataBlock& block,
                                                                int length, MIntArray &countAry );

        // methods to get attribute value.
        //
        double  rateValue( MDataBlock& block );
        double  speedValue( MDataBlock& block );
        MVector directionVector( MDataBlock& block );

        bool    isFullValue( int plugIndex, MDataBlock& block );
        double  inheritFactorValue( int plugIndex, MDataBlock& block );

        MTime   currentTimeValue( MDataBlock& block );
        MTime   startTimeValue( int plugIndex, MDataBlock& block );
        MTime   deltaTimeValue( int plugIndex, MDataBlock& block );

        // the previous position in the world space.
        //
        MPoint  lastWorldPoint;
};

// inlines
//
inline double sweptEmitter::rateValue( MDataBlock& block )
{
        MStatus status;

        MDataHandle hValue = block.inputValue( mRate, &status );

        double value = 0.0;
        if( status == MS::kSuccess )
                value = hValue.asDouble();

        return( value );
}

inline double sweptEmitter::speedValue( MDataBlock& block )
{
        MStatus status;

        MDataHandle hValue = block.inputValue( mSpeed, &status );

        double value = 0.0;
        if( status == MS::kSuccess )
                value = hValue.asDouble();

        return( value );
}

inline MVector sweptEmitter::directionVector( MDataBlock& block )
{
        MStatus status;
        MVector dirV(0.0, 0.0, 0.0);

        MDataHandle hValue = block.inputValue( mDirection, &status );

        if( status == MS::kSuccess )
        {
                double3 &value = hValue.asDouble3();

                dirV[0] = value[0];
                dirV[1] = value[1];
                dirV[2] = value[2];
        }

        return( dirV );
}

inline bool sweptEmitter::isFullValue( int plugIndex, MDataBlock& block )
{
        MStatus status;
        bool value = true;

        MArrayDataHandle mhValue = block.inputArrayValue( mIsFull, &status );
        if( status == MS::kSuccess )
        {
                status = mhValue.jumpToElement( plugIndex );
                if( status == MS::kSuccess )
                {
                        MDataHandle hValue = mhValue.inputValue( &status );
                        if( status == MS::kSuccess )
                                value = hValue.asBool();
                }
        }

        return( value );
}

inline double sweptEmitter::inheritFactorValue(int plugIndex,MDataBlock& block)
{
        MStatus status;
        double value = 0.0;

        MArrayDataHandle mhValue = block.inputArrayValue( mInheritFactor, &status );
        if( status == MS::kSuccess )
        {
                status = mhValue.jumpToElement( plugIndex );
                if( status == MS::kSuccess )
                {
                        MDataHandle hValue = mhValue.inputValue( &status );
                        if( status == MS::kSuccess )
                                value = hValue.asDouble();
                }
        }

        return( value );
}

inline MTime sweptEmitter::currentTimeValue( MDataBlock& block )
{
        MStatus status;

        MDataHandle hValue = block.inputValue( mCurrentTime, &status );

        MTime value(0.0);
        if( status == MS::kSuccess )
                value = hValue.asTime();

        return( value );
}

inline MTime sweptEmitter::startTimeValue( int plugIndex, MDataBlock& block )
{
        MStatus status;
        MTime value(0.0);

        MArrayDataHandle mhValue = block.inputArrayValue( mStartTime, &status );
        if( status == MS::kSuccess )
        {
                status = mhValue.jumpToElement( plugIndex );
                if( status == MS::kSuccess )
                {
                        MDataHandle hValue = mhValue.inputValue( &status );
                        if( status == MS::kSuccess )
                                value = hValue.asTime();
                }
        }

        return( value );
}

inline MTime sweptEmitter::deltaTimeValue( int plugIndex, MDataBlock& block )
{
        MStatus status;
        MTime value(0.0);

        MArrayDataHandle mhValue = block.inputArrayValue( mDeltaTime, &status );
        if( status == MS::kSuccess )
        {
                status = mhValue.jumpToElement( plugIndex );
                if( status == MS::kSuccess )
                {
                        MDataHandle hValue = mhValue.inputValue( &status );
                        if( status == MS::kSuccess )
                                value = hValue.asTime();
                }
        }

        return( value );
}