simpleEmitter/simpleEmitter.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>



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

class simpleEmitter: public MPxEmitterNode
{
public:
    simpleEmitter();
    ~simpleEmitter() override;

    static void     *creator();
    static MStatus  initialize();
    MStatus compute( const MPlug& plug, MDataBlock& block ) override;
    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, MDoubleArray &outTime );

    MStatus getWorldPosition( MPoint &p );
    MStatus getWorldPosition( MDataBlock& block, MPoint &p );
    MVector useRotation ( MVector &direction );

    // 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;

    void    draw (  M3dView  & view, const  MDagPath  & path,  M3dView::DisplayStyle  style, M3dView:: DisplayStatus ) override;
};

// inlines
//
inline double simpleEmitter::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 simpleEmitter::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 simpleEmitter::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 simpleEmitter::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 simpleEmitter::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 simpleEmitter::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 simpleEmitter::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 simpleEmitter::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 );
}