torusField/torusField.h

//-
// ==========================================================================
// Copyright 2015 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
//  The torusField node implements an attraction-and-repel field.
//
//  The field repels all objects between itself and repelDistance attribute
//  and attracts objects greater than attractDistance attribute from itself.  
//  This will eventually result in the objects clustering
//  in a torus shape around the field.
//

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

#include <maya/MGL.h>

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

class torusField: public MPxFieldNode
{
public:
    torusField() {};
    ~torusField() override {};

    static void     *creator();
    static MStatus  initialize();

    // will compute output force.
    //
    MStatus compute( const MPlug& plug, MDataBlock& block ) override;

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

    MStatus getForceAtPoint(const MVectorArray& point,
                            const MVectorArray& velocity,
                            const MDoubleArray& mass,
                            MVectorArray& force,
                            double deltaTime) override;

    MStatus iconSizeAndOrigin(  GLuint& width,
                        GLuint& height,
                        GLuint& xbo,
                        GLuint& ybo   ) override;
    MStatus iconBitmap(GLubyte* bitmap) override;

    //
    // attributes.
    //

    // minimum distance from field at which repel is applied
    //
    static MObject  aMinDistance;

    // min distance from field at which the force attracts
    //
    static MObject  aAttractDistance;

    // max distance from field at which the force repels.
    //
    static MObject  aRepelDistance;

    // drag exerted on the attractRepel force.
    //
    static MObject  aDrag;

    // amplitude/magnitude of the swarm force.
    //
    static MObject  aSwarmAmplitude;

    // frequency of the swarm force.
    //
    static MObject  aSwarmFrequency;

    // phase of the swarm force.
    //
    static MObject  aSwarmPhase;

    // Other data members
    //
    static MTypeId  id;

private:

    // methods to compute output force.
    //
    void    applyNoMaxDist( MDataBlock& block,
                            const MVectorArray &points,
                            const MVectorArray &velocities,
                            const MDoubleArray &masses,
                            MVectorArray &outputForce );

    void    applyMaxDist( MDataBlock& block,
                            const MVectorArray &points,
                            const MVectorArray &velocities,
                            const MDoubleArray &masses,
                            MVectorArray &outputForce );

    void    ownerPosition( MDataBlock& block, MVectorArray &vArray );
    MStatus getWorldPosition( MVector &vector );
    MStatus getWorldPosition( MDataBlock& block, MVector &vector );
    void    noiseFunction( double *inputNoise, double *out );

    // methods to get attribute value.
    //
    double  magnitudeValue( MDataBlock& block );
    double  attenuationValue( MDataBlock& block );
    double  maxDistanceValue( MDataBlock& block );
    bool    useMaxDistanceValue( MDataBlock& block );
    bool    applyPerVertexValue( MDataBlock& block );

    // methods to get attribute value of local attributes.
    //
    double  minDistanceValue( MDataBlock& block );
    double  attractDistanceValue( MDataBlock& block );
    double  repelDistanceValue( MDataBlock& block );
    double  dragValue( MDataBlock& block );
    double  swarmAmplitudeValue( MDataBlock& block );
    double  swarmFrequencyValue( MDataBlock& block );
    double  swarmPhaseValue( MDataBlock& block );

    MStatus ownerCentroidValue( MDataBlock& block, MVector &vector );
};

// inlines
//
inline double torusField::magnitudeValue( MDataBlock& block )
{
    MStatus status;

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

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

    return( value );
}

inline double torusField::attenuationValue( MDataBlock& block )
{
    MStatus status;

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

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

    return( value );
}

inline double torusField::maxDistanceValue( MDataBlock& block )
{
    MStatus status;

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

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

    return( value );
}

inline bool torusField::useMaxDistanceValue( MDataBlock& block )
{
    MStatus status;

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

    bool value = false;
    if( status == MS::kSuccess )
        value = hValue.asBool();

    return( value );
}

inline bool torusField::applyPerVertexValue( MDataBlock& block )
{
    MStatus status;

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

    bool value = false;
    if( status == MS::kSuccess )
        value = hValue.asBool();

    return( value );
}

inline double torusField::minDistanceValue( MDataBlock& block )
{
    MStatus status;

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

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

    return( value );
}

inline double torusField::attractDistanceValue( MDataBlock& block )
{
    MStatus status;

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

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

    return( value );
}

inline double torusField::repelDistanceValue( MDataBlock& block )
{
    MStatus status;

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

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

    return( value );
}

inline double torusField::dragValue( MDataBlock& block )
{
    MStatus status;

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

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

    return( value );
}

inline double torusField::swarmAmplitudeValue( MDataBlock& block )
{
    MStatus status;

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

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

    return( value );
}

inline double torusField::swarmFrequencyValue( MDataBlock& block )
{
    MStatus status;

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

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

    return( value );
}

inline double torusField::swarmPhaseValue( MDataBlock& block )
{
    MStatus status;

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

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

    return( value );
}

inline MStatus torusField::ownerCentroidValue(MDataBlock& block,MVector &vector)
{
    MStatus status;

    MDataHandle hValueX = block.inputValue( mOwnerCentroidX, &status );
    MDataHandle hValueY = block.inputValue( mOwnerCentroidY, &status );
    MDataHandle hValueZ = block.inputValue( mOwnerCentroidZ, &status );

    if( status == MS::kSuccess )
    {
        vector[0] = hValueX.asDouble();
        vector[1] = hValueY.asDouble();
        vector[2] = hValueZ.asDouble();
    }

    return( status );
}