dynExprField/dynExprField.cpp
 
 
 
dynExprField/dynExprField.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.
// ==========================================================================
//+

#include <math.h>

#include <dynExprField.h>

#include <maya/MIOStream.h>
#include <maya/MTime.h>
#include <maya/MFloatVector.h>
#include <maya/MVectorArray.h>
#include <maya/MDoubleArray.h>
#include <maya/MString.h>
#include <maya/MMatrix.h>

#include <maya/MFnDependencyNode.h>
#include <maya/MFnTypedAttribute.h>
#include <maya/MFnNumericAttribute.h>
#include <maya/MFnCompoundAttribute.h>
#include <maya/MFnUnitAttribute.h>
#include <maya/MFnVectorArrayData.h>
#include <maya/MFnDoubleArrayData.h>
#include <maya/MFnMatrixData.h>
#include <maya/MFnArrayAttrsData.h>

MObject dynExprField::mDirection;

MTypeId dynExprField::id( 0x00107340 );

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

MStatus dynExprField::initialize()
//
//      Descriptions:
//              Initialize the node, attributes.
//
{
        MStatus status;
        MFnNumericAttribute numAttr;

        // create the field basic attributes.
        //
        mDirection = numAttr.createPoint("direction","dir");
        numAttr.setDefault( 0.0, 1.0, 0.0 );
        numAttr.setKeyable(true);
        numAttr.setStorable(true);
        numAttr.setReadable(true);
        numAttr.setWritable(true);
        status = addAttribute( mDirection );
        attributeAffects(mDirection, mOutputForce);

        return( MS::kSuccess );
}


MStatus dynExprField::compute(const MPlug& plug, MDataBlock& block)
//
//      Descriptions:
//              compute output force.
//
{
        MStatus status;

        if( !(plug == mOutputForce) )
        return( MS::kUnknownParameter );

        // get the logical index of the element this plug refers to.
        //
        int multiIndex = plug.logicalIndex( &status );
        McheckErr(status, "ERROR in plug.logicalIndex.\n");

        // Get input data handle, use outputArrayValue since we do not
        // want to evaluate both inputs, only the one related to the
        // requested multiIndex. Evaluating both inputs at once would cause
        // a dependency graph loop.
        
        MArrayDataHandle hInputArray = block.outputArrayValue( mInputData, &status );
        McheckErr(status,"ERROR in hInputArray = block.outputArrayValue().\n");
        
        status = hInputArray.jumpToElement( multiIndex );
        McheckErr(status, "ERROR: hInputArray.jumpToElement failed.\n");
        
        // get children of aInputData.
        
        MDataHandle hCompond = hInputArray.inputValue( &status );
        McheckErr(status, "ERROR in hCompond=hInputArray.inputValue\n");
        
        MDataHandle hPosition = hCompond.child( mInputPositions );
        MObject dPosition = hPosition.data();
        MFnVectorArrayData fnPosition( dPosition );
        MVectorArray points = fnPosition.array( &status );
        McheckErr(status, "ERROR in fnPosition.array(), not find points.\n");
        
        // Comment out the following since velocity, and mass are 
        // not needed in this field.
        //
        // MDataHandle hVelocity = hCompond.child( mInputVelocities );
        // MObject dVelocity = hVelocity.data();
        // MFnVectorArrayData fnVelocity( dVelocity );
        // MVectorArray velocities = fnVelocity.array( &status );
        // McheckErr(status, "ERROR in fnVelocity.array(), not find velocities.\n");
        //
        // MDataHandle hMass = hCompond.child( mInputMass );
        // MObject dMass = hMass.data();
        // MFnDoubleArrayData fnMass( dMass );
        // MDoubleArray masses = fnMass.array( &status );
        // McheckErr(status, "ERROR in fnMass.array(), not find masses.\n");

        // The attribute mInputPPData contains the attribute in an array form 
        // parpared by the particleShape if the particleShape has per particle 
        // attribute fieldName_attrName.  
        //
        // Suppose a field with the name dynExprField1 is connecting to 
        // particleShape1, and the particleShape1 has per particle float attribute
        // dynExprField1_magnitude and vector attribute dynExprField1_direction,
        // then hInputPPArray will contains a MdoubleArray with the corresponding
        // name "magnitude" and a MvectorArray with the name "direction".  This 
        // is a mechanism to allow the field attributes being driven by dynamic 
        // expression.
        MArrayDataHandle mhInputPPData = block.inputArrayValue( mInputPPData, &status );
        McheckErr(status,"ERROR in mhInputPPData = block.inputArrayValue().\n");

        status = mhInputPPData.jumpToElement( multiIndex );
        McheckErr(status, "ERROR: mhInputPPArray.jumpToElement failed.\n");

        MDataHandle hInputPPData = mhInputPPData.inputValue( &status );
        McheckErr(status, "ERROR in hInputPPData = mhInputPPData.inputValue\n");

        MObject dInputPPData = hInputPPData.data();
        MFnArrayAttrsData inputPPArray( dInputPPData );

        MDataHandle hOwnerPPData = block.inputValue( mOwnerPPData, &status );
        McheckErr(status, "ERROR in hOwnerPPData = block.inputValue\n");

        MObject dOwnerPPData = hOwnerPPData.data();
        MFnArrayAttrsData ownerPPArray( dOwnerPPData );

        const MString magString("magnitude");
        MFnArrayAttrsData::Type doubleType(MFnArrayAttrsData::kDoubleArray);

        bool arrayExist;
        MDoubleArray magnitudeArray;
        arrayExist = inputPPArray.checkArrayExist(magString, doubleType, &status);
        // McheckErr(status, "ERROR in checkArrayExist(magnitude)\n");
        if(arrayExist) {
            magnitudeArray = inputPPArray.getDoubleData(magString, &status);
            // McheckErr(status, "ERROR in inputPPArray.doubleArray(magnitude)\n");
        }

        MDoubleArray magnitudeOwnerArray;
        arrayExist = ownerPPArray.checkArrayExist(magString, doubleType, &status);
        // McheckErr(status, "ERROR in checkArrayExist(magnitude)\n");
        if(arrayExist) {
            magnitudeOwnerArray = ownerPPArray.getDoubleData(magString, &status);
            // McheckErr(status, "ERROR in ownerPPArray.doubleArray(magnitude)\n");
        }

        const MString dirString("direction");
        MFnArrayAttrsData::Type vectorType(MFnArrayAttrsData::kVectorArray);

        arrayExist = inputPPArray.checkArrayExist(dirString, vectorType, &status);
        MVectorArray directionArray;
        // McheckErr(status, "ERROR in checkArrayExist(direction)\n");
        if(arrayExist) {
            directionArray = inputPPArray.getVectorData(dirString, &status);
            // McheckErr(status, "ERROR in inputPPArray.vectorArray(direction)\n");
        }

        arrayExist = ownerPPArray.checkArrayExist(dirString, vectorType, &status);
        MVectorArray directionOwnerArray;
        // McheckErr(status, "ERROR in checkArrayExist(direction)\n");
        if(arrayExist) {
            directionOwnerArray = ownerPPArray.getVectorData(dirString, &status);
            // McheckErr(status, "ERROR in ownerPPArray.vectorArray(direction)\n");
        }

        // Compute the output force.
        //
        MVectorArray forceArray;

        apply( block, points.length(), magnitudeArray, magnitudeOwnerArray, 
               directionArray, directionOwnerArray, forceArray );

        // get output data handle
        //
        MArrayDataHandle hOutArray = block.outputArrayValue( mOutputForce, &status);
        McheckErr(status, "ERROR in hOutArray = block.outputArrayValue.\n");
        MArrayDataBuilder bOutArray = hOutArray.builder( &status );
        McheckErr(status, "ERROR in bOutArray = hOutArray.builder.\n");

        // get output force array from block.
        //
        MDataHandle hOut = bOutArray.addElement(multiIndex, &status);
        McheckErr(status, "ERROR in hOut = bOutArray.addElement.\n");

        MFnVectorArrayData fnOutputForce;
        MObject dOutputForce = fnOutputForce.create( forceArray, &status );
        McheckErr(status, "ERROR in dOutputForce = fnOutputForce.create\n");

        // update data block with new output force data.
        //
        hOut.set( dOutputForce );
        block.setClean( plug );

        return( MS::kSuccess );
}

MStatus dynExprField::iconSizeAndOrigin(GLuint& width,
                                        GLuint& height,
                                        GLuint& xbo,
                                        GLuint& ybo   )
//
//      This method is not required to be overridden.  It should be overridden
//      if the plug-in has custom icon.
//
//      The width and height have to be a multiple of 32 on Windows and 16 on 
//      other platform.
//
//      Define an 8x8 icon at the lower left corner of the 32x32 grid. 
//      (xbo, ybo) of (4,4) makes sure the icon is center at origin.
//
{
        width = 32;
        height = 32;
        xbo = 4;
        ybo = 4;
        return MS::kSuccess;
}

MStatus dynExprField::iconBitmap(GLubyte* bitmap)
//
//      This method is not required to be overridden.  It should be overridden
//      if the plug-in has custom icon.
//
//      Define an 8x8 icon at the lower left corner of the 32x32 grid. 
//      (xbo, ybo) of (4,4) makes sure the icon is center at origin.
{
        bitmap[0]  = 0x18;
        bitmap[4]  = 0x18;
        bitmap[8]  = 0x18;
        bitmap[12] = 0x18;
        bitmap[16] = 0x18;
        bitmap[20] = 0x5A;
        bitmap[24] = 0x3C;
        bitmap[28] = 0x18;

        return MS::kSuccess;
}

MStatus initializePlugin(MObject obj)
{
        MStatus status;
        MFnPlugin plugin(obj, PLUGIN_COMPANY, "6.0", "Any");

        status = plugin.registerNode(  "dynExprField", 
                                       dynExprField::id,
                                      &dynExprField::creator, 
                                      &dynExprField::initialize,
                                       MPxNode::kFieldNode );
        if (!status) {
                status.perror("registerNode");
                return status;
        }

        return status;
}

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

        status = plugin.deregisterNode( dynExprField::id );
        if (!status) {
                status.perror("deregisterNode");
                return status;
        }

        return status;
}

double dynExprField::magnitude( MDataBlock& block )
{
        MStatus status;
        MDataHandle hValue = block.inputValue( mMagnitude, &status );

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

        return( value );
}

MVector dynExprField::direction( MDataBlock& block )
{
        MFloatVector &fV = block.inputValue(mDirection).asFloatVector();
        return( MVector(fV.x, fV.y, fV.z) );
}

void dynExprField::apply(
MDataBlock         &block,
int                 receptorSize,
const MDoubleArray &magnitudeArray,
const MDoubleArray &magnitudeOwnerArray,
const MVectorArray &directionArray,
const MVectorArray &directionOwnerArray,
MVectorArray       &outputForce
)
//
//      Compute output force for each particle.  If there exists the 
//      corresponding per particle attribute, use the data passed from
//      particle shape (stored in magnitudeArray and directionArray).  
//      Otherwise, use the attribute value from the field.
//
{
        // get the default values
        MVector defaultDir = direction(block);
        double  defaultMag = magnitude(block);
        int magArraySize = magnitudeArray.length();
        int dirArraySize = directionArray.length();
        int magOwnerArraySize = magnitudeOwnerArray.length();
        int dirOwnerArraySize = directionOwnerArray.length();
        int numOfOwner = magOwnerArraySize;
        if( dirOwnerArraySize > numOfOwner )
            numOfOwner = dirOwnerArraySize;

        double  magnitude = defaultMag;
        MVector direction = defaultDir;

        for (int ptIndex = 0; ptIndex < receptorSize; ptIndex ++ ) {
            if(receptorSize == magArraySize)
                magnitude = magnitudeArray[ptIndex];
            if(receptorSize == dirArraySize)
                direction = directionArray[ptIndex];
            if( numOfOwner > 0) {
                for( int nthOwner = 0; nthOwner < numOfOwner; nthOwner++ ) {
                    if(magOwnerArraySize == numOfOwner)
                        magnitude = magnitudeOwnerArray[nthOwner];
                    if(dirOwnerArraySize == numOfOwner)
                        direction = directionOwnerArray[nthOwner];
                    outputForce.append( direction * magnitude );
                }
            } else {
                outputForce.append( direction * magnitude );
            }
        }
}