//-
// ==========================================================================
// 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.
// ==========================================================================
//+
//
//  File: yTwist.cpp
//
//  Description:
// 		Example implementation of a deformer. This node
//		twists the deformed vertices around the y-axis.
//

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

#include <maya/MPxDeformerNode.h>
#include <maya/MItGeometry.h>

#include <maya/MTypeId.h> 
#include <maya/MPlug.h>
#include <maya/MDataBlock.h>
#include <maya/MDataHandle.h>

#include <maya/MFnNumericAttribute.h>
#include <maya/MFnPlugin.h>
#include <maya/MFnDependencyNode.h>

#include <maya/MPoint.h>
#include <maya/MMatrix.h>


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



class yTwist : public MPxDeformerNode
{
public:
						yTwist();
	virtual				~yTwist();

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

	// deformation function
	//
    virtual MStatus   	deform(MDataBlock& 		block,
							   MItGeometry& 	iter,
							   const MMatrix& 	mat,
							   unsigned int 	multiIndex);

public:
	// yTwist attributes
	//
	static  MObject     angle;  		// angle to twist
	
	static  MTypeId		id;

private:

};

MTypeId     yTwist::id( 0x8000e );

////////////////////////
// yTwist attributes  //
////////////////////////

MObject     yTwist::angle;


yTwist::yTwist() 
//
//	Description:
//		constructor
//
{ 
}

yTwist::~yTwist()
//
//	Description:
//		destructor
//
{}

void* yTwist::creator()
//
//	Description:
//		create the yTwist
//
{
	return new yTwist();
}

MStatus yTwist::initialize()
//
//	Description:
//		initialize the attributes
//
{
	// local attribute initialization
	//
	MFnNumericAttribute nAttr;
	angle=nAttr.create( "angle", "fa", MFnNumericData::kDouble );
	    nAttr.setDefault(0.0);
	    nAttr.setKeyable(true);
	addAttribute( angle); 

	// affects
	//
    attributeAffects( yTwist::angle, yTwist::outputGeom );

	return MS::kSuccess;
}

MStatus
yTwist::deform( MDataBlock& block,
				MItGeometry& iter,
				const MMatrix& /*m*/,
				unsigned int /*multiIndex*/)
//
// Method: deform
//
// Description:   Deform the point with a yTwist algorithm
//
// Arguments:
//   block		: the datablock of the node
//	 iter		: an iterator for the geometry to be deformed
//   m    		: matrix to transform the point into world space
//	 multiIndex : the index of the geometry that we are deforming
//
//
{
	MStatus status = MS::kSuccess;
	
	// determine the angle of the yTwist
	//
	MDataHandle angleData = block.inputValue(angle,&status);
	McheckErr(status, "Error getting angle data handle\n");
	double magnitude = angleData.asDouble();

	// determine the envelope (this is a global scale factor)
	//
	MDataHandle envData = block.inputValue(envelope,&status);
	McheckErr(status, "Error getting envelope data handle\n");	
	float env = envData.asFloat();	

	// iterate through each point in the geometry
	//
	for ( ; !iter.isDone(); iter.next()) {
		
		MPoint pt = iter.position();

		// do the twist
		//
		double ff = magnitude*pt.y*env;
		if (ff != 0.0) {
			double cct= cos(ff);
			double cst= sin(ff);
			double tt= pt.x*cct-pt.z*cst;
			pt.z= pt.x*cst + pt.z*cct;
			pt.x=tt;;
		}

		iter.setPosition(pt);
	}
	return status;
}

// standard initialization procedures
//

MStatus initializePlugin( MObject obj )
{
	MStatus result;
	MFnPlugin plugin( obj, PLUGIN_COMPANY, "3.0", "Any");
	result = plugin.registerNode( "yTwist", yTwist::id, yTwist::creator, 
								  yTwist::initialize, MPxNode::kDeformerNode );
	return result;
}

MStatus uninitializePlugin( MObject obj)
{
	MStatus result;
	MFnPlugin plugin( obj );
	result = plugin.deregisterNode( yTwist::id );
	return result;
}