listPolyHolesCmd.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 <maya/MIOStream.h>
#include <maya/MSimple.h>
#include <maya/MSelectionList.h>
#include <maya/M3dView.h>
#include <maya/MGlobal.h>
#include <maya/MFnDependencyNode.h>
#include <maya/MFnMesh.h>
#include <maya/MDagPath.h>
#include <math.h>

DeclareSimpleCommand( listPolyHoles, PLUGIN_COMPANY, "4.5");

MStatus listPolyHoles::doIt( const MArgList& args )
//
//      Description:
//              Implements the MEL listPolyHoles command.  This command outputs a list
//              of all the holes in each selected polymesh.
//              
//      Arguments:
//              args - the argument list that was passes to the command from MEL.  This
//                         command takes no arguments.
//
//      Return Value:
//              MS::kSuccess - command succeeded
//              MS::kFailure - command failed (returning this value will cause the 
//                     MEL script that is being run to terminate unless the
//                     error is caught using a "catch" statement.
//
{
        MStatus stat = MS::kSuccess;

        MSelectionList curSel;
        MGlobal::getActiveSelectionList( curSel );

        cout<<endl;
        cout<<"*****************"<<endl;
        cout<<"* listPolyHoles *"<<endl;
        cout<<"*****************"<<endl;

        // iterate through the selection list, and find holes in any selected
        // polygons.
        //
        int numSelected = curSel.length();
        for( int s = 0; s < numSelected; s++ )
        {
                MDagPath dagPath;
                MObject node;

                // get the selected item, figure out if it's a polymesh or not
                //
                curSel.getDagPath( s, dagPath );
                if( dagPath.extendToShape() != MS::kSuccess )
                {
                        // selection does not correspond to a DAG shape
                        //
                        cout<<" Error - object is not a polymesh"<<endl;
                        stat = MS::kFailure;
                        return stat;
                }

                node = dagPath.node();
                MFnDependencyNode fnNode( node );
                cout<<endl<<"Looking for holes in "<<fnNode.name().asChar()<<endl;
                
                MStatus polyStatus;
                MFnMesh fnMesh( node, &polyStatus );

                if( polyStatus == MS::kSuccess )
                {
                        // Retrieve the list of holes in the polymesh.
                        // 'holeInfo' array stores 3 integers for each hole:
                        // 
                        //      [ face, numVertices, startIndex ]
                        //
                        // where 'face' is the index of the face in which the 
                        // hole is found, 'numVertices' is the number of vertices
                        // that define the hole, and 'startIndex' is the starting
                        // index of the list of hole vertices in the 'holeVertices'
                        // array.
                        //
                        MIntArray holeInfo;

                        // 'holeVertices' array contains a linear listing of the
                        // vertices comprising all the holes in the selected polymesh.
                        // information from the 'holeInfo' array is used to index into
                        // this list to extract the list of vertices for each hole.
                        //
                        MIntArray holeVertices;
                        MStatus holeStatus;

                        holeInfo.clear();
                        holeVertices.clear();
                        
                        // get the holes
                        //
                        int numHoles = fnMesh.getHoles( holeInfo, holeVertices, &holeStatus );
                        if( holeStatus == MS::kSuccess )
                        {
                                cout<<"    Poly has "<<numHoles<<" holes"<<endl;

                                for( int h = 0; h < numHoles; h++ )
                                {
                                        // retrieve the hole face index, number of hole vertices, and
                                        // hole vertex list start index for the current hole.
                                        //
                                        int holeFace = holeInfo[3*h];
                                        int holeNumVertices = holeInfo[3*h+1];
                                        int holeStartIndex = holeInfo[3*h+2];

                                        cout<<"    Hole "<<h<<":"<<endl;
                                        cout<<"        Face "<<holeFace<<endl;
                                        cout<<"        Start index "<<holeStartIndex<<endl;
                                        cout<<"        "<<holeNumVertices<<" vertices: ";

                                        // retrieve the hole vertex indices from the 'holeVertices'
                                        // array.  The indices are a list of 'holeNumVertices' entries,
                                        // starting at index 'holeStartIndex'.
                                        //
                                        for( int v = 0; v < holeNumVertices; v++ )
                                        {
                                                int index = holeStartIndex + v;
                                                cout<<holeVertices[index];
                                        }

                                        cout<<endl;
                                }
                                
                        }
                        else
                        {
                                // something went wrong trying to retrieve the poly holes
                                //
                                cout<<"    Error retrieving polygon holes"<<endl;
                                stat = MS::kFailure;
                        }
                }
                else
                {
                        // the current selection item was not a polymesh, so we can't retrieve
                        // holes for it.
                        //
                        cout<<" Error - object is not a polymesh"<<endl;
                        stat = MS::kFailure;
                }
        }
        
        setResult( "listPolyHoles completed." );
        return stat;
}