splitUVCmd/splitUVCmd.cpp
 
 
 
splitUVCmd/splitUVCmd.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.
// ==========================================================================
//+

//
// File: splitUVCmd.cpp
//
// MEL Command: splitUV
//
// Author: Lonnie Li
//

#include "splitUVCmd.h"
#include "splitUVNode.h"

// Function Sets
//
#include <maya/MFnDependencyNode.h>
#include <maya/MFnMesh.h>
#include <maya/MFnSingleIndexedComponent.h>

// Iterators
//
#include <maya/MItSelectionList.h>
#include <maya/MItMeshPolygon.h>

// General Includes
//
#include <maya/MGlobal.h>
#include <maya/MSelectionList.h>
#include <maya/MPlug.h>

#include <maya/MIOStream.h>

// Status Checking Macro - MCheckStatus (Debugging tool)
//
#define MCheckStatus(status,message)    \
        if( MS::kSuccess != status ) {          \
                cerr << message << "\n";                \
                return status;                                  \
        }


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

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

void* splitUV::creator()
//
//      Description:
//              this method exists to give Maya a way to create new objects
//      of this type. 
//
//      Return Value:
//              a new object of this type
//
{
        return new splitUV();
}

bool splitUV::isUndoable() const
//
//      Description:
//              this method tells Maya this command is undoable.  It is added to the 
//              undo queue if it is.
//
//      Return Value:
//              true if this command is undoable.
//
{
        return true;
}

MStatus splitUV::doIt( const MArgList& )
//
//      Description:
//              implements the MEL splitUV command.
//
//      Arguments:
//              args - the argument list that was passes to the command from MEL
//
//      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 status;

        // Parse the selection list for objects with selected UV components.
        // To simplify things, we only take the first object that we find with
        // selected UVs and operate on that object alone.
        //
        // All other objects are ignored and return warning messages indicating
        // this limitation.
        //
        MSelectionList selList;
        MGlobal::getActiveSelectionList( selList );
        MItSelectionList selListIter( selList );
        selListIter.setFilter( MFn::kMesh );

        // The splitUV node only accepts a component list input, so we build
        // a component list using MFnComponentListData.
        //
        // MIntArrays could also be passed into the node to represent the uvIds,
        // but are less storage efficient than component lists, since consecutive 
        // components are bundled into a single entry in component lists.
        //
        MFnComponentListData compListFn;
        compListFn.create();
        bool found = false;
        bool foundMultiple = false;

        for( ; !selListIter.isDone(); selListIter.next() )
        {
                MDagPath dagPath;
                MObject component;
                selListIter.getDagPath( dagPath, component );

                // Check for selected UV components
                //
                if( component.apiType() == MFn::kMeshMapComponent )
                {
                        if( !found )
                        {
                                // The variable 'component' holds all selected components on the selected
                                // object, thus only a single call to MFnComponentListData::add() is needed
                                // to store the selected components for a given object.
                                //
                                compListFn.add( component );

                                // Copy the component list created by MFnComponentListData into our local
                                // component list MObject member.
                                //
                                fComponentList = compListFn.object();

                                // Locally store the actual uvIds of the selected UVs so that this command
                                // can directly modify the mesh in the case when there is no history and
                                // history is turned off.
                                //
                                MFnSingleIndexedComponent compFn( component );
                                compFn.getElements( fSelUVs );

                                // Ensure that this DAG path will point to the shape of our object.
                                // Set the DAG path for the polyModifierCmd.
                                //
                                dagPath.extendToShape();
                                setMeshNode( dagPath );
                                found = true;
                        }
                        else
                        {
                                // Break once we have found a multiple object holding selected UVs, since
                                // we are not interested in how many multiple objects there are, only
                                // the fact that there are multiple objects.
                                //
                                foundMultiple = true;
                                break;
                        }
                }
        }
        if( foundMultiple )
        {
                displayWarning("Found more than one object with selected UVs - Only operating on first found object.");
        }

        // Initialize the polyModifierCmd node type - mesh node already set
        //
        setModifierNodeType( splitUVNode::id );

        if( found )
        {
                if( validateUVs() )
                {
                        // Now, pass control over to the polyModifierCmd::doModifyPoly() method
                        // to handle the operation.
                        //
                        status = doModifyPoly();
                        
                        if( status == MS::kSuccess )
                        {
                                setResult( "splitUV command succeeded!" );
                        }
                        else
                        {
                                displayError( "splitUV command failed!" );
                        }
                }
                else
                {
                        displayError( "splitUV command failed: Selected UVs are not splittable" );
                        status = MS::kFailure;
                }
        }
        else
        {
                displayError( "splitUV command failed: Unable to find selected UVs" );
                status = MS::kFailure;
        }
        
        return status;
}

MStatus splitUV::redoIt()
//
//      Description:
//              Implements redo for the MEL splitUV command. 
//
//              This method is called when the user has undone a command of this type
//              and then redoes it.  No arguments are passed in as all of the necessary
//              information is cached by the doIt method.
//
//      Return Value:
//              MS::kSuccess - command succeeded
//              MS::kFailure - redoIt failed.  this is a serious problem that will
//                     likely cause the undo queue to be purged
//
{
        MStatus status;

        // Process the polyModifierCmd
        //
        status = redoModifyPoly();

        if( status == MS::kSuccess )
        {
                setResult( "splitUV command succeeded!" );
        }
        else
        {
                displayError( "splitUV command failed!" );
        }

        return status;
}

MStatus splitUV::undoIt()
//
//      Description:
//              implements undo for the MEL splitUV command.  
//
//              This method is called to undo a previous command of this type.  The 
//              system should be returned to the exact state that it was it previous 
//              to this command being executed.  That includes the selection state.
//
//      Return Value:
//              MS::kSuccess - command succeeded
//              MS::kFailure - redoIt failed.  this is a serious problem that will
//                     likely cause the undo queue to be purged
//
{
        MStatus status;

        status = undoModifyPoly();

        if( status == MS::kSuccess )
        {
                setResult( "splitUV undo succeeded!" );
        }
        else
        {
                setResult( "splitUV undo failed!" );
        }
    
        return status;
}

MStatus splitUV::initModifierNode( MObject modifierNode )
{
        MStatus status;

        // We need to tell the splitUV node which UVs to operate on. By overriding
        // the polyModifierCmd::initModifierNode() method, we can insert our own
        // modifierNode initialization code.
        //
        MFnDependencyNode depNodeFn( modifierNode );
        MObject uvListAttr;
        uvListAttr = depNodeFn.attribute( "inputComponents" );

        // Pass the component list down to the splitUV node
        //
        MPlug uvListPlug( modifierNode, uvListAttr );
        status = uvListPlug.setValue( fComponentList );

        return status;
}

MStatus splitUV::directModifier( MObject mesh )
{
        MStatus status;

        fSplitUVFactory.setMesh( mesh );
        fSplitUVFactory.setUVIds( fSelUVs );

        // Now, perform the splitUV
        //
        status = fSplitUVFactory.doIt();

        return status;
}

// Private Methods
//
bool splitUV::validateUVs()
//
// Description:
//
//              Validate the UVs for the splitUV operation. UVs are valid only if they are shared
//              by more than one face. While the splitUVNode is smart enough to not process the
//              split if a UV is not splittable, a splitUV node is still created by the polyModifierCmd.
//              So call this method to validate the UVs before calling doModifyPoly().
//
//              validateUVs() will return true so long as there is at least one valid UV. It will
//              also prune out any invalid UVs from both the component list and UVId array.
//
{
        // Get the mesh that we are operating on
        //
        MDagPath                dagPath = getMeshNode();
        MObject                 mesh = dagPath.node();

        // Get the number of faces sharing the selected UVs
        //
        MFnMesh                 meshFn( mesh );
        MItMeshPolygon  polyIter( mesh );
        MIntArray               selUVFaceCountArray;

        int i;
        int j;
        int count = 0;
        int selUVsCount = fSelUVs.length();

        for( i = 0; i < selUVsCount; i++ )
        {
                for( ; !polyIter.isDone(); polyIter.next() )
                {
                        if( polyIter.hasUVs() )
                        {
                                int polyVertCount = polyIter.polygonVertexCount();

                                for( j = 0; j < polyVertCount; j++ )
                                {
                                        int UVIndex = 0;
                                        polyIter.getUVIndex(j, UVIndex);

                                        if( UVIndex == fSelUVs[i] )
                                        {
                                                count++;
                                                break;
                                        }
                                }
                        }
                }

                selUVFaceCountArray.append(count);
        }

        // Now, check to make sure that at least one UV is being shared by more than one
        // face. So long as we have one UV that we can operate on, we should proceed and let
        // the splitUVNode ignore the UVs which are only shared by one face.
        //
        bool isValid = false;
        MIntArray validUVIndices;

        for( i = 0; i < selUVsCount; i++ )
        {
                if( selUVFaceCountArray[i] > 1 )
                {
                        isValid = true;
                        validUVIndices.append(i);
                }
        }

        if( isValid )
        {
                pruneUVs( validUVIndices );
        }

        return isValid;
}

MStatus splitUV::pruneUVs( MIntArray& validUVIndices )
//
// Description:
//
//              This method will remove any invalid UVIds from the component list and UVId array.
//              The benefit of this is to reduce the amount of extra processing that the node would
//              have to perform. It will result in less iterations through the mesh as there are
//              less UVs to search for.
//
{
        MStatus status;

        unsigned i;
        MIntArray validUVIds;

        for( i = 0; i < validUVIndices.length(); i++ )
        {
                int uvIndex = validUVIndices[i];
                validUVIds.append( fSelUVs[uvIndex] );
        }

        // Replace the local int array of UVIds
        //
        fSelUVs.clear();
        fSelUVs = validUVIds;

        // Build the list of valid components
        //
        MFnSingleIndexedComponent compFn;
        compFn.create( MFn::kMeshMapComponent, &status );
        MCheckStatus( status, "compFn.create( MFn::kMeshMapComponent )" );
        status = compFn.addElements( validUVIds );
        MCheckStatus( status, "compFn.addElements( validUVIds )" );
        MObject component = compFn.object();

        // Replace the component list
        //
        MFnComponentListData compListFn;
        compListFn.create();
        status = compListFn.add( component );
        MCheckStatus( status, "compListFn.add( component )" );

        fComponentList = compListFn.object();

        return status;
}