createClipCmd/createClipCmd.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.
// ==========================================================================
//+

// DESCRIPTION:
// 
// Produces the MEL command "createClip".
// 
// This example demonstrates the steps for creating a nonlinear animation clip
// using the API. The clip is created either on the selected items or on a character
// set node that is supplied using the -c/-char flag. The plug-in creates the animation
// curves that make up the clip, places them in a source clip, and then instances the
// source clip twice.
//
// To use this plug-in:
//  (1) Create a sphere and select it.
//  (2) Execute the command:
//      createClip
//  (3) Open the Maya Trax Editor to see the clips in place on the timeline. 
//

#include <math.h>
#include <maya/MPxCommand.h>
#include <maya/MStatus.h>
#include <maya/MArgList.h>
#include <maya/MFnPlugin.h>
#include <maya/MObject.h>
#include <maya/MGlobal.h>
#include <maya/MSelectionList.h>
#include <maya/MItSelectionList.h>
#include <maya/MObjectArray.h>
#include <maya/MPlugArray.h>
#include <maya/MFnCharacter.h>
#include <maya/MFnClip.h>
#include <maya/MFnAnimCurve.h>
#include <maya/MDGModifier.h>

#include <maya/MIOStream.h>

#define CheckError(stat,msg)        \
    if ( MS::kSuccess != stat ) {   \
        displayError(msg);          \
        continue;                   \
    }


class createClip : public MPxCommand
{
public:
                createClip();
        ~createClip() override;

    MStatus     parseArgs( const MArgList& args );
    MStatus     doIt ( const MArgList& args ) override;
    MStatus     redoIt () override;
    MStatus     undoIt () override;
    bool        isUndoable() const override;

    static      void* creator();

private:
    MObject     fCharacter;
    MDGModifier fMod;
};

createClip::createClip()
{
}

createClip::~createClip() {}

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

bool createClip::isUndoable() const
{
    return true;
}

MStatus createClip::undoIt()
{
    MStatus status = fMod.undoIt();
    return status;
}

MStatus createClip::parseArgs( const MArgList& args )
//
// No arguments to parse.
//
{
    MStatus         stat = MS::kSuccess;
    MString         arg;
    MSelectionList  list;
    bool            charNameUsed = 0;
    MString         charName;
    const MString   charFlag            ("-c");
    const MString   charFlagLong        ("-char");

    // Parse the arguments.
    for ( unsigned int i = 0; i < args.length(); i++ ) {
        arg = args.asString( i, &stat );
        if (!stat)              
            continue;
                
        if ( arg == charFlag || arg == charFlagLong ) {
            // get the char name
            //
            if (i == args.length()-1) {
                arg += ": must specify a character name";
                displayError(arg);
                return MS::kFailure;
            }
            i++;
            args.get(i, charName);
            list.add(charName);
            charNameUsed = 1;
        }
        else {
            arg += ": unknown argument";
            displayError(arg);
            return MS::kFailure;
        }
    }

    if (charNameUsed) {
        // get the character corresponding to the node name
        //
        MItSelectionList iter (list);
        for ( /* nothing */ ; !iter.isDone(); iter.next() ) {
            MObject node;
            iter.getDependNode(node);
            if (node.apiType() == MFn::kCharacter) {
                fCharacter = node;
                break;
            }
        }
        if (fCharacter.isNull()) {
            MString errMsg("Character flag must specify a character node.");
            displayError(errMsg);
            return MS::kFailure;
        }
    }
    
    return stat;
}


MStatus createClip::doIt( const MArgList& args )
{
    // parse the command arguments
    //
    MStatus stat = parseArgs(args);
    if (stat != MS::kSuccess) {
        return stat;
    }
    
    unsigned int count = 0;

    // if the character flag was used, create the clip on the specified
    // character, otherwise, create a character
    //
    MFnCharacter fnCharacter;
    if (fCharacter.isNull()) {
        MSelectionList activeList;
        MGlobal::getActiveSelectionList (activeList);
        if (0 == activeList.length()) {
            MString errMsg("No character was specified, and no objects were selected.");
            displayError(errMsg);
            return MS::kFailure;
        }
        // create a character using the selection list
        //
        fCharacter = fnCharacter.create(activeList,MFnSet::kNone,&stat);
        if (stat != MS::kSuccess) {
            MString errMsg("Failed to create character using the selection.");
            displayError(errMsg);
            return MS::kFailure;
        }
    } else {
        fnCharacter.setObject(fCharacter);
    }

    // Get the array of members of the character. We will create a clip
    // for them.
    //
    MPlugArray plugs;
    fnCharacter.getMemberPlugs(plugs);

    // Now create a animCurves to use as a clip for the character.
    // The curves will be set up between frames 0 and 10;
    //
    MTime start(0.0);
    MTime duration(10.0);
    MObjectArray clipCurves;
    
    for (count = 0; count < plugs.length(); ++count) {
        // Now create a bunch of animCurves to use as a clip for the
        // character
        //
        MFnAnimCurve fnCurve;
//      AnimCurveType plugType = fnCurve.timedAnimCurveTypeForPlug(plugs[count]);
        MObject curve = fnCurve.create(MFnAnimCurve::kAnimCurveTL); // plugType);
        fnCurve.addKeyframe(start,5.0);
        fnCurve.addKeyframe(duration,15.0);
        clipCurves.append(curve);
    }
    
    // Create a source clip node and add the animation to it
    //
    MFnClip fnClipCreate;
    MObject sourceClip = fnClipCreate.createSourceClip(start,duration,fMod,&stat);
    fnCharacter.attachSourceToCharacter(sourceClip,fMod);   
    for (count = 0; count < plugs.length(); ++count) {
        MPlug animPlug = plugs[count];
        fnCharacter.addCurveToClip(clipCurves[count],sourceClip,animPlug,fMod);
    }

    // instance the clip
    //
    MTime schedStart(15.0);
    MObject instancedClip = fnClipCreate.createInstancedClip(sourceClip,
                                                             schedStart,
                                                             fMod,
                                                             &stat);
    fnCharacter.attachInstanceToCharacter(instancedClip,fMod);

    // instance the clip a second time, at time 30
    //
    schedStart.setValue(30.0);
    MObject instancedClip2 = fnClipCreate.createInstancedClip(sourceClip,
                                                              schedStart,
                                                              fMod,
                                                              &stat);
    fnCharacter.attachInstanceToCharacter(instancedClip2,fMod);

    return stat;
}

MStatus createClip::redoIt()
{
    MStatus status = fMod.doIt();
    return status;
}

MStatus initializePlugin( MObject obj )
{
    MStatus   status;
    MFnPlugin plugin( obj, PLUGIN_COMPANY, "4.0", "Any");

    status = plugin.registerCommand( "createClip", createClip::creator );
    if (!status) {
        status.perror("registerCommand");
        return status;
    }

    return status;
}

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

    status = plugin.deregisterCommand( "createClip" );
    if (!status) {
        status.perror("deregisterCommand");
    }
    return status;
}