three.js/src/extras/animation/KeyFrameAnimation.js

/**
 * @author mikael emtinger / http://gomo.se/
 * @author mrdoob / http://mrdoob.com/
 * @author alteredq / http://alteredqualia.com/
 * @author khang duong
 * @author erik kitson
 */

THREE.KeyFrameAnimation = function ( data ) {

	this.root = data.node;
	this.data = THREE.AnimationHandler.init( data );
	this.hierarchy = THREE.AnimationHandler.parse( this.root );
	this.currentTime = 0;
	this.timeScale = 0.001;
	this.isPlaying = false;
	this.isPaused = true;
	this.loop = true;

	// initialize to first keyframes

	for ( var h = 0, hl = this.hierarchy.length; h < hl; h ++ ) {

		var keys = this.data.hierarchy[h].keys,
			sids = this.data.hierarchy[h].sids,
			obj = this.hierarchy[h];

		if ( keys.length && sids ) {

			for ( var s = 0; s < sids.length; s++ ) {

				var sid = sids[ s ],
					next = this.getNextKeyWith( sid, h, 0 );

				if ( next ) {

					next.apply( sid );

				}

			}

			obj.matrixAutoUpdate = false;
			this.data.hierarchy[h].node.updateMatrix();
			obj.matrixWorldNeedsUpdate = true;

		}

	}

};


THREE.KeyFrameAnimation.prototype.play = function ( startTime ) {

	this.currentTime = startTime !== undefined ? startTime : 0;

	if ( this.isPlaying === false ) {

		this.isPlaying = true;

		// reset key cache

		var h, hl = this.hierarchy.length,
			object,
			node;

		for ( h = 0; h < hl; h++ ) {

			object = this.hierarchy[ h ];
			node = this.data.hierarchy[ h ];

			if ( node.animationCache === undefined ) {

				node.animationCache = {};
				node.animationCache.prevKey = null;
				node.animationCache.nextKey = null;
				node.animationCache.originalMatrix = object instanceof THREE.Bone ? object.skinMatrix : object.matrix;

			}

			var keys = this.data.hierarchy[h].keys;

			if (keys.length) {

				node.animationCache.prevKey = keys[ 0 ];
				node.animationCache.nextKey = keys[ 1 ];

				this.startTime = Math.min( keys[0].time, this.startTime );
				this.endTime = Math.max( keys[keys.length - 1].time, this.endTime );

			}

		}

		this.update( 0 );

	}

	this.isPaused = false;

	THREE.AnimationHandler.play( this );

};


THREE.KeyFrameAnimation.prototype.stop = function() {

	this.isPlaying = false;
	this.isPaused  = false;

	THREE.AnimationHandler.stop( this );

	// reset JIT matrix and remove cache

	for ( var h = 0; h < this.data.hierarchy.length; h++ ) {
		
		var obj = this.hierarchy[ h ];
		var node = this.data.hierarchy[ h ];

		if ( node.animationCache !== undefined ) {

			var original = node.animationCache.originalMatrix;

			if( obj instanceof THREE.Bone ) {

				original.copy( obj.skinMatrix );
				obj.skinMatrix = original;

			} else {

				original.copy( obj.matrix );
				obj.matrix = original;

			}

			delete node.animationCache;

		}

	}

};


// Update

THREE.KeyFrameAnimation.prototype.update = function ( delta ) {

	if ( this.isPlaying === false ) return;

	this.currentTime += delta * this.timeScale;

	//

	var duration = this.data.length;

	if ( this.loop === true && this.currentTime > duration ) {

		this.currentTime %= duration;

	}

	this.currentTime = Math.min( this.currentTime, duration );

	for ( var h = 0, hl = this.hierarchy.length; h < hl; h++ ) {

		var object = this.hierarchy[ h ];
		var node = this.data.hierarchy[ h ];

		var keys = node.keys,
			animationCache = node.animationCache;


		if ( keys.length ) {

			var prevKey = animationCache.prevKey;
			var nextKey = animationCache.nextKey;

			if ( nextKey.time <= this.currentTime ) {

				while ( nextKey.time < this.currentTime && nextKey.index > prevKey.index ) {

					prevKey = nextKey;
					nextKey = keys[ prevKey.index + 1 ];

				}

				animationCache.prevKey = prevKey;
				animationCache.nextKey = nextKey;

			}

			if ( nextKey.time >= this.currentTime ) {

				prevKey.interpolate( nextKey, this.currentTime );

			} else {

				prevKey.interpolate( nextKey, nextKey.time );

			}

			this.data.hierarchy[ h ].node.updateMatrix();
			object.matrixWorldNeedsUpdate = true;

		}

	}

};

// Get next key with

THREE.KeyFrameAnimation.prototype.getNextKeyWith = function( sid, h, key ) {

	var keys = this.data.hierarchy[ h ].keys;
	key = key % keys.length;

	for ( ; key < keys.length; key++ ) {

		if ( keys[ key ].hasTarget( sid ) ) {

			return keys[ key ];

		}

	}

	return keys[ 0 ];

};

// Get previous key with

THREE.KeyFrameAnimation.prototype.getPrevKeyWith = function( sid, h, key ) {

	var keys = this.data.hierarchy[ h ].keys;
	key = key >= 0 ? key : key + keys.length;

	for ( ; key >= 0; key-- ) {

		if ( keys[ key ].hasTarget( sid ) ) {

			return keys[ key ];

		}

	}

	return keys[ keys.length - 1 ];

};