PropertyBinding.js

/**
 *
 * A track bound to a real value in the scene graph.
 * 
 * @author Ben Houston / http://clara.io/
 * @author David Sarno / http://lighthaus.us/
 */

THREE.PropertyBinding = function ( rootNode, trackName ) {

	this.rootNode = rootNode;
	this.trackName = trackName;

	var parseResults = THREE.PropertyBinding.parseTrackName( trackName );

	//console.log( parseResults );
	this.directoryName = parseResults.directoryName;
	this.nodeName = parseResults.nodeName;
	this.objectName = parseResults.objectName;
	this.objectIndex = parseResults.objectIndex;
	this.propertyName = parseResults.propertyName;
	this.propertyIndex = parseResults.propertyIndex;

	this.node = THREE.PropertyBinding.findNode( rootNode, this.nodeName );

	this.cumulativeValue = null;
	this.cumulativeWeight = 0;
};

THREE.PropertyBinding.prototype = {

	constructor: THREE.PropertyBinding,

	reset: function() {

		this.cumulativeValue = null;
		this.cumulativeWeight = 0;

	},

	accumulate: function( value, weight ) {
		
		var lerp = THREE.AnimationUtils.getLerpFunc( value, true );

		this.accumulate = function( value, weight ) {

			if( this.cumulativeWeight === 0 ) {

				if( this.cumulativeValue === null ) {
					this.cumulativeValue = THREE.AnimationUtils.clone( value );
				}
				this.cumulativeWeight = weight;
				//console.log( this );
	
			}
			else {

				var lerpAlpha = weight / ( this.cumulativeWeight + weight );
				this.cumulativeValue = lerp( this.cumulativeValue, value, lerpAlpha );
				this.cumulativeWeight += weight;
				//console.log( this );

			}
		}

		this.accumulate( value, weight );

	},

	apply: function() {

		// for speed capture the setter pattern as a closure (sort of a memoization pattern: https://en.wikipedia.org/wiki/Memoization)
		if( ! this.internalApply ) {

			 //console.log( "PropertyBinding", this );

			 var equalsFunc = THREE.AnimationUtils.getEqualsFunc( this.cumulativeValue );

			 var targetObject = this.node;

	 		// ensure there is a value node
			if( ! targetObject ) {
				console.error( "  trying to update node for track: " + this.trackName + " but it wasn't found." );
				return;
			}

			if( this.objectName ) {
				// special case were we need to reach deeper into the hierarchy to get the face materials....
				if( this.objectName === "materials" ) {
					if( ! targetObject.material ) {
						console.error( '  can not bind to material as node does not have a material', this );
						return;				
					}
					if( ! targetObject.material.materials ) {
						console.error( '  can not bind to material.materials as node.material does not have a materials array', this );
						return;				
					}
					targetObject = targetObject.material.materials;
				}
				else if( this.objectName === "bones" ) {
					if( ! targetObject.skeleton ) {
						console.error( '  can not bind to bones as node does not have a skeleton', this );
					}
					targetObject = targetObject.skeleton.bones;

					// TODO/OPTIMIZE, skip this if propertyIndex is already an integer, and convert the integer string to a true integer.
					
					// support resolving morphTarget names into indices.
					//console.log( "  resolving bone name: ", this.objectIndex );
					for( var i = 0; i < this.node.skeleton.bones.length; i ++ ) {
						if( this.node.skeleton.bones[i].name === this.objectIndex ) {
							//console.log( "  resolved to index: ", i );
							this.objectIndex = i;
							break;
						}
					}
				}
				else {

					if( targetObject[ this.objectName ] === undefined ) {
						console.error( '  can not bind to objectName of node, undefined', this );			
						return;
					}
					targetObject = targetObject[ this.objectName ];
				}
				
				if( this.objectIndex !== undefined ) {
					if( targetObject[ this.objectIndex ] === undefined ) {
						console.error( "  trying to bind to objectIndex of objectName, but is undefined:", this, targetObject );
						return;				
					}

					targetObject = targetObject[ this.objectIndex ];
				}

			}

	 		// special case mappings
	 		var nodeProperty = targetObject[ this.propertyName ];
			if( ! nodeProperty ) {
				console.error( "  trying to update property for track: " + this.nodeName + '.' + this.propertyName + " but it wasn't found.", targetObject );				
				return;
			}

			// access a sub element of the property array (only primitives are supported right now)
			if( this.propertyIndex !== undefined ) {

				if( this.propertyName === "morphTargetInfluences" ) {
					// TODO/OPTIMIZE, skip this if propertyIndex is already an integer, and convert the integer string to a true integer.
					
					// support resolving morphTarget names into indices.
					//console.log( "  resolving morphTargetInfluence name: ", this.propertyIndex );
					if( ! this.node.geometry ) {
						console.error( '  can not bind to morphTargetInfluences becasuse node does not have a geometry', this );				
					}
					if( ! this.node.geometry.morphTargets ) {
						console.error( '  can not bind to morphTargetInfluences becasuse node does not have a geometry.morphTargets', this );				
					}
					
					for( var i = 0; i < this.node.geometry.morphTargets.length; i ++ ) {
						if( this.node.geometry.morphTargets[i].name === this.propertyIndex ) {
							//console.log( "  resolved to index: ", i );
							this.propertyIndex = i;
							break;
						}
					}
				}

				//console.log( '  update property array ' + this.propertyName + '[' + this.propertyIndex + '] via assignment.' );				
				this.internalApply = function() {
					if( ! equalsFunc( nodeProperty[ this.propertyIndex ], this.cumulativeValue ) ) {
						nodeProperty[ this.propertyIndex ] = this.cumulativeValue;
						return true;
					}
					return false;
				};
			}
			// must use copy for Object3D.Euler/Quaternion		
			else if( nodeProperty.copy ) {
				//console.log( '  update property ' + this.name + '.' + this.propertyName + ' via a set() function.' );				
				this.internalApply = function() {
					if( ! equalsFunc( nodeProperty, this.cumulativeValue ) ) {
						nodeProperty.copy( this.cumulativeValue );
						return true;
					}
					return false;
				}
			}
			// otherwise just set the property directly on the node (do not use nodeProperty as it may not be a reference object)
			else {

				//console.log( '  update property ' + this.name + '.' + this.propertyName + ' via assignment.' );				
				this.internalApply = function() {
					if( ! equalsFunc( targetObject[ this.propertyName ], this.cumulativeValue ) ) {
						targetObject[ this.propertyName ] = this.cumulativeValue;	
						return true;
					}
					return false;
				}
			}

			// trigger node dirty			
			if( targetObject.needsUpdate !== undefined ) { // material
				//console.log( '  triggering material as dirty' );
				this.triggerDirty = function() {
					this.node.needsUpdate = true;
				}
			}			
			else if( targetObject.matrixWorldNeedsUpdate !== undefined ) { // node transform
				//console.log( '  triggering node as dirty' );
				this.triggerDirty = function() {
					targetObject.matrixWorldNeedsUpdate = true;
				}
			}

		}

		// early exit if there is nothing to apply.
		if( this.cumulativeWeight > 0 ) {
		
			var valueChanged = this.internalApply();

			if( valueChanged && this.triggerDirty ) {
				this.triggerDirty();
			}

			// reset accumulator
			this.cumulativeValue = null;
			this.cumulativeWeight = 0;

		}
	},

	get: function() {

		throw new Error( "TODO" );

	}

};


THREE.PropertyBinding.parseTrackName = function( trackName ) {

	// matches strings in the form of:
	//    nodeName.property
	//    nodeName.property[accessor]
	//    nodeName.material.property[accessor]
	//    uuid.property[accessor]
	//    uuid.objectName[objectIndex].propertyName[propertyIndex]
	//    parentName/nodeName.property
	//    parentName/parentName/nodeName.property[index]
	//	  .bone[Armature.DEF_cog].position
	// created and tested via https://regex101.com/#javascript

	var re = /^(([\w]+\/)*)([\w-\d]+)?(\.([\w]+)(\[([\w\d\[\]\_. ]+)\])?)?(\.([\w.]+)(\[([\w\d\[\]\_. ]+)\])?)$/; 
	var matches = re.exec(trackName);

	if( ! matches ) {
		throw new Error( "cannot parse trackName at all: " + trackName );
	}

    if (matches.index === re.lastIndex) {
        re.lastIndex++;
    }

	var results = {
		directoryName: matches[1],
		nodeName: matches[3], 	// allowed to be null, specified root node.
		objectName: matches[5],
		objectIndex: matches[7],
		propertyName: matches[9],
		propertyIndex: matches[11]	// allowed to be null, specifies that the whole property is set.
	};

	//console.log( "PropertyBinding.parseTrackName", trackName, results, matches );

	if( results.propertyName === null || results.propertyName.length === 0 ) {
		throw new Error( "can not parse propertyName from trackName: " + trackName );
	}

	return results;

};

// TODO: Cache this at some point
THREE.PropertyBinding.findNode = function( root, nodeName ) {

	//console.log( 'AnimationUtils.findNode( ' + root.name + ', nodeName: ' + nodeName + ')');
	
	if( ! nodeName || nodeName === "" || nodeName === "root" || nodeName === "." || nodeName === -1 || nodeName === root.name || nodeName === root.uuid ) {

		//console.log( '  root.' );
		return root;

	}

	// (2) search into skeleton bones.
	if( root.skeleton ) {

		var searchSkeleton = function( skeleton ) {

			for( var i = 0; i < skeleton.bones.length; i ++ ) {

				var bone = skeleton.bones[i];

				if( bone.name === nodeName ) {

					return bone;

				}
			}

			return null;

		};

		var bone = searchSkeleton( root.skeleton );

		if( bone ) {

			//console.log( '  bone: ' + bone.name + '.' );
			return bone;

		}
	}

	// (3) search into node subtree.
	if( root.children ) {

		var searchNodeSubtree = function( children ) {

			for( var i = 0; i < children.length; i ++ ) {

				var childNode = children[i];

				if( childNode.name === nodeName || childNode.uuid === nodeName ) {

					return childNode;

				}

				var result = searchNodeSubtree( childNode.children );

				if( result ) return result;

			}

			return null;	

		};

		var subTreeNode = searchNodeSubtree( root.children );

		if( subTreeNode ) {

			//console.log( '  node: ' + subTreeNode.name + '.' );
			return subTreeNode;

		}

	}

	//console.log( "   <null>.  No node found for name: " + nodeName );

	return null;
}