source: other-projects/playing-in-the-street/summer-2013/trunk/Playing-in-the-Street-WPF/Content/Web/mrdoob-three.js-4862f5f/src/objects/Bone.js@ 28897

/**
 * @author mikael emtinger / http://gomo.se/
 * @author alteredq / http://alteredqualia.com/
 */

THREE.Bone = function( belongsToSkin ) {

    THREE.Object3D.call( this );

    this.skin = belongsToSkin;
    this.skinMatrix = new THREE.Matrix4();

};

THREE.Bone.prototype = Object.create( THREE.Object3D.prototype );

THREE.Bone.prototype.update = function ( parentSkinMatrix, forceUpdate ) {

    // update local

    if ( this.matrixAutoUpdate ) {

        forceUpdate |= this.updateMatrix();

    }

    // update skin matrix

    if ( forceUpdate || this.matrixWorldNeedsUpdate ) {

        if( parentSkinMatrix ) {

            this.skinMatrix.multiplyMatrices( parentSkinMatrix, this.matrix );

        } else {

            this.skinMatrix.copy( this.matrix );

        }

        this.matrixWorldNeedsUpdate = false;
        forceUpdate = true;

    }

    // update children

    var child, i, l = this.children.length;

    for ( i = 0; i < l; i ++ ) {

        this.children[ i ].update( this.skinMatrix, forceUpdate );

    }

};