/**
 * @author mr.doob / http://mrdoob.com/
 * @author kile / http://kile.stravaganza.org/
 */

THREE.Geometry = function () {

	this.vertices = [];
	this.faces = [];
	this.uvs = [];

};

THREE.Geometry.prototype = {

	computeCentroids: function () {

		var f, fl, face;

		for ( f = 0, fl = this.faces.length; f < fl; f++ ) {

			face = this.faces[ f ];
			face.centroid.set( 0, 0, 0 );

			if ( face instanceof THREE.Face3 ) {

				face.centroid.addSelf( this.vertices[ face.a ].position );
				face.centroid.addSelf( this.vertices[ face.b ].position );
				face.centroid.addSelf( this.vertices[ face.c ].position );
				face.centroid.divideScalar( 3 );

			} else if ( face instanceof THREE.Face4 ) {

				face.centroid.addSelf( this.vertices[ face.a ].position );
				face.centroid.addSelf( this.vertices[ face.b ].position );
				face.centroid.addSelf( this.vertices[ face.c ].position );
				face.centroid.addSelf( this.vertices[ face.d ].position );
				face.centroid.divideScalar( 4 );

			}

		}

	},

	computeNormals: function () {

		var v, vl, vertex, f, fl, face, vA, vB, vC, cb = new THREE.Vector3(), ab = new THREE.Vector3();

		for ( v = 0, vl = this.vertices.length; v < vl; v++ ) {

			vertex = this.vertices[ v ];
			vertex.normal.set( 0, 0, 0 );

		}

		for ( f = 0, fl = this.faces.length; f < fl; f++ ) {

			face = this.faces[ f ];

			vA = this.vertices[ face.a ];
			vB = this.vertices[ face.b ];
			vC = this.vertices[ face.c ];

			cb.sub( vC.position, vB.position );
			ab.sub( vA.position, vB.position );
			cb.crossSelf( ab );

			if ( !cb.isZero() ) {

				cb.normalize();

			}

			face.normal.copy( cb );

		}

	},

	toString: function () {

		return 'THREE.Geometry ( vertices: ' + this.vertices + ', faces: ' + this.faces + ' )';

	}

};