Geometry.js

/**
 * @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 ( useVertexNormals ) {

		var n, nl, 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 ];

            if ( useVertexNormals && face.vertexNormals.length  ) {
                
                // set face normal to average of vertex normals
                
                cb.set( 0, 0, 0 );

                for ( n = 0, nl = face.normal.length; n < nl; n++ ) {
                    cb.x += face.vertexNormals[n].x;
                    cb.y += face.vertexNormals[n].y;
                    cb.z += face.vertexNormals[n].z;
                }

                cb.x /= 3;
                cb.y /= 3;
                cb.z /= 3;

                if ( !cb.isZero() ) {

                    cb.normalize();

                }

                face.normal.copy( cb );
            }
            
            else {
                
                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 );
            }

		}

	},
    
    computeBoundingBox: function ( ) {
        
        if ( this.vertices.length > 0 ) {
            
            this.bbox = { 'x': [ this.vertices[ 0 ].position.x, this.vertices[ 0 ].position.x ], 
                          'y': [ this.vertices[ 0 ].position.y, this.vertices[ 0 ].position.y ], 
                          'z': [ this.vertices[ 0 ].position.z, this.vertices[ 0 ].position.z ] };
            
            var v, vl;
            
            for ( v = 1, vl = this.vertices.length; v < vl; v++ ) {

                vertex = this.vertices[ v ];
                
                if ( vertex.position.x < this.bbox.x[ 0 ] )
                    this.bbox.x[ 0 ] = vertex.position.x;
                else if ( vertex.position.x > this.bbox.x[ 1 ] )
                    this.bbox.x[ 1 ] = vertex.position.x;

                if ( vertex.position.y < this.bbox.y[ 0 ] )
                    this.bbox.y[ 0 ] = vertex.position.y;
                else if ( vertex.position.y > this.bbox.y[ 1 ] )
                    this.bbox.y[ 1 ] = vertex.position.y;

                if ( vertex.position.z < this.bbox.z[ 0 ] )
                    this.bbox.z[ 0 ] = vertex.position.z;
                else if ( vertex.position.z > this.bbox.z[ 1 ] )
                    this.bbox.z[ 1 ] = vertex.position.z;

            }
        }
    },

	toString: function () {

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

	}

};