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

/**
 * @author mrdoob / http://mrdoob.com/
 */

THREE.SphereGeometry = function ( radius, widthSegments, heightSegments, phiStart, phiLength, thetaStart, thetaLength ) {

    THREE.Geometry.call( this );

    this.radius = radius = radius || 50;

    this.widthSegments = widthSegments = Math.max( 3, Math.floor( widthSegments ) || 8 );
    this.heightSegments = heightSegments = Math.max( 2, Math.floor( heightSegments ) || 6 );

    this.phiStart = phiStart = phiStart !== undefined ? phiStart : 0;
    this.phiLength = phiLength = phiLength !== undefined ? phiLength : Math.PI * 2;

    this.thetaStart = thetaStart = thetaStart !== undefined ? thetaStart : 0;
    this.thetaLength = thetaLength = thetaLength !== undefined ? thetaLength : Math.PI;

    var x, y, vertices = [], uvs = [];

    for ( y = 0; y <= heightSegments; y ++ ) {

        var verticesRow = [];
        var uvsRow = [];

        for ( x = 0; x <= widthSegments; x ++ ) {

            var u = x / widthSegments;
            var v = y / heightSegments;

            var vertex = new THREE.Vector3();
            vertex.x = - radius * Math.cos( phiStart + u * phiLength ) * Math.sin( thetaStart + v * thetaLength );
            vertex.y = radius * Math.cos( thetaStart + v * thetaLength );
            vertex.z = radius * Math.sin( phiStart + u * phiLength ) * Math.sin( thetaStart + v * thetaLength );

            this.vertices.push( vertex );

            verticesRow.push( this.vertices.length - 1 );
            uvsRow.push( new THREE.Vector2( u, 1 - v ) );

        }

        vertices.push( verticesRow );
        uvs.push( uvsRow );

    }

    for ( y = 0; y < this.heightSegments; y ++ ) {

        for ( x = 0; x < this.widthSegments; x ++ ) {

            var v1 = vertices[ y ][ x + 1 ];
            var v2 = vertices[ y ][ x ];
            var v3 = vertices[ y + 1 ][ x ];
            var v4 = vertices[ y + 1 ][ x + 1 ];

            var n1 = this.vertices[ v1 ].clone().normalize();
            var n2 = this.vertices[ v2 ].clone().normalize();
            var n3 = this.vertices[ v3 ].clone().normalize();
            var n4 = this.vertices[ v4 ].clone().normalize();

            var uv1 = uvs[ y ][ x + 1 ].clone();
            var uv2 = uvs[ y ][ x ].clone();
            var uv3 = uvs[ y + 1 ][ x ].clone();
            var uv4 = uvs[ y + 1 ][ x + 1 ].clone();

            if ( Math.abs( this.vertices[ v1 ].y ) === this.radius ) {

                uv1.x = ( uv1.x + uv2.x ) / 2;
                this.faces.push( new THREE.Face3( v1, v3, v4, [ n1, n3, n4 ] ) );
                this.faceVertexUvs[ 0 ].push( [ uv1, uv3, uv4 ] );

            } else if ( Math.abs( this.vertices[ v3 ].y ) === this.radius ) {

                uv3.x = ( uv3.x + uv4.x ) / 2;
                this.faces.push( new THREE.Face3( v1, v2, v3, [ n1, n2, n3 ] ) );
                this.faceVertexUvs[ 0 ].push( [ uv1, uv2, uv3 ] );

            } else {

                this.faces.push( new THREE.Face3( v1, v2, v4, [ n1, n2, n4 ] ) );
                this.faceVertexUvs[ 0 ].push( [ uv1, uv2, uv4 ] );

                this.faces.push( new THREE.Face3( v2, v3, v4, [ n2.clone(), n3, n4.clone() ] ) );
                this.faceVertexUvs[ 0 ].push( [ uv2.clone(), uv3, uv4.clone() ] );

            }

        }

    }

    this.computeCentroids();
    this.computeFaceNormals();

    this.boundingSphere = new THREE.Sphere( new THREE.Vector3(), radius );

};

THREE.SphereGeometry.prototype = Object.create( THREE.Geometry.prototype );