Merge pull request #5851 from WestLangley/dev-cylinder

Support Sector of CylinderGeometry

src/extras/geometries/CylinderGeometry.js

@@ -2,7 +2,7 @@
  * @author mrdoob / http://mrdoob.com/
  */
 
-THREE.CylinderGeometry = function ( radiusTop, radiusBottom, height, radialSegments, heightSegments, openEnded ) {
+THREE.CylinderGeometry = function ( radiusTop, radiusBottom, height, radialSegments, heightSegments, openEnded, thetaStart, thetaLength ) {
 
 	THREE.Geometry.call( this );
 
@@ -14,7 +14,9 @@ THREE.CylinderGeometry = function ( radiusTop, radiusBottom, height, radialSegme
 		height: height,
 		radialSegments: radialSegments,
 		heightSegments: heightSegments,
-		openEnded: openEnded
+		openEnded: openEnded,
+		thetaStart: thetaStart,
+		thetaLength: thetaLength
 	};
 
 	radiusTop = radiusTop !== undefined ? radiusTop : 20;
@@ -25,6 +27,8 @@ THREE.CylinderGeometry = function ( radiusTop, radiusBottom, height, radialSegme
 	heightSegments = heightSegments || 1;
 
 	openEnded = openEnded !== undefined ? openEnded : false;
+	thetaStart = thetaStart !== undefined ? thetaStart : 0;
+	thetaLength = thetaLength !== undefined ? thetaLength : 2 * Math.PI;
 
 	var heightHalf = height / 2;
 
@@ -43,9 +47,9 @@ THREE.CylinderGeometry = function ( radiusTop, radiusBottom, height, radialSegme
 			var u = x / radialSegments;
 
 			var vertex = new THREE.Vector3();
-			vertex.x = radius * Math.sin( u * Math.PI * 2 );
+			vertex.x = radius * Math.sin( u * thetaLength + thetaStart );
 			vertex.y = - v * height + heightHalf;
-			vertex.z = radius * Math.cos( u * Math.PI * 2 );
+			vertex.z = radius * Math.cos( u * thetaLength + thetaStart );
 
 			this.vertices.push( vertex );
 
@@ -141,16 +145,16 @@ THREE.CylinderGeometry = function ( radiusTop, radiusBottom, height, radialSegme
 
 		for ( x = 0; x < radialSegments; x ++ ) {
 
-			var v1 = vertices[ y ][ x + 1 ];
-			var v2 = vertices[ y ][ x ];
+			var v1 = vertices[ heightSegments ][ x + 1 ];
+			var v2 = vertices[ heightSegments ][ x ];
 			var v3 = this.vertices.length - 1;
 
 			var n1 = new THREE.Vector3( 0, - 1, 0 );
 			var n2 = new THREE.Vector3( 0, - 1, 0 );
 			var n3 = new THREE.Vector3( 0, - 1, 0 );
 
-			var uv1 = uvs[ y ][ x + 1 ].clone();
-			var uv2 = uvs[ y ][ x ].clone();
+			var uv1 = uvs[ heightSegments ][ x + 1 ].clone();
+			var uv2 = uvs[ heightSegments ][ x ].clone();
 			var uv3 = new THREE.Vector2( uv2.x, 1 );
 
 			this.faces.push( new THREE.Face3( v1, v2, v3, [ n1, n2, n3 ] ) );
@@ -162,7 +166,7 @@ THREE.CylinderGeometry = function ( radiusTop, radiusBottom, height, radialSegme
 
 	this.computeFaceNormals();
 
-}
+};
 
 THREE.CylinderGeometry.prototype = Object.create( THREE.Geometry.prototype );
 THREE.CylinderGeometry.prototype.constructor = THREE.CylinderGeometry;