|
|
@@ -0,0 +1,120 @@
|
|
|
+/**
|
|
|
+ * @author Mugen87 / https://github.com/Mugen87
|
|
|
+ */
|
|
|
+
|
|
|
+THREE.RingBufferGeometry = function ( innerRadius, outerRadius, thetaSegments, phiSegments, thetaStart, thetaLength ) {
|
|
|
+
|
|
|
+ THREE.BufferGeometry.call( this );
|
|
|
+
|
|
|
+ this.type = 'RingBufferGeometry';
|
|
|
+
|
|
|
+ this.parameters = {
|
|
|
+ innerRadius: innerRadius,
|
|
|
+ outerRadius: outerRadius,
|
|
|
+ thetaSegments: thetaSegments,
|
|
|
+ phiSegments: phiSegments,
|
|
|
+ thetaStart: thetaStart,
|
|
|
+ thetaLength: thetaLength
|
|
|
+ };
|
|
|
+
|
|
|
+ innerRadius = innerRadius || 0;
|
|
|
+ outerRadius = outerRadius || 50;
|
|
|
+
|
|
|
+ thetaStart = thetaStart !== undefined ? thetaStart : 0;
|
|
|
+ thetaLength = thetaLength !== undefined ? thetaLength : Math.PI * 2;
|
|
|
+
|
|
|
+ thetaSegments = thetaSegments !== undefined ? Math.max( 3, thetaSegments ) : 8;
|
|
|
+ phiSegments = phiSegments !== undefined ? Math.max( 1, phiSegments ) : 8;
|
|
|
+
|
|
|
+ // these are used to calculate buffer length
|
|
|
+ var vertexCount = ( thetaSegments + 1 ) * ( phiSegments + 1 );
|
|
|
+ var indexCount = thetaSegments * phiSegments * 2 * 3;
|
|
|
+
|
|
|
+ // buffers
|
|
|
+ var indices = new THREE.BufferAttribute( new ( indexCount > 65535 ? Uint32Array : Uint16Array )( indexCount ) , 1 );
|
|
|
+ var vertices = new THREE.BufferAttribute( new Float32Array( vertexCount * 3 ), 3 );
|
|
|
+ var normals = new THREE.BufferAttribute( new Float32Array( vertexCount * 3 ), 3 );
|
|
|
+ var uvs = new THREE.BufferAttribute( new Float32Array( vertexCount * 2 ), 2 );
|
|
|
+
|
|
|
+ // some helper variables
|
|
|
+ var index = 0, indexOffset = 0, segment;
|
|
|
+ var radius = innerRadius;
|
|
|
+ var radiusStep = ( ( outerRadius - innerRadius ) / phiSegments );
|
|
|
+ var vertex = new THREE.Vector3();
|
|
|
+ var uv = new THREE.Vector2();
|
|
|
+ var j, i;
|
|
|
+
|
|
|
+ // generate vertices, normals and uvs
|
|
|
+
|
|
|
+ // values are generate from the inside of the ring to the outside
|
|
|
+
|
|
|
+ for ( j = 0; j <= phiSegments; j ++ ) {
|
|
|
+
|
|
|
+ for ( i = 0; i <= thetaSegments; i ++ ) {
|
|
|
+
|
|
|
+ segment = thetaStart + i / thetaSegments * thetaLength;
|
|
|
+
|
|
|
+ // vertex
|
|
|
+ vertex.x = radius * Math.cos( segment );
|
|
|
+ vertex.y = radius * Math.sin( segment );
|
|
|
+ vertices.setXYZ( index, vertex.x, vertex.y, vertex.z );
|
|
|
+
|
|
|
+ // normal
|
|
|
+ normals.setXYZ( index, 0, 0, 1 );
|
|
|
+
|
|
|
+ // uv
|
|
|
+ uv.x = ( vertex.x / outerRadius + 1 ) / 2;
|
|
|
+ uv.y = ( vertex.y / outerRadius + 1 ) / 2;
|
|
|
+ uvs.setXY( index, uv.x, uv.y );
|
|
|
+
|
|
|
+ // increase index
|
|
|
+ index++;
|
|
|
+
|
|
|
+ }
|
|
|
+
|
|
|
+ // increase the radius for next row of vertices
|
|
|
+ radius += radiusStep;
|
|
|
+
|
|
|
+ }
|
|
|
+
|
|
|
+ // generate indices
|
|
|
+
|
|
|
+ for ( j = 0; j < phiSegments; j ++ ) {
|
|
|
+
|
|
|
+ var thetaSegmentLevel = j * ( thetaSegments + 1 );
|
|
|
+
|
|
|
+ for ( i = 0; i < thetaSegments; i ++ ) {
|
|
|
+
|
|
|
+ segment = i + thetaSegmentLevel;
|
|
|
+
|
|
|
+ // indices
|
|
|
+ var a = segment;
|
|
|
+ var b = segment + thetaSegments + 1;
|
|
|
+ var c = segment + thetaSegments + 2;
|
|
|
+ var d = segment + 1;
|
|
|
+
|
|
|
+ // face one
|
|
|
+ indices.setX( indexOffset, a ); indexOffset++;
|
|
|
+ indices.setX( indexOffset, b ); indexOffset++;
|
|
|
+ indices.setX( indexOffset, c ); indexOffset++;
|
|
|
+
|
|
|
+ // face two
|
|
|
+ indices.setX( indexOffset, a ); indexOffset++;
|
|
|
+ indices.setX( indexOffset, c ); indexOffset++;
|
|
|
+ indices.setX( indexOffset, d ); indexOffset++;
|
|
|
+
|
|
|
+ }
|
|
|
+
|
|
|
+ }
|
|
|
+
|
|
|
+ // build geometry
|
|
|
+
|
|
|
+ this.setIndex( indices );
|
|
|
+ this.addAttribute( 'position', vertices );
|
|
|
+ this.addAttribute( 'normal', normals );
|
|
|
+ this.addAttribute( 'uv', uvs );
|
|
|
+
|
|
|
+};
|
|
|
+
|
|
|
+THREE.RingBufferGeometry.prototype = Object.create( THREE.BufferGeometry.prototype );
|
|
|
+THREE.RingBufferGeometry.prototype.constructor = THREE.RingBufferGeometry;
|
Mr.doob