public constructor()

in packages/gltf-gen/src/geometry/sphere.ts [21:79]
44 lines of code
8 McCabe index (conditional complexity)

	public constructor(radius: number, longLines = 12, latLines = 8, material: Material = null) {
		super({material});

		// generate north pole
		const north = new Vertex({
			position: new Vector3(0, radius, 0),
			normal: new Vector3(0, 1, 0),
			texCoord0: new Vector2(0.5, 1)
		});
		this.vertices.push(north);

		const longAngle = 2 * Math.PI / longLines,
			latAngle = Math.PI / latLines;

		// generate verts in rings starting from the north pole
		for (let lat = latAngle; lat < Math.PI - 0.001; lat += latAngle) {
			const ringStart = this.vertices.length;
			for (let long = 0; long < 2 * Math.PI + 0.001; long += longAngle) {

				// generate a vertex
				const normal = new Vector3(
					Math.sin(lat) * Math.cos(long),
					Math.cos(lat),
					Math.sin(lat) * Math.sin(long));
				const vert = new Vertex({
					position: normal.scale(radius),
					normal: normal,
					texCoord0: new Vector2(1 - long / (2 * Math.PI), lat / Math.PI)
				});

				// get the indices of the neighboring verts
				const i = this.vertices.push(vert) - 1,
					longNbr = i - 1 + (i === ringStart ? longLines + 1 : 0),
					latNbr = i <= longLines + 1 ? 0 : i - longLines - 1,
					latLongNbr = longNbr - longLines - 1;

				// fill in the tri/quad connecting this vert to the sphereA
				this.triangles.push(i, longNbr, latNbr);
				if (latLongNbr > 0) {
					this.triangles.push(longNbr, latLongNbr, latNbr);
				}
			}
		}

		// generate south pole
		const south = new Vertex({
			position: new Vector3(0, -radius, 0),
			normal: new Vector3(0, -1, 0),
			texCoord0: new Vector2(0.5, 0)
		});
		const southIdx = this.vertices.push(south) - 1;

		// connect last long ring to the south pole
		const ringStart = southIdx - longLines - 1;
		for (let i = southIdx - longLines - 1; i < southIdx; i++) {
			const longNbr = i - 1 + (i === ringStart ? longLines + 1 : 0);
			this.triangles.push(longNbr, i, southIdx);
		}
	}