playcanvas/build/playcanvas/src/scene/geometry/torus-geometry.js

PlayCanvas WebGL game engine

import { math } from '../../core/math/math.js';
import { calculateTangents } from './geometry-utils.js';
import { Geometry } from './geometry.js';

class TorusGeometry extends Geometry {
		constructor(opts = {}){
				super();
				const rc = opts.tubeRadius ?? 0.2;
				const rt = opts.ringRadius ?? 0.3;
				const sectorAngle = (opts.sectorAngle ?? 360) * math.DEG_TO_RAD;
				const segments = opts.segments ?? 30;
				const sides = opts.sides ?? 20;
				const positions = [];
				const normals = [];
				const uvs = [];
				const indices = [];
				for(let i = 0; i <= sides; i++){
						for(let j = 0; j <= segments; j++){
								const x = Math.cos(sectorAngle * j / segments) * (rt + rc * Math.cos(2 * Math.PI * i / sides));
								const y = Math.sin(2 * Math.PI * i / sides) * rc;
								const z = Math.sin(sectorAngle * j / segments) * (rt + rc * Math.cos(2 * Math.PI * i / sides));
								const nx = Math.cos(sectorAngle * j / segments) * Math.cos(2 * Math.PI * i / sides);
								const ny = Math.sin(2 * Math.PI * i / sides);
								const nz = Math.sin(sectorAngle * j / segments) * Math.cos(2 * Math.PI * i / sides);
								const u = i / sides;
								const v = 1 - j / segments;
								positions.push(x, y, z);
								normals.push(nx, ny, nz);
								uvs.push(u, 1.0 - v);
								if (i < sides && j < segments) {
										const first = i * (segments + 1) + j;
										const second = (i + 1) * (segments + 1) + j;
										const third = i * (segments + 1) + (j + 1);
										const fourth = (i + 1) * (segments + 1) + (j + 1);
										indices.push(first, second, third);
										indices.push(second, fourth, third);
								}
						}
				}
				this.positions = positions;
				this.normals = normals;
				this.uvs = uvs;
				this.uvs1 = uvs;
				this.indices = indices;
				if (opts.calculateTangents) {
						this.tangents = calculateTangents(positions, normals, uvs, indices);
				}
		}
}

export { TorusGeometry };