playcanvas/build/playcanvas/src/core/shape/tri.js

PlayCanvas WebGL game engine

import { Vec3 } from '../math/vec3.js';

const e1 = new Vec3();
const e2 = new Vec3();
const h = new Vec3();
const s = new Vec3();
const q = new Vec3();
const EPSILON = 1e-6;
class Tri {
		constructor(v0 = Vec3.ZERO, v1 = Vec3.ZERO, v2 = Vec3.ZERO){
				this.v0 = new Vec3();
				this.v1 = new Vec3();
				this.v2 = new Vec3();
				this.set(v0, v1, v2);
		}
		set(v0, v1, v2) {
				this.v0.copy(v0);
				this.v1.copy(v1);
				this.v2.copy(v2);
				return this;
		}
		intersectsRay(ray, point) {
				e1.sub2(this.v1, this.v0);
				e2.sub2(this.v2, this.v0);
				h.cross(ray.direction, e2);
				const a = e1.dot(h);
				if (a > -1e-6 && a < EPSILON) {
						return false;
				}
				const f = 1 / a;
				s.sub2(ray.origin, this.v0);
				const u = f * s.dot(h);
				if (u < 0 || u > 1) {
						return false;
				}
				q.cross(s, e1);
				const v = f * ray.direction.dot(q);
				if (v < 0 || u + v > 1) {
						return false;
				}
				const t = f * e2.dot(q);
				if (t > EPSILON) {
						if (point instanceof Vec3) {
								point.copy(ray.direction).mulScalar(t).add(ray.origin);
						}
						return true;
				}
				return false;
		}
		toString() {
				return `[${this.v0.toString()}, ${this.v1.toString()}, ${this.v2.toString()}]`;
		}
}

export { Tri };