the-world-engine/dist/esm/engine/physics/2d/Collision2D.js

three.js based, unity like game engine for browser

import { Vector2 } from "three/src/Three";

import { Vec2, WorldManifold } from "../../../box2d.ts/build/index";

import { ContactPoint2D } from "./ContactPoint2D";

export class Collision2D {
    di=null;
    fi=new WorldManifold;
    pi=null;
    Ci=null;
    vi=null;
    bi=null;
    Di=0;
    Vi=new Vector2;
    setData(t) {
        this.di = t;
        const i = t.GetFixtureA();
        const e = t.GetFixtureB();
        const o = i.GetUserData();
        const r = e.GetUserData();
        const n = i.GetBody();
        const s = e.GetBody();
        this.pi = o;
        this.Ci = n.GetUserData().rigidbody;
        this.vi = r;
        this.bi = s.GetUserData().rigidbody;
        this.Di = t.GetManifold().pointCount;
        const l = Collision2D._tempVec.Copy(n.GetLinearVelocity());
        const h = l.SelfSub(s.GetLinearVelocity());
        this.Vi.set(h.x, h.y);
    }
    static _tempVec=new Vec2;
    get collider() {
        return this.pi;
    }
    get rigidbody() {
        return this.Ci;
    }
    get otherCollider() {
        return this.vi;
    }
    get otherRigidbody() {
        return this.bi;
    }
    get contactCount() {
        return this.Di;
    }
    getContacts(t) {
        if (!this.di) return 0;
        let i = 0;
        const e = this.di.GetManifold();
        for (let o = 0; o < e.pointCount; ++o) {
            if (!t[i]) t[i] = new ContactPoint2D;
            this.di.GetWorldManifold(this.fi);
            t[i].setData(this.di, e.points[o], this.fi.normal, this.fi.points[o], this.fi.separations[o], this.Vi);
            i += 1;
        }
        return i;
    }
    getContact(t, i) {
        if (!this.di) return null;
        const e = this.di.GetManifold();
        if (t < 0 || e.pointCount <= t) return null;
        if (!i) i = new ContactPoint2D;
        this.di.GetWorldManifold(this.fi);
        i.setData(this.di, e.points[t], this.fi.normal, this.fi.points[t], this.fi.separations[t], this.Vi);
        return i;
    }
    get enabled() {
        return this.di?.IsEnabled() ?? false;
    }
    set enabled(t) {
        this.di?.SetEnabled(t);
    }
    get relativeVelocity() {
        return this.Vi;
    }
}