the-world-engine/dist/esm/box2d.ts/build/controllers/b2_tensor_damping_controller.js

three.js based, unity like game engine for browser

import { b2Controller } from "./b2_controller.js";

import { b2Mat22, b2Vec2, b2Max } from "../common/b2_math.js";

import { b2_epsilon } from "../common/b2_settings.js";

export class b2TensorDampingController extends b2Controller {
    constructor() {
        super(...arguments);
        this.T = new b2Mat22;
        this.maxTimestep = 0;
    }
    Step(t) {
        let e = t.dt;
        if (e <= b2_epsilon) {
            return;
        }
        if (e > this.maxTimestep && this.maxTimestep > 0) {
            e = this.maxTimestep;
        }
        for (let t = this.m_bodyList; t; t = t.nextBody) {
            const o = t.body;
            if (!o.IsAwake()) {
                continue;
            }
            const s = o.GetWorldVector(b2Mat22.MulMV(this.T, o.GetLocalVector(o.GetLinearVelocity(), b2Vec2.s_t0), b2Vec2.s_t1), b2TensorDampingController.Step_s_damping);
            o.SetLinearVelocity(b2Vec2.AddVV(o.GetLinearVelocity(), b2Vec2.MulSV(e, s, b2Vec2.s_t0), b2Vec2.s_t1));
        }
    }
    Draw(t) {}
    SetAxisAligned(t, e) {
        this.T.ex.x = -t;
        this.T.ex.y = 0;
        this.T.ey.x = 0;
        this.T.ey.y = -e;
        if (t > 0 || e > 0) {
            this.maxTimestep = 1 / b2Max(t, e);
        } else {
            this.maxTimestep = 0;
        }
    }
}

b2TensorDampingController.Step_s_damping = new b2Vec2;