Working version of train following spline path

2023-02-07 08:36:58 -07:00
commit f1c991bd3e
17 changed files with 2350 additions and 0 deletions
--- a/physics/mover.ts
+++ b/physics/mover.ts
@@ -0,0 +1,112 @@
+import { Vector } from "../math/vector.ts";
+
+export class Mover {
+  position: Vector;
+  velocity: Vector;
+  acceleration: Vector;
+  maxSpeed: number;
+  maxForce: number;
+  _trailingPoint: number;
+  protected _leadingPoint: number;
+
+  get trailingPoint() {
+    const desired = this.velocity.copy();
+    desired.normalize();
+    desired.mult(-this._trailingPoint);
+
+    return Vector.add(this.position, desired);
+  }
+  get leadingPoint() {
+    const desired = this.velocity.copy();
+    desired.normalize();
+    desired.mult(this._leadingPoint);
+
+    return Vector.add(this.position, desired);
+  }
+
+  ctx?: CanvasRenderingContext2D;
+
+  boundingBox: {
+    pos: Vector;
+    size: Vector;
+  }
+
+  constructor();
+  constructor(random: boolean);
+  constructor(pos?: Vector, vel?: Vector, acc?: Vector);
+  constructor(posOrRandom?: Vector | boolean, vel?: Vector, acc?: Vector) {
+    if (typeof posOrRandom === 'boolean' && posOrRandom) {
+      this.position = Vector.random2D(new Vector());
+      this.velocity = Vector.random2D(new Vector());
+      this.acceleration = new Vector()
+    } else {
+      this.position = posOrRandom || new Vector();
+      this.velocity = vel || new Vector();
+      this.acceleration = acc || new Vector()
+    }
+    this.boundingBox = {
+      size: new Vector(20, 10),
+      pos: new Vector(this.position.x - 10, this.position.y - 5)
+    }
+
+    this.maxSpeed = 3;
+    this.maxForce = .3;
+
+    this._trailingPoint = 0;
+    this._leadingPoint = 0;
+
+    this.init();
+  }
+
+  init() {
+    // 
+  }
+
+  move() {
+    this.velocity.limit(this.maxSpeed);
+    this.acceleration.limit(this.maxForce);
+    this.velocity.add(this.acceleration);
+    this.position.add(this.velocity);
+    this.edges();
+    this.draw();
+  }
+
+  edges() {
+    if (!this.ctx) return;
+
+    if (this.position.x > this.ctx.canvas.width) this.position.x = 0;
+    if (this.position.y > this.ctx.canvas.height) this.position.y = 0;
+    if (this.position.x < 0) this.position.x = this.ctx.canvas.width;
+    if (this.position.y < 0) this.position.y = this.ctx.canvas.height;
+  }
+
+  draw() {
+    if (!this.ctx) return;
+
+    this.ctx.fillStyle = 'white'
+    this.ctx.save();
+    this.ctx.translate(this.position.x, this.position.y);
+    this.ctx.rotate(this.velocity.heading() || 0);
+    this.ctx.translate(-this.position.x, -this.position.y);
+    // this.ctx.rotate(Math.PI)
+    // this.ctx.rotate(.5);
+    this.ctx.translate(-(this.boundingBox.size.x / 2), -(this.boundingBox.size.y / 2));
+    this.ctx.fillRect(this.position.x, this.position.y, this.boundingBox.size.x, this.boundingBox.size.y);
+    this.ctx.restore();
+  }
+
+  setContext(ctx: CanvasRenderingContext2D) {
+    this.ctx = ctx;
+  }
+
+  applyForce(force: Vector) {
+    this.acceleration.add(force);
+  }
+
+  static edges(point: Vector, width: number, height: number) {
+    if (point.x > width) point.x = 0;
+    if (point.y > height) point.y = 0;
+    if (point.x < 0) point.x = width;
+    if (point.y < 0) point.y = height;
+  }
+}