point.js

class Point {
    /**
     * 
     * @param {number} x 
     * @param {number} y 
     * @param {number=} vx 
     * @param {number=} vy 
     * @param {number=} radius 
     */
    constructor(x, y, vx, vy, radius) {
      this.pos = new Vector(x, y);
      this.oldpos = new Vector(x + (vx || 0), y + (vy || 0));
      this.bounce = 0.99;
      this.friction = 0.97;
      this.groundFriction = 0.7;
      this.gravity = new Vector(0, 1);
      this.pinned = false;
      this.radius = radius || 5;
      this.color = '#e62a4f';
      this.mass = 1;
      this.sticks = [];
      // this.behaviors = [];
      this.forceAcc = 1;
      this.uid = ''
    }
  
    /**
     * 
     * @param {Vector} g 
     */
    setGravity(g) {
      this.gravity = g;
      return this;
    }
    /**
     * 
     * @param {number} f 
     */
    setFriction(f) {
      this.friction = f;
      return this;
    }
    /**
     * 
     * @param {number} f 
     */
    setGroundFriction(f) {
      this.groundFriction = f;
      return this;
    }
    /**
     * 
     * @param {number} b
     */
    setBounce(b) {
      this.bounce = b;
      return this;
    }
    /**
     * 
     * @param {number} f 
     * @returns {Point}
     */
    setForceAcc(f) {
      this.forceAcc = f;
      return this;
    }
    /**
     * 
     * @param {number} m 
     * @returns {Point}
     */
    setMass(m) {
      this.mass = m;
      return this;
    }
    /**
     * 
     * @param {number} radius 
     * @returns {Point}
     */
    setRadius(radius) {
      this.radius = radius;
      return this;
    }
  
    /**
     * @param {string} color 
     * @returns {Point}
     */
    setColor(color) {
      this.color = color;
      return this;
    }
  
    /**
     * @param {Vector} vel 
     * @returns {Point}
     */
    setVelocity(vel) {
      this.oldpos.setXY(vel.x, vel.y);
      return this;
    }
  
    /**
     * @returns {Point}
     */
    pin() {
      this.pinned = true;
      return this;
    }
    /**
     * @returns {Point}
     */
    unpin() {
      this.pinned = false;
      return this;
    }
  
    resetVelocity() {
      this.oldpos.setXY(this.pos.x, this.pos.y);
    }
  
    /**
     * 
     * @param {number} angle 
     * @param {number} offset 
     */
    rotate(angle, offset) {
      let x = offset.x + (this.pos.x - offset.x) * Math.cos(angle) - (this.pos.y - offset.y) * Math.sin(angle);
      let y = offset.y + (this.pos.x - offset.x) * Math.sin(angle) + (this.pos.y - offset.y) * Math.cos(angle);
      this.pos.setXY(x, y);
    }
  
    /**
     * 
     * @param {Point} p 
     * @param {number} radius 
     * @param {number} strength 
     */
    resolveBehaviors(p, radius = this.radius, strength = this.forceAcc) {
      var delta = Vector.sub(this.pos, p.pos);
      var dist = delta.magSq();
  
      let magR = radius * radius;
      if (dist < magR) {
        var f = delta.normalizeTo(1 - (dist / magR)).mult(strength);
        this.applyForce(f);
      }
    }
  
    /**
     * 
     * @param {number|Vector} f 
     */
    applyForce(f) {
      this.pos.add(f);
    }
  
    /**
     * 
     * @param {number} x 
     * @param {number} y 
     * @param {number} time 
     * @param {number} radius 
     * @param {number} speed 
     */
    addMotor(x, y, time, radius, speed) {
      this.pos.x = x + radius * Math.cos(time * speed);
      this.pos.y = y + radius * Math.sin(time * speed);
    }
  
    /**
     * @param {Verly} verlyInstance 
     */
    constrain(verlyInstance) {
      // if (this.pos.y > HEIGHT - 1) {
      //   this.pos.y = HEIGHT - 1;
      // }
      // if (this.pos.x < 0) {
      //   this.pos.x = 0;
      // }
      // if (this.pos.x > WIDTH - 1) {
      //   this.pos.x = WIDTH - 1;
      // }
      // let vel = Vector.sub(this.pos, this.oldpos);
      if (this.pos.x > verlyInstance.WIDTH - this.radius) {
        this.pos.x = verlyInstance.WIDTH - this.radius;
        // this.oldpos.x = (this.pos.x + vel.x) * this.bounce;
      }
      if (this.pos.x < this.radius) {
        this.pos.x = this.radius;
        // this.oldpos.x = (this.pos.x + vel.x) * this.bounce;
      }
      if (this.pos.y > verlyInstance.HEIGHT - this.radius) {
        this.pos.y = verlyInstance.HEIGHT - this.radius;
        // this.oldpos.y = (this.pos.y + vel.y) * this.bounce;
      }
      if (this.pos.y < this.radius) {
        this.pos.y = this.radius;
        // this.oldpos.y = (this.pos.y + vel.y) * this.bounce;
      }
    };
  
  
    /**
     * @param {Verly} verlyInstance 
     */
    update(verlyInstance) {
      if (this.pinned) return;
      let vel = Vector.sub(this.pos, this.oldpos);
      vel.mult(this.friction);
      // if the point touches the ground set groundFriction
      if (this.pos.y >= verlyInstance.HEIGHT - this.radius && vel.magSq() > 0.000001) {
        var m = vel.mag();
        vel.x /= m;
        vel.y /= m;
        vel.mult(m * this.groundFriction);
      }
      this.oldpos.setXY(this.pos.x, this.pos.y);
      this.pos.add(vel);
      this.pos.add(this.gravity);
    }
  
    /**
     * @param {CanvasRenderingContext2D} ctx 
     */
    render(ctx) {
      ctx.beginPath();
      ctx.fillStyle = this.color;
      ctx.arc(this.pos.x, this.pos.y, this.radius, 0, Math.PI * 2);
      ctx.fill();
      ctx.closePath();
    }
  }