XiaohanYa · April 17, 2017 03:25 · Apr 17, 2017
diff --git a/planet1.js b/planet1.js
@@ -0,0 +1,162 @@
+"use strict";
+
+class Ball {
+  constructor(x, y, c) {
+    this.pos = createVector(x, y);
+    this.vel = createVector(2, 2);
+    this.acc = createVector();
+
+    this.mass = random(5, 30);
+    this.rad = this.mass;
+    this.strokeWeight = random(5, 10);
+
+    this.strokeColor = color(255, c);
+    this.fillColor = color(random(255), random(255), random(0, 20));
+    this.cDampling = 0.9;
+  }
+  applyForce(force) {
+    force.div(this.mass);
+    this.acc.add(force);
+
+  }
+  attract(other) {
+    var attraction = p5.Vector.sub(other.pos, this.pos);
+    var distance = dist(other.pos, this.pos);
+    attraction.normalize();
+    force.mult((this.mass * other.mass) / (distance * distance));
+    this.applyForce(attraction);
+  }
+
+  drag() {
+    var distance = dist(mouseX, mouseY, this.pos.x, this.pos.y);
+    if (mouseIsPressed && distance < this.rad + 50) {
+      this.pos.x = mouseX;
+      this.pos.y = mouseY;
+    }
+  }
+
+  update() {
+    this.vel.add(this.acc);
+    this.pos.add(this.vel);
+    this.acc.mult(0);
+
+    this.vel.mult(this.cDampling);
+  }
+
+  display() {
+    push();
+    stroke(this.strokeColor);
+    strokeWeight(this.strokeWeight);
+    fill(this.fillColor);
+    ellipse(this.pos.x, this.pos.y, this.rad * 2, this.rad * 2);
+    pop();
+  }
+
+}
+"use strict";
+
+class Spring {
+  constructor(ballA, ballB, len) {
+    this.ballA = ballA;
+    this.ballB = ballB;
+    this.len = len;
+
+    this.k = 0.2;
+  }
+  display() {
+    push();
+    stroke(255);
+    strokeWeight(2);
+    line(this.ballA.pos.x, this.ballA.pos.y, this.ballB.pos.x, this.ballB.pos.y);
+    pop();
+  }
+
+  update() {
+    //vector
+    var vector = p5.Vector.sub(this.ballA.pos, this.ballB.pos);
+    var distance = vector.mag();
+    var direction = vector.copy().normalize();
+
+    //force
+    var stretch = distance - this.len;
+    var force = direction.copy();
+    //hooke's law
+    force.mult(-1 * this.k * stretch);
+    this.ballA.applyForce(force);
+    force.mult(-1);
+    this.ballB.applyForce(force);
+  }
+
+}
+
+
+////JSON
+var params = {
+  debugMode: false //it's ","
+};
+
+var gui = new dat.gui.GUI();
+gui.add(params, "debugMode");
+
+
+
+//
+var numOfBalls = 3;
+var balls = [];
+var springs = [];
+var centerBall;
+
+function setup() {
+  createCanvas(500, 600);
+  for (var i = 0; i < numOfBalls; i++) {
+    balls.push(new Ball(random(width), random(height), 180 - i * 50));
+  }
+  for (var i = 0; i < balls.length; i++) {
+    if (i < balls.length - 1) {
+      springs.push(new Spring(balls[i], balls[i + 1], 350 + 70 * i + random(20)));
+    } else {
+      springs.push(new Spring(balls[i], balls[0], 350 + 70 * i + random(20)));
+    }
+  }
+
+  centerBall = new Ball(random(30), random(30), 255);
+
+}
+
+function draw() {
+  background(0);
+
+  push();
+  translate(width / 2, height / 2);
+  rotate(frameCount * 0.01);
+  centerBall.strokeColor = color(255, 50);
+  centerBall.strokeWeight = 30;
+  centerBall.fillColor = color(0, 20, 255);
+  centerBall.rad = 60;
+
+  centerBall.update();
+  centerBall.display();
+
+
+  for (var i = 0; i < springs.length; i++) {
+    springs[i].update();
+    if (params.debugMode) {
+      springs[i].display();
+    }
+  }
+
+  for (var i = 0; i < balls.length; i++) {
+
+    var force = p5.Vector.sub(centerBall.pos, balls[i].pos);
+    force.mult(random(0.01, 0.03) * balls[i].mass);
+    balls[i].applyForce(force);
+
+    balls[i].update();
+    balls[i].display();
+  }
+  pop();
+}
+
+
+
+//