From f095ed2095ecebbf340566cd7872e91428405f1c Mon Sep 17 00:00:00 2001
From: Aakash Varier <aakashvarier2001@gmail.com>
Date: Wed, 26 May 2021 20:59:37 +0530
Subject: [PATCH] Three body simulation

---
 three body/attractor.js | 25 ++++++++++++++++++++++
 three body/particle.js  | 46 ++++++++++++++++++++++++++++++++++++++++
 three body/sketch.js    | 47 +++++++++++++++++++++++++++++++++++++++++
 3 files changed, 118 insertions(+)
 create mode 100644 three body/attractor.js
 create mode 100644 three body/particle.js
 create mode 100644 three body/sketch.js

diff --git a/three body/attractor.js b/three body/attractor.js
new file mode 100644
index 0000000..e5c3e56
--- /dev/null
+++ b/three body/attractor.js	
@@ -0,0 +1,25 @@
+class attractor {
+  constructor(m) {
+    this.m = m;
+    this.pos = createVector(0, 0);
+    this.r = sqrt(this.m) * 2;
+    this.G = 0.3;
+  }
+  attract(particle) {
+    let dir = p5.Vector.sub(this.pos, particle.pos);
+
+    let mag = constrain(dir.magSq(), 100, 1000);
+    let force = (this.G * this.m * particle.m) / mag;
+    dir.setMag(force);
+    particle.applyforce(dir);
+  }
+  display() {
+    stroke(255);
+    ellipse(this.pos.x, this.pos.y, this.r * 2, this.r * 2);
+  }
+  applyforce(Force) {
+    // let f = Force.copy();
+    // f.div(this.m);
+    this.acc.add(Force);
+  }
+}
diff --git a/three body/particle.js b/three body/particle.js
new file mode 100644
index 0000000..0bbe3a9
--- /dev/null
+++ b/three body/particle.js	
@@ -0,0 +1,46 @@
+class Particle {
+  constructor(x, y, m) {
+    this.acc = createVector(0, 0);
+    this.vel = p5.Vector.random2D();
+    this.vel.mult(random(50, 100));
+    // this.vel.limit(10);
+    // this.vel.rotate(90);
+    this.vel.limit(5);
+    this.pos = createVector(random(-ww / 2, ww / 2), random(-wh / 2, wh / 2));
+    this.dx = x;
+    this.dy = y;
+    this.m = m;
+    this.G = 0.3;
+  }
+  update() {
+    this.vel.add(this.acc);
+    this.pos.add(this.vel);
+    this.acc.set(0, 0);
+  }
+  display() {
+    stroke(255);
+    strokeWeight(10);
+    ellipse(this.pos.x, this.pos.y, this.dx, this.dy);
+  }
+  applyforce(Force) {
+    // let f = Force.copy();
+    // f.div(this.m);
+    this.acc.add(Force);
+  }
+  attract(particle) {
+    let dir = p5.Vector.sub(this.pos, particle.pos);
+
+    let mag = constrain(dir.magSq(), 100, 1000);
+    let force = (this.G * this.m * particle.m) / mag;
+    dir.setMag(force);
+    particle.applyforce(dir);
+  }
+  bounce() {
+    if (this.pos.x > ww / 2 || this.pos.x < -ww / 2) {
+      this.vel.x = -1 * this.vel.x;
+    }
+    if (this.pos.y > wh / 2 || this.pos.y < -wh / 2) {
+      this.vel.y = -1 * this.vel.y;
+    }
+  }
+}
diff --git a/three body/sketch.js b/three body/sketch.js
new file mode 100644
index 0000000..3ea0360
--- /dev/null
+++ b/three body/sketch.js	
@@ -0,0 +1,47 @@
+let ww = window.innerWidth;
+let wh = window.innerHeight;
+// let m = 0;
+// let n = 1;
+
+function setup() {
+  createCanvas(ww, wh);
+  p1 = new Particle(10, 10, 50);
+  p2 = new Particle(10, 10, 50);
+  q = new attractor(10);
+}
+
+function draw() {
+  translate(ww / 2, wh / 2);
+  p1.display();
+  p2.display();
+  // let gravity = createVector(0, 0.5);
+  // let gravityForce = p5.Vector.mult(gravity, p.m);
+  // let wind = createVector(
+  //   random(-noise(m), noise(m)) / 3,
+  //   random(-noise(n), noise(n)) / 3
+  // );
+  background(0);
+  // p.applyforce(gravityForce);
+  // p.applyforce(wind);
+  p1.update();
+  p2.update();
+  // p1.bounce();
+  // p2.bounce();
+  p1.display();
+  p2.display();
+  p1.attract(p2);
+  // p1.attract(q);
+  p2.attract(p1);
+  // p2.attract(q);
+  q.attract(p1);
+  q.attract(p2);
+  // q.display();
+
+  // n += 0.001;
+  // m += 0.001;
+  if (mouseIsPressed) {
+    q.pos.x = mouseX - ww / 2;
+    q.pos.y = mouseY - wh / 2;
+  }
+  q.display();
+}