universe.js

ether = new p5()



class Mass {
  constructor(name, x, y, radius, mass, c = 'grey', isGridDot = false) {
      this.name = name
      this.mass = mass
      this.radius = radius
      this.pos = createVector(x, y)
      this.vel = createVector(0, 0)
      this.accel = createVector(0, 0)
      this.c = c
      this.isGridDot = isGridDot
  }

  draw() {
    let scaledXpos = this.pos.x * scale + dim / 2
    let scaledYpos = this.pos.y * scale + dim / 2
    let scaledRadius = this.radius * scale * 1000

    if (this.isGridDot) {
      curveVertex(scaledXpos, scaledYpos)
      stroke(0)
    } else {
      fill(color(this.c))
      circle(scaledXpos,
             scaledYpos,
             scaledRadius)
    }
  }

  // Josh's code
  // drawDot() {
  //   x0 = dot's current position
  //   a1 = computeAcceleration(x0, universe)
  //   x1 = computeNewPosition(a1, x0)
  //   a2 = computeAcceleration(x1, universe)
  //   if (a1 and a2 point in opposite directions) {
  //     don't draw this dot
  //   } else {
  //     draw this dot
  //   }
  // }

  updateForce() {
    this.accel.x = 0;
    this.accel.y = 0;

    var i;
    for (i = 0; i < universe.length; i++) {
      let obj = universe[i]
      if (this == obj) { continue }

      let m1 = this.mass
      let m2 = obj.mass
      let r = this.distance(obj)
      let force = G*m1*m2 / Math.pow(r, 2)
      let r_hat = this.unitDistance(obj)
      let force_x = force * -r_hat[0]
      let force_y = force * -r_hat[1]
      this.accel.x += force_x / this.mass
      this.accel.y += force_y / this.mass
    }

    this.vel.x += this.accel.x * delta_t
    this.vel.y += this.accel.y * delta_t
  }

  updatePosition() {
    this.pos.x += this.isGridDot ? this.vel.x * delta_t * 10000 : this.vel.x * delta_t // + 0.5 * this.accel.x * Math.pow(delta_t, 2)
    this.pos.y += this.isGridDot ? this.vel.y * delta_t * 10000 : this.vel.y * delta_t // + 0.5 * this.accel.y * Math.pow(delta_t, 2)
  }

  distance(other) {
    return dist(this.pos.x, this.pos.y, other.pos.x, other.pos.y);
  }

  unitDistance(other) {
    return [(this.pos.x - other.pos.x) / this.distance(other),
            (this.pos.y - other.pos.y) / this.distance(other)]
  }
}





let t = 0
let fr = 60
const scale = 1 / Math.pow(10, 9)  // in meters
let delta_t = 86140
const G = 6.67408 * Math.pow(10, -11)
const dim = 1500
let universe = [
  Sun = new Mass("Sun", 0, 0, 695.51 * Math.pow(10, 5), 1.989 * Math.pow(10, 30), c = 'yellow'),
  Mercury = new Mass("Mercury", 0, -57.91 * Math.pow(10, 9), 2.4397 * Math.pow(10, 6), 3.285 * Math.pow(10, 23), c = 'grey'),
  Venus = new Mass("Venus", 0, -108.2 * Math.pow(10, 9), 6.0518 * Math.pow(10, 6), 4.867 * Math.pow(10, 24), c = 'brown'),
  Earth = new Mass("Earth", 0, -152 * Math.pow(10, 9), 6.371 * Math.pow(10, 6), 5.972 * Math.pow(10, 24), c = 'blue'),
  // Moon = new Mass("Moon", 0, -152.3844 * Math.pow(10, 9), 1.7371 * Math.pow(10, 6), 7.34767309 * Math.pow(10, 22), c = 'grey'),
  Mars = new Mass("Mars", 0, -227.9 * Math.pow(10, 9), 3.3895 * Math.pow(10, 6), 6.39 * Math.pow(10, 23), c = 'red'),
  Jupiter = new Mass("Jupiter", 0, -778.5 * Math.pow(10, 9), 69.911 * Math.pow(10, 6), 1.898 * Math.pow(10, 30), c = 'orange')
]
Mercury.vel.x = 47400
Venus.vel.x = 35000
Earth.vel.x = 30000
// Moon.vel.x = 31000
Mars.vel.x = 24000
Jupiter.vel.x = 13100



function setup() {
  frameRate(fr)
  createCanvas(dim, dim)
}



function draw() {
  background(230)
  noStroke()

  createGrid()

  // noFill()
  // beginShape()
  // Draw grid
  // endShape()

  print(`Days: ${t / 86140}`)
  t += delta_t

  for (var key in universe) { universe[key].draw() }
  for (var key in universe) { universe[key].updateForce() }
  for (var key in universe) { universe[key].updatePosition() }
}


function createGrid() {
  noFill()
  for (var i = -dim/2; i <= dim/2; i+=150) {
    beginShape()
    // curveVertex(i, -dim/2)
    for (var j = -dim/2; j <= dim/2; j+=30) {
      p = new Mass(
        name = `p1_${i}_${j}`,
        x = i * Math.pow(10, 9),
        y = j * Math.pow(10, 9),
        radius = 1,
        mass = 1.989 * Math.pow(10, 30),
        c = 'grey',
        isGridDot = true
      )
      p.updateForce()
      p.updatePosition()
      p.draw()
    }
    // curveVertex(i, dim/2)
    endShape()
  }

  for (var i = -dim/2; i <= dim/2; i+=150) {
    beginShape()
    // curveVertex(-dim/2, j)
    for (var j = -dim/2; j <= dim/2; j+=10) {
      p = new Mass(
        name = `p1_${j}_${i}`,
        x = j * Math.pow(10, 9),
        y = i * Math.pow(10, 9),
        radius = 1,
        mass = 1.989 * Math.pow(10, 30),
        c = 'grey',
        isGridDot = true
      )
      p.updateForce()
      p.updatePosition()
      p.draw()
    }
    // curveVertex(dim/2, j)
    endShape()
  }
}