const c = 30

const G = 7

let photons = []

let captiveRange

​

let firstTime = true

let massEditor

let photonEditor

let spacingEditor

let trailEditor

let blackHoleEditor

let backgroundEditor

let imageEditor

let angleEditor

​

​

let spaceBackground

let spaceCanvas

let canvas

let photonColour = 255

let trailColour = 255

​

let fullEnd = false

​

let backgroundColour = 255

let tempBackgroundColour = 255

​

const dt = 0.1

​

let windowSizeX 

let windowSizeY

​

function firstSetup() {

  windowSizeX = windowWidth

  windowSizeY = windowHeight

  let spacingConstant = 120

​

  MassEdit()

​

  BlackHoleEditor(spacingConstant)

​

  PhotonEdit(spacingConstant)

​

  SpacingEdit(spacingConstant)

  AngleEdit(spacingConstant)

​

  TrailEdit(spacingConstant)

​

  BackgroundEditor(spacingConstant)

​

  ImageEditor(spacingConstant)

​

  spaceCanvas = createGraphics(windowSizeX,windowSizeY)

  spaceCanvas.background(0)

  for (i = 0; i < 150; i++) {

    spaceCanvas.strokeWeight(random(1, 8))

    spaceCanvas.stroke(random(100, 255), random(50, 200))

    spaceCanvas.point(random(0, 1920), random(0, 1080))

  }

​

  let resetBtn = createButton('Reset')

  resetBtn.mousePressed(resetSketch)

  resetBtn.position(windowWidth - resetBtn.width, 0)

}

​

function setup() {

  if (firstTime) {

    firstSetup()

    firstTime = false

  }

  drawn = false

  canvas = createCanvas(windowSizeX,windowSizeY);

  canvas.position(0, 100)

​

​

  m87 = new BlackHole(width / 2, height / 2, int(massEditor.value()), blackHoleEditor.value())

  captiveRange = 12 * m87.radius

​

  let photonNum = photonEditor.value()

  let photonSpacing = spacingEditor.value()

  let trailFlag = trailEditor.value()

​

  // angleMode(DEGREES)

  // let angle = angleEditor.value() / 2

  // let photonCount = 0

  // for (i = -angle; i <= angle; i += (angle * 2)/photonNum) {

  //   let xSpeed = abs(cos(i))

  //   let ySpeed = sin(i)

  //     photons.push(new Photon(-5, height / 2, xSpeed, ySpeed, photonColour, trailFlag, trailColour,5))    

  // }

  // for (i = 0; i <= photonNum; i++) {

  //   photons.push(new Photon(-5, height / 2 - (i * photonSpacing), c, 0, photonColour, trailFlag, trailColour,5))

  // }

  for (i = 0; i < width ; i+= 5) {

    photons.push(new Photon(i, -5, 0, c, photonColour, trailFlag, color(255,0,0),5))

    photons.push(new Photon(i, height + 5, 0, -c, photonColour, trailFlag, color(0,255,0),5))

  }

  for (j = 0; j < height ; j+= 5) {

    photons.push(new Photon(-5, j, c, 0, photonColour, trailFlag, color(0,0,255),5))

    photons.push(new Photon(width + 5, j, -c, 0, photonColour, trailFlag, color(255,0,255),5))

  }

  //console.log(photons.length)

​

  loop()

​

}

​

function keyPressed() {

 if (keyCode == ENTER) {

   resetSketch()

 }

}

​

function draw() {

  switch (backgroundEditor.value()) {

    case 'White':

      background(backgroundColour)

      break

    case 'Black':

      background(backgroundColour)

      break

    case 'Space':

      image(spaceCanvas, 0, 0)

      break

  }

      m87.show()

​

  let photonsDone = 0

  for (let p of photons) {

​

    let distFromHole = dist(m87.position.x, m87.position.y, p.position.x, p.position.y)

    if (( distFromHole < captiveRange && distFromHole > 0.5 * m87.radius && p.position.y > - 100 && p.position.y < height + 100 && p.position.x > -50 && p.position.x < width + 50)) {

      let force = m87.pull(p)

      // only pull photon towards black hole if its nearby

    }

​

    if (p.draw != 2) {

      if ((((width / 2) - 0.25 * m87.radius < p.position.x) && (p.position.x < (width / 2) + 0.25 * m87.radius) && ((height / 2) - 0.25 * m87.radius < p.position.y) && (p.position.y < (height / 2) + 0.25 * m87.radius)) || (-10 > p.position.x) || (width + 10 < p.position.x) || (-500 > p.position.y) || (height + 500 < p.position.y)) {

        p.draw = 1

        photonsDone += 1

        // stop drawing photon if it's off the screen or in the black hole

      }

    }

​

​

    if (p.draw == 0) {

      p.update()

    }

    // if this particle is done stop updating it's position

    p.show()

​

  }

​

  if (photonsDone == photons.length) {

    noLoop()

​

    if (trailEditor.value() == 'After') {

      for (i = 0; i < photons.length; i++) {

          photons[i].trail = 'After'

          photons[i].draw = 2

          photons[i].trailRes = 1

        }

        drawAfterTrail()      

    }

    if (imageEditor.value() == 'On') {

          saveCurrentCanvas()

    }

  }

​

  m87.showEventHorizon()

}

​

function drawAfterTrail() {

  for (let p of photons) {

    p.show()

  }

}

​

function resetSketch() {

  photons.splice(0, photons.length)

  backgroundColour = tempBackgroundColour

  setup()

}

​

function saveCurrentCanvas() {

  let fileName = 'p5 Black Hole Simulation - img' + day() + '-' + month() + '-' + year() + '--' + hour() + '_' + minute() + '_' + second()

  m87.showEventHorizon()

  saveCanvas(canvas, fileName, 'jpg')

}