let nBuildings = 25

let clouds = []

let nClouds = 35

let lightningP = 0.98

let pWindow = 100

let prevPW = 100

let counter = 0

​

let headerSize = 20

​

let strikeCounts = []

​

let windowSlider;

let lightningSlider;

let pCheckbox;

let showExp = false;

​

​

let strikeTracker = []

let stWidth = 1

let stCol = [

  80, 100, 150,

  255, 255, 150

]

let posY = 0

​

let fact = [1]

​

for (let i=1;i<9;i++) {

  fact.push(fact[fact.length-1]*i)

}

​

function setup() {  

  if (1200 > windowWidth) {

    createCanvas(windowWidth, windowWidth/2)

    headerSize *= windowWidth/1200

  } else {

    createCanvas(1200, 600);

  }

  for (let i=0;i<nBuildings;i++) {

    buildings.push([

      floor(random(width/2-20)),

      floor(random(height/7)),

      floor(random(50))]

    )

  }

  for (let i=0;i<nClouds;i++) {

    clouds.push([

      i*(width/2)/nClouds,

      floor(random(20+height/8)),

      floor(random(8))

    ])

  }

  stWidth = width*0.4/pWindow

  windowSlider = createSlider(1, 100, 50, 1)

  windowSlider.position(width/2, height+10)

  windowSlider.style("width", width*0.12 + "px")

  lightningSlider = createSlider(0.01, 0.99, 0.05, 0.01)

  lightningSlider.position(width*0.8, height+10)

  lightningSlider.style("width", width*0.12 + "px")

​

  pCheckbox = createCheckbox("Show Expected", false)

  pCheckbox.position(width*0.65, height+10)

  pCheckbox.style("font-size", headerSize+"px")

  pCheckbox.style("font-family", "sans-serif")

  pCheckbox.changed(()=>{showExp=!showExp})

}

​

​

function draw() {

  //background(220);

  pWindow = windowSlider.value()

  if (abs(1-lightningP-lightningSlider.value()) > 0.01) {

    strikeCounts = []

    posY=0

  }

  lightningP = 1-lightningSlider.value()

  if (pWindow != prevPW) {

    strikeCounts = []

    posY=0

  }

  prevPW = pWindow

  push(); // Sky

  fill(80, 100, 150, 80)

  rect(0, 0, width/2, height)

  pop();

  push();

  translate(0, height)

  noStroke()

  for (let b of buildings) {

    fill(30+parseInt(b[2]))

    rect(b[0], -b[1], sqrt(b[1])*2, b[1])

  }

  fill(0)

  rect(width/4-1, -height/4, 2, height/4)

  rect(width/4-5, -height/4+10, 10, height/4-10)

  pop();

  push(); // Fog

  fill(100, 10)

  noStroke()

  rect(0, height*7/8, width/2, height/8)

  rect(0, height*8/9, width/2, height/9)

  rect(0, height*9/10, width/2, height/10)

  pop();

  push()

  let endPos = createVector(width/4, height*0.75)

  if (random() > lightningP) {

    counter++

    strikeTracker.push(1)

    console.log("LIGHTNING")

    let startPos = createVector(random(width/2), 0)

​

    let nMids = floor(random(4)+1)

    let mids = []

    for (let i=0;i<nMids;i++) {

      mids.push(

        createVector(random(width/8)+width/4, random(height*0.75-20)+10)

      )

    }

    mids = mids.sort((a,b)=>(a.y-b.y))

    fill(255, 255, 150)

    noStroke()

    beginShape()

    vertex(startPos.x-nMids-1, startPos.y)

    for (let i=0;i<nMids;i++) {

      vertex(mids[i].x-i, mids[i].y)

    }

    vertex(endPos.x, endPos.y)

    for (let i=0;i<nMids;i++) {

      let ind = nMids-1-i

      vertex(mids[ind].x+ind, mids[ind].y)

    }

    vertex(startPos.x+nMids+1, startPos.y)

    endShape(CLOSE)

  } else {

    strikeTracker.push(0)

  }

  pop()

  push() // Clouds

  noStroke()

  for (let i=0;i<clouds.length;i++) {

    let c = clouds[i]

    fill(100+c[2], 200)

    circle(c[0]+noise(frameCount/300+i*100)*10, 

           c[1]/2+noise(frameCount/200+i*500)*10-10, 

           c[1])

  }

  pop()

  push()

  fill(0)

  noStroke()

  rect(width/2, 0, width/20, height)

  rect(width/2, 0, width/2, height*0.05)

  rect(width/2 + width/20 + pWindow*stWidth, 0, width/2, height*0.45)

  rect(width/2, height*0.45, width/2, height*0.55)

  pop()

  push()

  stroke(255)

  fill(255)

  textAlign(CENTER)

  textSize(headerSize)

  text("Lightning Strikes", width*0.75, headerSize)

  pop()

  push()

  noStroke()

  translate(width*0.75, height*0.25)

  let val = strikeTracker[strikeTracker.length-1]

  let posX = floor(((strikeTracker.length-1)%pWindow)*stWidth - width*0.2)

  fill(stCol[val*3], stCol[val*3+1], stCol[val*3+2])

  rect(posX-1, -height*0.2+10*posY, stWidth+2, height*0.4-10*posY)

  stroke(255, 255, 0)

  line(posX+stWidth+1, -height*0.2+10*posY+1, posX+stWidth+1, height*0.2)

  stroke(0)

  line(posX, -height*0.2+10*posY, posX+stWidth+1, -height*0.2+10*posY)

  if (strikeTracker.length >= pWindow) {

    posY++

    strikeTracker = []

    strikeCounts.push(counter)

    counter = 0

  }

  if (posY >= height*0.04) {

    posY = 0

    strikeCounts = []

  }

  pop()

  let hist = {

    "0":0,

    "1":0,

    "2":0,

    "3":0,

    "4":0,

    "5":0,

    "6":0,

    "7":0,

    "8":0,

    ">8":0

  }

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

    if (strikeCounts[i] < 9) {

      hist[strikeCounts[i]]+= 1

    } else {

      hist[">8"] += 1

    }

  }

  push()

  textAlign(CENTER)

  stroke(255)

  translate(width*0.55, height*0.85)

  strokeWeight(2)

  fill(255)

  line(0, -height*0.35, 0, 0)

  line(0, 0, width*0.4, 0)

  let intSpace = width*0.04

  textSize(headerSize)

  if (showExp) {

    let lambda = (1-lightningP)*pWindow

    let e_ = exp(1)

    beginShape()

    noFill()

    strokeWeight(3)

    stroke(0, 255, 0, 180)

    let eightplus = height*0.04

    for (let i=0;i<9;i++) {

      let expected = pow(lambda, i)*

          pow(e_, -lambda)/

          fact[i]*

          height*0.2

      eightplus-=expected/5

      vertex((i+0.5)*intSpace, -expected*8/5)

    }

    vertex((9.5)*intSpace, -eightplus*10)

    endShape()

    fill(0, 255, 0, 180)

    noStroke()

    text(`λ = ${round(lambda, 2)}`, 9*intSpace, -height*0.25)

  }

  for (let i=1;i<11;i++) {

    strokeWeight(2)

    stroke(255)

    fill(255)

    line(intSpace*i, 0, intSpace*i, height*0.02)

    strokeWeight(0)

    let id_ = String(i-1)

    if (id_ > 8) {

      id_ = ">8"

    } 

    text(id_, intSpace*(i-0.5), height*0.03)

    fill(255, 255, 150)

    rect(intSpace*(i-1), -8*parseInt(hist[id_]), intSpace, 8*hist[id_])

    fill(255)

    if (hist[id_] > 0 && id_ < 9) {

      text(hist[id_], 

           intSpace*(i-1+0.5), 

           -8*(hist[id_]+0.5))

    } else if (hist[id_] > 0) {

      text(hist[">8"], 

           intSpace*(i-1+0.5), 

           -8*(hist[id_]+0.5))

    }

  }

​

  pop()

  push()

  strokeWeight(0)

  fill(255)

  textAlign(CENTER)

  textSize(headerSize*0.75)

  text("Window Size", width*0.56, height-10)

  text(`Pr(Lightning): ${round(1-lightningP, 2)}`, width*0.85, height-10)

  text(`Poisson Window Size: ${pWindow} frame(s)`, width*0.55+stWidth*pWindow/2 + (pWindow<50)*(50-pWindow), height*0.48)

  translate(width*0.53, height*0.66)

  rotate(-PI/2)

  text(`# of ${pWindow}-frame samples\nwith X strikes`, 0, 0)

  pop()

  push()

  stroke(255, 0, 0, sin(frameCount*PI/120)*100)

  strokeWeight(2)

  point(endPos.x, endPos.y)

  pop()

}