let n = 400; //number of particle

let stroke_r;

​

let baseImg;

let showImg = false;

​

let controller = function() {

  this.strokeSize = 80;

}

let panel = new controller();

​

​

​

function setup() {

  pixelDensity(1);

  createCanvas(600, 400);

  background(0);

​

  // blendMode(ADD);

  //generate image

  baseImg = createGraphics(600, 400);

  baseImg.background(0);

  // setupImg();

  let gui = new dat.GUI();

  gui.add(panel, 'strokeSize', 0, 100);

  // initialize particles

  // for (let i = 0; i < n; i++) {

  //   particles.push(new Particle());

  // }

}

​

function draw() {

  background(0);

  // tint(255, 10);

  stroke_r = panel.strokeSize;

  renderImg(stroke_r);

​

  for (let i = 0; i < 5; i++) {

    particles.push(new Particle());

  }

  if (particles.length > n) {

    particles.splice(0,5);

  }

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

  //   let p = particles[i];

  //   p.calcforce();

  //   p.applyforce();

  //   p.display();

  // }

  for(let i=particles.length-1; i>=0; i--){

    let p = particles[i];

    p.calcforce();

    p.applyforce();

    p.update();

    p.display();

    // if (p.age > 50) {

    //   particles.splice(i, 1);

    // }

    if (p.age > 50) {

      p.startDying();

    }

    if (p.dead == true) {

      particles.splice(i, 1);

    }

  }

  push();

  strokeWeight(1);

  stroke(255);

  fill(255);

  text("Press 'i' to show base image", 20,20);

  pop();

}

​

​

function setupImg() {

  baseImg.loadPixels();

  let widthd = width * pixelDensity();

  let heightd = height * pixelDensity();

  for (let i = 0; i < widthd; i++) {

    for (let j = 0; j < heightd; j++) {

      let x = i / pixelDensity();

      let y = j / pixelDensity();

      baseImg.pixels[(i + j * widthd) * 4] = 0;

      baseImg.pixels[(i + j * widthd) * 4 + 1] = 0;

      baseImg.pixels[(i + j * widthd) * 4 + 2] = 0;

      baseImg.pixels[(i + j * widthd) * 4 + 3] = 255;

    }

  }

  baseImg.updatePixels();

}

​

​

​

​

function renderImg(stroke_r) {

  baseImg.loadPixels();

  // let wl = (mouseX-stroke_r);

  // let wr = (mouseX+stroke_r);

  // let hu = (mouseY+stroke_r);

  // let hd = (mouseY-stroke_r);

  if (mouseIsPressed) {

    for (let i = 0; i <= width*pixelDensity(); i++) {

      for (let j = 0; j <= height*pixelDensity(); j++) {

        let d = dist(mouseX, mouseY, i/pixelDensity(), j/pixelDensity());

        if (d <= stroke_r) {

          baseImg.pixels[(i + j*pixelDensity()*width) * 4] += ((stroke_r-d)/stroke_r)*80;

          baseImg.pixels[(i + j*pixelDensity()*width) * 4+1] += ((stroke_r-d)/stroke_r)*80;

          baseImg.pixels[(i + j*pixelDensity()*width) * 4+2] += ((stroke_r-d)/stroke_r)*80;

        }

      }

    }

  }

  baseImg.updatePixels();

  if (showImg == true) {

    image(baseImg, 0, 0);

  }

}

​

function keyPressed() {

  if (key == "i" || key == "I") {

    showImg = !showImg;

  }

}

​