​

// load in the shader

function preload() {

  golShader = loadShader('gol.vert', 'gol.frag');

}

​

function setup() {

  createCanvas(600, 600);

  // pixelDensity(1); 

  background(0);

  stroke(255);

}

​

function draw() {

  // Draw a line on the canvas if the mouse is pressed

  if(mouseIsPressed) {

    line(pmouseX, pmouseY, mouseX, mouseY);

  }  

  if(frameCount % 10 == 0) {

    filterShader(golShader); 

  }

}

​

function keyReleased() {

  if(key === "r") {

    stroke(255, 0, 0);

  } else if(key === "g") {

    stroke(0, 255, 0);

  } else if(key === "b") {

    stroke(0, 0, 255);    

  } else if(key === "w") {

    stroke(255);

  }

}