text: //https://thebookofshaders.com/edit.php?log=161127201905
  
  let turbulence;
  
  function preload() {
      // load the shader definitions from files
      turbulence = loadShader('shader.vert', 'shader.frag');
  }
  
  function setup() {
      createCanvas(windowWidth, windowHeight, WEBGL);
      // use the shader
      shader(turbulence);
      noStroke();
      turbulence.setUniform('u_time', random(10))
      turbulence.setUniform('w', windowWidth)
      turbulence.setUniform('h', windowHeight)
  
  }
  
  function draw() {
      background(0)
  
      turbulence.setUniform('mouseX', 0.1+ mouseX/windowWidth)
      turbulence.setUniform('mouseY', 0.1+ mouseY/windowHeight)
  
      quad(-1, -1, 1, -1, 1, 1, -1, 1);
  }
  
  function mouseReleased(){
      turbulence.setUniform('u_time',random(10))
  }
  
  function windowResized() {
      resizeCanvas(windowWidth, windowHeight)
      turbulence.setUniform('w', windowWidth)
      turbulence.setUniform('h', windowHeight)
  
  }
  