let canvas;

let defShad;

​

function preload() {

  img = loadImage('test.png');

}

​

function setup() {

  canvas = createCanvas(400, 400, WEBGL);

  noStroke();

  defShad = createShader(vertShader, fragShader);

​

  canvas.getTexture(img).setInterpolation(NEAREST, NEAREST);

}

​

function draw() {

  background(0);

  shader(defShad);

  {

    // The shaders didn't apply to what was drawn with image() and to a shape with a texture applied with texture()

    image(img, -width / 2, -height / 2, width, height);

    push();

    {

      texture(img);

      rect(0, 0, 100, 100);

    }

    pop();

​

    // The shaders only apply to this

    rect(-100, -100, 100, 100);

  }

  resetShader();

}