code: function makeTexture (f) {
    var texData = []
  
    for (var y = 0; y < TEX_W; y++) {
      var r = []
      for (var x = 0; x < TEX_H; x++) {
        var rand = rng()
        var g = rand > f ? 255 : 0
  
        r.push([g, g, g, 255])
      }
      texData.push(r)
    }
  
    return regl.texture({
      mag: 'nearest',
      wrap: 'repeat',
      data: texData
    })
  }
docs: /*
  To implement the transition effect, we have a bunch of textures that we cycle through, and
  render to the stencul buffer.
  
  The texture returned by makeTexture(0) is all white, and makeTexture(1.0) is all black.
  But makeTexture(0.5) will be random noise, where about in average, half the pixels are white, and
  the other half are black.