@Override
  public boolean equals(Object o) {
    return o instanceof VignetteFilterTransformation &&
      ((VignetteFilterTransformation) o).center.equals(center.x, center.y) &&
      Arrays.equals(((VignetteFilterTransformation) o).vignetteColor, vignetteColor) &&
      ((VignetteFilterTransformation) o).vignetteStart == vignetteStart &&
      ((VignetteFilterTransformation) o).vignetteEnd == vignetteEnd;
  }
Performs a vignetting effect, fading out the image at the edges
The directional intensity of the vignetting,
with a default of x = 0.5, y = 0.5, start = 0, end = 0.75
transformations/src/main/java/jp/wasabeef/glide/transformations/gpu/VignetteFilterTransformation.java