colorOffset function

Image colorOffset (
  1. Image src,
  2. {int red: 0,
  3. int green: 0,
  4. int blue: 0,
  5. int alpha: 0}
)

Add the red, green, blue and alpha values to the src image colors, a per-channel brightness.

Implementation

Image colorOffset(Image src,
    {int red = 0, int green = 0, int blue = 0, int alpha = 0}) {
  var pixels = src.getBytes();
  for (var i = 0, len = pixels.length; i < len; i += 4) {
    pixels[i] = clamp255(pixels[i] + red);
    pixels[i + 1] = clamp255(pixels[i + 1] + green);
    pixels[i + 2] = clamp255(pixels[i + 2] + blue);
    pixels[i + 3] = clamp255(pixels[i + 3] + alpha);
  }

  return src;
}