adjustSaturation method

void adjustSaturation(num value)

Implementation

void adjustSaturation(num value) {
  final v = min(max(value, -1), 1) + 1;
  final i = 1 - v;
  final r = i * _lumaR;
  final g = i * _lumaG;
  final b = i * _lumaB;

  _concat([r + v, g, b, 0, r, g + v, b, 0, r, g, b + v, 0, 0, 0, 0, 1],
      [0, 0, 0, 0]);
}