toGrayscale static method
Convert a input
color to a gray scaled color and store it in result
.
Implementation
static void toGrayscale(Vector4 input, Vector4 result) {
final value = 0.21 * input.r + 0.71 * input.g + 0.07 * input.b;
result
..r = value
..g = value
..b = value
..a = input.a;
}