Flutter: x-axis gradient

main.dart

/// Main area of interest, this function will
/// return color for each particular color on our [ui.Image]
int generatePixel(int x, int y, Size size) {
  /// Compute unified vector, values of its components
  /// will be between 0 and 1
  var uv = Vector2(x / size.width, y / size.height);

  /// [Vector2.xxx] is a getter which returns [Vector3]
  /// with first component of given [Vector2], uv in our case.
  return toColorInt(uv.xxx);
}