untransform method

UPoint untransform(
  1. UPoint point,
  2. double? scale
)

Implementation

UPoint untransform(UPoint point, double? scale) {
  scale ??= 1.0;
  var x = (point.x / scale - b) / a;
  var y = (point.y / scale - d) / c;
  return UPoint(x, y);
}