scaleMouse method
Implementation
void scaleMouse(Vector2 to, [double sensitivity=1.0]){
if(!scaleAllowed) return;
final double x = ((to.x - from.x))/10000*sensitivity;
final double y = ((to.y - from.y))/10000*sensitivity;
//size = Size(size.width+x,size.height+y);
scale.x += x;
scale.y += y;
from.x = to.x;
from.y = to.y;
updateTransform();
}