public static Vector2 CGPointApplyAffineTransform(Vector2 point, CGAffineTransform xform){
Vector2 p;
p.x=xform.a*point.x+xform.c*point.y+xform.tx;
p.y=xform.b*point.x+xform.d*point.y+xform.ty;
return p;
}
public static Vector2 CGSizeApplyAffineTransform(Vector2 size,CGAffineTransform xform){