/// draw the object, sets xo_ and yo_ cached values
void draw(Painter &, int x, int y) const;
/// appends itself with macro arguments substituted
void substitute(MathMacro const & macro);
/// draw the object, sets xo_ and yo_ cached values
void draw(Painter &, int x, int y) const;
/// appends itself with macro arguments substituted
void substitute(MathMacro const & macro);