StrokeLineGradient
virtual void StrokeLineGradient(const BPoint& start, const BPoint& end, BGradient& gradient) {}
virtual void StrokeLineGradient(const BPoint& start, const BPoint& end, BGradient& gradient);
callbacks.StrokeLineGradient(*start, *end, *gradient);
virtual void StrokeLineGradient(const BPoint& start, const BPoint& end, BGradient& gradient);
virtual void StrokeLineGradient(const BPoint& start, const BPoint& end, BGradient& gradient);