void create_new_stroke(GdkEvent *event);
void continue_stroke(GdkEvent *event);
void finalize_stroke(void);
void do_eraser(GdkEvent *event, double radius, gboolean whole_strokes);
void create_new_stroke(GdkEvent *event);
void continue_stroke(GdkEvent *event);
void finalize_stroke(void);
void do_eraser(GdkEvent *event, double radius, gboolean whole_strokes);