> The curve is keeping going, from left to right. When reach > the right border, > it will loopback to the left border, and do this again and again. > > But, when the curve loopback to the left border, the existent > drawing will not > be erased immediately. Instead, the older drawing will be > erased step by step, > where the new curve is drawing. > > Considering the efficiency. In this case, which widget should > I draw on? > Fl_Box, Fl_Window or others? How can I erase the image step by step, > not erase all of it? Which function should I use?
How many sample points in your line? When I did this, I just used an Fl_Box, and redrew the entire curve every time (partial updates were too much effort and hard to do.) So I simply kept the last 512 or so points in a circular buffer, and redraw the entire list on every redraw. Then it was simply a matter of putting the new samples into the list in the right place and it Just Worked. Have you looked in the links bazaar for oscilloscope widgets contributed by other users? I think there used to be some, and they would most likely do just exactly what you want... SELEX Sensors and Airborne Systems Limited Registered Office: Sigma House, Christopher Martin Road, Basildon, Essex SS14 3EL A company registered in England & Wales. Company no. 02426132 ******************************************************************** This email and any attachments are confidential to the intended recipient and may also be privileged. If you are not the intended recipient please delete it from your system and notify the sender. You should not copy it or use it for any purpose nor disclose or distribute its contents to any other person. ******************************************************************** _______________________________________________ fltk mailing list [email protected] http://lists.easysw.com/mailman/listinfo/fltk
