Slow repaint problem

  • Thread starter Thread starter Ray Mitchell
  • Start date Start date
R

Ray Mitchell

Hello,

I realize this is probably a very ambiguous question but I
don't know enough about the way everything works to ask it
intelligently. I have a 3rd party application that can be
installed as a control. It's purpose is to provide
generic x-y coordinate 2D line graphs. It's actually
really a neat and versatile application. I have a dialog
that has 8 of these graphs on it. Whenever I drag another
window over it, then drag it back off, the redraw of the
graphs takes a good 5 seconds. You can actually see it
redrawing all the axes, tick marks, and labels. I have a
2.7GHz system and I've never seen this problem with any
other application. I have a similar Java application and
the redraw is so quick you can't see it happen. Does this
behaviour mean anything obvious to any of you? If so,
please explain and possibly tell me how I can remedy the
problem. Someone told me the application should be
greating a bitmap then telling the system to draw the
bitmap rather than whatever it's doing now. I do have the
source code.

Thanks,
Ray Mitchell
 
First, you should try this on another machine to see if this is something to
do with a slow video memory or the way the video memory is accessed.

Second, You can try and make the control do "double-buffering" to minimize
flicker during re-draw (this actually internally draws onto a bitmap buffer
and blasts it to the screen, instead of directly drawing on the screen)

-vJ
 
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