Re: SetPixelFormat failing

[James W. W. <ja...@wr...>]

"Lane Roathe" <la...@if...> wrote (in September):

>Recently I found that a SetPixelFormat call in Quesa was failing;
>specifically the line
>
>     if (!SetPixelFormat(theContext->theDC, pixelFormat, &pixelFormatDesc))
>
>in "./Renderers/Common/GLDrawContext.c"
>
>
>Nothing had changed, except I updated my video drivers. This has probably
>been the cause of almost all of my non-solvable OpenGL issues with Bugdom
>and Nanosaur with a lot of customers who purchased one of these games
>(ie, lots of refunds).
>
>Anyone have any ideas on why this would fail? It's when it's creating a
>new GL context, and the pixel format's "cColorBits" are zero (meaning, I
>would assume, the default).
>
>Anyway, the fix I found was to remove the error checking on this line;
>when removed everything works just fine.
>
>Thoughts on a "proper" solution welcome.


I was getting a SetPixelFormat error in Geom Test when I changed from 
the interactive to the wireframe renderer.  I noticed that the IR had 
requested 16 depth bits, whereas WF requested 32 bits.  When I 
changed things so that both asked for 32 bits, the error went away. 
Perhaps once you have chosen a particular depth buffer size for a 
window, you aren't allowed to change?

Also, I've seen a MS document saying that you can get SetPixelFormat 
errors if you don't have the WS_CLIPCHILDREN and WS_CLIPSIBLINGS 
window styles on a window use for OpenGL.
-- 
   James W. Walker, ScriptPerfection Enterprises, Inc.
   <http://www.write-brain.com/>