View Full Version : PixelFormat-Problems

07-21-2002, 04:37 AM
I have some trouble witht the Pixelformat. It seems that the Pixelformat depends on the used Videocard/driver or something else Hardware-specific. Does anyone knows the exact dependency of the available Pixelformats on a videocard??

The trouble i have is that on some videocards a Pixelformat would be choosen that provide a black corner if the Viewport reaches a specific size. On an other system with an other videocard this does not happenend.
Perhaps anyone has more experience with this topic and can explain me what the reason for such a strange behaviour could be.

Thanks in advance
P. Gmeiner

07-21-2002, 06:54 AM
Yes, what pixel formats are available is hardware specific. Some cards might, for example, support a 32-bit z-buffer while others don't. An application can only specify its minimum requirements and hope that the driver has a pixel format that closely matches the specified requirements.

I don't really understand what you mean with the black corner thing? Maybe you could elaborate a bit more on that and somebody can help you with your specific problem.
Anyway, pixel formats are different on different cards/drivers, depending on their capabilities.


07-21-2002, 07:27 AM
Is this the bug where software OpenGL contexts sometimes don't resize with the window?

Or it might be a bug in some specific driver. Print the output of glGetString() for GL_RENDERER and GL_VENDOR and compare.

07-22-2002, 01:44 AM
When the window would be resized to a specific size the Drawing-Window appears black. So that no more other Graphical things on this position were drawn. The size of the black edge differs from every Application run. Is that possible that the Pixelformat depends on the installed graphic-driver?

07-22-2002, 10:33 AM
If when the image is draw the center of projection is correctly placed inside the viewport but has a black border to the right and bottom of the image then its almost certianly the MFC / Microsoft OGL bug. There is a post thats got a reference to a MS Technical Article that describes a work around. ( Good luck finding it!). I think the work around is to call the viewport resizeing functions twice, can't remember which ones. Its a very annoying bug (if its this one)

07-23-2002, 01:57 AM
Yes it seems that this can be the reason for the behaviour, i have found it on the microsoft-page with a work around for this. I would try this to solve the Problem. Thank you for your help.