Hi there! 1) Does the "cColorBits" value in the PIXELFORMAT structure have to be the same value as the "dmBitsPerPel" in the DEVMODE structure, which I use to change the screen settings (with ChangeDisplaySettings; I call this before I set the rendering context) ? 2) What happens if it is not the same value? Which color depth will be taken (from PIXELFORMAT or from DEVMODE) ? 3) Is it possible to change the color depth during runtime without calling "ChangeDisplaySettings" (over "SetPixelFormat") ? 4) Do I have to make a new rendering context (and device context?) every time I call "ChangeDisplaySettings" ? I know, many questions, but it''s really important to me ...

1- I think they are not required to be the same, even they usually are. If not the same (2) the framebuffer will be of the type specified in the pixelformat and will be downsampled after rasterization, in the DAC.

3- For a windows limitation, changing the pixel format is not so simple. You have to blow up your render context and restart from scratch. It is possible to do this without passing from ChangeDisplaySettings. Not really sure to tell the truth... I automated everything this stuff months ago...

4- Quite sure it''s not really required. You have to when you change pixel format.

Many of those things can also vary from driver to driver.