app_server doesn't appear to correctly fall back to single buffer mode if allocating the double buffered frame buffer fails (or doesn't correctly detect that it failed).

[BeOSR]

When setting the Screen pref to 1280x1024x32bpp or higher, the bottom 35% of the screen becomes black. The pointer is drawn in that zone, but windows etc are not. This does not happen in 1280x1024x16bpp, or 1182x864x32bbp.

Gfx card is MGA Millennium G200 8Mb AGP, and 1280x1024x32bpp works fine in R5, Dano & Zeta.

Using Geforce TNT 16Mb AGP does not generate this behaviour.

[axeld]

This is likely being caused by the app_server's double buffering implementation. It doubles the height of the screen, and maybe the Matrox card does not like this.

[BeOSR]

Problem solved by upgrading G200 to G400MAX 32Mb...

8Mb card probably doesn't have enough memory to allow double buffering at this resolution/color depth?

[anevilyak]

Indeed, 1280x1024@32pp equates to approximately a 5MB frame buffer, ergo doubling that would most definitely not fit into the 8MB of graphics RAM total that the card had. Though we should probably be smarter about handling that case by the sounds of it.

[anevilyak]

Updating ticket to reflect the actual problem.