Gerard Robin wrote: > Being Nvidia and X installed , i continu to search a good answer : > After many experimentations, I did not notice any change between > 24bpp and 32 bpp.
There is no difference between 24 and 32 bpp on NVidia hardware. Both of them give you a 32 bit 8:8:8:8 RGBA front and backbuffer, a 32 bit Z depth and (now) an 8 bit stencil buffer, for a grand total of 104 "real" bits per pixel. You can inspect the list of OpenGL visuals available using the "glxinfo" command line tool if you like. The real choice underneath the (glut or SDL) abstraction layer is much more complicated than a single number. The reason that this suddenly breaks with the new drivers is that the new drivers have a new feature: they can now support 16 bit color buffers even when the desktop is at 32bpp. But these 16 bit modes do *not* support 8 bit stencil, which is required for the shadow implementation. So it used to by that when FlightGear asked for a "16bpp stencil" framebuffer on a 32bpp desktop, it got a 32 bit mode anyway. But now, the driver can actually fulfill the request, so it provides a mode that won't work with shadows. FlightGear asks for a default color depth of 16bpp, but it also asks for stencil; this is essentially a bug. These are not compatible requests on any modern GPUs, which only support 8 bit stencil in true color modes. Andy _______________________________________________ Flightgear-devel mailing list Flightgear-devel@flightgear.org http://mail.flightgear.org/mailman/listinfo/flightgear-devel 2f585eeea02e2c79d7b1d8c4963bae2d
