> [...] > > > Right, but resolution is just a matter of RAMDAC parameters. All > > > I want is a 3856x1536 framebuffer with one RAMDAC displaying a > > > 2048x1536 window and the other displaying a 1808x1356 window. I > > > don't care about one tiny MB of VRAM being invisible. > > > > True, this should be possible as long as the pixel format is the > > same; I misunderstood before, this is indeed a driver limitation. > > And it has to be the same pixel format if it's the same (wide) buffer. > :-)
I know SGI hardware supports multiple pixel formats in one framebuffer, but I'm not sure it is possible to render to more than visual at a time; I doubt it. > > > BTW, the 8800 is limited to 2048x2048 for OpenGL contexts, but > > > that seems to be per context, and I'm not inderested in > > > stretching a single context over both screens anyway. (I'm not > > > interested in stretching *anything* over both screens; just > > > moving windows across them, which is not possible with > > > independent desktops.) > > > > That is a problem since there is no way an application can know > > about this limitation and I don't think X has a way of returning > > "window too large" on a window config request. > > The driver is supposed to just clip at 2048x2048. Some tester > concluded it does on Windoze, but I haven't tried it on the Linux > drivers. (Though they even have the same bugs as the Windows drivers, > so I'd guess they're pretty closely related...) Perhaps, with a performance penalty, these very large windows could be rendered in multiple passes... --ms
