On 9/5/07, Dieter <[EMAIL PROTECTED]> wrote: > >> I was not thinking that the VGA would scale arbitrarily. > > > My underlying concern is that regardless of how much we may wish VGA > > compatibility didn't exist, not only does it have to, it will be the > > first thing a "user" sees when using an open graphics based card on an > > x86 system. The last thing we want it for the first impression to be > > "Boy this sucks..." > > > > We certainly need to have a reasonable update rate in both text and > > graphics VGA mode since x86 systems will use these modes during OS installs. > > The other day I was helping a friend upgrade a machine from Linux to BSD. > I was having trouble reading the tiny font, so he pushed a couple of buttons > and the text zoomed to full screen. MUCH easier to read. So I'd say that > scaling (and an easy to read font) is fairly important, FAR more important > than "eye candy GUI" stuff.
The 80x25 text mode with an 8x16 font requires 640x400. Normally, the font is widened to 9x16 and they display 720x400, but we really don't have to, and I have used graphical consoles under Linux before where they don't use the 9x16, and it looked just fine. At 800x600, centering the 640x400 should look good enough. AT 1024x768, we could do an integer 1.5 scaling. Heck, we could even do a smooth scaling where a 2x2 set of pixels from the font are scaled in the nanocontroller to 3x3. That would bring us up to 960x600, which wouldn't look too bad centered. For 1280x1024, a simple 2x scaling to 1280x800 would look just fine. For 1600x1200, I would suggest a 2x scaling. 2.5 would look a little better but the computation cost would be too high if we did it smoothly. We'd have to see how it looked if we did an integer scaling, where alternate columns/rows are scaled 2x and 3x. We might scale vertically by 3x or 2.5x. I'm trying to avoid using the GPU here, in part because it would be best if we had VGA done BEFORE the GPU was finished. For 1920x1200, it's a simple 3x scaling to 1920x1200. For 1920x1080, we'd have to do 3x horizontally and 2x or 2.5x vertically. As an aside, we should consider supporting the EGA text mode that uses an 8x14 font. At some points in the boot process, that's the mode some BIOSs use. The EnergyStar thing doesn't look right otherwise. For that, they actually redefine parts of the font just to make the shape. -- Timothy Normand Miller http://www.cse.ohio-state.edu/~millerti Open Graphics Project _______________________________________________ Open-graphics mailing list [email protected] http://lists.duskglow.com/mailman/listinfo/open-graphics List service provided by Duskglow Consulting, LLC (www.duskglow.com)
