SVGA console

[Marco Gerards]

Hi,

Currently the console client only support (minimally) VGA. It it not
really hard to add some more VGA support and even basic SVGA support.

For better VGA support I want to add some features. First I'd like to
add modeline support. This is how SVGATextMode, Xfree, svgalib,
etc. setup a videomode. This is really easy to do, actually I already
have most code to configure the hardware.

As usual there  are some problems I can think of, to understand the
problem I will show some lines from a SVGATextMode configuration file
first:

"80x25x9"          28.3   640  680  776  800    400  412  414  449 font  9x16
"80x28x9"          28.3   640  680  776  800    392  412  414  449 font  9x14

There two lines are copied from TextConfig. The lines begins with a
dimension name, "80x25x9" on the first line for example. This name is
only for the user, the rest of the line are hardware parameters to set
up this mode.

As you might have noticed the parameters for the hardware are almost
identical, except for the 400 and 449 and the font on the first line
everything is the same.

What I'm trying to make clear here is that many dimensions are set
simply by using another font. This is how it works on all operating
systems.

(Ofcourse there are other things required to change the dimensions of
the screen, but this one gives me problems)

The problem I have is that if the console should work perfectly it
should automatically pick the right font. If we let the user pick the
font the dimensions might turn out to be very unlogical.

So the best thing would be making it possible for the vga console to
pick the fonts. What is the best way to do this? Assuming the font has
the same names as used in this file? 9x16 would be
"/lib/hud/fonts/9x16.bdf" and after loading the font we should also
check if there are bold, italic and bold+italic fonts? That makes the
most sense to me.

We can also leave it as it is, but that will force the user to think
about how to change dimensions. I think that is not a thing most users
care to learn about.

One disadvantage of the approach is that some fonts have more unicode
characters than other fonts. Selecting another font by switching
dimensions might confuse the user a bit. But IMO this is not as bad as
teaching _all_ users how to setup the code. as usual I'm open for
suggestions. :)

Another issue is the screen blanking screensaver. IMO this shouldn't
be separate driver/plugin, but it should be a part of the vga
driver. I want this because they both access the same hardware. The
vga driver needs a lock for hardware access because of this.

Is there something else I forgot or something that isn't clear?

Thanks,
Marco