Re: [Linux-fbdev-users] How many colors?

[cga2000 <cg...@op...>]

On Wed, Sep 12, 2007 at 03:58:35PM EDT, James Lehman wrote:
> Cool!
> 
> I'm glad you like it.
> 
> I'll have to get my stuff together and release version 10.0.

Definitely worth it.

> It uses function pointers that get set only once whenever a change is made
> to the frame buffer resolution. That way the right function gets called
> automatically with no time wasted on a switch statement. It is WAY faster
> than the version that is on the web now. 

Quite surprising.  I ran ./demo and the other stuff and I had a distinct
feeling that my ancient mach64 was a lot friskier than usual.

> It is written in C, but it acts like C++.
> 
> I guess I don't really understand your first question. You can't get
> more than 16 colors out of any terminal because the program that runs
> to display in the terminal has no way to ask for more than the 16
> usual colors. 

Not sure I follow you.  I've been running mutt and vim in an xterm with
256 colors for over a year.  By "terminal" do you mean a hardware
device (as opposed to an emulator) ..?

> The colors are set with escape sequences; a coded string of
> characters. These can also set absolute cursor position anywhere on
> the screen and do other things like reverse the text foreground and
> background or make it blink.  It's not really graphics at all. You
> have no pixels; only character cells; 

Yes. In a 256-color xterm you can display a succession of 256 cells
with the background or foreground set set to 256 colors chosen between
the 16 system colors, the 216 extended colors, and 24 shades of grey.

Which means you could simultaneously display a 256-character snippet of
text with each letter a different color.  But each letter would be
displayed in one single/solid color.  You would not be able to display
an O that changes color clockwise from slategrey, to teal, to cadetblue,
to hotpink .. etc. because the smallest addressable display area is the
cell and each character occupies an entire cell.

What I understand from Antonino's reply is that contrary to xterm and
a couple other X terminal emulators, the linux console does not have
the "physical" capability to display more than 16 colors.

So if I wanted to use the 256-color feature of mutt, vim, ELinks,
I would have to run an emulator that has this capability.

Unfortunately, there does not seem to be one available.

Hope this clarifies my earlier post.

cga