Re: question on armhf color depth

[Gene Heskett <gheskett@shentel.net>]

On Sunday 09 April 2017 12:09:20 Alan Corey wrote:

> Color depth is a deep subject (couldn't resist).  Different windows
> (every X program technically has it's own window) can run at different
> depths even right next to each other.  Programs request a depth from X
> or the window manager, not to mention a color map and graphics
> context.  If you have xwininfo (command line program so it's not in
> menus) try it a little:
>
> pi2# xwininfo
>
> xwininfo: Please select the window about which you
>           would like information by clicking the
>           mouse in that window.
>
> xwininfo: Window id: 0x300008c "Gmail - question on armhf color depth
> - Mozilla Firefox"
>
>   Absolute upper-left X:  35
>   Absolute upper-left Y:  65
>   Relative upper-left X:  1
>   Relative upper-left Y:  30
>   Width: 1189
>   Height: 870
>   Depth: 24
>   Visual: 0x21
>   Visual Class: TrueColor
>   Border width: 0
>   Class: InputOutput
>   Colormap: 0x20 (installed)
>   Bit Gravity State: NorthWestGravity
>   Window Gravity State: NorthWestGravity
>   Backing Store State: NotUseful
>   Save Under State: no
>   Map State: IsViewable
>   Override Redirect State: no
>   Corners:  +35+65  -696+65  -696-145  +35-145
>   -geometry 1189x870+34+35
>
> The Pi seems to make more use of a frame buffer than machines with
> separate video cards.  Devoting more RAM to the GPU in raspi-config
> may have a little effect, I have 64 megs.  A frame buffer is
> memory-mapped video you can actually write into.  fbset may show you
> something:
>
xwininfo reports on the windsow clicked in and since I'm logged into the 
pi with an ssh -Y profile, it dutifully reports on the shell window on 
this machine.


> pi2# fbset

The pi is running on a cheap AOC monitor that can only do 1366 by 780 or 
some such relatively odd-ball size I had to set in the kernels 
cmdline.txt.

Interestingly this 1366x768 is NOT listed by fbset!  So it looks like 
I'll have to go to its console to run xwininfo, brb.

Out at the pi, its 1366x768, 16 bit. The rest of it is a copy of what you 
pasted in above.

I'll take a look at fbset's man page. And I think video ram is 128 megs.
Maybe I'll learn something. :)

Thanks Alan.

[...]

Cheers, Gene Heskett
-- 
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