[Linux-fbdev-devel] Re: fbdev, console, (video) overlay/underlay & fbtv

[Romain D. <do...@ir...>]

Gerd Knorr wrote:

> I'd still think it is better to leave that completely up to the driver
> because it's more flexible and gives the driver full control.
> paddedX/paddedY will take care about any alignments / paddings and will
> probably catch most cases, but there might be other constrains ...

OK, I will change to that effect (unless there's someone else
that disagree).

> Don't know anything about the ruby design, but with the current
> console it simply doesn't work.  fbi and fbtv switch the console
> into graphics mode (ioctl(tty,KDSETMODE, KD_GRAPHICS)).  And they
> _have_ to do that for several reasons:

I missing something there. `fbi' doesn't change anything on my
display except it blanks it before (and after) displaying the
image. I had a hacked pm3fb with 8+24 overlay (not video overlay),
with fbcon in the upper 8 bits (CI8) and a 24 bits underlay. `fbi'
did simply put the picture in the lower 24 bits, anc after a C-c
the image would stay as an underlay in the console. No fancy
text mode here... but then I don't do VGA :-)

I don't think every app should know what every other app
do. FBcon use the FB layer, so do `fbi', `fbtv' or whatever.
One can have a FB layer _without_ fbcon, say in a multihead
setup, and that shouldn't prevent any app to run. Simply
do whatever is required by the user in wherever memory area
he wants. Every app should be made to behave nicely to other,
i.e. not overwrite memory it doesn't need unless asked
otherwise. That way, you can have fbcon using the FB as
a console, an image viewer displaying an image anywhere
in it, and another app overlaying a picture or video.
If a VT is in `text mode', whatever that could be, then
obviously you can't use it for graphic display.

With my current model it works over pm3fb: I get fbcon
to scroll under the overlay without problem (not that
the overlay has anything useful in it, _that_ doesn't
work yet ;-)

-- 
DOLBEAU Romain               | l'histoire est entierement vraie, puisque
ENS Cachan / Ker Lann        |     je l'ai imaginee d'un bout a l'autre
do...@ir...             |           -- Boris Vian