Re: [Linux-fbdev-devel] Some questions

[Antonino D. <ad...@po...>]

On Wed, 2003-03-05 at 23:40, Geert Uytterhoeven wrote:
> On 5 Mar 2003, Antonino Daplas wrote:
> > On Wed, 2003-03-05 at 22:06, Thomas Winischhofer wrote:
> > > > Yes, that's the Real Thing :-)  fbcon_resize has a "fuzzy mode" too --
> > > > it won't do an fb_set_var() if the change in dimensions is only a
> > > > fraction of a character's dimension.
> > > 
> > > Ack. Is 16 fuzzy enough, what do you think?
> > 
> > I think you should only accept modes where the difference is a fraction
> > of a character width or height.  A difference more than that and
> > clear_margins() will not work correctly.  
> 
> Indeed, accel_clear_margins() calculates the margins as
> 
>     unsigned int cw = vc->vc_font.width;
>     unsigned int ch = vc->vc_font.height;
>     unsigned int rw = info->var.xres % cw;
>     unsigned int bh = info->var.yres % ch;
> 
> However, if it would use
> 
>     unsigned int rw = info->var.xres - (vc->vc_cols*cw);
>     unsigned int bh = info->var.yres - (vc->vc_rows*ch);
> 
> it would work with higher differences, too. And it would be a bit faster
> (multiply and subtract vs. modulo).
> 

Yes, I believe so.  This way, it will make rounding off of values more
clear cut and still produce an acceptable display (albeit with possibly
wider margins).

Tony