Re: [Linux-fbdev-devel] question on _putc, _putcs, _bmove..

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

Petr Vandrovec wrote:

> It is bug. clear_margin is stupid procedure anyway as
> it corrupts screen buffer contents, so if you are using
> non-zero xoffset, you should make sure that there is no
> right margin...

Why should it corrupts memory ? Properly written,
you only erase the rows/columns that are displayed
and not used, i.e.

right margin: from (yoffset)
                to (yoffset + yres)
          and from (conp->vc_cols * fontwidth(p) + xoffset)
                to (xoffset + xres)

bottom margin: from (xoffset)
                 to (xoffset + xres)
           and from (conp->vc_rows * fontheight(p) + yoffset)
                 to (yoffset + yres)

and the fbcon-* do it properly except they forgot the xoffset.

-- 
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