The DirectFB library uses its own module to support the multiply layers.
See source code of any DirectFB driver.
e.g see line 716 of followed file ( ati128 )
http://git.directfb.org/?p=core/DirectFB.git;a=blob;f=gfxdrivers/ati128/ati128.c;h=bdba1aa9a6a6d82fde3d729983cadb7f63a9e3ea;hb=1317af26ea1fb28a762b331f65df566053050e93

and source of the overlay
http://git.directfb.org/?p=core/DirectFB.git;a=blob;f=gfxdrivers/ati128/ati128_overlay.c;h=efe279ca22b071d9ad071a6c692f0edd4f0fe5a5;hb=1317af26ea1fb28a762b331f65df566053050e93



2007/9/14, Timur Tabi <[EMAIL PROTECTED]>:
>
> I've been examining the source code to DirectFB, but I can't figure out
> what
> mechanism DirectFB uses to support multiple layers.
>
> I have a framebuffer driver for our hardware, which supports three
> buffers.
> The hardware merges the data from all three buffers into one image.  It
> uses
> the alpha channel on the 2nd and 3rd planes to determine how to merge.
>
> The driver currently creates three devices, /dev/fb0, /dev/fb1, and
> /dev/fb2.
>   I'm beginning to think that this is the wrong approach, however, since
> fb1
> and fb2 are tied to fb0 but the framebuffer API does not appear to have
> any
> mechanism for enforcing that connection.
>
> So I was wondering what is the best way to implement these three buffers
> in my
> driver so that DirectFB's layer feature will work well.
>
> --
> Timur Tabi
> Linux Kernel Developer @ Freescale
>
>
> _______________________________________________
> directfb-dev mailing list
> [email protected]
> http://mail.directfb.org/cgi-bin/mailman/listinfo/directfb-dev
>



-- 
Best Regards
Nikita Egorov
[EMAIL PROTECTED]
[EMAIL PROTECTED]
_______________________________________________
directfb-dev mailing list
[email protected]
http://mail.directfb.org/cgi-bin/mailman/listinfo/directfb-dev

Reply via email to