Re: How is graphics rendered in various older computing devices supported by NetBSD

Hello Martin, 

Thank you for your answer. I have one more related query though- does the rasops library enable detection of screen resolution in its supported devices?

Yours sincerely,
Arvind.


01.10.2019, 09:48, "Martin Husemann" <[email protected]>:
> On Tue, Oct 01, 2019 at 03:35:42AM +0530, Arvind Arvind Pro wrote:
>>  Or is the graphics/text rendered based on the type of graphics
>>  adapter- eg SVGA(Super Video Graphics Adapter) / EGA(Extended Graphics
>>  Adapter) and so on? If someone can shed more light on this it would be
>>  very helpful.
>
> Heh, those are pretty modern graphic cards ;-)
>
> Indeed the rendering depends on the framebuffer device and is done
> differently in various drivers. Many of the old graphics adpaters have
> hardware acceleartion (e.g. for scrolling) and the framebuffer driver
> makes use of that. A classic example is the cg6 device used on old
> sun machines, see:
>
>         https://man.netbsd.org/cgi-bin/man-cgi?cgsix+.sparc+NetBSD-current
>
> Most (all?) of these drivers use a common library called "rasops", see
>
>         https://man.netbsd.org/cgi-bin/man-cgi?rasops+.sparc+NetBSD-current
>
> and attach a "wsdisplay" console device:
>
>         https://man.netbsd.org/cgi-bin/man-cgi?wsdisplay+.sparc+NetBSD-current
>
> You can find the various drivers by doing a "full search" on nxr for rasops:
>
>         https://nxr.netbsd.org/s?n=25&start=0&q=rasops&sort=relevancy&project=src
>
> Does that answer your question?
>
> Martin