Re: Question about DGA

On Tue, 2 Jul 2002, Lawrence Lee (Shanghai) wrote:

> hi,all
> I'm studying the Graphics Card Driver in xwindow. I'm very confused with
> DGA(direct Graphics Architecture). Why an application needs DGA?Is DGA more
> faster? Like set mode, why xfree86 provides the DGA method?
> Thanks


   DGA is an extension to allow the driver to essentially switch
to another VT and leave the graphics hardware initialized so a
client can render to the framebuffer directly and all by itself.
It was intended as a sort of replacement for svgalib which was
struggling to get hardware supported at the time, while XFree86 had
fairly good driver coverage.  I consider it to be a legacy feature
which is deprecated.  The existence of DGA complicates the driver
somewhat.


                        Mark.