From: Marcus Sundberg <mackan@stacken.kth.se>
  To  : ggi-develop@eskimo.com
  Date: Fri, 11 Sep 1998 14:54:29 +0000

Re: SYNC mode should go

Andrew Apted wrote:
> 
> Marcus writes:
> 
> >  The screen is not guaranteed to be updated until you call ggiUnlock()
> >
> >  For apps that only access the framebuffer ggiUnlock(vis);ggiLock(vis);
> >  will have the same effect as ggiFlush(vis); currently does. Apps that
> >  mixes accel/direct access will call the functions as apropriate.
> >  Apps that don't hit the DirectBuffer at all should call ggiFlush()
> >  to flush the accel queue,but they could call ggiLock();ggiUnlock()
> >  to get the same effect.  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
>    ^^^^^^^^^^^^^^^^^^^^^^
> Hmmm, sounds a bit fuzzy to me.  Are you just saying that ggiUnlock()
> does an implicit ggiFlush() ?

ggiFlush() will flush the accelqueue, and ggiLock() will make the
hardware ready for direct framebuffer access, which implies flushing
the accelqueue.

In the docs we will state that if you have done a ggiLock(),
you cant use the drawing functions until you call ggiUnlock(),
and also that it's not guaranteed that what you have drawn directly
to the framebuffer will be visible until you call ggiUnlock().

The latter is neccesary to know when the X-targets buffer should
be flushed.

Please forget what I said in the marked text above. ;)
It WILL work like I said, but it's a purely technical consequence
and should not be recommended or even mentioned in the docs.

//Marcus
-- 
-------------------------------+------------------------------------
        Marcus Sundberg        | http://www.stacken.kth.se/~mackan/
 Royal Institute of Technology |       Phone: +46 707 295404
       Stockholm, Sweden       |   E-Mail: mackan@stacken.kth.se