A quick follow-up on my own posting: I've just enabled multi-threaded
GL for all of my app except for when I want to synchronise user input
with screen output e.g. when dragging on my globe. I'd be interested
to learn whether synchronising user input with screen output is
something others have had to contend with when going multi-threaded.
Cheers,
-C
On 28/05/2007, at 8:29 PM, Christopher Hunt wrote:
Having finally built my application for Intel (what took you, I
hear you say), I find that enabling Mac OS X's gl multi-threading
capability causes an interesting side effect.
Firstly I don't think my application is particularly CPU bound when
it comes to GL anyhow so I'm not sure that there's a performance
gain to be had with GL multi-threading. Regardless, I enabled it
and my application's CPU based functions are definitely sped up
given the multi-threading mode - however I now see a lag between my
app's processing and what gets rendered. For example, I have a
globe with the earth textured on to it. The earth can be dragged
around using the mouse as you'd expect. What I find is that the
earth continues to spin a bit after I've stopped dragging. If I
disable the multi-threading mode of GL then my rendering is
synchronised with my mouse dragging and there is continued spinning.
Interesting?
I'm double-buffering and flushing via my context's flushBuffer
method to sync with vertical retrace.
Perhaps the GL multi-threaded mode is not for my app given its
present efficiency but I thought I'd share this observation in case
there's something I'm missing i.e. perhaps I should using multi-
threading GL but somehow synchronise with the GL thread when I'm
flushing my context...
Ideas? Comments?
BTW: I'm using a 2.66Ghz Quad Xeon so there's some real parallelism
happening. :-)
Cheers,
-C
_______________________________________________
Do not post admin requests to the list. They will be ignored.
Mac-opengl mailing list (email@hidden)
Help/Unsubscribe/Update your Subscription:
http://lists.apple.com/mailman/options/mac-opengl/email@hidden
