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Hello everybody,<br>
<br>
I'm trying to switch on or off the vsync on my NVidia K4200 on Win7
64 bits by using traits->vsync and setting the NVidia parameter
to 'Use Application parameters" for the vsync.<br>
<br>
Setting vsync to true, works, I can see the OSG_INFO
"GraphicsWindowWin32::setSyncToVBlank" as expected.<br>
<br>
The problem is I cannot set it to false, because by default the
NVidia behaviour is vsync = true (i.e. if nothing is specified the
drivers choice is vsync=true). <br>
<br>
After digging a little bit I've found in GraphicWindowWin32.cpp
GraphicsWindowWin32::realizeImplementation() that :<br>
<ol>
<li>vsync is only changed if it is true -> the
setSyncToVBlank(bool) is only called if the traits->vsync is
true, so you cannot change it to false.</li>
<li>Removing the protection (if vsync equal true), the
setSyncToVBlank is not called either because it is in an if
condition depending on vsync equal true (if (_traits.valid()
&& (_traits->sharedContext.valid() ||
_traits->vsync || _traits->swapGroupEnabled)))<br>
</li>
</ol>
<p>The question is why is there this double protection on the vsync
equal true ? Is there a risk that I don't understand (and then
please can someone explain <span class="moz-smiley-s1"><span> :-)
</span></span> ) about desactivating the vsync ?<br>
</p>
<p>Thanks a lot,<br>
</p>
<p>Christian<br>
</p>
<pre class="moz-signature" cols="72">--
SCHULTE Christian
Ingénieur Recherche
Responsable du Laboratoire de Simulation
ONERA - DCSD/PSEV
Département Commande des Systèmes et Dynamique du Vol
ONERA - Centre de Salon de Provence
BA 701
13661 SALON AIR Cedex - France
Tel :04.90.17.01.45</pre>
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