Changed default sense of GLContext optimization flag to false. Now

must explicitly specify -Djogl.GLContext.optimize on the command line
to enable it. Added note to the user guide in the section on X11
platforms discussing this.


git-svn-id: file:///usr/local/projects/SUN/JOGL/git-svn/svn-server-sync/jogl/trunk@795 232f8b59-042b-4e1e-8c03-345bb8c30851

1 files changed, 21 insertions, 1 deletions

diff --git a/doc/userguide/index.html b/doc/userguide/index.html
index 9bfe0caa4..a76b36b5c 100644
--- a/doc/userguide/index.html
+++ b/doc/userguide/index.html
@@ -846,7 +846,27 @@ hardware.
 
 <P>
 
-No outstanding issues at this time.
+Support has been added to the JOGL library for allowing multiple
+threads to each have an OpenGL context current simultaneously, for
+example to implement multi-head CAVE-like environments. Normally a
+global AWT lock is held between calls to GLContext.makeCurrent() /
+release() for on-screen heavyweight contexts (for example, those
+associated with a Canvas or GLCanvas). We have found this to be
+necessary for stability purposes on all supported X11 platforms, even
+with relatively robust drivers such as those from NVidia.
+
+</P>
+<P>
+
+To enable multiple GLContexts to be made current simultaneously on X11
+platforms, specify the command line argument
+<CODE>-Djogl.GLContext.optimize</CODE> when starting the JVM. Note
+that this may incur robustness problems, in particular when resizing
+or moving windows. We have also found that ATI's proprietary drivers
+do not work at all with this flag, apparently because they cause GLX
+tokens to be sent to the X server for various GL calls even for direct
+contexts. For this reason if the GLX vendor is ATI then this flag
+currently has no effect.
 
 </P>