http://forum.openscenegraph.org/viewtopic.php?t=7846
However, in the recent thread you refer to, my code was in a Camera
post-draw callback which doesn't get a RenderInfo as a parameter, it gets a
Camera as a parameter. So, I get the contextID with the following:
camera.getGraphicsContext()->getState()->getContextID(). This might look
like a hack, as you said, but it isn't.
But how should YOU get the contextID?
>From your post, it sounds like you need to get the contextID from your
Viewer. A Viewer could manage many contexts. It has the concept of a current
context, but this is protected so you can't access it. However, you can get
a std::vector of GraphicsContexts from your Viewer. See
osgViewer::ViewerBase::getContexts(...). After you figure out which
GraphicsContext you are interested in, you can call
getState()->getContextID() on that GraphicsContext.
osg::isGLExtensionSupported(gc->getState()->getContextID(), "GL_ARB_multitexture") || osg::isGLExtensionSupported(gc->getState()->getContextID(), "GL_EXT_multitexture")
