Hi All, I've a question or two regarding rendering contexts. While the usage is OSX specific, the question is not.
I'm rendering into a CAOpenGLLayer (I can't render directly to a NSOpenGLView because I'm also using CALayer objects within the view - and these conflict with the NSOpenGLView, at least in my experience). In essence this means I manage the OpenGL context, create an osg::Viewer and use the setupViewerAsEmbeddedInWindow method. I have no problem using the context created by CAOpenGLLayer (I'm basing my code on the existing CocoaViewer which essentially does the same thing), I do have problems when the context which OSG is now using needs to be reset. In CAOpenGLLayer, a context reset can be caused by (for example) a user moving the window to another screen. In this case the context might be recreated because CAOpenGLLayer wants to use either a different graphics card or a different pixel format. >From what I can gather, while I'm managing the real OpenGL context myself, OSG >is managing it's own texture ID's (and I presume other scene OpenGL >resources). When the real OpenGL context is reset, OSG still believes all of >it's existing resources to be valid, because I've not explicitly told it >otherwise. >From this I have two questions: a) How do I tell OSG to throw away it's managed resources (texture ID's, etc), such that they are recreated at the next render pass? Can I do this? Is it even wise? Or should I be looking to throw away the viewer and recreate it? b) Instead of the above, should I rather have OSG manage it's own context and then after each OSG render pass copy the rendered result to the layer? For (b) I was considering rendering to a texture backed FBO, then DMA'ing that texture to RAM. I'd then DMA that back into the CAOpenGLLayer context. Thus OSG wouldn't have to be concerned at all with what the layer is with it's context, nor context resets. This (to me) sounds like a reasonable idea. It'd keep the OSG engine separated from the CAOpenGLLayer side of things, and would allow OSG to manage everything about it's rendering pipeline. The only part I don't like is the additional texture-copy to get the result into another context. p.s: The scene being drawn is small, with only many hundreds of vertices and <100 textures. Thank you! Cheers, Neil ------------------ Read this topic online here: http://forum.openscenegraph.org/viewtopic.php?p=49506#49506 _______________________________________________ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
