Re: [osg-users] Drawable init method?
Sorry about this delay, i did not notice when i looked and the compileGLObjects method that it was also const, which still confuses me. First of all thanks for the explanation! Still, how is one supposed to create any opengl element (VBOs, textures...) to use inside the drawImplementation method when overriding it? I apologize if it is something simple and i am not seeing it, but i havent found an example that has such scenario. If there is one, could someone please point me to it? Thanks in advance! Cheers, Alexandre -- Read this topic online here: http://forum.openscenegraph.org/viewtopic.php?p=51961#51961 ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
Re: [osg-users] Drawable init method?
Hi Alexandre, On 15 January 2013 12:47, Alexandre Valdetaro osgfo...@tevs.eu wrote: Sorry about this delay, i did not notice when i looked and the compileGLObjects method that it was also const, which still confuses me. First of all thanks for the explanation! Still, how is one supposed to create any opengl element (VBOs, textures...) to use inside the drawImplementation method when overriding it? I apologize if it is something simple and i am not seeing it, but i havent found an example that has such scenario. If there is one, could someone please point me to it? The compileGLObjects() and draw/drawImplementation() methods are const to give a strong hint to the developer that these classes can be run multi-threaded and should not usually modify local data. For data like OpenGL objects one does need to modify it during the draw calls but these are the exception and have to be multi-buffered with one element in each buffer used for each graphics context, as each graphics thread has at most one thread the thread safety is not compromised as long as the buffers used are pre-allocated to be big enough to contain all the elements required. Does this make sense? Robert. ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
Re: [osg-users] Drawable init method?
Hummm, now i understand. I really makes perfect sense. I will follow your advice and implement the gl objects in a multibuffered way then. Thanks a lot for the explanation, it really helped. Cheers, Alexandre -- Read this topic online here: http://forum.openscenegraph.org/viewtopic.php?p=51964#51964 ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
Re: [osg-users] Drawable init method?
Ok, that was exactly what i needed. Thanks a lot! Cheers, Alex -- Read this topic online here: http://forum.openscenegraph.org/viewtopic.php?p=51624#51624 ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
Re: [osg-users] Drawable init method?
Hi Alexandre, All OpenGL calls have be done from a thread with a valid graphics context current, as the OSG allows multi-threaded, multi-context usage one has to be careful when and where you do OpenGL calls. For a Drawable the three times when it's guaranteed to be safe to do OpenGL calls is when overriding the Drawable::compileGLObjects() or drawImplementation() or when using a DrawCallback. Robert. On 7 December 2012 01:39, Alexandre Valdetaro osgfo...@tevs.eu wrote: Hi, I just figured out that i was having a lot of trouble when creating vbos inside a drawable because there was no opengl context set during its initialization. After searching for a while i found out that if i initialized the vbos inside drawImplementation method then everything would work. There is one problem however, drawImplementation is const. I ended up setting all my members to mutable and all my methods to const so i could make it work. And now it is working. Isn't there a more proper way of initializing stuff inside a drawable? I would expect a initialize method or something like it, or a non const drawImplementation method. I also tried to set the context before initializing the drawable without using the drawImplementation method to no avail. Thanks a lot fellows Cheers, Alexandre -- Read this topic online here: http://forum.openscenegraph.org/viewtopic.php?p=51451#51451 ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
[osg-users] Drawable init method?
Hi, I just figured out that i was having a lot of trouble when creating vbos inside a drawable because there was no opengl context set during its initialization. After searching for a while i found out that if i initialized the vbos inside drawImplementation method then everything would work. There is one problem however, drawImplementation is const. I ended up setting all my members to mutable and all my methods to const so i could make it work. And now it is working. Isn't there a more proper way of initializing stuff inside a drawable? I would expect a initialize method or something like it, or a non const drawImplementation method. I also tried to set the context before initializing the drawable without using the drawImplementation method to no avail. Thanks a lot fellows Cheers, Alexandre -- Read this topic online here: http://forum.openscenegraph.org/viewtopic.php?p=51451#51451 ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
