Hi Robert You are probably right it is a little iOS specific.
Yes I've only seen this issue on iOS and pretty sure it is due to the use of FBO for windows. It is also that we essentially need to do the glResolveMultisampleFrameBuffer() and have that buffer bound when we do the readpixels. Otherwise it just returns black. I wasn't really sure how to go about making this more generic, other than perhaps some kind of prepareForScreenCapture, or forceResolveBuffers in GraphicsWindow? Tom On 1 October 2013 09:42, Robert Osfield <[email protected]> wrote: > Hi Thomas, > > I've just done a review and while the changes aren't significant and > are fine by themselves I do wonder if it's the best way forward. My > main concern is that it's solution for specific platform that won't be > obvious to most users - one has to know that you need to do this with > IOS when using AA and want to do screen capture. > > Do you know if this problem exists on other platforms where AA is > used? I'm wondering if it's just the issue with that face that IOS > uses FBO's for main windows. Where I'm going is trying to work out > whether this feature is something that we'd want to formalize - but > such as having the bind/resolve method available at higher level and > available to all platforms that might need it. > > Even if we do just keep the implementation and API IOS specific I > wonder if the naming might be too specific w.r.t > bindScreenShotBuffer(). Is the action effectively focused around the > glResolveMultisampleFrameBuffer() then perhaps naming should reflect > this and the doxygen comments explain when and where it is appropriate > to call it. > > Thoughts? > Robert. > > Robert. > > > > On 15 September 2013 01:23, Thomas Hogarth <[email protected]> > wrote: > > Hi Robert > > > > Attached are a changed GraphicsWindow and GraphicsWindow.mm from r13788 > that > > provide some functions to help with Screen Capture when using > AntiAliasing. > > > > Basically in a Final Draw Callback the multisample buffer needs resolving > > before you > > can call readpixels, else you just get black. > > > > Something like > > > > osgViewer::GraphicsWindowIOS* osgWindow = > > > dynamic_cast<osgViewer::GraphicsWindowIOS*>(renderInfo.getCurrentCamera()->getGraphicsContext()); > > > > osgWindow->bindScreenShotBuffer(); > > > > glReadPixels(x, y, width, height, GL_RGBA, GL_UNSIGNED_BYTE, buffer); > > > > _______________________________________________ > > osg-submissions mailing list > > [email protected] > > > http://lists.openscenegraph.org/listinfo.cgi/osg-submissions-openscenegraph.org > > >
_______________________________________________ osg-submissions mailing list [email protected] http://lists.openscenegraph.org/listinfo.cgi/osg-submissions-openscenegraph.org
