Posted by KJTdev on Aug 01, 2016; 11:45am
URL: https://forum.jogamp.org/How-to-read-from-the-default-frame-buffer-after-binding-and-unbinding-an-FBO-with-JOGL-tp4037007p4037013.html

Thanks for the suggestion. Unfortunately, that function only gives me a black image. I currently just implemented a workaround where textures generated from FBOs are just cached and then reused in the next render loop so I don't need to bind/unbind any FBOs when taking a screenshot. I am still looking into why this doesn't work though. I should add that the first of the two err.println (Info: GLReadBufferUtil.readPixels: pre-exisiting GL error 0x502 ) is actually coming from my testing. The second comes from line 237 of GLReadBufferUtil. No error is found at any time before from glGetError().