Posted by gouessej on May 07, 2012; 6:40pm
URL: https://forum.jogamp.org/Exceedingly-expensive-glReadPixels-operation-on-Mac-tp3968736p3969324.html

Hi

glReadPixels is generally considered as very slow and it is even worse when mixing it with shaders. Sometimes it is completely emulated in software, it depends on the driver. Actually, even the official OpenGL FAQ discourages the use of OpenGL picking.