I am so-o-o-o-o pissed (if you'll excuse my French...)
I have wasted a week or so trying to understand why I was not able to do a simple animation (like horizontally moving a small rectangle across the screen at a steady pace) without getting VERY annoying hiccups in the animation. I won't tell you all the things I have tried, from using the animator, to timers, multi-threading, and eventually trying to use OpenGL (which, as we all know is a pain)... I eventually had a closer look at the OpenGLAppExample app and saw that the animation was not as flawless as I initially thought and did have regular "hiccups" too, less easy to see because the rotating teapot was hiding things, much more so than a plain rectangle supposed to move at a regular, steady pace across the screen.
I saw this thread on the forum talking about animation problems with El Capitan and tried my code and also the OpenGLAppExample app on an old MacBookPro with 10.10 (Yosemite) on it and... it worked fine. No hiccups whatsoever, both on my various test apps (using or not OpenGL) and on OpenGLAppExample...
Before I curse Apple forever I would like to know if anyone could make the same comparison playing the OpenGLAppExample under both a 10.11 and 10.10 versions (10.11.1 vs 1.10.2 to be precise) and confirm that there are problems under 10.11.1, and not under 10.10.2.
P.S. I am using the latest commits from Juce github
<EDIT> oh and btw I tried the same demo on my old Dell computer running under Win7 and it worked fine too. Incidentally, the teapot is spinning about 5 times faster under Win 7 than under MacOS 10.11...