Per https://forum.jogamp.org/2-5-0-refresh-problem-only-on-intel-mac-td4043708.html Here's another thread tracking progress on the issue: https://github.com/MarginallyClever/Makelangelo-software/issues/813 Here's all the code: https://github.com/MarginallyClever/RepaintMacIntel Editor4.java compiles and runs but does not display the basic triangle on OSX, either intel or apple silicon.