MarioAndroid’s Matrix.setRotateEulerM(…) function contains a bug and returns a wrong matrix result when rotating around the Y-axis. Googling android setRotateEulerM bug returns just 15 hits out of which only the first one is relevant: a neglected AOSP issue, marked as obsolete, that luckily contains the fix in comment #3. This bug has been reported in 2010 for Android 2.2 and still exists today in Android 6.0.1.
Left: rotation gone wrong. Right: rotation with fixed function.
Can it really be the case that almost nobody is using this function although there are thousands of OpenGL apps and games around? Why is it not discussed more frequently? Why is it marked as obsolete? Is this not a bug, but a case of incorrect usage?
Mario