Hello,
I am currently debugging a rendering issue and isolated the problem to a specific code line.
How is it possible, that the following code (yes, two consecutive calls to glColorMaski)…
glColorMaski(1, false, false, false, true);
glColorMaski(1, true, true, true, true);
…produces different results than this…
//glColorMaski(1, false, false, false, true);
glColorMaski(1, true, true, true, true);
As soon as I comment out the first glColorMaski, it seems my GBuffer
(second color attachment) is not working properly anymore.
But how is that possible since in both cases the second call to
glColorMaski should overwrite the state change of the first call 
Note that an FBO with two color attachments is activated when
calling glColorMaski (I know glColorMaski is a global state) and
I am running Windows 10 x64 with an AMD Radeon HD 5850
with latest drivers.
Driver bug? I am a bit lost.
Help is really appreciated!