GtkGLArea should not auto-(en|dis)able GL_DEPTH_TEST by whether depth buffer is used
Submitted by ami..@..ail.de
Link to original bug (#783999)
Description
The GtkGLArea widget automatically enables GL_DEPTH_TEST as soon as a depth buffer is used during every draw call. This is however wrong behaviour. Just having a depth buffer in the frame buffer does not mean every render operation includes querying the depth buffer.
GL_DEPTH_TEST defaults to being disabled and the widget shouldn't change that.
I wanted to draw a simple triangle and searched for ages why it didn't appear until I cleared the depth buffer. Clearly wrong behaviour in my opinion.
Now GL_DEPTH_TEST is also disabled by GtkGLArea when no depth buffer is used which does not hurt but still I would suggest that the widget doesn't touch this state.
Version: 3.22.x