Rendering issues and ghosting (on Intel chips)

[hsanjuan]

This is a follow up to #44 and #47, because I still have instances of ghosting. It is not just runway elements but buildings and what-not, and it does not happen always.

Per comments in #44, the messages that I saw may not even be related to ghosting itself, that said, I still see HW GL_SELECT does not support draw mode GL_LINES_ADJACENCY around the place.

I suspect that this is just an intel driver bug on old openGL. I have no idea what can be done here, other than upgrading to a newer openGL which is probably a titanic effort.

Extended renderer info (GLX_MESA_query_renderer):
    Vendor: Intel (0x8086)
    Device: Mesa Intel(R) Graphics (ADL GT2) (0x46a6)
    Version: 23.2.1
    Accelerated: yes
    Video memory: 31792MB
    Unified memory: yes
    Preferred profile: core (0x1)
    Max core profile version: 4.6
    Max compat profile version: 4.6
    Max GLES1 profile version: 1.1
    Max GLES[23] profile version: 3.2
OpenGL vendor string: Intel
OpenGL renderer string: Mesa Intel(R) Graphics (ADL GT2)
OpenGL core profile version string: 4.6 (Core Profile) Mesa 23.2.1
OpenGL core profile shading language version string: 4.60
OpenGL core profile context flags: (none)
OpenGL core profile profile mask: core profile

[jmbau]

I just added some news in #44 concerning GL_SELECT does not support draw mode GL_LINES_ADJACENCY.