Rendering issues on OpenGL 2.1

[_mental_]

Occasionally I found several rendering issues while using OpenGL 2.1 with the latest GZDoom. I have a very limited access to graphics hardware with the modern OpenGL support, so I have troubles with debugging these bugs (or maybe features that are not yet implemented in compatibility renderer).

The first one is on dead-wire, somehow related to 3D floors:

9fae1728-2812-11e6-8c02-ef71c892f385.png

9f8fb094-2812-11e6-8c8f-3908e77808d8.png

The second one is on The DOOM Tribute Project's MAP01:

gz2.png

gz.png

In both case some of walls are not renderer. GZDoom 1.x nor the latest 2.x using OpenGL 4.5 Core Profile don't have these problems.

[toshiaki2115]

get svn build. but leatest svn have crash issue.
I in 2.1 mode as far as was confirmed was 100% crash and driving a light source for the first pillar (where the shotgun zombies are hidden) of the Japanese community Project Map1.
This is the same in any kind of MOD.
It was confirmed a specific (particularly complex) cases to 100% crash in the light source generation in terrain.
It is suspicious behavior of respect to the light source of brightmap is outside, but it works 100%.

[_mental_]

Graf, could you please take a look at this fix? It solves all 3D floors issues I encountered but I want to make sure that nothing was missed.
And could please also move the unrelated report to a separate topic? Those crashes have nothing in common with this bug.

[Graf Zahl]

Hard to tell without a decent diff viewer. If you could make this a pull request instead it'd be easier to check. From what I've seen you just switched the order of checks, right?

[_mental_]

I changed the order of checks and replaced return with goto. PR is here.