glDoom gets updated, unofficially

[Redneckerz]

Introduction:

The story of glDoom is a weird one: Being the first OpenGL port for Doom, its source code got lost and was never retrieved, until April 2010, when glDoom reappeared on SourceForge. Over a year later, a DoomWorld thread appeared to discuss this:

The latest released version carries the label v0.95a.

Fast forward to April 2020. Exactly ten years after glDoom made an appearance on SourceForge, an unofficial update appeared on Github by Russian programmer Vsevolod Popov, aka RedPowar. He released versions 0.95b on April 4, and 0.95c on April 8, 2020.

They contain several improvements to the glDoom:

• New floor/ceiling generation code (derived from Doom Legacy)
• Aspect ratio fix (correct rendering on 16:9 displays). glDoom can now render for example in 1920x1080p resolution properly
• Fixed invisible area culling (behind walls in sectors without ceiling)
• Few bugfixes for buffer overflows & invalid memory pointers

In closing:
I think its rather neat (and a mere coincidence ofcourse) that this port has gotten an update to make it work with modern monitors, but also some actual new features aswell. glDoom is thus an interesting alternative to play Doom in OpenGL.

Downloads:

• glDoom 0.95c binary and source code
• glDoom 0.95b binary and source code

[The Doommer]

Happy to see a lost Source Port has been revived.

Honestly, having only GZDoom as the option wasn't the greatest thing ever.

 

[slayermbm]

Nice job unearthing these news and reporting them here @Redneckerz! I like to test Doom on all of them to compare the strong and weak points of each one.

[fabian]

1 hour ago, The Doommer said:

Happy to see a lost Source Port has been revived.

Honestly, having only GZDoom as the option wasn't the greatest thing ever.

 

GlBoom+ is still there. 

[The Doommer]

19 minutes ago, fabian said:

GlBoom+

Yeah, why do I always forget about that one?

 

 

 

[drfrag]

There are others.

[The Doommer]

I don't think you mean Skulltag-based ones, since they were based on ZDoom.

 

But, I've never heard of much.

[drfrag]

Vavoom, Legacy, EDGE.

[Dark Pulse]

Chocolate, Crispy, Eternity.

[Redneckerz]

1 hour ago, The Doommer said:

I don't think you mean Skulltag-based ones, since they were based on ZDoom.

 

But, I've never heard of much.

Skulktag 97b till c3 used the ZDoomGL 0.81 renderer. It then was changed to GZDoom.

34 minutes ago, Dark Pulse said:

Chocolate, Crispy, Eternity.

But those arent OpenGL ports.

 

2 hours ago, slayermbm said:

Nice job unearthing these news and reporting them here @Redneckerz! I like to test Doom on all of them to compare the strong and weak points of each one.

^^

[Dark Pulse]

20 minutes ago, Redneckerz said:

But those arent OpenGL ports.

My bad, kind of forgot he was talking about GL-accelerated ports.

 

Still, it's not like it couldn't be added to any of those. Though now arguably Vulkan would be a better exercise.

[taufan99]

Another nice rediscovery! Congratulations, Redneckerz.

[Mr.Rocket]

Neat!

Stock demos seem to work correctly.

What blew me away is that there was a small list of game servers showing up!

[seed]

9 hours ago, The Doommer said:

Happy to see a lost Source Port has been revived.

Honestly, having only GZDoom as the option wasn't the greatest thing ever.

 

Then perhaps you should start looking around, there's many other ports available, all serving different goals.

[Lila Feuer]

Anyone remember ZDoomGL?

[Redneckerz]

2 hours ago, Lila Feuer said:

Anyone remember ZDoomGL?

Yes.

 

Both versions (Kokak's and @timmie's)  have a widely branched history tree with a dozen or so sub versions so it has been quite a task to map the correct dates, features and so on together. Its a recurring pattern whenever Kokak is involved, the man has made more ports on his own than most would even attempt to in their Doom carreers :P

Some tidbits:

• Kokak's ZDoom is based on ZDoom 1.22 and has stuff like dynamic lights, corona's, MD2 models.
• Timmie's ZDoom is based on ZDoom 2.0.96 (Last version) and, among others, features a Quake 3-esque shader system, introduced in 0.75, to enable multitexturing effects. Its an OpenGL 1.2 renderer.
• Although they are distinctive as Kokak and Timmie, i prefer (v1) and (v2) as they essentially are two seperate versions. I also prefer using this nomenclature to distinguish them between the ZDoom versions used.
• Timmie also started on an actual V2 release of ZDoomGL, which would make the above sound problematic. It was however also known as 2.0. That version was going to use GLSL shaders and requiring OpenGL 2.0. Screenshots exist demonstrating it, but a binary was never shared, so it can't be determined what its performance was.
• Skulltag 97b till 97c3 used the last version of ZDoomGL from Timmie (0.81) as its OpenGL renderer. This had the additional benefit that the underlying ZDoom codebase got upgraded for ZDoomGL from 2.0.96 to 2.1.7.
• Skulltag 97d briefly had both ZDoomGL and GZDoom renderers selectable, but it got removed.
• ScoreDoomST is based on Skulltag 97c2, thus it inherits the ZDoomGL renderer. ScoreDoomST (and thus ZDoomGL) in this incarnation was supported all the way up till 2013, quite the longevity for a renderer from 2005 that was not known to be ultra stable.

Both versions are also infamous for being quite buggy, Kokak's version more so than Timmie's. Timmie's version also had the notorious side effect of delivering about half the performance than the GZDoom equivalent at the time. Having tested the latest ZDoomGL this weekend, this seems to hold true. I still got playable framerates on my junk PC, and it looks pretty nice, but stutter was pretty apparent. GZDoom 1.0.29 didn't exhibit this, nor does LZDoom.

 

The only real damn shame is:

• Because Kokak's OpenGL renderer was so finnicky, nobody has used its technology back in the day, even with ports that share the same basis (Odamex, for instance). It might also be because of the aforementioned confusion (Timmie's ZDoomGL was simply marketed as ''ZDoomGL'', to the point where they had to make a mention on the homepage that both versions had very little, if anything, in common)
• Timmie's shader system never was put to good use, but it is understandable as to why. As far as i can see, it enabled new effects through fixed-function functionality present on most GPU's at the time, but it did this in a time where games with actual pixel/vertex shaders became more common. Even GZDoom moved to this, which mean't that fixed-function shader tech was on its way out. It also didn't help that, like mentioned, ZDoomGL's performance was just half of GZDoom at the time.
• Nevertheless, its shader documentation is available.