HQNX turns crisscrossing diagonals into blackness

[AcidLead]

I know this hasn't really been discussed for years, and I know I made the fatal mistake of joining simply to register a complaint, but it's bothering me and I figured it was better to say something.

I happen to have an ATI Radeon HD 7800 and yes, I too have the "failed transparency" effect, down to it sometimes flickering between functional and not if the lighting conditions are right. Furthermore, it only happens when shader lights are enabled. With them off, the textures become functional again... at the expense of wads that make heavy use of ambient dynamic lights (*cough* unloved *cough*) looking disastrously, hideously ugly. HQnX and Scale#x do not seem to factor into my problem, for what it's worth.

I don't know if anyone can do anything this, but it's the one very irksome thing that wounds the highly impressive port that is GZDoom.

[Gez]

Well it's interesting if you get this even with texture resize filters turned entirely off. Because then it means the problem originates from somewhere else in the code, and it was just a coincidence that it had required HQ resizing to get it to happen previously.

[AcidLead]

I flipped all the texture settings into as many combinations as I could first to get it to correct itself, and when that didn't work I attacked the dynamic lights settings page; just the one setting, the shader use setting, toggled the problem, and I didn't have to restart to see the effects.

Maybe I'm getting the same result problem from a different source, although I haven't yet had time to put GZDoom on other computers and see how they react. I would really like to get more data on this problem if it has any chance at all of helping get it fixed.

[Graf Zahl]

Nothing what has been posted here gets me any closer to the problem.

If it only happens on AMD, what specific settings are being used? (Best post your complete zdoom.ini.)
Especially with the dynamic lights, what does this happen with - shader lights on or off? Both options use substantially different render paths and without this info there is no hope finding it.

[Gez]

Furthermore, it only happens when shader lights are enabled. With them off, the textures become functional again...

[Blue Shadow]

I have an AMD (Radeon HD 7670M, to be exact), but I didn't seem to be able to replicate this bug, whether with shader lights being on or off (maybe I'm missing a key-setting here...).

Here is my ini file (along with the console log):

ini + log.zip

[Graf Zahl]

Yeah, that's what I was suspecting. If every AMD user had this problem I'd hear a lot more about it...

[Graf Zahl]

I just found something that may be relevant here:

If you experience this problem, please check the setting of the gl_direct_state_change CVAR.
If this is 0, please set it to 1. The implementation for the '0' case is incorrect and can produce glitches with transparency.

[Gez]

Interesting!

Unfortunately, no. What I've noticed is that when the issue appears, changing that value from "true" to "false" will restore transparency for the next frame (and only the next frame). However, changing from "false" to "true" has no visible effect.

[Gez]

Alexey Lysiuk found and fixed the problem: https://github.com/coelckers/gzdoom/com ... fe38f24f00