Vbo being unbound causing Clouds to crash after a few seconds on MC 1.18.2

[Mathias-Boulay]

Hey there ! I've been trying to track down a bug for some time with the gl4es, sadly nothing so far.

While running minecraft 1.18.2, activating fancy clouds will make the game crash in a few seconds. While at first, my custom shader conversion was to blame, applying it to gl4es 1.1.4 instead of the current upstream works wonderfully. This means there is a regression of some kind with the current upstream.

EDIT: The behavior has been observed on a snapdragon 845 (adreno 630)

[Mathias-Boulay]

Link to the gl4es 1.1.5 latestlog (crashed)

[Mathias-Boulay]

Welp, I failed to generate the logs for 1.1.4, but it may not be that important

[ptitSeb]

1.1.5 logs are enough, don't bother with 1.1.4. I'll check all that later, thanks

[Mathias-Boulay]

Noted :smile:

[CosineMath]

Minecraft 1.18.2 vanilla works with 2856e133 and glslang on my device Mali GPU.

[Mathias-Boulay]

Minecraft 1.18.2 vanilla works with 2856e133 and glslang on my device Mali GPU.

The crashing behavior was not observed on all gpu vendors actually :thinking: @CosineMath maybe I could test your version and test how my gpu reacts ?

[Mathias-Boulay]

I just remembered, and I dunno if it is linked to the current issue or if it is a separated issue, but the text appeared darker on mali/power vr gpus, and not on adreno ones

[Mathias-Boulay]

I just realized today that I didn't upload the code, nor the tombstone file, let me get that real quick

[Mathias-Boulay]

fork with shaderconv

[Mathias-Boulay]

tombstone_01.zip

[Mathias-Boulay]

@ptitSeb For the exercice, I did port the shaderconv to upstream (visible here) and the tombstone is the same, regardless of whether I'm porting to #version 320es or #version 100

[Mathias-Boulay]

@ptitSeb Porting the shader convertion to 6e05e716a401ba25910bf9b5df80f3123cd6b768, exact same tombstone, a NPE. I guess the faulty commit isn't so far now 🤔

[Mathias-Boulay]

Okay, finally nailed down the commit. It was sadly what I expected: https://github.com/ptitSeb/gl4es/commit/0b173f318dd8a0a4232300cb5264487fb7d17415

[ptitSeb]

Oh, yeah, it's a big commit, and quite usefull IIRC.

I guess at some point there is an issue and the VBO get unattached or something like that, making the GPU Driver crash by seeking data that don't exist anymore :(

[Mathias-Boulay]

The question being, when does the buffer get detached without gl4es realizing ? I've seen the commits made to help #238 but they didn't fix the problem, since it has been reproduced on the current upstream

[Mathias-Boulay]

I guess I should ask myself the question the other way: How do we detect a detached VBO ?

[ptitSeb]

It's difficult, but I suppose you can track when VBO are attached / detached.

[Mathias-Boulay]

Isn't this the partially point of the "used" integer inside the bind_buffers_t struct ?

btw, discord might be easier for communication (or rather me asking questions 👀)