Upgrade SDFGI to HDDAGI

[OrangeeZ]

What problem(s) does this PR solve?

This PR is a rebase of HDDA GI from #86267 . It includes changes suggested by the reviewers at the time.

TODO:

• There are three errors when engine tries to release invalid rid's for three render buffer that HDDA GI uses. It looks like Godot changes screen resolution on startup and these buffers inside p_render_buffers get invalidated, but I don't understand why those references persist.
• Under DX12, probe occlusion works incorrectly. It looks correct under Vulkan.
• Linux + mono tests fail with

  scons: *** [/home/runner/work/godot-pineapple/godot-pineapple/godot-cpp/bin/libgodot-cpp.linux.template_debug.dev.x86_64.a] sh: Argument list too long

• Linux + X11 + RADV: message spam at startup

  ERROR: Non-compute shaders can't be used in compute pipelines
  at: compute_pipeline_create (servers/rendering/rendering_device.cpp:5025)

• Sudden area brightness changes when using 50% or 70% height. Easy to reproduce if standing close to a wall and looking up and down (is it a bug? Did SDFGI have this problem?)
• When a probe is selected in "Display Advanced" clicking anywhere else clears selection, but pressing escape does not and the probe remains selected and displays occlusion state.

If this PR is of any interest, hopefully someone can help me with those issues. Any suggestions are appreciated,
I tested the new GI in editor and play in editor under Windows, but I can't check Linux/Mac, so maybe someone running those OS'es can help.

[clayjohn]

@DeanLemans Please don't hop into the comments just to be argumentative. Stay on topic so that the PR can actually move forward

[MopanionStudios]

Wonderful job thus far, though I would recommend changing the dynamic_gi_enabled bool to be a group enable rather than in the dropdown for Dynamic GI in the world environment, just for uniformities sake.

Other effects such as SSR, SSAO, and SSIL as you can see have the toggle embedded next to the name, which makes it easier to see if its on or not and to toggle it. Right now, you need to open the dropdown to toggle the enabled value for Dynamic GI.

[Shinwoh]

Hello, I'm sharing this just in case it's useful, because their GI solution looks very similar to HDDAGI, as they use HDDA too
https://media.gdcvault.com/gdc2023/Slides/HSGI+Cross-Platform_Jiaxuan_Zhang.pdf
I'm talking about the mobile version though, idk about graphics but hopefully something could help solve the artifacts HDDAGI has, like light leaking

[MopanionStudios]

iirc, one of Juan's ideas was to add a screen-space buffer for occlusion to help with light leaking.

[Image-unavailable]

Quick testing on Linux X11 RADV, it seems to be working fine.

However, there is some amount of spam of these errors at startup:

ERROR: Non-compute shaders can't be used in compute pipelines
   at: compute_pipeline_create (servers/rendering/rendering_device.cpp:5025)

[OrangeeZ]

Hi @Image-unavailable , I can't reproduce this spam at least on Windows with Vulkan. Can you send me a minimal repro project or just the project you were testing on if it's not too large?

[Image-unavailable]

I tested with this project: #74965

I have verified that downloading the zip and extracting it, then opening with this PR, results in the error spam.

There's other warnings that get spammed when doing this, but those are related to some things being broken in the project files, and not the error spam.

[Calinou]

The new Vector2i/Vector3i operators should be documented.

[passivestar]

There's noticeable light popping when the camera moves but it probably shouldn't be an obstacle to this PR because it's an improvement over SDFGI and it can be iterated on post-merge

Maybe it would be interesting in the future to consider the possibility of quarter-height cascades (indoor genres like corridor fps dont have much verticality) and maybe a view bias slider to sample closer to camera to mitigate leaks (unity APV has it and it seems to help, the current normal bias gives splotches on normal-mapped surfaces no matter what you set it to)

[Saul2022]

For context of what passivestar said , this is with full resolution and max sethings. It still can be merged as it's indeed much better than sdfgi, but those high density cascades should be able to help ( I HOPE SO )

Screen_Recording_20260531_113808.1.mp4