`gfx_ssao.lua` and ` gfx_orb_effects_gl4.lua` shaders appear "cut" in half horizontally on AMD/Linux

[AntlerForce]

Description

Video: https://imgur.com/a/UeRAn1R

This visual bug was introduced with the big lighting update in this commit: 9f684b3

It didn't appear when I tried the version of the ssao widget from the version before: https://github.com/beyond-all-reason/Beyond-All-Reason/blob/356450e36d65c291c1b1f09e2016a2bcecef6170/luaui/Widgets/gfx_ssao.lua

It only appears on map where water is present. It's not affected by /luarules disablecusgl4 or /water 0.

It is an exclusive issue to shaders that use DrawWorldPreParticles https://github.com/search?q=repo%3Abeyond-all-reason%2FBeyond-All-Reason%20drawworldpreparticles&type=code

Both widgets have the line if drawAboveWater and not drawReflection and not drawRefraction then under DrawWorldPreParticles. I can reverse the effect, cull the top half of the screen instead of the bottom half, by replacing drawAboveWater with drawBelowWater in both widgets. Or, if I remove drawAboveWater from the orbs widget it looks normal again but I do the same with SSAO, the bug is gone when the camera is stationary but the line re-appears when the camera is zooming in/out or panning up/down.

Expected Behaviour

No visible cutoff line in this location.

Actual Behaviour

Visible cutoff on AMD/Linux graphics configs.

Reproduction steps

It's easy to see this bug in the trees on the map aethermoor_creek_1.0 or angel_crossing_1.5.1, or by looking at the orbs above a Juno, Keeper, Fusion, or Advanced Fusion.

Other

Might affect AMD/Windows too. Doesn't occur on Nvidia/Linux.
Might be an engine bug with DrawWorldPreParticles.