The screen-space reflections (shaders/reflection_depth.frag, shaders/reflection_trace.frag, render.Reflections,
D42) follow Godot Engine's rework of its screen-space reflections (https://github.com/godotengine/godot, pull
request 111210, servers/rendering/renderer_rd/shaders/effects/screen_space_reflection.glsl and
screen_space_reflection_hiz.glsl): the closest depth's levels, the walk down and up them with the depth as its
parameter, the bias against a ray meeting its own face, the screen's margin, the cone's level. Changed: written as
GL 3.3 fragment passes over a depth that grows away from the eye, at half the screen's size, read through a pack's
own test of what reflects.

The hashed alpha test (shaders/lib/alpha_hash.glsl, D44) follows Godot Engine's port of Wyman and McGuire's
"Hashed Alpha Testing" (2017) in servers/rendering/renderer_rd/shaders/scene_forward_aa_inc.glsl
(compute_alpha_hash_threshold, hash_2d, hash_3d): the hash, the two power-of-two scales blended, and the blend's
distribution undone. Changed: written for GL 3.3, with the derivatives taken before any branch on the texel, a step
by each phase of the TAA's offset, and a threshold never 0.

Godot is licensed under the MIT License, which follows.

Copyright (c) 2014-present Godot Engine contributors (see AUTHORS.md).
Copyright (c) 2007-2014 Juan Linietsky, Ariel Manzur.

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