# Notices for the bundled Horizon AirDef fork

Upstream Horizon portions retain their MIT notices (HORIZON-MIT.txt).
The fork includes SPR-derived GPL-3.0-only source files. Its existing notice explains the GPL terms
for a combined build: `horizon/crates/horizon-client/src/acoustics/THIRD_PARTY_SPR.md`.
Game archives also include that notice and Horizon THIRD_PARTY_NOTICES.md.
GPL-3.0.txt is the unmodified license from Sound Physics Remastered commit
453654ece086f40c97712d9016baa4dee7c4f6d2:
https://github.com/henkelmax/sound-physics-remastered/blob/453654ece086f40c97712d9016baa4dee7c4f6d2/LICENSE

Corresponding fork source: https://gitea.maoniao.team/chexit/horizon-airdef
AirDef source and build scripts: https://gitea.maoniao.team/chexit/airdef
The exact engine revision is the `horizon/` gitlink; packaged build-identity.json records the pin.
Build instructions: docs/ENGINE.md and docs/INSTALL.md in the AirDef source.
This notice does not change the licenses of the respective source files.