From ff94c0635060f17423e7372d6e33ca9e4ce6b883 Mon Sep 17 00:00:00 2001
From: Dany Petit <danypetit.be@gmail.com>
Date: Sat, 29 Aug 2026 22:24:00 +0200
Subject: [PATCH 1/2] fix(cmake): FindLibNoise returns the parent of noise/ as
 include dir

The module searched for 'noise.h' with PATH_SUFFIXES 'include/noise',
which resolves to <prefix>/include/noise. Since the sources include
libnoise as <noise/noise.h>, the include dir must be <prefix>/include.

Searching for 'noise/noise.h' with suffix 'include' makes system
installs work without a manual -DLibNoise_INCLUDE_DIR override.
---
 cmake/find-modules/FindLibNoise.cmake | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/cmake/find-modules/FindLibNoise.cmake b/cmake/find-modules/FindLibNoise.cmake
index af4860166a..ba58969e58 100644
--- a/cmake/find-modules/FindLibNoise.cmake
+++ b/cmake/find-modules/FindLibNoise.cmake
@@ -8,8 +8,10 @@ endif ()
 
 include(FindPackageHandleStandardArgs)
 
-find_path(LibNoise_INCLUDE_DIR noise.h
-        PATH_SUFFIXES include include/noise include/libnoise
+# Cytopia includes libnoise as <noise/noise.h>, so the include directory must
+# be the parent of the noise/ folder (e.g. <prefix>/include), not the folder itself.
+find_path(LibNoise_INCLUDE_DIR noise/noise.h
+        PATH_SUFFIXES include
         HINTS ${LIBNOISE_DIR} $ENV{LIBNOISE_DIR}
         )
 find_library(LibNoise_LIBRARY

From 49f9fb7c51cc35f73be363b753159ff0df51cd39 Mon Sep 17 00:00:00 2001
From: Dany Petit <danypetit.be@gmail.com>
Date: Sat, 29 Aug 2026 23:00:40 +0200
Subject: [PATCH 2/2] fix(cmake): FindLibNoise supports the Debian/Ubuntu
 header layout

Distro packages install the headers in <prefix>/include/libnoise/ while
the sources include <noise/noise.h> (upstream/Conan layout uses
<prefix>/include/noise/). When only the libnoise/ layout is found, the
find module now creates a noise-compat directory in the build tree with
a 'noise' symlink pointing at the distro folder.

Verified against both layouts: the game and the test suite build with
distro packages (Ubuntu libnoise-dev 1.0.0) and with a source install.
---
 cmake/find-modules/FindLibNoise.cmake | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/cmake/find-modules/FindLibNoise.cmake b/cmake/find-modules/FindLibNoise.cmake
index ba58969e58..8369421c3c 100644
--- a/cmake/find-modules/FindLibNoise.cmake
+++ b/cmake/find-modules/FindLibNoise.cmake
@@ -14,6 +14,24 @@ find_path(LibNoise_INCLUDE_DIR noise/noise.h
         PATH_SUFFIXES include
         HINTS ${LIBNOISE_DIR} $ENV{LIBNOISE_DIR}
         )
+
+# Debian/Ubuntu install the headers in <prefix>/include/libnoise/ instead of
+# <prefix>/include/noise/. Provide a compatibility symlink so that
+# <noise/noise.h> keeps working with distro packages.
+if (NOT LibNoise_INCLUDE_DIR)
+    find_path(LibNoise_INCLUDE_DIR libnoise/noise.h
+            PATH_SUFFIXES include
+            HINTS ${LIBNOISE_DIR} $ENV{LIBNOISE_DIR}
+            )
+    if (LibNoise_INCLUDE_DIR)
+        set(_noise_compat_dir "${CMAKE_BINARY_DIR}/noise-compat")
+        file(MAKE_DIRECTORY "${_noise_compat_dir}")
+        if (NOT EXISTS "${_noise_compat_dir}/noise")
+            file(CREATE_LINK "${LibNoise_INCLUDE_DIR}/libnoise" "${_noise_compat_dir}/noise" SYMBOLIC)
+        endif ()
+        set(LibNoise_INCLUDE_DIR "${_noise_compat_dir}")
+    endif ()
+endif ()
 find_library(LibNoise_LIBRARY
         NAMES noise noiseutils noise-static noiseutils-static
         PATH_SUFFIXES lib/x64 lib/x86