(Unix) Added the libgit2 library as a dependency

CMake/Packages/FindLibgit2.cmake

@@ -0,0 +1,25 @@
+# Find the git2 library.
+#
+# GIT2_INCLUDE_DIRS - Where to find git2.h, etc.
+# GIT2_LIBRARIES    - List of libraries when using libgit2.
+# GIT2_FOUND        - True if libgit2 is found.
+
+# GIT2_INCLUDE_PATH
+find_path(GIT2_INCLUDE_PATH NAMES git2.h)
+# GIT2_LIBRARY
+find_library(GIT2_LIBRARY NAMES git2)
+
+# Handle the QUIETLY and REQUIRED arguments and set GIT2_FOUND to TRUE if all listed variables are TRUE.
+include(FindPackageHandleStandardArgs)
+find_package_handle_standard_args(Libgit2 REQUIRED_VARS GIT2_LIBRARY GIT2_INCLUDE_PATH)
+
+if(GIT2_FOUND)
+  set(GIT2_INCLUDE_DIR  ${GIT2_INCLUDE_PATH})
+  set(GIT2_INCLUDE_DIRS ${GIT2_INCLUDE_PATH})
+  set(GIT2_LIBRARIES    ${GIT2_LIBRARY})
+endif()
+
+mark_as_advanced(
+  GIT2_INCLUDE_PATH
+  GIT2_LIBRARY
+)

CMakeLists.txt

@@ -134,6 +134,7 @@ elseif(NOT EMSCRIPTEN)
     find_package(FFmpeg REQUIRED)
     find_package(FreeImage REQUIRED)
     find_package(Freetype REQUIRED)
+    find_package(Libgit2 REQUIRED)
     find_package(Pugixml REQUIRED)
     find_package(SDL2 REQUIRED)
 endif()
@@ -451,6 +452,7 @@ else()
                             ${FFMPEG_INCLUDE_DIRS}
                             ${FreeImage_INCLUDE_DIRS}
                             ${FREETYPE_INCLUDE_DIRS}
+                            ${GIT2_INCLUDE_PATH}
                             ${PUGIXML_INCLUDE_DIRS}
                             ${SDL2_INCLUDE_DIR})
 endif()
@@ -563,6 +565,7 @@ else()
                          ${FFMPEG_LIBRARIES}
                          ${FreeImage_LIBRARIES}
                          ${FREETYPE_LIBRARIES}
+                         ${GIT2_LIBRARY}
                          ${PUGIXML_LIBRARIES}
                          ${SDL2_LIBRARY})
 endif()