From 9840eeabe80eecb9a3b91f34b7fb4bf3845cc702 Mon Sep 17 00:00:00 2001
From: JosiahWI <41302989+JosiahWI@users.noreply.github.com>
Date: Tue, 13 Apr 2021 14:08:16 -0500
Subject: [PATCH] CMake Config and Version exports (#22)

---
 CMakeLists.txt                 | 48 +++++++++++++++++++++++++++++-----
 Config.cmake.in                |  5 ++++
 source/Irrlicht/CMakeLists.txt | 10 ++-----
 3 files changed, 48 insertions(+), 15 deletions(-)
 create mode 100644 Config.cmake.in

diff --git a/CMakeLists.txt b/CMakeLists.txt
index d23959dc..2c690db5 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -1,13 +1,11 @@
 cmake_minimum_required(VERSION 3.5)
 
-project(Irrlicht CXX)
+project(Irrlicht
+	VERSION 1.9.0
+	LANGUAGES CXX
+)
 
-set(IRRLICHT_VERSION_MAJOR 1)
-set(IRRLICHT_VERSION_MINOR 9)
-set(IRRLICHT_VERSION_RELEASE 0)
-
-set(VERSION "${IRRLICHT_VERSION_MAJOR}.${IRRLICHT_VERSION_MINOR}.${IRRLICHT_VERSION_RELEASE}")
-message(STATUS "*** Building IrrlichtMt ${VERSION} ***")
+message(STATUS "*** Building IrrlichtMt ${PROJECT_VERSION} ***")
 
 if(ANDROID)
 	set(CMAKE_LIBRARY_OUTPUT_DIRECTORY ${CMAKE_BINARY_DIR}/lib/Android)
@@ -28,3 +26,39 @@ endif()
 
 list(APPEND CMAKE_MODULE_PATH "${CMAKE_CURRENT_SOURCE_DIR}/cmake")
 add_subdirectory(source/Irrlicht)
+
+# Installation of library and headers.
+include(GNUInstallDirs)
+install(TARGETS IrrlichtMt
+	EXPORT IrrlichtMt-export
+	DESTINATION "${CMAKE_INSTALL_LIBDIR}"
+)
+
+install(DIRECTORY "${PROJECT_SOURCE_DIR}/include/"
+	DESTINATION "${CMAKE_INSTALL_INCLUDEDIR}/IrrlichtMt"
+)
+
+# Installation of CMake target and configuration files.
+install(EXPORT IrrlichtMt-export
+	FILE IrrlichtMtTargets.cmake
+	NAMESPACE IrrlichtMt::
+	DESTINATION "${CMAKE_INSTALL_LIBDIR}/cmake/IrrlichtMt"
+)
+
+include(CMakePackageConfigHelpers)
+configure_package_config_file("${CMAKE_CURRENT_SOURCE_DIR}/Config.cmake.in"
+	"${CMAKE_CURRENT_BINARY_DIR}/IrrlichtMtConfig.cmake"
+	INSTALL_DESTINATION "${CMAKE_INSTALL_LIBDIR}/cmake/IrrlichtMt"
+	NO_SET_AND_CHECK_MACRO
+	NO_CHECK_REQUIRED_COMPONENTS_MACRO
+)
+write_basic_package_version_file(
+	"${CMAKE_CURRENT_BINARY_DIR}/IrrlichtMtConfigVersion.cmake"
+	COMPATIBILITY AnyNewerVersion
+)
+
+install(FILES
+	"${CMAKE_CURRENT_BINARY_DIR}/IrrlichtMtConfig.cmake"
+	"${CMAKE_CURRENT_BINARY_DIR}/IrrlichtMtConfigVersion.cmake"
+	DESTINATION "${CMAKE_INSTALL_LIBDIR}/cmake/IrrlichtMt"
+)
diff --git a/Config.cmake.in b/Config.cmake.in
new file mode 100644
index 00000000..96194f3c
--- /dev/null
+++ b/Config.cmake.in
@@ -0,0 +1,5 @@
+@PACKAGE_INIT@
+
+if(NOT TARGET IrrlichtMt::IrrlichtMt)
+	include("${CMAKE_CURRENT_LIST_DIR}/IrrlichtMtTargets.cmake")
+endif()
diff --git a/source/Irrlicht/CMakeLists.txt b/source/Irrlicht/CMakeLists.txt
index 621f7bd8..f8bf8196 100644
--- a/source/Irrlicht/CMakeLists.txt
+++ b/source/Irrlicht/CMakeLists.txt
@@ -394,16 +394,10 @@ add_library(IrrlichtMt
 )
 
 set_target_properties(IrrlichtMt PROPERTIES
-	VERSION ${VERSION}
-	SOVERSION ${IRRLICHT_VERSION_MAJOR}.${IRRLICHT_VERSION_MINOR}
+	VERSION ${PROJECT_VERSION}
+	SOVERSION ${PROJECT_VERSION_MAJOR}.${PROJECT_VERSION_MINOR}
 )
 
 if(WIN32)
 	set_target_properties(IrrlichtMt PROPERTIES PREFIX "") # for DLL name
 endif()
-
-# Installation
-
-include(GNUInstallDirs)
-install(TARGETS IrrlichtMt DESTINATION "${CMAKE_INSTALL_LIBDIR}")
-install(DIRECTORY "${CMAKE_SOURCE_DIR}/include/" DESTINATION "${CMAKE_INSTALL_INCLUDEDIR}/irrlichtmt")