misc: adjusted CMakeLists.txt to be compatible with vcpkg

CMakeLists.txt

@@ -1,46 +1,115 @@
 cmake_minimum_required(VERSION 3.0)
 project(enet C)
 
-# configure projects
-if (ENET_STATIC)
+# -----------------------------
+# 1) Build options
+# -----------------------------
+option(ENET_STATIC "Build enet as a static library" ON)
+option(ENET_SHARED "Build enet as a shared library" OFF)
+option(ENET_TEST  "Build enet tests" ON)
+
+# -----------------------------
+# 2) Static library
+# -----------------------------
+if(ENET_STATIC)
     add_library(enet_static STATIC test/library.c)
 
-    if (WIN32)
+    if(WIN32)
         target_link_libraries(enet_static PUBLIC winmm ws2_32)
-
         if(MSVC)
-            target_compile_options(enet_static PRIVATE -W3)
+            target_compile_options(enet_static PRIVATE /W3)
         endif()
     else()
         target_compile_options(enet_static PRIVATE -Wno-error)
     endif()
 
-    target_include_directories(enet_static PUBLIC ${PROJECT_SOURCE_DIR}/include)
+    target_include_directories(enet_static PUBLIC
+        $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/include>
+        $<INSTALL_INTERFACE:include>
+    )
+
+    add_library(enet::enet_static ALIAS enet_static)
 endif()
 
-if (ENET_SHARED)
+# -----------------------------
+# 3) Shared library
+# -----------------------------
+if(ENET_SHARED)
     add_library(enet_shared SHARED test/library.c)
     target_compile_definitions(enet_shared PUBLIC -DENET_DLL)
 
-    if (WIN32)
+    if(WIN32)
         target_link_libraries(enet_shared PUBLIC winmm ws2_32)
-
         if(MSVC)
-            target_compile_options(enet_shared PRIVATE -W3)
+            target_compile_options(enet_shared PRIVATE /W3)
         endif()
     else()
         target_compile_options(enet_shared PRIVATE -Wno-error)
     endif()
 
-    target_include_directories(enet_shared PUBLIC ${PROJECT_SOURCE_DIR}/include)
+    target_include_directories(enet_shared PUBLIC
+        $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/include>
+        $<INSTALL_INTERFACE:include>
+    )
+
+    add_library(enet::enet_shared ALIAS enet_shared)
 endif()
 
-if (ENET_TEST)
+# -----------------------------
+# 4) Tests (optional)
+# -----------------------------
+if(ENET_TEST)
     add_executable(enet_test test/build.c)
-    target_include_directories(enet_test PRIVATE ${PROJECT_SOURCE_DIR}/include)
+    target_include_directories(enet_test PRIVATE ${CMAKE_CURRENT_SOURCE_DIR}/include)
 
-    if (WIN32)
+    if(WIN32)
         target_link_libraries(enet_test PUBLIC winmm ws2_32)
     endif()
+
+    if(TARGET enet_static)
+        target_link_libraries(enet_test PRIVATE enet_static)
+    elseif(TARGET enet_shared)
+        target_link_libraries(enet_test PRIVATE enet_shared)
+    endif()
+endif()
+
+# -----------------------------
+# 5) Installation
+# -----------------------------
+set(_enet_targets_to_install "")
+
+if(TARGET enet_static)
+    list(APPEND _enet_targets_to_install enet_static)
+    set_target_properties(enet_static PROPERTIES OUTPUT_NAME "enet")
+endif()
+
+if(TARGET enet_shared)
+    list(APPEND _enet_targets_to_install enet_shared)
+    set_target_properties(enet_shared PROPERTIES OUTPUT_NAME "enet")
+endif()
+
+if(_enet_targets_to_install)
+    install(
+        TARGETS ${_enet_targets_to_install}
+        EXPORT enetTargets
+        RUNTIME DESTINATION bin
+        LIBRARY DESTINATION lib
+        ARCHIVE DESTINATION lib
+        INCLUDES DESTINATION include
+    )
+
+    install(
+        DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}/include/
+        DESTINATION include
+        FILES_MATCHING
+        PATTERN "*.h"
+    )
+
+    install(
+        EXPORT enetTargets
+        FILE enetConfig.cmake
+        NAMESPACE enet::
+        DESTINATION lib/cmake/enet
+    )
 endif()