fix: ensure proper installation checks and target definitions in CMake files

Author: ronan-fesselier

cmake/nfxResourceInstall.cmake

@@ -2,6 +2,11 @@
 # nfx-resource - Library installation
 #==============================================================================
 
+if(NFX_RESOURCE_INSTALL_INCLUDED)
+    return()
+endif()
+set(NFX_RESOURCE_INSTALL_INCLUDED TRUE CACHE INTERNAL "")
+
 include(GNUInstallDirs)
 include(CMakePackageConfigHelpers)
 

cmake/nfxResourceTarget.cmake

@@ -6,27 +6,31 @@
 # Resource generator
 #----------------------------------------------
 
-add_executable(nfx-resourcegenerator-cli
-    src/resourcefenerator-cli.cpp
-)
-set_target_properties(nfx-resourcegenerator-cli PROPERTIES
-    CXX_STANDARD 20
-    CXX_STANDARD_REQUIRED ON
-    RUNTIME_OUTPUT_DIRECTORY "${CMAKE_CURRENT_BINARY_DIR}/bin"
-)
-add_executable(nfx::resourcegen ALIAS nfx-resourcegenerator-cli)
+if(NOT TARGET nfx-resourcegenerator-cli)
+    add_executable(nfx-resourcegenerator-cli
+        src/resourcefenerator-cli.cpp
+    )
+    set_target_properties(nfx-resourcegenerator-cli PROPERTIES
+        CXX_STANDARD 20
+        CXX_STANDARD_REQUIRED ON
+        RUNTIME_OUTPUT_DIRECTORY "${CMAKE_CURRENT_BINARY_DIR}/bin"
+    )
+    add_executable(nfx::resourcegen ALIAS nfx-resourcegenerator-cli)
+endif()
 
 #----------------------------------------------
 # Header-only library
 #----------------------------------------------
 
-add_library(nfx-resource INTERFACE)
-add_library(nfx::resource ALIAS nfx-resource)
+if(NOT TARGET nfx-resource)
+    add_library(nfx-resource INTERFACE)
+    add_library(nfx::resource ALIAS nfx-resource)
 
-target_include_directories(nfx-resource
-    INTERFACE
-        $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/include>
-        $<INSTALL_INTERFACE:include>
-)
+    target_include_directories(nfx-resource
+        INTERFACE
+            $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/include>
+            $<INSTALL_INTERFACE:include>
+    )
 
-target_compile_features(nfx-resource INTERFACE cxx_std_20)
+    target_compile_features(nfx-resource INTERFACE cxx_std_20)
+endif()