Fix CMake errors with the default setting. Update CMAKE_MINIMUM_REQUIRED to VERSION 3.5 for CMake 4.x compatibility.

Author: tokjun

CMakeLists.txt

@@ -1,6 +1,6 @@
 PROJECT(OpenIGTLink)
 
-CMAKE_MINIMUM_REQUIRED(VERSION 3.1)
+CMAKE_MINIMUM_REQUIRED(VERSION 3.5)
 
 INCLUDE(ExternalProject)
 

Examples/CMakeLists.txt

@@ -1,4 +1,4 @@
-cmake_minimum_required(VERSION 2.4)
+cmake_minimum_required(VERSION 3.5)
 
 #
 # Examples

Testing/CMakeLists.txt

@@ -1,10 +1,10 @@
 PROJECT( OpenIGTLinkTesting )
 
-cmake_minimum_required(VERSION 2.8.11)
-find_package(OpenIGTLink REQUIRED)
-include(${OpenIGTLink_USE_FILE})
-include_directories(${OpenIGTLink_INCLUDE_DIRS})
-link_directories(${OpenIGTLink_LIBRARY_DIRS})
+cmake_minimum_required(VERSION 3.5)
+# Use the parent project's OpenIGTLink target instead of find_package
+# since we're building OpenIGTLink in the same CMake project
+include_directories(${OpenIGTLink_SOURCE_DIR}/Source)
+include_directories(${OpenIGTLink_BINARY_DIR})
 include_directories(${PROJECT_BINARY_DIR})
 configure_file(${PROJECT_SOURCE_DIR}/igtlTestConfig.h.in ${PROJECT_BINARY_DIR}/igtlTestConfig.h)
 ENABLE_TESTING()