cmake/simplify-finding-openexr (#174)

* first Cmake searches for OpenEXR v2 with FindModule, then Cmake searches for OpenEXR v3 with Config

CMakeLists.txt

@@ -58,14 +58,52 @@ else()
   message( STATUS " ZLIB is automatically linked when using OpenEXR 3.x but CTL needs to link to ZLIB if using OpenEXR 2.x" )
 endif()
 
-find_package(OpenEXR 3 CONFIG QUIET)
+# find OpenEXR
+find_package(IlmBase QUIET)
+if(IlmBase_FOUND)
+  message(STATUS "Found IlmBase ${IlmBase_VERSION}")
+  find_package(OpenEXR 2 QUIET)
+endif()
+
+if(NOT OpenEXR_FOUND)
+  find_package(OpenEXR CONFIG 3 REQUIRED)
+  if(OpenEXR_FOUND)
+    set(OpenEXR_FOUND_WITH_CONFIG TRUE BOOL "found OpenEXR with Config")
+  endif()
+endif()
+
 if(OpenEXR_FOUND)
   message(STATUS "Found OpenEXR ${OpenEXR_VERSION}")
-else()
-  message(STATUS "OpenEXR v3 not found, looking for IlmBase and OpenEXR v2")
-  find_package(IlmBase REQUIRED)
-  find_package(OpenEXR 2 REQUIRED)
-endif()
+  set(USE_OPENEXR TRUE CACHE BOOL "Add OpenEXR support")
+  add_definitions(-DOJPH_ENABLE_OPENEXR_SUPPORT)
+  if(OpenEXR_FOUND_WITH_CONFIG)
+    message(STATUS " found OpenEXR with Config")
+  else(OpenEXR_FOUND_WITH_CONFIG)
+    message(STATUS " found OpenEXR with FindModule")
+  endif(OpenEXR_FOUND_WITH_CONFIG)
+else(OpenEXR_FOUND)
+  message(ERROR "OpenEXR is a required dependency but it has not been found")
+endif(OpenEXR_FOUND)
+
+if(IlmBase_FOUND)
+  message(STATUS "IlmBase info:")
+  message(STATUS "       IlmBase_VERSION = ${IlmBase_VERSION}")
+  message(STATUS "   IlmBase_INCLUDE_DIR = ${IlmBase_INCLUDE_DIR}")
+  message(STATUS "  IlmBase_INCLUDE_DIRS = ${IlmBase_INCLUDE_DIRS}")
+  message(STATUS "       IlmBase_LIBRARY = ${IlmBase_LIBRARY}")
+  message(STATUS "     IlmBase_LIBRARIES = ${IlmBase_LIBRARIES}")
+endif(IlmBase_FOUND)
+
+if(OpenEXR_FOUND)
+  message(STATUS "OpenEXR info:")
+  message(STATUS "       OpenEXR_VERSION = ${OpenEXR_VERSION}")
+  if( NOT OpenEXR_FOUND_WITH_CONFIG)
+    message(STATUS "   OpenEXR_INCLUDE_DIR = ${OpenEXR_INCLUDE_DIR}")
+    message(STATUS "  OpenEXR_INCLUDE_DIRS = ${OpenEXR_INCLUDE_DIRS}")
+    message(STATUS "       OpenEXR_LIBRARY = ${OpenEXR_LIBRARY}")
+    message(STATUS "     OpenEXR_LIBRARIES = ${OpenEXR_LIBRARIES}")
+  endif(NOT OpenEXR_FOUND_WITH_CONFIG)
+endif(OpenEXR_FOUND)
 
 add_subdirectory(lib)
 add_subdirectory(doc)