Fix issue with defines not being set correctly for win32

we always build shared libraries now, so even if the default is to build
static, the python bindings are forced to build shared, which means they
need to set the defines to export the symbols appropriately, add extra
variable set

Signed-off-by: Kimball Thurston <kdt3rd@gmail.com>

PyIlmBase/config/ModuleDefine.cmake

@@ -23,19 +23,21 @@ function(PYILMBASE_ADD_LIBRARY_PRIV libname)
     OUTPUT_NAME "${PYILMBASE_CURLIB_OUTROOT}${libname}${PYILMBASE_LIB_SUFFIX}"
   )
   target_compile_features(${libname} PUBLIC cxx_std_${OPENEXR_CXX_STANDARD})
-  if(PYILMBASE_CURLIB_PRIV_EXPORT AND BUILD_SHARED_LIBS)
+  # we are always building shared, so don't check for that
+  if(PYILMBASE_CURLIB_PRIV_EXPORT)
     target_compile_definitions(${libname} PRIVATE ${PYILMBASE_CURLIB_PRIV_EXPORT})
-    if(WIN32)
-      target_compile_definitions(${libname} PUBLIC OPENEXR_DLL)
-    endif()
   endif()
+  target_compile_definitions(${libname} PUBLIC OPENEXR_DLL)
+
   if(PYILMBASE_CURLIB_CURDIR)
     target_include_directories(${libname} PUBLIC $<BUILD_INTERFACE:${PYILMBASE_CURLIB_CURDIR}>)
   endif()
   if(PYILMBASE_CURLIB_CURBINDIR)
     target_include_directories(${libname} PRIVATE $<BUILD_INTERFACE:${PYILMBASE_CURLIB_CURBINDIR}>)
   endif()
-  target_include_directories(${libname} PUBLIC ${Boost_INCLUDE_DIR})
+  if(Boost_INCLUDE_DIR)
+    target_include_directories(${libname} PUBLIC ${Boost_INCLUDE_DIR})
+  endif()
   target_link_libraries(${libname} PUBLIC ${PYILMBASE_CURLIB_DEPENDENCIES})
   if(PYILMBASE_CURLIB_PRIVATE_DEPS)
     target_link_libraries(${libname} PRIVATE ${PYILMBASE_CURLIB_PRIVATE_DEPS})