modules: find the OpenAL DLL also with the imported target.

And update the DLL copying to handle Debug as well.

modules/FindOpenAL.cmake

@@ -11,8 +11,8 @@
 #
 #  OPENAL_LIBRARY       - OpenAL library
 #  OPENAL_DLL_RELEASE   - OpenAL release DLL on Windows, if found. Note that
-#   (at least in case of the binary OpenAL Soft distribution) it's named
-#   soft_oal.dll and you need to rename it to OpenAL32.dll to make it work.
+#   in case of the binary OpenAL Soft distribution it's named soft_oal.dll and
+#   you need to rename it to OpenAL32.dll to make it work.
 #  OPENAL_INCLUDE_DIR   - Include dir
 #
 
@@ -69,6 +69,17 @@ if(TARGET OpenAL OR TARGET OpenAL::OpenAL)
         # that ourselves.
         get_target_property(_OPENAL_SOURCE_DIR OpenAL SOURCE_DIR)
         set_target_properties(OpenAL::OpenAL PROPERTIES INTERFACE_INCLUDE_DIRECTORIES ${_OPENAL_SOURCE_DIR}/include/AL)
+
+    # For the imported target get the DLL location
+    else()
+        if(CORRADE_TARGET_WINDOWS)
+            get_target_property(OPENAL_DLL_DEBUG OpenAL::OpenAL   IMPORTED_LOCATION_DEBUG)
+            get_target_property(OPENAL_DLL_RELEASE OpenAL::OpenAL IMPORTED_LOCATION_RELEASE)
+            # Release not found, fall back to RelWithDebInfo
+            if(NOT OPENAL_DLL_RELEASE)
+                get_target_property(OPENAL_DLL_RELEASE OpenAL::OpenAL IMPORTED_LOCATION_RELWITHDEBINFO)
+            endif()
+        endif()
     endif()
 
     # Just to make FPHSA print some meaningful location, nothing else.
@@ -81,11 +92,6 @@ if(TARGET OpenAL OR TARGET OpenAL::OpenAL)
     find_package_handle_standard_args("OpenAL" DEFAULT_MSG
         _OPENAL_INTERFACE_INCLUDE_DIRECTORIES)
 
-    if(CORRADE_TARGET_WINDOWS)
-        # TODO: investigate if OpenAL Soft has IMPORTED_LOCATION_ / IMPLIB like
-        #   GLFW does so we can provide OPENAL_DLL
-    endif()
-
     return()
 endif()
 

src/Magnum/Audio/CMakeLists.txt

@@ -110,14 +110,22 @@ install(TARGETS MagnumAudio
 install(FILES ${MagnumAudio_HEADERS} DESTINATION ${MAGNUM_INCLUDE_INSTALL_DIR}/Audio)
 
 # Copy the OpenAL DLL next to the place where all executables are stored to
-# help people running the apps. TODO: update if we ever have a debug DLL
-if(CMAKE_RUNTIME_OUTPUT_DIRECTORY AND CORRADE_TARGET_WINDOWS AND OPENAL_DLL_RELEASE)
+# help people running the apps.
+if(CMAKE_RUNTIME_OUTPUT_DIRECTORY AND CORRADE_TARGET_WINDOWS AND (OPENAL_DLL_DEBUG OR OPENAL_DLL_RELEASE))
     # Not exactly sure why, but in the OpenAL Soft binary distribution it's
     # named soft_oal.dll and needs to be renamed to OpenAL32.dll to work
-    # correctly
+    # correctly. Not the case with OpenAL Soft built by hand.
+    if(OPENAL_DLL_DEBUG AND OPENAL_DLL_RELEASE)
+        add_custom_command(TARGET MagnumAudio POST_BUILD
+            COMMAND ${CMAKE_COMMAND} -E copy_if_different $<$<CONFIG:Debug>:${OPENAL_DLL_DEBUG}>$<$<NOT:$<CONFIG:Debug>>:${OPENAL_DLL_RELEASE}> ${CMAKE_RUNTIME_OUTPUT_DIRECTORY}/OpenAL32.dll)
+    elseif(OPENAL_DLL_DEBUG)
+        add_custom_command(TARGET MagnumAudio POST_BUILD
+            COMMAND ${CMAKE_COMMAND} -E copy_if_different ${OPENAL_DLL_DEBUG} ${CMAKE_RUNTIME_OUTPUT_DIRECTORY}/OpenAL32.dll)
+    else()
         add_custom_command(TARGET MagnumAudio POST_BUILD
             COMMAND ${CMAKE_COMMAND} -E copy_if_different ${OPENAL_DLL_RELEASE} ${CMAKE_RUNTIME_OUTPUT_DIRECTORY}/OpenAL32.dll)
     endif()
+endif()
 
 # Magnum Audio target alias for superprojects
 add_library(Magnum::Audio ALIAS MagnumAudio)