move ui/impl.cmake to src/

Now that there is no separate UI-specific wrapper, it belongs to the implementation rather than to the UI, probably

cherry-picked from: qt-wgpu-skel:9742916bd6932498e87b12d514ac209595ad216c

CMakeLists.txt

@@ -13,4 +13,5 @@ include(diplomat.cmake)
 
 qt_standard_project_setup()
 
+add_subdirectory(src)
 add_subdirectory(ui)

src/CMakeLists.txt

@@ -32,7 +32,7 @@ add_custom_target(build_impl
 	DEPENDS "${impl_basename}.a"
 )
 
-add_library(photon_light_impl STATIC IMPORTED)
+add_library(photon_light_impl STATIC IMPORTED GLOBAL)
 
 set_target_properties(photon_light_impl PROPERTIES
 	IMPORTED_LOCATION "${impl_basename}.a"
@@ -48,11 +48,16 @@ set(bindings
 add_custom_command(
 	OUTPUT ${bindings}
 	COMMAND ${diplomat} cpp "${bindings_dir}"
-	MAIN_DEPENDENCY "${CMAKE_SOURCE_DIR}/src/lib.rs"
+	MAIN_DEPENDENCY "lib.rs"
 	WORKING_DIRECTORY "${CMAKE_SOURCE_DIR}"
 	VERBATIM
 	${diplomat_cmake_args}
 )
 
+# HACK ensure CMake *actually adds* the command above
+add_custom_target(codegen_impl
+	DEPENDS ${bindings}
+)
+
 target_sources(photon_light_impl INTERFACE ${bindings})
 target_include_directories(photon_light_impl INTERFACE "${bindings_dir}")

ui/CMakeLists.txt

@@ -1,5 +1,3 @@
-include(impl.cmake)
-
 qt_add_executable(photon-light
 	src/main.cxx
 	src/main_window.cxx