nsyshid: add libusb backend

This adds a backend for nsyshid, that uses libusb to provide passthrough access to real usb devices.

CMakeLists.txt

@@ -102,6 +102,12 @@ if (WIN32)
 endif()
 option(ENABLE_CUBEB "Enabled cubeb backend" ON)
 
+# usb hid backends
+option(ENABLE_NSYSHID_LIBUSB "Enables the libusb backend for nsyshid" ON)
+if (ENABLE_NSYSHID_LIBUSB)
+	add_compile_definitions(NSYSHID_ENABLE_BACKEND_LIBUSB)
+endif ()
+
 option(ENABLE_WXWIDGETS "Build with wxWidgets UI (Currently required)" ON)
 
 set(THREADS_PREFER_PTHREAD_FLAG true)

src/Cafe/CMakeLists.txt

@@ -438,6 +438,8 @@ add_library(CemuCafe
   OS/libs/nsyshid/AttachDefaultBackends.cpp
   OS/libs/nsyshid/Whitelist.cpp
   OS/libs/nsyshid/Whitelist.h
+  OS/libs/nsyshid/BackendLibusb.cpp
+  OS/libs/nsyshid/BackendLibusb.h
   OS/libs/nsyskbd/nsyskbd.cpp
   OS/libs/nsyskbd/nsyskbd.h
   OS/libs/nsysnet/nsysnet.cpp
@@ -528,6 +530,12 @@ if (ENABLE_WAYLAND)
   target_link_libraries(CemuCafe PUBLIC Wayland::Client)
 endif()
 
+if (ENABLE_NSYSHID_LIBUSB)
+	find_package(libusb CONFIG REQUIRED)
+	target_include_directories(CemuCafe PRIVATE ${LIBUSB_INCLUDE_DIRS})
+	target_link_libraries(CemuCafe PRIVATE ${LIBUSB_LIBRARIES})
+endif ()
+
 if (ENABLE_WXWIDGETS)
 	target_link_libraries(CemuCafe PRIVATE wx::base wx::core)
 endif()

src/Cafe/OS/libs/nsyshid/AttachDefaultBackends.cpp

@@ -1,8 +1,22 @@
 #include "nsyshid.h"
 #include "Backend.h"
 
+#if NSYSHID_ENABLE_BACKEND_LIBUSB
+
+#include "BackendLibusb.h"
+
+#endif
+
 namespace nsyshid::backend {
 	void attachDefaultBackends() {
-
+#if NSYSHID_ENABLE_BACKEND_LIBUSB
+		// add libusb backend
+		{
+			auto backendLibusb = std::make_shared<backend::libusb::BackendLibusb>();
+			if (backendLibusb->isInitialisedOk()) {
+				attachBackend(backendLibusb);
+			}
+		}
+#endif //NSYSHID_ENABLE_BACKEND_LIBUSB
 	}
 }