Simplifying HID creation.

Part of #296.

src/xenia/hid/input_system.cc

@@ -12,11 +12,57 @@
 #include "xenia/emulator.h"
 #include "xenia/cpu/processor.h"
 #include "xenia/hid/input_driver.h"
+#include "xenia/hid/hid-private.h"
 #include "xenia/profiling.h"
 
+#include "xenia/hid/nop/nop_hid.h"
+#if XE_PLATFORM_WIN32
+#include "xenia/hid/winkey/winkey_hid.h"
+#include "xenia/hid/xinput/xinput_hid.h"
+#endif  // WIN32
+
 namespace xe {
 namespace hid {
 
+std::unique_ptr<InputSystem> InputSystem::Create(Emulator* emulator) {
+  auto input_system = std::make_unique<InputSystem>(emulator);
+
+  if (FLAGS_hid.compare("nop") == 0) {
+    input_system->AddDriver(xe::hid::nop::Create(input_system.get()));
+#if XE_PLATFORM_WIN32
+  } else if (FLAGS_hid.compare("winkey") == 0) {
+    input_system->AddDriver(xe::hid::winkey::Create(input_system.get()));
+  } else if (FLAGS_hid.compare("xinput") == 0) {
+    input_system->AddDriver(xe::hid::xinput::Create(input_system.get()));
+#endif  // WIN32
+  } else {
+    // Create all available.
+    bool any_created = false;
+
+// NOTE: in any mode we create as many as we can, falling back to nop.
+
+#if XE_PLATFORM_WIN32
+    auto xinput_driver = xe::hid::xinput::Create(input_system.get());
+    if (xinput_driver) {
+      input_system->AddDriver(std::move(xinput_driver));
+      any_created = true;
+    }
+    auto winkey_driver = xe::hid::winkey::Create(input_system.get());
+    if (winkey_driver) {
+      input_system->AddDriver(std::move(winkey_driver));
+      any_created = true;
+    }
+#endif  // WIN32
+
+    // Fallback to nop if none created.
+    if (!any_created) {
+      input_system->AddDriver(xe::hid::nop::Create(input_system.get()));
+    }
+  }
+
+  return input_system;
+}
+
 InputSystem::InputSystem(Emulator* emulator)
     : emulator_(emulator), memory_(emulator->memory()) {}