move MotionEmu from core/frontend to input_common as a InputDevice

src/input_common/motion_emu.h

@@ -0,0 +1,47 @@
+// Copyright 2017 Citra Emulator Project
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#pragma once
+#include "common/thread.h"
+#include "common/vector_math.h"
+#include "core/frontend/input.h"
+
+namespace InputCommon {
+
+class MotionEmuDevice;
+
+class MotionEmu : public Input::Factory<Input::MotionDevice> {
+public:
+    /**
+     * Creates a motion device emulated from mouse input
+     * @param params contains parameters for creating the device:
+     *     - "update_period": update period in milliseconds
+     *     - "sensitivity": the coefficient converting mouse movement to tilting angle
+     */
+    std::unique_ptr<Input::MotionDevice> Create(const Common::ParamPackage& params) override;
+
+    /**
+     * Signals that a motion sensor tilt has begun.
+     * @param x the x-coordinate of the cursor
+     * @param y the y-coordinate of the cursor
+     */
+    void BeginTilt(int x, int y);
+
+    /**
+     * Signals that a motion sensor tilt is occurring.
+     * @param x the x-coordinate of the cursor
+     * @param y the y-coordinate of the cursor
+     */
+    void Tilt(int x, int y);
+
+    /**
+     * Signals that a motion sensor tilt has ended.
+     */
+    void EndTilt();
+
+private:
+    std::weak_ptr<MotionEmuDevice> current_device;
+};
+
+} // namespace InputCommon