Input: UDP Client to provide motion and touch controls

An implementation of the cemuhook motion/touch protocol, this adds the
ability for users to connect several different devices to citra to send
direct motion and touch data to citra.

Co-Authored-By: jroweboy <jroweboy@gmail.com>

src/input_common/udp/client.h

@@ -0,0 +1,96 @@
+// Copyright 2018 Citra Emulator Project
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#pragma once
+
+#include <functional>
+#include <memory>
+#include <mutex>
+#include <optional>
+#include <string>
+#include <thread>
+#include <tuple>
+#include <vector>
+#include "common/common_types.h"
+#include "common/thread.h"
+#include "common/vector_math.h"
+
+namespace InputCommon::CemuhookUDP {
+
+static constexpr u16 DEFAULT_PORT = 26760;
+static constexpr const char* DEFAULT_ADDR = "127.0.0.1";
+
+class Socket;
+
+namespace Response {
+struct PadData;
+struct PortInfo;
+struct Version;
+} // namespace Response
+
+struct DeviceStatus {
+    std::mutex update_mutex;
+    std::tuple<Common::Vec3<float>, Common::Vec3<float>> motion_status;
+    std::tuple<float, float, bool> touch_status;
+
+    // calibration data for scaling the device's touch area to 3ds
+    struct CalibrationData {
+        u16 min_x;
+        u16 min_y;
+        u16 max_x;
+        u16 max_y;
+    };
+    std::optional<CalibrationData> touch_calibration;
+};
+
+class Client {
+public:
+    explicit Client(std::shared_ptr<DeviceStatus> status, const std::string& host = DEFAULT_ADDR,
+                    u16 port = DEFAULT_PORT, u8 pad_index = 0, u32 client_id = 24872);
+    ~Client();
+    void ReloadSocket(const std::string& host = "127.0.0.1", u16 port = 26760, u8 pad_index = 0,
+                      u32 client_id = 24872);
+
+private:
+    void OnVersion(Response::Version);
+    void OnPortInfo(Response::PortInfo);
+    void OnPadData(Response::PadData);
+    void StartCommunication(const std::string& host, u16 port, u8 pad_index, u32 client_id);
+
+    std::unique_ptr<Socket> socket;
+    std::shared_ptr<DeviceStatus> status;
+    std::thread thread;
+    u64 packet_sequence = 0;
+};
+
+/// An async job allowing configuration of the touchpad calibration.
+class CalibrationConfigurationJob {
+public:
+    enum class Status {
+        Initialized,
+        Ready,
+        Stage1Completed,
+        Completed,
+    };
+    /**
+     * Constructs and starts the job with the specified parameter.
+     *
+     * @param status_callback Callback for job status updates
+     * @param data_callback Called when calibration data is ready
+     */
+    explicit CalibrationConfigurationJob(const std::string& host, u16 port, u8 pad_index,
+                                         u32 client_id, std::function<void(Status)> status_callback,
+                                         std::function<void(u16, u16, u16, u16)> data_callback);
+    ~CalibrationConfigurationJob();
+    void Stop();
+
+private:
+    Common::Event complete_event;
+};
+
+void TestCommunication(const std::string& host, u16 port, u8 pad_index, u32 client_id,
+                       std::function<void()> success_callback,
+                       std::function<void()> failure_callback);
+
+} // namespace InputCommon::CemuhookUDP