device/gamepad/raw_input_gamepad_device_win.h

// Copyright 2018 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef DEVICE_GAMEPAD_RAW_INPUT_GAMEPAD_DEVICE_WIN_H_
#define DEVICE_GAMEPAD_RAW_INPUT_GAMEPAD_DEVICE_WIN_H_

#include <Unknwn.h>
#include <WinDef.h>
#include <hidsdi.h>
#include <stdint.h>
#include <stdlib.h>
#include <windows.h>

#include <memory>
#include <vector>

#include "base/memory/weak_ptr.h"
#include "device/gamepad/abstract_haptic_gamepad.h"
#include "device/gamepad/public/cpp/gamepad.h"

namespace device {

class HidHapticGamepad;
class Dualshock4Controller;

class RawInputGamepadDeviceWin final : public AbstractHapticGamepad {
 public:
  // Relevant usage IDs within the Generic Desktop usage page. RawInput gamepads
  // must have one of these usage IDs.
  static const uint16_t kGenericDesktopJoystick = 0x04;
  static const uint16_t kGenericDesktopGamePad = 0x05;
  static const uint16_t kGenericDesktopMultiAxisController = 0x08;

  RawInputGamepadDeviceWin(HANDLE device_handle, int source_id);
  RawInputGamepadDeviceWin(const RawInputGamepadDeviceWin&) = delete;
  RawInputGamepadDeviceWin& operator=(const RawInputGamepadDeviceWin&) = delete;
  ~RawInputGamepadDeviceWin() override;

  static bool IsGamepadUsageId(uint16_t usage);

  int GetSourceId() const { return source_id_; }
  uint16_t GetVendorId() const { return vendor_id_; }
  uint16_t GetVersionNumber() const { return version_number_; }
  uint16_t GetProductId() const { return product_id_; }
  std::wstring GetDeviceName() const { return name_; }
  std::wstring GetProductString() const { return product_string_; }

  // Return true if this device is a gamepad.
  bool IsValid() const { return is_valid_; }

  // Return true if this device supports vibration effects.
  bool SupportsVibration() const;

  // Updates the current gamepad state with data from a RAWINPUT event.
  void UpdateGamepad(RAWINPUT* input);

  // Read the current gamepad state into |pad|.
  void ReadPadState(Gamepad* pad) const;

  // AbstractHapticGamepad implementation.
  void SetVibration(double strong_magnitude, double weak_magnitude) override;
  base::WeakPtr<AbstractHapticGamepad> GetWeakPtr() override;

 private:
  // Axis state and capabilities for a single RawInput axis.
  struct RawGamepadAxis {
    HIDP_VALUE_CAPS caps;
    float value;
    bool active;
    unsigned long bitmask;
  };

  // AbstractHapticGamepad implementation.
  void DoShutdown() override;

  // "Returns an open handle for the HID device, or an invalid handle if the
  // device could not be opened."
  base::win::ScopedHandle OpenHidHandle();

  // Fetch information about this device. Returns true if the device appears to
  // be a valid gamepad.
  bool QueryDeviceInfo();

  // Fetch HID properties (RID_DEVICE_INFO_HID). Returns false on failure.
  bool QueryHidInfo();

  // Fetch the device name (RIDI_DEVICENAME). Returns false on failure.
  bool QueryDeviceName();

  // Fetch the product string. Returns false if none is available.
  bool QueryProductString(base::win::ScopedHandle& hid_handle);

  // These methods fetch information about the capabilities of buttons and axes
  // on the device.
  bool QueryDeviceCapabilities();
  void QueryButtonCapabilities(uint16_t button_count);
  void QueryNormalButtonCapabilities(
      base::span<const HIDP_BUTTON_CAPS> button_caps);
  void QuerySpecialButtonCapabilities(
      base::span<const HIDP_BUTTON_CAPS> button_caps);
  void QueryAxisCapabilities(uint16_t axis_count);

  // Reads the value of the axis at index |axis_index| from |input| and scales
  // to the range [-1.0,+1.0].
  void UpdateAxisValue(size_t axis_index, RAWINPUT& input);

  // True if the device described by this object is a valid RawInput gamepad.
  bool is_valid_ = false;

  // The device handle.
  HANDLE handle_ = nullptr;

  // The index assigned to this gamepad by the data fetcher.
  int source_id_ = 0;

  // The last time the pad state was updated.
  int64_t last_update_timestamp_;

  uint16_t vendor_id_ = 0;
  uint16_t product_id_ = 0;
  uint16_t version_number_ = 0;
  uint16_t usage_ = 0;
  std::wstring name_;
  std::wstring product_string_;

  size_t buttons_length_ = 0;
  bool buttons_[Gamepad::kButtonsLengthCap];

  // Keep track of which button indices are in use.
  std::vector<bool> button_indices_used_;

  // Bitfield to keep track of which axes indices are in use.
  uint32_t axes_used_ = 0;
  static_assert(Gamepad::kAxesLengthCap <=
                    std::numeric_limits<uint32_t>::digits,
                "axes_used_ is not large enough");

  // Mapping from "Special" usage index (defined by the kSpecialUsages table)
  // to an index within the |buttons_| array, or -1 if the special usage is not
  // mapped for this device.
  std::vector<int> special_button_map_;

  size_t axes_length_ = 0;
  RawGamepadAxis axes_[Gamepad::kAxesLengthCap];

  // Buffer used for querying device capabilities. |ppd_buffer_| owns the
  // memory pointed to by |preparsed_data_|.
  std::unique_ptr<uint8_t[]> ppd_buffer_;
  PHIDP_PREPARSED_DATA preparsed_data_ = nullptr;

  // Dualshock4-specific functionality (e.g., haptics), if available.
  std::unique_ptr<Dualshock4Controller> dualshock4_;

  // A controller that uses a HID output report for vibration effects.
  std::unique_ptr<HidHapticGamepad> hid_haptics_;

  base::WeakPtrFactory<RawInputGamepadDeviceWin> weak_factory_{this};
};

}  // namespace device

#endif  // DEVICE_GAMEPAD_RAW_INPUT_GAMEPAD_DEVICE_WIN_H_