CJoystick.h

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/* +------------------------------------------------------------------------+
   |                     Mobile Robot Programming Toolkit (MRPT)            |
   |                          https://www.mrpt.org/                         |
   |                                                                        |
   | Copyright (c) 2005-2020, Individual contributors, see AUTHORS file     |
   | See: https://www.mrpt.org/Authors - All rights reserved.               |
   | Released under BSD License. See: https://www.mrpt.org/License          |
   +------------------------------------------------------------------------+ */
#pragma once

#include <vector>

/*---------------------------------------------------------------
    Class
  ---------------------------------------------------------------*/
namespace mrpt::hwdrivers
{
/** Access to joysticks and gamepads (read buttons and position), and request
 * number of joysticks in the system.
 * \ingroup mrpt_hwdrivers_grp
 */
class CJoystick
{
   private:
    /** The axis limits:
     */
    int m_x_min, m_x_max, m_y_min, m_y_max, m_z_min, m_z_max;

#if defined(MRPT_OS_LINUX)
    /** File FD for the joystick, or -1 if not open (Linux only) */
    int m_joy_fd{-1};
    /** The index of the joystick open in m_joy_fd (Linux only) */
    int m_joy_index{-1};
    /** Using an event system we only have deltas, need to keep the whole
     * joystick state (Linux only) */
    std::vector<bool> m_joystate_btns;
    /** Using an event system we only have deltas, need to keep the whole
     * joystick state (Linux only) */
    std::vector<int> m_joystate_axes;
#endif

   public:
    /** Constructor
     */
    CJoystick();

    /** Destructor
     */
    virtual ~CJoystick();

    /** Returns the number of Joysticks in the computer.
     */
    static int getJoysticksCount();

    /** Gets joystick information.
     *
     *   This method will try first to open the joystick, so you can safely call
     * it while the joystick is plugged and removed arbitrarly.
     *
     * \param nJoy The index of the joystick to query: The first one is 0, the
     * second 1, etc... See CJoystick::getJoysticksCount to discover the number
     * of joysticks in the system.
     * \param x The x axis position, range [-1,1]
     * \param y The y axis position, range [-1,1]
     * \param z The z axis position, range [-1,1]
     * \param buttons Each element will hold true if buttons are pressed. The
     * size of the vector will be set automatically to the number of buttons.
     * \param raw_x_pos If it is desired the raw integer measurement from
     * JoyStick, set this pointer to a desired placeholder.
     * \param raw_y_pos If it is desired the raw integer measurement from
     * JoyStick, set this pointer to a desired placeholder.
     * \param raw_z_pos If it is desired the raw integer measurement from
     * JoyStick, set this pointer to a desired placeholder.
     *
     * \return Returns true if successfull, false on error, for example, if
     * joystick is not present.
     *
     * \sa setLimits
     */
    bool getJoystickPosition(
        int nJoy, float& x, float& y, float& z, std::vector<bool>& buttons,
        int* raw_x_pos = nullptr, int* raw_y_pos = nullptr,
        int* raw_z_pos = nullptr);

/** Set the axis limit values, for computing a [-1,1] position index easily
 * (Only required to calibrate analog joystick).
 *   It seems that these values must been calibrated for each joystick model.
 *
 * \sa getJoystickPosition
 */
#ifdef _WIN32
    void setLimits(
        int x_min = 0, int x_max = 0xFFFF, int y_min = 0, int y_max = 0xFFFF,
        int z_min = 0, int z_max = 0xFFFF);
#else
    void setLimits(
        int x_min = -32767, int x_max = 32767, int y_min = -32767,
        int y_max = 32767, int z_min = -32767, int z_max = 32767);
#endif
};  // End of class def.

}  // namespace mrpt::hwdrivers