CJoystick.cpp

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/* +------------------------------------------------------------------------+
   |                     Mobile Robot Programming Toolkit (MRPT)            |
   |                          http://www.mrpt.org/                          |
   |                                                                        |
   | Copyright (c) 2005-2017, Individual contributors, see AUTHORS file     |
   | See: http://www.mrpt.org/Authors - All rights reserved.                |
   | Released under BSD License. See details in http://www.mrpt.org/License |
   +------------------------------------------------------------------------+ */

#include "hwdrivers-precomp.h"  // Precompiled headers

#include <mrpt/config.h>

#ifdef MRPT_OS_WINDOWS
#include <windows.h>
#include <mmsystem.h>

#if !defined(__GNUC__)
#pragma comment(lib, "WINMM.LIB")
#endif
#endif

#if defined(MRPT_OS_LINUX) || defined(MRPT_OS_APPLE)
// Linux
#include <sys/ioctl.h>
#include <sys/time.h>
#include <sys/types.h>
#include <stdlib.h>
#include <fcntl.h>
#include <unistd.h>
#include <stdio.h>
#include <errno.h>
#include <string.h>
#include <stdlib.h>
#include <cstdint>

#if defined(MRPT_OS_LINUX) && defined(HAVE_LINUX_INPUT_H)
#include <linux/input.h>
#include <linux/joystick.h>
#endif
#endif

#include <mrpt/hwdrivers/CJoystick.h>

using namespace mrpt::hwdrivers;

/*---------------------------------------------------------------
                                        Constructor
 ---------------------------------------------------------------*/
CJoystick::CJoystick()
#if defined(MRPT_OS_LINUX) && defined(HAVE_LINUX_INPUT_H)
        : m_joy_fd(-1), m_joy_index(-1)
#endif
{
        setLimits();
}

/*---------------------------------------------------------------
                                        Destructor
 ---------------------------------------------------------------*/
CJoystick::~CJoystick()
{
#if defined(MRPT_OS_LINUX) && defined(HAVE_LINUX_INPUT_H)
        // Close joystick, if open:
        if (m_joy_fd > 0)
        {
                close(m_joy_fd);
                m_joy_fd = -1;
        }
#endif
}

/*---------------------------------------------------------------
                                        getJoysticksCount
  Returns the number of Joysticks in the computer.
 ---------------------------------------------------------------*/
int CJoystick::getJoysticksCount()
{
        MRPT_START
#ifdef MRPT_OS_WINDOWS
        return joyGetNumDevs();
#elif defined(MRPT_OS_LINUX) && defined(HAVE_LINUX_INPUT_H)
        // Try to open several joy devs:
        int joy_fd = -1;
        int nJoys = 0;

        do
        {
                if (-1 !=
                        (joy_fd = open(format("/dev/input/js%i", nJoys).c_str(), O_RDONLY)))
                {
                        nJoys++;
                        close(joy_fd);
                }
        } while (joy_fd != -1);

        return nJoys;
#else
        // Apple:
        return 0;
#endif
        MRPT_END
}

/*---------------------------------------------------------------
  Gets joystick information.

  \return Returns true if successfull, false on error, for example, if joystick
 is not present.
 ---------------------------------------------------------------*/
bool CJoystick::getJoystickPosition(
        int nJoy, float& x, float& y, float& z, std::vector<bool>& buttons,
        int* raw_x_pos, int* raw_y_pos, int* raw_z_pos)
{
        MRPT_START
#ifdef MRPT_OS_WINDOWS
        JOYINFO jinfo;

        int ID = JOYSTICKID1 + nJoy;

        // Get joy pos:
        if (JOYERR_NOERROR != joyGetPos(ID, &jinfo)) return false;  // Error.

        // Output data:
        x = (jinfo.wXpos - m_x_min) / (float)(m_x_max - m_x_min);
        y = (jinfo.wYpos - m_y_min) / (float)(m_y_max - m_y_min);
        z = (jinfo.wZpos - m_z_min) / (float)(m_z_max - m_z_min);

        x = 2 * x - 1;
        y = 2 * y - 1;
        z = 2 * z - 1;

        buttons.resize(4);

        buttons[0] = 0 != (jinfo.wButtons & JOY_BUTTON1);
        buttons[1] = 0 != (jinfo.wButtons & JOY_BUTTON2);
        buttons[2] = 0 != (jinfo.wButtons & JOY_BUTTON3);
        buttons[3] = 0 != (jinfo.wButtons & JOY_BUTTON4);

        if (raw_x_pos) *raw_x_pos = jinfo.wXpos;
        if (raw_y_pos) *raw_y_pos = jinfo.wYpos;
        if (raw_z_pos) *raw_z_pos = jinfo.wZpos;

        return true;
#elif defined(MRPT_OS_LINUX) && defined(HAVE_LINUX_INPUT_H)
        // Already open?
        if (m_joy_index == nJoy && m_joy_fd != -1)
        {
                // Ok
        }
        else
        {
                // Close previous opened joy?
                if (m_joy_fd != -1) close(m_joy_fd);

                // Go, try open joystick:
                if ((m_joy_fd =
                                 open(format("/dev/input/js%i", nJoy).c_str(), O_RDONLY)) < 0)
                        return false;

                // Perfect!
                m_joy_index = nJoy;

                // Read in non-blocking way: **** Refer to sources of "jstest"!!!! ***
                fcntl(m_joy_fd, F_SETFL, O_NONBLOCK);
        }

        struct js_event js;

        while (read(m_joy_fd, &js, sizeof(struct js_event)) ==
                   sizeof(struct js_event))
        {
                // Button?
                if (js.type & JS_EVENT_BUTTON)
                {
                        // js.number: Button number
                        if (m_joystate_btns.size() < (size_t)js.number + 1)
                                m_joystate_btns.resize(js.number + 1);
                        m_joystate_btns[js.number] = js.value != 0;
                }

                // Axes?
                if (js.type & JS_EVENT_AXIS)
                {
                        // std::cout << "joy: event axis" << std::endl;
                        if (m_joystate_axes.size() < (size_t)js.number + 1)
                                m_joystate_axes.resize(js.number + 1);
                        m_joystate_axes[js.number] = js.value;
                }
        }

        if (errno != EAGAIN)
        {
                // Joystick disconnected?
                m_joy_fd = -1;
                m_joy_index = -1;
                return false;
        }

        // Fill out data:
        const size_t nAxis = m_joystate_axes.size();
        if (nAxis >= 1)
        {
                x = -1 +
                        2 * (m_joystate_axes[0] - m_x_min) / (float)(m_x_max - m_x_min);
                if (raw_x_pos) *raw_x_pos = m_joystate_axes[0];
        }

        if (nAxis >= 2)
        {
                y = -1 +
                        2 * (m_joystate_axes[1] - m_y_min) / (float)(m_y_max - m_y_min);
                if (raw_y_pos) *raw_y_pos = m_joystate_axes[1];
        }

        if (nAxis >= 3)
        {
                z = -1 +
                        2 * (m_joystate_axes[2] - m_z_min) / (float)(m_z_max - m_z_min);
                if (raw_z_pos) *raw_z_pos = m_joystate_axes[2];
        }
        else
        {
                z = 0;
        }

        buttons = m_joystate_btns;

        return true;
#else
        // Apple.
        return false;
#endif
        MRPT_END
}

/** Set the axis limit values, for computing a [-1,1] position index easily.
*   It seems that these values must been calibrated for each joystick model.
*
* \sa getJoystickPosition
*/
void CJoystick::setLimits(
        int x_min, int x_max, int y_min, int y_max, int z_min, int z_max)
{
        m_x_max = x_max;
        m_x_min = x_min;

        m_y_max = y_max;
        m_y_min = y_min;

        m_z_max = z_max;
        m_z_min = z_min;
}