src/joystick/beos/SDL_bejoystick.cc

/*
  Simple DirectMedia Layer
  Copyright (C) 1997-2012 Sam Lantinga <slouken@libsdl.org>

  This software is provided 'as-is', without any express or implied
  warranty.  In no event will the authors be held liable for any damages
  arising from the use of this software.

  Permission is granted to anyone to use this software for any purpose,
  including commercial applications, and to alter it and redistribute it
  freely, subject to the following restrictions:

  1. The origin of this software must not be misrepresented; you must not
     claim that you wrote the original software. If you use this software
     in a product, an acknowledgment in the product documentation would be
     appreciated but is not required.
  2. Altered source versions must be plainly marked as such, and must not be
     misrepresented as being the original software.
  3. This notice may not be removed or altered from any source distribution.
*/
#include "SDL_config.h"

#ifdef SDL_JOYSTICK_BEOS

/* This is the system specific header for the SDL joystick API */

#include <be/support/String.h>
#include <be/device/Joystick.h>

extern "C"
{

#include "SDL_joystick.h"
#include "../SDL_sysjoystick.h"
#include "../SDL_joystick_c.h"


/* The maximum number of joysticks we'll detect */
#define MAX_JOYSTICKS	16

/* A list of available joysticks */
    static char *SDL_joyport[MAX_JOYSTICKS];
    static char *SDL_joyname[MAX_JOYSTICKS];

/* The private structure used to keep track of a joystick */
    struct joystick_hwdata
    {
        BJoystick *stick;
        uint8 *new_hats;
        int16 *new_axes;
    };

/* Function to scan the system for joysticks.
 * This function should set SDL_numjoysticks to the number of available
 * joysticks.  Joystick 0 should be the system default joystick.
 * It should return 0, or -1 on an unrecoverable fatal error.
 */
    int SDL_SYS_JoystickInit(void)
    {
        BJoystick joystick;
        int numjoysticks;
        int i;
        int32 nports;
        char name[B_OS_NAME_LENGTH];

        /* Search for attached joysticks */
          nports = joystick.CountDevices();
          numjoysticks = 0;
          SDL_memset(SDL_joyport, 0, (sizeof SDL_joyport));
          SDL_memset(SDL_joyname, 0, (sizeof SDL_joyname));
        for (i = 0; (SDL_numjoysticks < MAX_JOYSTICKS) && (i < nports); ++i)
        {
            if (joystick.GetDeviceName(i, name) == B_OK) {
                if (joystick.Open(name) != B_ERROR) {
                    BString stick_name;
                      joystick.GetControllerName(&stick_name);
                      SDL_joyport[numjoysticks] = strdup(name);
                      SDL_joyname[numjoysticks] = strdup(stick_name.String());
                      numjoysticks++;
                      joystick.Close();
                }
            }
        }
        return (numjoysticks);
    }

/* Function to get the device-dependent name of a joystick */
    const char *SDL_SYS_JoystickName(int index)
    {
        return SDL_joyname[index];
    }

/* Function to open a joystick for use.
   The joystick to open is specified by the index field of the joystick.
   This should fill the nbuttons and naxes fields of the joystick structure.
   It returns 0, or -1 if there is an error.
 */
    int SDL_SYS_JoystickOpen(SDL_Joystick * joystick)
    {
        BJoystick *stick;

        /* Create the joystick data structure */
        joystick->hwdata = (struct joystick_hwdata *)
            SDL_malloc(sizeof(*joystick->hwdata));
        if (joystick->hwdata == NULL) {
            SDL_OutOfMemory();
            return (-1);
        }
        SDL_memset(joystick->hwdata, 0, sizeof(*joystick->hwdata));
        stick = new BJoystick;
        joystick->hwdata->stick = stick;

        /* Open the requested joystick for use */
        if (stick->Open(SDL_joyport[joystick->index]) == B_ERROR) {
            SDL_SetError("Unable to open joystick");
            SDL_SYS_JoystickClose(joystick);
            return (-1);
        }

        /* Set the joystick to calibrated mode */
        stick->EnableCalibration();

        /* Get the number of buttons, hats, and axes on the joystick */
        joystick->nbuttons = stick->CountButtons();
        joystick->naxes = stick->CountAxes();
        joystick->nhats = stick->CountHats();

        joystick->hwdata->new_axes = (int16 *)
            SDL_malloc(joystick->naxes * sizeof(int16));
        joystick->hwdata->new_hats = (uint8 *)
            SDL_malloc(joystick->nhats * sizeof(uint8));
        if (!joystick->hwdata->new_hats || !joystick->hwdata->new_axes) {
            SDL_OutOfMemory();
            SDL_SYS_JoystickClose(joystick);
            return (-1);
        }

        /* We're done! */
        return (0);
    }

/* Function to update the state of a joystick - called as a device poll.
 * This function shouldn't update the joystick structure directly,
 * but instead should call SDL_PrivateJoystick*() to deliver events
 * and update joystick device state.
 */
    void SDL_SYS_JoystickUpdate(SDL_Joystick * joystick)
    {
        static const Uint8 hat_map[9] = {
            SDL_HAT_CENTERED,
            SDL_HAT_UP,
            SDL_HAT_RIGHTUP,
            SDL_HAT_RIGHT,
            SDL_HAT_RIGHTDOWN,
            SDL_HAT_DOWN,
            SDL_HAT_LEFTDOWN,
            SDL_HAT_LEFT,
            SDL_HAT_LEFTUP
        };
        const int JITTER = (32768 / 10);        /* 10% jitter threshold (ok?) */

        BJoystick *stick;
        int i, change;
        int16 *axes;
        uint8 *hats;
        uint32 buttons;

        /* Set up data pointers */
        stick = joystick->hwdata->stick;
        axes = joystick->hwdata->new_axes;
        hats = joystick->hwdata->new_hats;

        /* Get the new joystick state */
        stick->Update();
        stick->GetAxisValues(axes);
        stick->GetHatValues(hats);
        buttons = stick->ButtonValues();

        /* Generate axis motion events */
        for (i = 0; i < joystick->naxes; ++i) {
            change = ((int32) axes[i] - joystick->axes[i]);
            if ((change > JITTER) || (change < -JITTER)) {
                SDL_PrivateJoystickAxis(joystick, i, axes[i]);
            }
        }

        /* Generate hat change events */
        for (i = 0; i < joystick->nhats; ++i) {
            if (hats[i] != joystick->hats[i]) {
                SDL_PrivateJoystickHat(joystick, i, hat_map[hats[i]]);
            }
        }

        /* Generate button events */
        for (i = 0; i < joystick->nbuttons; ++i) {
            if ((buttons & 0x01) != joystick->buttons[i]) {
                SDL_PrivateJoystickButton(joystick, i, (buttons & 0x01));
            }
            buttons >>= 1;
        }
    }

/* Function to close a joystick after use */
    void SDL_SYS_JoystickClose(SDL_Joystick * joystick)
    {
        if (joystick->hwdata) {
            joystick->hwdata->stick->Close();
            delete joystick->hwdata->stick;
            if (joystick->hwdata->new_hats) {
                SDL_free(joystick->hwdata->new_hats);
            }
            if (joystick->hwdata->new_axes) {
                SDL_free(joystick->hwdata->new_axes);
            }
            SDL_free(joystick->hwdata);
            joystick->hwdata = NULL;
        }
    }

/* Function to perform any system-specific joystick related cleanup */
    void SDL_SYS_JoystickQuit(void)
    {
        int i;

        for (i = 0; SDL_joyport[i]; ++i) {
            SDL_free(SDL_joyport[i]);
        }
        SDL_joyport[0] = NULL;

        for (i = 0; SDL_joyname[i]; ++i) {
            SDL_free(SDL_joyname[i]);
        }
        SDL_joyname[0] = NULL;
    }

};                              // extern "C"

#endif /* SDL_JOYSTICK_BEOS */
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