src/joystick/SDL_joystick.c - third_party/sdl - Git at Google

 /*
     SDL - Simple DirectMedia Layer
     Copyright (C) 1997-2009 Sam Lantinga

     This library is free software; you can redistribute it and/or
     modify it under the terms of the GNU Lesser General Public
     License as published by the Free Software Foundation; either
     version 2.1 of the License, or (at your option) any later version.

     This library is distributed in the hope that it will be useful,
     but WITHOUT ANY WARRANTY; without even the implied warranty of
     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
     Lesser General Public License for more details.

     You should have received a copy of the GNU Lesser General Public
     License along with this library; if not, write to the Free Software
     Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA

     Sam Lantinga
     slouken@libsdl.org
 */
 #include "SDL_config.h"

 /* This is the joystick API for Simple DirectMedia Layer */

 #include "SDL_events.h"
 #include "SDL_sysjoystick.h"
 #include "SDL_joystick_c.h"
 #if !SDL_EVENTS_DISABLED
 #include "../events/SDL_events_c.h"
 #endif

 /* This is used for Quake III Arena */
 #if SDL_EVENTS_DISABLED
 #define SDL_Lock_EventThread()
 #define SDL_Unlock_EventThread()
 #endif

 Uint8 SDL_numjoysticks = 0;
 SDL_Joystick **SDL_joysticks = NULL;
 static SDL_Joystick *default_joystick = NULL;

 int SDL_JoystickInit(void)
 {
 	int arraylen;
 	int status;

 	SDL_numjoysticks = 0;
 	status = SDL_SYS_JoystickInit();
 	if ( status >= 0 ) {
 		arraylen = (status+1)*sizeof(*SDL_joysticks);
 		SDL_joysticks = (SDL_Joystick **)SDL_malloc(arraylen);
 		if ( SDL_joysticks == NULL ) {
 			SDL_numjoysticks = 0;
 		} else {
 			SDL_memset(SDL_joysticks, 0, arraylen);
 			SDL_numjoysticks = status;
 		}
 		status = 0;
 	}
 	default_joystick = NULL;
 	return(status);
 }

 /*
  * Count the number of joysticks attached to the system
  */
 int SDL_NumJoysticks(void)
 {
 	return SDL_numjoysticks;
 }

 /*
  * Get the implementation dependent name of a joystick
  */
 const char *SDL_JoystickName(int device_index)
 {
 	if ( (device_index < 0) || (device_index >= SDL_numjoysticks) ) {
 		SDL_SetError("There are %d joysticks available",
 		             SDL_numjoysticks);
 		return(NULL);
 	}
 	return(SDL_SYS_JoystickName(device_index));
 }

 /*
  * Open a joystick for use - the index passed as an argument refers to
  * the N'th joystick on the system.  This index is the value which will
  * identify this joystick in future joystick events.
  *
  * This function returns a joystick identifier, or NULL if an error occurred.
  */
 SDL_Joystick *SDL_JoystickOpen(int device_index)
 {
 	int i;
 	SDL_Joystick *joystick;

 	if ( (device_index < 0) || (device_index >= SDL_numjoysticks) ) {
 		SDL_SetError("There are %d joysticks available",
 		             SDL_numjoysticks);
 		return(NULL);
 	}

 	/* If the joystick is already open, return it */
 	for ( i=0; SDL_joysticks[i]; ++i ) {
 		if ( device_index == SDL_joysticks[i]->index ) {
 			joystick = SDL_joysticks[i];
 			++joystick->ref_count;
 			return(joystick);
 		}
 	}

 	/* Create and initialize the joystick */
 	joystick = (SDL_Joystick *)SDL_malloc((sizeof *joystick));
 	if ( !joystick ) {
 		return(NULL);
 	}

 	SDL_memset(joystick, 0, (sizeof *joystick));
 	joystick->index = device_index;
 	if ( SDL_SYS_JoystickOpen(joystick) < 0 ) {
 		SDL_free(joystick);
 		return(NULL);
 	}

 	if ( joystick->naxes > 0 ) {
 		joystick->axes = (Sint16 *)SDL_malloc
 			(joystick->naxes*sizeof(Sint16));
 	}
 	if ( joystick->nhats > 0 ) {
 		joystick->hats = (Uint8 *)SDL_malloc
 			(joystick->nhats*sizeof(Uint8));
 	}
 	if ( joystick->nballs > 0 ) {
 		joystick->balls = (struct balldelta *)SDL_malloc
 			(joystick->nballs*sizeof(*joystick->balls));
 	}
 	if ( joystick->nbuttons > 0 ) {
 		joystick->buttons = (Uint8 *)SDL_malloc
 			(joystick->nbuttons*sizeof(Uint8));
 	}
 	if ( ((joystick->naxes > 0) && !joystick->axes)
 	  || ((joystick->nhats > 0) && !joystick->hats)
 	  || ((joystick->nballs > 0) && !joystick->balls)
 	  || ((joystick->nbuttons > 0) && !joystick->buttons)) {
 		SDL_OutOfMemory();
 		SDL_JoystickClose(joystick);
 		return(NULL);
 	}

 	if ( joystick->axes ) {
 		SDL_memset(joystick->axes, 0,
 			joystick->naxes*sizeof(Sint16));
 	}
 	if ( joystick->hats ) {
 		SDL_memset(joystick->hats, 0,
 			joystick->nhats*sizeof(Uint8));
 	}
 	if ( joystick->balls ) {
 		SDL_memset(joystick->balls, 0,
 			joystick->nballs*sizeof(*joystick->balls));
 	}
 	if ( joystick->buttons ) {
 		SDL_memset(joystick->buttons, 0,
 			joystick->nbuttons*sizeof(Uint8));
 	}

 	/* Add joystick to list */
 	++joystick->ref_count;
 	SDL_Lock_EventThread();
 	for ( i=0; SDL_joysticks[i]; ++i )
 		/* Skip to next joystick */ ;
 	SDL_joysticks[i] = joystick;
 	SDL_Unlock_EventThread();

 	return(joystick);
 }

 /*
  * Returns 1 if the joystick has been opened, or 0 if it has not.
  */
 int SDL_JoystickOpened(int device_index)
 {
 	int i, opened;

 	opened = 0;
 	for ( i=0; SDL_joysticks[i]; ++i ) {
 		if ( SDL_joysticks[i]->index == (Uint8)device_index ) {
 			opened = 1;
 			break;
 		}
 	}
 	return(opened);
 }

 static int ValidJoystick(SDL_Joystick **joystick)
 {
 	int valid;

 	if ( *joystick == NULL ) {
 		*joystick = default_joystick;
 	}
 	if ( *joystick == NULL ) {
 		SDL_SetError("Joystick hasn't been opened yet");
 		valid = 0;
 	} else {
 		valid = 1;
 	}
 	return valid;
 }

 /*
  * Get the device index of an opened joystick.
  */
 int SDL_JoystickIndex(SDL_Joystick *joystick)
 {
 	if ( ! ValidJoystick(&joystick) ) {
 		return(-1);
 	}
 	return(joystick->index);
 }

 /*
  * Get the number of multi-dimensional axis controls on a joystick
  */
 int SDL_JoystickNumAxes(SDL_Joystick *joystick)
 {
 	if ( ! ValidJoystick(&joystick) ) {
 		return(-1);
 	}
 	return(joystick->naxes);
 }

 /*
  * Get the number of hats on a joystick
  */
 int SDL_JoystickNumHats(SDL_Joystick *joystick)
 {
 	if ( ! ValidJoystick(&joystick) ) {
 		return(-1);
 	}
 	return(joystick->nhats);
 }

 /*
  * Get the number of trackballs on a joystick
  */
 int SDL_JoystickNumBalls(SDL_Joystick *joystick)
 {
 	if ( ! ValidJoystick(&joystick) ) {
 		return(-1);
 	}
 	return(joystick->nballs);
 }

 /*
  * Get the number of buttons on a joystick
  */
 int SDL_JoystickNumButtons(SDL_Joystick *joystick)
 {
 	if ( ! ValidJoystick(&joystick) ) {
 		return(-1);
 	}
 	return(joystick->nbuttons);
 }

 /*
  * Get the current state of an axis control on a joystick
  */
 Sint16 SDL_JoystickGetAxis(SDL_Joystick *joystick, int axis)
 {
 	Sint16 state;

 	if ( ! ValidJoystick(&joystick) ) {
 		return(0);
 	}
 	if ( axis < joystick->naxes ) {
 		state = joystick->axes[axis];
 	} else {
 		SDL_SetError("Joystick only has %d axes", joystick->naxes);
 		state = 0;
 	}
 	return(state);
 }

 /*
  * Get the current state of a hat on a joystick
  */
 Uint8 SDL_JoystickGetHat(SDL_Joystick *joystick, int hat)
 {
 	Uint8 state;

 	if ( ! ValidJoystick(&joystick) ) {
 		return(0);
 	}
 	if ( hat < joystick->nhats ) {
 		state = joystick->hats[hat];
 	} else {
 		SDL_SetError("Joystick only has %d hats", joystick->nhats);
 		state = 0;
 	}
 	return(state);
 }

 /*
  * Get the ball axis change since the last poll
  */
 int SDL_JoystickGetBall(SDL_Joystick *joystick, int ball, int *dx, int *dy)
 {
 	int retval;

 	if ( ! ValidJoystick(&joystick) ) {
 		return(-1);
 	}

 	retval = 0;
 	if ( ball < joystick->nballs ) {
 		if ( dx ) {
 			*dx = joystick->balls[ball].dx;
 		}
 		if ( dy ) {
 			*dy = joystick->balls[ball].dy;
 		}
 		joystick->balls[ball].dx = 0;
 		joystick->balls[ball].dy = 0;
 	} else {
 		SDL_SetError("Joystick only has %d balls", joystick->nballs);
 		retval = -1;
 	}
 	return(retval);
 }

 /*
  * Get the current state of a button on a joystick
  */
 Uint8 SDL_JoystickGetButton(SDL_Joystick *joystick, int button)
 {
 	Uint8 state;

 	if ( ! ValidJoystick(&joystick) ) {
 		return(0);
 	}
 	if ( button < joystick->nbuttons ) {
 		state = joystick->buttons[button];
 	} else {
 		SDL_SetError("Joystick only has %d buttons",joystick->nbuttons);
 		state = 0;
 	}
 	return(state);
 }

 /*
  * Close a joystick previously opened with SDL_JoystickOpen()
  */
 void SDL_JoystickClose(SDL_Joystick *joystick)
 {
 	int i;

 	if ( ! ValidJoystick(&joystick) ) {
 		return;
 	}

 	/* First decrement ref count */
 	if ( --joystick->ref_count > 0 ) {
 		return;
 	}

 	/* Lock the event queue - prevent joystick polling */
 	SDL_Lock_EventThread();

 	if ( joystick == default_joystick ) {
 		default_joystick = NULL;
 	}
 	SDL_SYS_JoystickClose(joystick);

 	/* Remove joystick from list */
 	for ( i=0; SDL_joysticks[i]; ++i ) {
 		if ( joystick == SDL_joysticks[i] ) {
 			SDL_memmove(&SDL_joysticks[i], &SDL_joysticks[i+1],
 			       (SDL_numjoysticks-i)*sizeof(joystick));
 			break;
 		}
 	}

 	/* Let the event thread keep running */
 	SDL_Unlock_EventThread();

 	/* Free the data associated with this joystick */
 	if ( joystick->axes ) {
 		SDL_free(joystick->axes);
 	}
 	if ( joystick->hats ) {
 		SDL_free(joystick->hats);
 	}
 	if ( joystick->balls ) {
 		SDL_free(joystick->balls);
 	}
 	if ( joystick->buttons ) {
 		SDL_free(joystick->buttons);
 	}
 	SDL_free(joystick);
 }

 void SDL_JoystickQuit(void)
 {
 	/* Stop the event polling */
 	SDL_Lock_EventThread();
 	SDL_numjoysticks = 0;
 	SDL_Unlock_EventThread();

 	/* Quit the joystick setup */
 	SDL_SYS_JoystickQuit();
 	if ( SDL_joysticks ) {
 		SDL_free(SDL_joysticks);
 		SDL_joysticks = NULL;
 	}
 }


 /* These are global for SDL_sysjoystick.c and SDL_events.c */

 int SDL_PrivateJoystickAxis(SDL_Joystick *joystick, Uint8 axis, Sint16 value)
 {
 	int posted;

 	/* Update internal joystick state */
 	joystick->axes[axis] = value;

 	/* Post the event, if desired */
 	posted = 0;
 #if !SDL_EVENTS_DISABLED
 	if ( SDL_ProcessEvents[SDL_JOYAXISMOTION] == SDL_ENABLE ) {
 		SDL_Event event;
 		event.type = SDL_JOYAXISMOTION;
 		event.jaxis.which = joystick->index;
 		event.jaxis.axis = axis;
 		event.jaxis.value = value;
 		if ( (SDL_EventOK == NULL) || (*SDL_EventOK)(&event) ) {
 			posted = 1;
 			SDL_PushEvent(&event);
 		}
 	}
 #endif /* !SDL_EVENTS_DISABLED */
 	return(posted);
 }

 int SDL_PrivateJoystickHat(SDL_Joystick *joystick, Uint8 hat, Uint8 value)
 {
 	int posted;

 	/* Update internal joystick state */
 	joystick->hats[hat] = value;

 	/* Post the event, if desired */
 	posted = 0;
 #if !SDL_EVENTS_DISABLED
 	if ( SDL_ProcessEvents[SDL_JOYHATMOTION] == SDL_ENABLE ) {
 		SDL_Event event;
 		event.jhat.type = SDL_JOYHATMOTION;
 		event.jhat.which = joystick->index;
 		event.jhat.hat = hat;
 		event.jhat.value = value;
 		if ( (SDL_EventOK == NULL) || (*SDL_EventOK)(&event) ) {
 			posted = 1;
 			SDL_PushEvent(&event);
 		}
 	}
 #endif /* !SDL_EVENTS_DISABLED */
 	return(posted);
 }

 int SDL_PrivateJoystickBall(SDL_Joystick *joystick, Uint8 ball,
 					Sint16 xrel, Sint16 yrel)
 {
 	int posted;

 	/* Update internal mouse state */
 	joystick->balls[ball].dx += xrel;
 	joystick->balls[ball].dy += yrel;

 	/* Post the event, if desired */
 	posted = 0;
 #if !SDL_EVENTS_DISABLED
 	if ( SDL_ProcessEvents[SDL_JOYBALLMOTION] == SDL_ENABLE ) {
 		SDL_Event event;
 		event.jball.type = SDL_JOYBALLMOTION;
 		event.jball.which = joystick->index;
 		event.jball.ball = ball;
 		event.jball.xrel = xrel;
 		event.jball.yrel = yrel;
 		if ( (SDL_EventOK == NULL) || (*SDL_EventOK)(&event) ) {
 			posted = 1;
 			SDL_PushEvent(&event);
 		}
 	}
 #endif /* !SDL_EVENTS_DISABLED */
 	return(posted);
 }

 int SDL_PrivateJoystickButton(SDL_Joystick *joystick, Uint8 button, Uint8 state)
 {
 	int posted;
 #if !SDL_EVENTS_DISABLED
 	SDL_Event event;

 	switch ( state ) {
 		case SDL_PRESSED:
 			event.type = SDL_JOYBUTTONDOWN;
 			break;
 		case SDL_RELEASED:
 			event.type = SDL_JOYBUTTONUP;
 			break;
 		default:
 			/* Invalid state -- bail */
 			return(0);
 	}
 #endif /* !SDL_EVENTS_DISABLED */

 	/* Update internal joystick state */
 	joystick->buttons[button] = state;

 	/* Post the event, if desired */
 	posted = 0;
 #if !SDL_EVENTS_DISABLED
 	if ( SDL_ProcessEvents[event.type] == SDL_ENABLE ) {
 		event.jbutton.which = joystick->index;
 		event.jbutton.button = button;
 		event.jbutton.state = state;
 		if ( (SDL_EventOK == NULL) || (*SDL_EventOK)(&event) ) {
 			posted = 1;
 			SDL_PushEvent(&event);
 		}
 	}
 #endif /* !SDL_EVENTS_DISABLED */
 	return(posted);
 }

 void SDL_JoystickUpdate(void)
 {
 	int i;

 	for ( i=0; SDL_joysticks[i]; ++i ) {
 		SDL_SYS_JoystickUpdate(SDL_joysticks[i]);
 	}
 }

 int SDL_JoystickEventState(int state)
 {
 #if SDL_EVENTS_DISABLED
 	return SDL_IGNORE;
 #else
 	const Uint8 event_list[] = {
 		SDL_JOYAXISMOTION, SDL_JOYBALLMOTION, SDL_JOYHATMOTION,
 		SDL_JOYBUTTONDOWN, SDL_JOYBUTTONUP,
 	};
 	unsigned int i;

 	switch (state) {
 		case SDL_QUERY:
 			state = SDL_IGNORE;
 			for ( i=0; i<SDL_arraysize(event_list); ++i ) {
 				state = SDL_EventState(event_list[i],SDL_QUERY);
 				if ( state == SDL_ENABLE ) {
 					break;
 				}
 			}
 			break;
 		default:
 			for ( i=0; i<SDL_arraysize(event_list); ++i ) {
 				SDL_EventState(event_list[i], state);
 			}
 			break;
 	}
 	return(state);
 #endif /* SDL_EVENTS_DISABLED */
 }
	/*
	SDL - Simple DirectMedia Layer
	Copyright (C) 1997-2009 Sam Lantinga

	This library is free software; you can redistribute it and/or
	modify it under the terms of the GNU Lesser General Public
	License as published by the Free Software Foundation; either
	version 2.1 of the License, or (at your option) any later version.

	This library is distributed in the hope that it will be useful,
	but WITHOUT ANY WARRANTY; without even the implied warranty of
	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	Lesser General Public License for more details.

	You should have received a copy of the GNU Lesser General Public
	License along with this library; if not, write to the Free Software
	Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA

	Sam Lantinga
	slouken@libsdl.org
	*/
	#include "SDL_config.h"

	/* This is the joystick API for Simple DirectMedia Layer */

	#include "SDL_events.h"
	#include "SDL_sysjoystick.h"
	#include "SDL_joystick_c.h"
	#if !SDL_EVENTS_DISABLED
	#include "../events/SDL_events_c.h"
	#endif

	/* This is used for Quake III Arena */
	#if SDL_EVENTS_DISABLED
	#define SDL_Lock_EventThread()
	#define SDL_Unlock_EventThread()
	#endif

	Uint8 SDL_numjoysticks = 0;
	SDL_Joystick **SDL_joysticks = NULL;
	static SDL_Joystick *default_joystick = NULL;

	int SDL_JoystickInit(void)
	{
	int arraylen;
	int status;

	SDL_numjoysticks = 0;
	status = SDL_SYS_JoystickInit();
	if ( status >= 0 ) {
	arraylen = (status+1)sizeof(SDL_joysticks);
	SDL_joysticks = (SDL_Joystick **)SDL_malloc(arraylen);
	if ( SDL_joysticks == NULL ) {
	SDL_numjoysticks = 0;
	} else {
	SDL_memset(SDL_joysticks, 0, arraylen);
	SDL_numjoysticks = status;
	}
	status = 0;
	}
	default_joystick = NULL;
	return(status);
	}

	/*
	* Count the number of joysticks attached to the system
	*/
	int SDL_NumJoysticks(void)
	{
	return SDL_numjoysticks;
	}

	/*
	* Get the implementation dependent name of a joystick
	*/
	const char *SDL_JoystickName(int device_index)
	{
	if ( (device_index < 0) \|\| (device_index >= SDL_numjoysticks) ) {
	SDL_SetError("There are %d joysticks available",
	SDL_numjoysticks);
	return(NULL);
	}
	return(SDL_SYS_JoystickName(device_index));
	}

	/*
	* Open a joystick for use - the index passed as an argument refers to
	* the N'th joystick on the system. This index is the value which will
	* identify this joystick in future joystick events.
	*
	* This function returns a joystick identifier, or NULL if an error occurred.
	*/
	SDL_Joystick *SDL_JoystickOpen(int device_index)
	{
	int i;
	SDL_Joystick *joystick;

	if ( (device_index < 0) \|\| (device_index >= SDL_numjoysticks) ) {
	SDL_SetError("There are %d joysticks available",
	SDL_numjoysticks);
	return(NULL);
	}

	/* If the joystick is already open, return it */
	for ( i=0; SDL_joysticks[i]; ++i ) {
	if ( device_index == SDL_joysticks[i]->index ) {
	joystick = SDL_joysticks[i];
	++joystick->ref_count;
	return(joystick);
	}
	}

	/* Create and initialize the joystick */
	joystick = (SDL_Joystick )SDL_malloc((sizeof joystick));
	if ( !joystick ) {
	return(NULL);
	}

	SDL_memset(joystick, 0, (sizeof *joystick));
	joystick->index = device_index;
	if ( SDL_SYS_JoystickOpen(joystick) < 0 ) {
	SDL_free(joystick);
	return(NULL);
	}

	if ( joystick->naxes > 0 ) {
	joystick->axes = (Sint16 *)SDL_malloc
	(joystick->naxes*sizeof(Sint16));
	}
	if ( joystick->nhats > 0 ) {
	joystick->hats = (Uint8 *)SDL_malloc
	(joystick->nhats*sizeof(Uint8));
	}
	if ( joystick->nballs > 0 ) {
	joystick->balls = (struct balldelta *)SDL_malloc
	(joystick->nballssizeof(joystick->balls));
	}
	if ( joystick->nbuttons > 0 ) {
	joystick->buttons = (Uint8 *)SDL_malloc
	(joystick->nbuttons*sizeof(Uint8));
	}
	if ( ((joystick->naxes > 0) && !joystick->axes)
	\|\| ((joystick->nhats > 0) && !joystick->hats)
	\|\| ((joystick->nballs > 0) && !joystick->balls)
	\|\| ((joystick->nbuttons > 0) && !joystick->buttons)) {
	SDL_OutOfMemory();
	SDL_JoystickClose(joystick);
	return(NULL);
	}

	if ( joystick->axes ) {
	SDL_memset(joystick->axes, 0,
	joystick->naxes*sizeof(Sint16));
	}
	if ( joystick->hats ) {
	SDL_memset(joystick->hats, 0,
	joystick->nhats*sizeof(Uint8));
	}
	if ( joystick->balls ) {
	SDL_memset(joystick->balls, 0,
	joystick->nballssizeof(joystick->balls));
	}
	if ( joystick->buttons ) {
	SDL_memset(joystick->buttons, 0,
	joystick->nbuttons*sizeof(Uint8));
	}

	/* Add joystick to list */
	++joystick->ref_count;
	SDL_Lock_EventThread();
	for ( i=0; SDL_joysticks[i]; ++i )
	/* Skip to next joystick */ ;
	SDL_joysticks[i] = joystick;
	SDL_Unlock_EventThread();

	return(joystick);
	}

	/*
	* Returns 1 if the joystick has been opened, or 0 if it has not.
	*/
	int SDL_JoystickOpened(int device_index)
	{
	int i, opened;

	opened = 0;
	for ( i=0; SDL_joysticks[i]; ++i ) {
	if ( SDL_joysticks[i]->index == (Uint8)device_index ) {
	opened = 1;
	break;
	}
	}
	return(opened);
	}

	static int ValidJoystick(SDL_Joystick **joystick)
	{
	int valid;

	if ( *joystick == NULL ) {
	*joystick = default_joystick;
	}
	if ( *joystick == NULL ) {
	SDL_SetError("Joystick hasn't been opened yet");
	valid = 0;
	} else {
	valid = 1;
	}
	return valid;
	}

	/*
	* Get the device index of an opened joystick.
	*/
	int SDL_JoystickIndex(SDL_Joystick *joystick)
	{
	if ( ! ValidJoystick(&joystick) ) {
	return(-1);
	}
	return(joystick->index);
	}

	/*
	* Get the number of multi-dimensional axis controls on a joystick
	*/
	int SDL_JoystickNumAxes(SDL_Joystick *joystick)
	{
	if ( ! ValidJoystick(&joystick) ) {
	return(-1);
	}
	return(joystick->naxes);
	}

	/*
	* Get the number of hats on a joystick
	*/
	int SDL_JoystickNumHats(SDL_Joystick *joystick)
	{
	if ( ! ValidJoystick(&joystick) ) {
	return(-1);
	}
	return(joystick->nhats);
	}

	/*
	* Get the number of trackballs on a joystick
	*/
	int SDL_JoystickNumBalls(SDL_Joystick *joystick)
	{
	if ( ! ValidJoystick(&joystick) ) {
	return(-1);
	}
	return(joystick->nballs);
	}

	/*
	* Get the number of buttons on a joystick
	*/
	int SDL_JoystickNumButtons(SDL_Joystick *joystick)
	{
	if ( ! ValidJoystick(&joystick) ) {
	return(-1);
	}
	return(joystick->nbuttons);
	}

	/*
	* Get the current state of an axis control on a joystick
	*/
	Sint16 SDL_JoystickGetAxis(SDL_Joystick *joystick, int axis)
	{
	Sint16 state;

	if ( ! ValidJoystick(&joystick) ) {
	return(0);
	}
	if ( axis < joystick->naxes ) {
	state = joystick->axes[axis];
	} else {
	SDL_SetError("Joystick only has %d axes", joystick->naxes);
	state = 0;
	}
	return(state);
	}

	/*
	* Get the current state of a hat on a joystick
	*/
	Uint8 SDL_JoystickGetHat(SDL_Joystick *joystick, int hat)
	{
	Uint8 state;

	if ( ! ValidJoystick(&joystick) ) {
	return(0);
	}
	if ( hat < joystick->nhats ) {
	state = joystick->hats[hat];
	} else {
	SDL_SetError("Joystick only has %d hats", joystick->nhats);
	state = 0;
	}
	return(state);
	}

	/*
	* Get the ball axis change since the last poll
	*/
	int SDL_JoystickGetBall(SDL_Joystick joystick, int ball, int dx, int *dy)
	{
	int retval;

	if ( ! ValidJoystick(&joystick) ) {
	return(-1);
	}

	retval = 0;
	if ( ball < joystick->nballs ) {
	if ( dx ) {
	*dx = joystick->balls[ball].dx;
	}
	if ( dy ) {
	*dy = joystick->balls[ball].dy;
	}
	joystick->balls[ball].dx = 0;
	joystick->balls[ball].dy = 0;
	} else {
	SDL_SetError("Joystick only has %d balls", joystick->nballs);
	retval = -1;
	}
	return(retval);
	}

	/*
	* Get the current state of a button on a joystick
	*/
	Uint8 SDL_JoystickGetButton(SDL_Joystick *joystick, int button)
	{
	Uint8 state;

	if ( ! ValidJoystick(&joystick) ) {
	return(0);
	}
	if ( button < joystick->nbuttons ) {
	state = joystick->buttons[button];
	} else {
	SDL_SetError("Joystick only has %d buttons",joystick->nbuttons);
	state = 0;
	}
	return(state);
	}

	/*
	* Close a joystick previously opened with SDL_JoystickOpen()
	*/
	void SDL_JoystickClose(SDL_Joystick *joystick)
	{
	int i;

	if ( ! ValidJoystick(&joystick) ) {
	return;
	}

	/* First decrement ref count */
	if ( --joystick->ref_count > 0 ) {
	return;
	}

	/* Lock the event queue - prevent joystick polling */
	SDL_Lock_EventThread();

	if ( joystick == default_joystick ) {
	default_joystick = NULL;
	}
	SDL_SYS_JoystickClose(joystick);

	/* Remove joystick from list */
	for ( i=0; SDL_joysticks[i]; ++i ) {
	if ( joystick == SDL_joysticks[i] ) {
	SDL_memmove(&SDL_joysticks[i], &SDL_joysticks[i+1],
	(SDL_numjoysticks-i)*sizeof(joystick));
	break;
	}
	}

	/* Let the event thread keep running */
	SDL_Unlock_EventThread();

	/* Free the data associated with this joystick */
	if ( joystick->axes ) {
	SDL_free(joystick->axes);
	}
	if ( joystick->hats ) {
	SDL_free(joystick->hats);
	}
	if ( joystick->balls ) {
	SDL_free(joystick->balls);
	}
	if ( joystick->buttons ) {
	SDL_free(joystick->buttons);
	}
	SDL_free(joystick);
	}

	void SDL_JoystickQuit(void)
	{
	/* Stop the event polling */
	SDL_Lock_EventThread();
	SDL_numjoysticks = 0;
	SDL_Unlock_EventThread();

	/* Quit the joystick setup */
	SDL_SYS_JoystickQuit();
	if ( SDL_joysticks ) {
	SDL_free(SDL_joysticks);
	SDL_joysticks = NULL;
	}
	}


	/* These are global for SDL_sysjoystick.c and SDL_events.c */

	int SDL_PrivateJoystickAxis(SDL_Joystick *joystick, Uint8 axis, Sint16 value)
	{
	int posted;

	/* Update internal joystick state */
	joystick->axes[axis] = value;

	/* Post the event, if desired */
	posted = 0;
	#if !SDL_EVENTS_DISABLED
	if ( SDL_ProcessEvents[SDL_JOYAXISMOTION] == SDL_ENABLE ) {
	SDL_Event event;
	event.type = SDL_JOYAXISMOTION;
	event.jaxis.which = joystick->index;
	event.jaxis.axis = axis;
	event.jaxis.value = value;
	if ( (SDL_EventOK == NULL) \|\| (*SDL_EventOK)(&event) ) {
	posted = 1;
	SDL_PushEvent(&event);
	}
	}
	#endif /* !SDL_EVENTS_DISABLED */
	return(posted);
	}

	int SDL_PrivateJoystickHat(SDL_Joystick *joystick, Uint8 hat, Uint8 value)
	{
	int posted;

	/* Update internal joystick state */
	joystick->hats[hat] = value;

	/* Post the event, if desired */
	posted = 0;
	#if !SDL_EVENTS_DISABLED
	if ( SDL_ProcessEvents[SDL_JOYHATMOTION] == SDL_ENABLE ) {
	SDL_Event event;
	event.jhat.type = SDL_JOYHATMOTION;
	event.jhat.which = joystick->index;
	event.jhat.hat = hat;
	event.jhat.value = value;
	if ( (SDL_EventOK == NULL) \|\| (*SDL_EventOK)(&event) ) {
	posted = 1;
	SDL_PushEvent(&event);
	}
	}
	#endif /* !SDL_EVENTS_DISABLED */
	return(posted);
	}

	int SDL_PrivateJoystickBall(SDL_Joystick *joystick, Uint8 ball,
	Sint16 xrel, Sint16 yrel)
	{
	int posted;

	/* Update internal mouse state */
	joystick->balls[ball].dx += xrel;
	joystick->balls[ball].dy += yrel;

	/* Post the event, if desired */
	posted = 0;
	#if !SDL_EVENTS_DISABLED
	if ( SDL_ProcessEvents[SDL_JOYBALLMOTION] == SDL_ENABLE ) {
	SDL_Event event;
	event.jball.type = SDL_JOYBALLMOTION;
	event.jball.which = joystick->index;
	event.jball.ball = ball;
	event.jball.xrel = xrel;
	event.jball.yrel = yrel;
	if ( (SDL_EventOK == NULL) \|\| (*SDL_EventOK)(&event) ) {
	posted = 1;
	SDL_PushEvent(&event);
	}
	}
	#endif /* !SDL_EVENTS_DISABLED */
	return(posted);
	}

	int SDL_PrivateJoystickButton(SDL_Joystick *joystick, Uint8 button, Uint8 state)
	{
	int posted;
	#if !SDL_EVENTS_DISABLED
	SDL_Event event;

	switch ( state ) {
	case SDL_PRESSED:
	event.type = SDL_JOYBUTTONDOWN;
	break;
	case SDL_RELEASED:
	event.type = SDL_JOYBUTTONUP;
	break;
	default:
	/* Invalid state -- bail */
	return(0);
	}
	#endif /* !SDL_EVENTS_DISABLED */

	/* Update internal joystick state */
	joystick->buttons[button] = state;

	/* Post the event, if desired */
	posted = 0;
	#if !SDL_EVENTS_DISABLED
	if ( SDL_ProcessEvents[event.type] == SDL_ENABLE ) {
	event.jbutton.which = joystick->index;
	event.jbutton.button = button;
	event.jbutton.state = state;
	if ( (SDL_EventOK == NULL) \|\| (*SDL_EventOK)(&event) ) {
	posted = 1;
	SDL_PushEvent(&event);
	}
	}
	#endif /* !SDL_EVENTS_DISABLED */
	return(posted);
	}

	void SDL_JoystickUpdate(void)
	{
	int i;

	for ( i=0; SDL_joysticks[i]; ++i ) {
	SDL_SYS_JoystickUpdate(SDL_joysticks[i]);
	}
	}

	int SDL_JoystickEventState(int state)
	{
	#if SDL_EVENTS_DISABLED
	return SDL_IGNORE;
	#else
	const Uint8 event_list[] = {
	SDL_JOYAXISMOTION, SDL_JOYBALLMOTION, SDL_JOYHATMOTION,
	SDL_JOYBUTTONDOWN, SDL_JOYBUTTONUP,
	};
	unsigned int i;

	switch (state) {
	case SDL_QUERY:
	state = SDL_IGNORE;
	for ( i=0; i<SDL_arraysize(event_list); ++i ) {
	state = SDL_EventState(event_list[i],SDL_QUERY);
	if ( state == SDL_ENABLE ) {
	break;
	}
	}
	break;
	default:
	for ( i=0; i<SDL_arraysize(event_list); ++i ) {
	SDL_EventState(event_list[i], state);
	}
	break;
	}
	return(state);
	#endif /* SDL_EVENTS_DISABLED */
	}