distrib/sdl-1.2.12/src/joystick/os2/SDL_sysjoystick.c

/*
    SDL - Simple DirectMedia Layer
    Copyright (C) 1997-2006 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"

#ifdef SDL_JOYSTICK_OS2

/* OS/2 Joystick driver, contributed by Daniel Caetano */

#include <mem.h>

#define INCL_DOSDEVICES
#define INCL_DOSDEVIOCTL
#define INCL_DOSMEMMGR
#include <os2.h>
#include "joyos2.h"

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

HFILE hJoyPort = NULL;		/* Joystick GAME$ Port Address */
#define MAX_JOYSTICKS	2	/* Maximum of two joysticks */
#define MAX_AXES	4			/* each joystick can have up to 4 axes */
#define MAX_BUTTONS	8		/* 8 buttons */
#define MAX_HATS	0			/* 0 hats - OS/2 doesn't support it */
#define MAX_BALLS	0			/* and 0 balls - OS/2 doesn't support it */
#define AXIS_MIN -32768		/* minimum value for axes coordinate */
#define AXIS_MAX 32767		/* maximum value for axes coordinate */
#define MAX_JOYNAME	128	/* Joystick name may have 128 characters */
/* limit axes to 256 possible positions to filter out noise */
#define JOY_AXIS_THRESHOLD (((AXIS_MAX)-(AXIS_MIN))/256)
/* Calc Button Flag for buttons A to D */
#define JOY_BUTTON_FLAG(n) (1<<n)

/* Joystick data... hold information about detected devices */
typedef struct SYS_JoyData_s
{
Sint8					id;								// Device ID
char					szDeviceName[MAX_JOYNAME];	// Device Name
char					axes;								// Number of axes
char					buttons;							// Number of buttons
char					hats;								// Number of buttons
char					balls;							// Number of buttons
int					axes_min[MAX_AXES];			// minimum callibration value for axes
int					axes_med[MAX_AXES];			// medium callibration value for axes
int					axes_max[MAX_AXES];			// maximum callibration value for axes
int					buttoncalc[4];					// Used for buttons 5, 6, 7 and 8.
} SYS_JoyData_t, *SYS_JoyData_p;

SYS_JoyData_t SYS_JoyData[MAX_JOYSTICKS];


/* Structure used to convert data from OS/2 driver format to SDL format */
struct joystick_hwdata
{
Sint8					id;
struct _transaxes
	{
	int offset;					/* Center Offset */
	float scale1;				/* Center to left/up Scale */
	float scale2;				/* Center to right/down Scale */
	} transaxes[MAX_AXES];
};

/* Structure used to get values from Joystick Environment Variable */
struct _joycfg
{
char	name[MAX_JOYNAME];
unsigned int	axes;
unsigned int	buttons;
unsigned int	hats;
unsigned int	balls;
};

/* OS/2 Implementation Function Prototypes */
APIRET joyPortOpen(HFILE * hGame);
void joyPortClose(HFILE * hGame);
int joyGetData(char *joyenv, char *name, char stopchar, size_t maxchars);
int joyGetEnv(struct _joycfg * joydata);



/************************************************************************/
/* 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)
{
APIRET rc;											/* Generic OS/2 return code */
GAME_PORT_STRUCT	stJoyStatus;				/* Joystick Status Structure */
GAME_PARM_STRUCT	stGameParms;				/* Joystick Parameter Structure */
GAME_CALIB_STRUCT	stGameCalib;				/* Calibration Struct */
ULONG ulDataLen;									/* Size of data */
ULONG ulLastTick;						/* Tick Counter for timing operations */
Uint8 maxdevs;										/* Maximum number of devices */
Uint8 numdevs;										/* Number of present devices */
Uint8 maxbut;										/* Maximum number of buttons... */
Uint8 i;												/* Temporary Count Vars */
Uint8 ucNewJoystickMask;										/* Mask for Joystick Detection */
struct _joycfg joycfg;							/* Joy Configuration from envvar */


/* Get Max Number of Devices */
rc = joyPortOpen(&hJoyPort); /* Open GAME$ port */
if (rc != 0) return 0;	/* Cannot open... report no joystick */
ulDataLen = sizeof(stGameParms);
rc = DosDevIOCtl(hJoyPort, IOCTL_CAT_USER, GAME_GET_PARMS,
	NULL, 0, NULL, &stGameParms, ulDataLen, &ulDataLen); /* Ask device info */
if (rc != 0)
	{
	joyPortClose(&hJoyPort);
	SDL_SetError("Could not read joystick port.");
	return -1;
	}
if (stGameParms.useA != 0) maxdevs++;
if (stGameParms.useB != 0) maxdevs++;
if ( maxdevs > MAX_JOYSTICKS ) maxdevs = MAX_JOYSTICKS;

/* Defines min/max axes values (callibration) */
ulDataLen = sizeof(stGameCalib);
rc = DosDevIOCtl(hJoyPort, IOCTL_CAT_USER, GAME_GET_CALIB,
	NULL, 0, NULL, &stGameCalib, ulDataLen, &ulDataLen);
if (rc != 0)
	{
	joyPortClose(&hJoyPort);
	SDL_SetError("Could not read callibration data.");
	return -1;
	}

/* Determine how many joysticks are active */
numdevs = 0;	/* Points no device */
ucNewJoystickMask = 0x0F;	/* read all 4 joystick axis */
ulDataLen = sizeof(ucNewJoystickMask);
rc = DosDevIOCtl(hJoyPort, IOCTL_CAT_USER, GAME_PORT_RESET,
		&ucNewJoystickMask, ulDataLen, &ulDataLen, NULL, 0, NULL);
if (rc == 0)
	{
	ulDataLen = sizeof(stJoyStatus);
	rc = DosDevIOCtl(hJoyPort, IOCTL_CAT_USER, GAME_PORT_GET,
		NULL, 0, NULL, &stJoyStatus, ulDataLen, &ulDataLen);
	if (rc != 0)
		{
		joyPortClose(&hJoyPort);
		SDL_SetError("Could not call joystick port.");
		return -1;
		}
	ulLastTick = stJoyStatus.ulJs_Ticks;
	while (stJoyStatus.ulJs_Ticks == ulLastTick)
		{
		rc = DosDevIOCtl(hJoyPort, IOCTL_CAT_USER, GAME_PORT_GET,
			NULL, 0, NULL, &stJoyStatus, ulDataLen, &ulDataLen);
		}
	if ((stJoyStatus.ucJs_JoyStickMask & 0x03) > 0) numdevs++;
	if (((stJoyStatus.ucJs_JoyStickMask >> 2) & 0x03) > 0) numdevs++;
	}

if (numdevs>maxdevs) numdevs=maxdevs;

/* If *any* joystick was detected... Let's configure SDL for them */
if (numdevs > 0)
	{
	/* Verify if it is a "user defined" joystick */
	if (joyGetEnv(&joycfg))
		{
		GAME_3POS_STRUCT * axis[4];
		axis[0] = &stGameCalib.Ax;
		axis[1] = &stGameCalib.Ay;
		axis[2] = &stGameCalib.Bx;
		axis[3] = &stGameCalib.By;
		/* Say it has one device only (user defined is always one device only) */
		numdevs = 1;
		/* Define Device 0 as... */
		SYS_JoyData[0].id=0;
		/* Define Number of Axes... up to 4 */
		if (joycfg.axes>MAX_AXES) joycfg.axes = MAX_AXES;
		SYS_JoyData[0].axes = joycfg.axes;
		/* Define number of buttons... 8 if 2 axes, 6 if 3 axes and 4 if 4 axes */
		maxbut = MAX_BUTTONS;
		if (joycfg.axes>2) maxbut-=((joycfg.axes-2)<<1); /* MAX_BUTTONS - 2*(axes-2) */
		if (joycfg.buttons > maxbut) joycfg.buttons = maxbut;
		SYS_JoyData[0].buttons = joycfg.buttons;
		/* Define number of hats */
		if (joycfg.hats > MAX_HATS) joycfg.hats = MAX_HATS;
		SYS_JoyData[0].hats = joycfg.hats;
		/* Define number of balls */
		if (joycfg.balls > MAX_BALLS) joycfg.balls = MAX_BALLS;
		SYS_JoyData[0].balls = joycfg.balls;
		/* Initialize Axes Callibration Values */
		for (i=0; i<joycfg.axes; i++)
			{
			SYS_JoyData[0].axes_min[i] = axis[i]->lower;
			SYS_JoyData[0].axes_med[i] = axis[i]->centre;
			SYS_JoyData[0].axes_max[i] = axis[i]->upper;
			}
		/* Initialize Buttons 5 to 8 structures */
		if (joycfg.buttons>=5) SYS_JoyData[0].buttoncalc[0]=((axis[2]->lower+axis[3]->centre)>>1);
		if (joycfg.buttons>=6) SYS_JoyData[0].buttoncalc[1]=((axis[3]->lower+axis[3]->centre)>>1);
		if (joycfg.buttons>=7) SYS_JoyData[0].buttoncalc[2]=((axis[2]->upper+axis[3]->centre)>>1);
		if (joycfg.buttons>=8) SYS_JoyData[0].buttoncalc[3]=((axis[3]->upper+axis[3]->centre)>>1);
		/* Intialize Joystick Name */
		SDL_strlcpy (SYS_JoyData[0].szDeviceName,joycfg.name, SDL_arraysize(SYS_JoyData[0].szDeviceName));
		}
	/* Default Init ... autoconfig */
	else
		{
		/* if two devices were detected... configure as Joy1 4 axis and Joy2 2 axis */
		if (numdevs==2)
			{
			/* Define Device 0 as 4 axes, 4 buttons */
			SYS_JoyData[0].id=0;
			SYS_JoyData[0].axes = 4;
			SYS_JoyData[0].buttons = 4;
			SYS_JoyData[0].hats = 0;
			SYS_JoyData[0].balls = 0;
			SYS_JoyData[0].axes_min[0] = stGameCalib.Ax.lower;
			SYS_JoyData[0].axes_med[0] = stGameCalib.Ax.centre;
			SYS_JoyData[0].axes_max[0] = stGameCalib.Ax.upper;
			SYS_JoyData[0].axes_min[1] = stGameCalib.Ay.lower;
			SYS_JoyData[0].axes_med[1] = stGameCalib.Ay.centre;
			SYS_JoyData[0].axes_max[1] = stGameCalib.Ay.upper;
			SYS_JoyData[0].axes_min[2] = stGameCalib.Bx.lower;
			SYS_JoyData[0].axes_med[2] = stGameCalib.Bx.centre;
			SYS_JoyData[0].axes_max[2] = stGameCalib.Bx.upper;
			SYS_JoyData[0].axes_min[3] = stGameCalib.By.lower;
			SYS_JoyData[0].axes_med[3] = stGameCalib.By.centre;
			SYS_JoyData[0].axes_max[3] = stGameCalib.By.upper;
			/* Define Device 1 as 2 axes, 2 buttons */
			SYS_JoyData[1].id=1;
			SYS_JoyData[1].axes = 2;
			SYS_JoyData[1].buttons = 2;
			SYS_JoyData[1].hats = 0;
			SYS_JoyData[1].balls = 0;
			SYS_JoyData[1].axes_min[0] = stGameCalib.Bx.lower;
			SYS_JoyData[1].axes_med[0] = stGameCalib.Bx.centre;
			SYS_JoyData[1].axes_max[0] = stGameCalib.Bx.upper;
			SYS_JoyData[1].axes_min[1] = stGameCalib.By.lower;
			SYS_JoyData[1].axes_med[1] = stGameCalib.By.centre;
			SYS_JoyData[1].axes_max[1] = stGameCalib.By.upper;
			}
		/* One joystick only? */
		else
			{
			/* If it is joystick A... */
			if ((stJoyStatus.ucJs_JoyStickMask & 0x03) > 0)
				{
				/* Define Device 0 as 2 axes, 4 buttons */
				SYS_JoyData[0].id=0;
				SYS_JoyData[0].axes = 2;
				SYS_JoyData[0].buttons = 4;
				SYS_JoyData[0].hats = 0;
				SYS_JoyData[0].balls = 0;
				SYS_JoyData[0].axes_min[0] = stGameCalib.Ax.lower;
				SYS_JoyData[0].axes_med[0] = stGameCalib.Ax.centre;
				SYS_JoyData[0].axes_max[0] = stGameCalib.Ax.upper;
				SYS_JoyData[0].axes_min[1] = stGameCalib.Ay.lower;
				SYS_JoyData[0].axes_med[1] = stGameCalib.Ay.centre;
				SYS_JoyData[0].axes_max[1] = stGameCalib.Ay.upper;
				}
			/* If not, it is joystick B */
			else
				{
				/* Define Device 1 as 2 axes, 2 buttons */
				SYS_JoyData[0].id=1;
				SYS_JoyData[0].axes = 2;
				SYS_JoyData[0].buttons = 2;
				SYS_JoyData[0].hats = 0;
				SYS_JoyData[0].balls = 0;
				SYS_JoyData[0].axes_min[0] = stGameCalib.Bx.lower;
				SYS_JoyData[0].axes_med[0] = stGameCalib.Bx.centre;
				SYS_JoyData[0].axes_max[0] = stGameCalib.Bx.upper;
				SYS_JoyData[0].axes_min[1] = stGameCalib.By.lower;
				SYS_JoyData[0].axes_med[1] = stGameCalib.By.centre;
				SYS_JoyData[0].axes_max[1] = stGameCalib.By.upper;
				}
			}
		/* Hack to define Joystick Port Names */
		if ( numdevs > maxdevs ) numdevs = maxdevs;
		for (i=0; i<numdevs; i++)
                  SDL_snprintf (SYS_JoyData[i].szDeviceName, SDL_arraysize(SYS_JoyData[i].szDeviceName), "Default Joystick %c", 'A'+SYS_JoyData[i].id);

                }
	}
/* Return the number of devices found */
return(numdevs);
}


/***********************************************************/
/* Function to get the device-dependent name of a joystick */
/***********************************************************/
const char *SDL_SYS_JoystickName(int index)
{
/* No need to verify if device exists, already done in upper layer */
return(SYS_JoyData[index].szDeviceName);
}



/******************************************************************************/
/* 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)
{
int index;		/* Index shortcut for index in joystick structure */
int i;			/* Generic Counter */

/* allocate memory for system specific hardware data */
joystick->hwdata = (struct joystick_hwdata *) SDL_malloc(sizeof(*joystick->hwdata));
if (joystick->hwdata == NULL)
	{
	SDL_OutOfMemory();
	return(-1);
	}
/* Reset Hardware Data */
SDL_memset(joystick->hwdata, 0, sizeof(*joystick->hwdata));

/* ShortCut Pointer */
index = joystick->index;
/* Define offsets and scales for all axes */
joystick->hwdata->id = SYS_JoyData[index].id;
for ( i = 0; i < MAX_AXES; ++i )
	{
	if ( (i<2) || i < SYS_JoyData[index].axes )
		{
		joystick->hwdata->transaxes[i].offset = ((AXIS_MAX + AXIS_MIN)>>1) - SYS_JoyData[index].axes_med[i];
		//joystick->hwdata->transaxes[i].scale = (float)((AXIS_MAX - AXIS_MIN)/(SYS_JoyData[index].axes_max[i]-SYS_JoyData[index].axes_min[i]));
		joystick->hwdata->transaxes[i].scale1 = (float)abs((AXIS_MIN/SYS_JoyData[index].axes_min[i]));
		joystick->hwdata->transaxes[i].scale2 = (float)abs((AXIS_MAX/SYS_JoyData[index].axes_max[i]));
		}
	else
		{
		joystick->hwdata->transaxes[i].offset = 0;
		//joystick->hwdata->transaxes[i].scale = 1.0; /* Just in case */
		joystick->hwdata->transaxes[i].scale1 = 1.0; /* Just in case */
		joystick->hwdata->transaxes[i].scale2 = 1.0; /* Just in case */
		}
	}

/* fill nbuttons, naxes, and nhats fields */
joystick->nbuttons = SYS_JoyData[index].buttons;
joystick->naxes = SYS_JoyData[index].axes;
/* joystick->nhats = SYS_JoyData[index].hats; */
joystick->nhats = 0; /* No support for hats at this time */
/* joystick->nballs = SYS_JoyData[index].balls; */
joystick->nballs = 0; /* No support for balls at this time */
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)
{
APIRET rc;									/* Generic OS/2 return code */
int index;									/* index shortcurt to joystick index */
int i;										/* Generic counter */
int normbut;								/* Number of buttons reported by joystick */
int corr;									/* Correction for button names */
Sint16 value, change;					/* Values used to update axis values */
struct _transaxes *transaxes;			/* Shortcut for Correction structure */
Uint32 pos[MAX_AXES];					/* Vector to inform the Axis status */
ULONG ulDataLen;							/* Size of data */
GAME_STATUS_STRUCT stGameStatus;		/* Joystick Status Structure */

ulDataLen = sizeof(stGameStatus);
rc = DosDevIOCtl(hJoyPort, IOCTL_CAT_USER, GAME_GET_STATUS,
	NULL, 0, NULL, &stGameStatus, ulDataLen, &ulDataLen);
if (rc != 0)
	{
	SDL_SetError("Could not read joystick status.");
	return; /* Could not read data */
	}

/* Shortcut pointer */
index = joystick->index;
/* joystick motion events */

if (SYS_JoyData[index].id == 0)
	{
	pos[0] = stGameStatus.curdata.A.x;
	pos[1] = stGameStatus.curdata.A.y;
	if (SYS_JoyData[index].axes >= 3)	pos[2] = stGameStatus.curdata.B.x;
	else pos[2]=0;
	if (SYS_JoyData[index].axes >= 4)	pos[3] = stGameStatus.curdata.B.y;
	else pos[3]=0;
	pos[4]=0;	/* OS/2 basic drivers do not support more than 4 axes joysticks */
	pos[5]=0;
	}
else if (SYS_JoyData[index].id == 1)
	{
	pos[0] = stGameStatus.curdata.B.x;
	pos[1] = stGameStatus.curdata.B.y;
	pos[2]=0;
	pos[3]=0;
	pos[4]=0;
	pos[5]=0;
	}

/* Corrects the movements using the callibration */
transaxes = joystick->hwdata->transaxes;
for (i = 0; i < joystick->naxes; i++)
	{
	value = pos[i] + transaxes[i].offset;
	if (value<0)
		{
		value*=transaxes[i].scale1;
		if (value>0) value = AXIS_MIN;
		}
	else
		{
		value*=transaxes[i].scale2;
		if (value<0) value = AXIS_MAX;
		}
	change = (value - joystick->axes[i]);
	if ( (change < -JOY_AXIS_THRESHOLD) || (change > JOY_AXIS_THRESHOLD) )
		{
		SDL_PrivateJoystickAxis(joystick, (Uint8)i, (Sint16)value);
		}
	}

/* joystick button A to D events */
if (SYS_JoyData[index].id == 1) corr = 2;
else corr = 0;
normbut=4;	/* Number of normal buttons */
if (joystick->nbuttons<normbut) normbut = joystick->nbuttons;
for ( i = corr; (i-corr) < normbut; ++i )
	{
	/*
		Button A: 1110 0000
		Button B: 1101 0000
		Button C: 1011 0000
		Button D: 0111 0000
	*/
	if ( (~stGameStatus.curdata.butMask)>>4 & JOY_BUTTON_FLAG(i) )
		{
		if ( ! joystick->buttons[i-corr] )
			{
			SDL_PrivateJoystickButton(joystick, (Uint8)(i-corr), SDL_PRESSED);
			}
		}
	else
		{
		if ( joystick->buttons[i-corr] )
			{
			SDL_PrivateJoystickButton(joystick, (Uint8)(i-corr), SDL_RELEASED);
			}
		}
	}

/* Joystick button E to H buttons */
	/*
		Button E: Axis 2 X Left
		Button F: Axis 2 Y Up
		Button G: Axis 2 X Right
		Button H: Axis 2 Y Down
	*/
if (joystick->nbuttons>=5)
	{
	if (stGameStatus.curdata.B.x < SYS_JoyData[index].buttoncalc[0]) SDL_PrivateJoystickButton(joystick, (Uint8)4, SDL_PRESSED);
	else SDL_PrivateJoystickButton(joystick, (Uint8)4, SDL_RELEASED);
	}
if (joystick->nbuttons>=6)
	{
	if (stGameStatus.curdata.B.y < SYS_JoyData[index].buttoncalc[1]) SDL_PrivateJoystickButton(joystick, (Uint8)5, SDL_PRESSED);
	else SDL_PrivateJoystickButton(joystick, (Uint8)5, SDL_RELEASED);
	}
if (joystick->nbuttons>=7)
	{
	if (stGameStatus.curdata.B.x > SYS_JoyData[index].buttoncalc[2]) SDL_PrivateJoystickButton(joystick, (Uint8)6, SDL_PRESSED);
	else SDL_PrivateJoystickButton(joystick, (Uint8)6, SDL_RELEASED);
	}
if (joystick->nbuttons>=8)
	{
	if (stGameStatus.curdata.B.y > SYS_JoyData[index].buttoncalc[3]) SDL_PrivateJoystickButton(joystick, (Uint8)7, SDL_PRESSED);
	else SDL_PrivateJoystickButton(joystick, (Uint8)7, SDL_RELEASED);
	}

/* joystick hat events */
/* Not Supported under OS/2 */
/* joystick ball events */
/* Not Supported under OS/2 */
}



/******************************************/
/* Function to close a joystick after use */
/******************************************/
void SDL_SYS_JoystickClose(SDL_Joystick *joystick)
{
if (joystick->hwdata != NULL)
	{
	/* free system specific hardware data */
	SDL_free(joystick->hwdata);
	}
}



/********************************************************************/
/* Function to perform any system-specific joystick related cleanup */
/********************************************************************/
void SDL_SYS_JoystickQuit(void)
{
joyPortClose(&hJoyPort);
}



/************************/
/************************/
/* OS/2 Implementations */
/************************/
/************************/


/*****************************************/
/* Open Joystick Port, if not opened yet */
/*****************************************/
APIRET joyPortOpen(HFILE * hGame)
{
APIRET		rc;				/* Generic Return Code */
ULONG			ulAction;		/* ? */
ULONG			ulVersion;		/* Version of joystick driver */
ULONG			ulDataLen;		/* Size of version data */

/* Verifies if joyport is not already open... */
if (*hGame != NULL) return 0;
/* Open GAME$ for read */
rc = DosOpen((PSZ)GAMEPDDNAME, hGame, &ulAction, 0, FILE_READONLY,
	FILE_OPEN, OPEN_ACCESS_READONLY | OPEN_SHARE_DENYNONE, NULL);
if (rc != 0)
	{
	SDL_SetError("Could not open Joystick Port.");
	return -1;
	}
	
/* Get Joystick Driver Version... must be 2.0 or higher */
ulVersion = 0;
ulDataLen = sizeof(ulVersion);
rc = DosDevIOCtl( *hGame, IOCTL_CAT_USER, GAME_GET_VERSION,
	NULL, 0, NULL, &ulVersion, ulDataLen, &ulDataLen);
if (rc != 0)
	{
	joyPortClose(hGame);
	SDL_SetError("Could not get Joystick Driver version.");
	return -1;	
	}
if (ulVersion < GAME_VERSION)
	{
	joyPortClose(hGame);
	SDL_SetError("Driver too old. At least IBM driver version 2.0 required.");
	return -1;
	}
return 0;
}



/****************************/
/* Close JoyPort, if opened */
/****************************/
void joyPortClose(HFILE * hGame)
{
if (*hGame != NULL) DosClose(*hGame);
*hGame = NULL;
}



/***************************/
/* Get SDL Joystick EnvVar */
/***************************/
int joyGetEnv(struct _joycfg * joydata)
{
char *joyenv;				/* Pointer to tested character */
char tempnumber[5];		/* Temporary place to put numeric texts */

joyenv = SDL_getenv("SDL_OS2_JOYSTICK");
if (joyenv == NULL) return 0;
/* Joystick Environment is defined! */
while (*joyenv==' ' && *joyenv!=0) joyenv++; /* jump spaces... */
/* If the string name starts with '... get if fully */
if (*joyenv=='\'') joyenv+=joyGetData(++joyenv,joydata->name,'\'',sizeof(joydata->name));
/* If not, get it until the next space */
else if (*joyenv=='\"') joyenv+=joyGetData(++joyenv,joydata->name,'\"',sizeof(joydata->name));
else joyenv+=joyGetData(joyenv,joydata->name,' ',sizeof(joydata->name));
/* Now get the number of axes */
while (*joyenv==' ' && *joyenv!=0) joyenv++; /* jump spaces... */
joyenv+=joyGetData(joyenv,tempnumber,' ',sizeof(tempnumber));
joydata->axes = atoi(tempnumber);
/* Now get the number of buttons */
while (*joyenv==' ' && *joyenv!=0) joyenv++; /* jump spaces... */
joyenv+=joyGetData(joyenv,tempnumber,' ',sizeof(tempnumber));
joydata->buttons = atoi(tempnumber);
/* Now get the number of hats */
while (*joyenv==' ' && *joyenv!=0) joyenv++; /* jump spaces... */
joyenv+=joyGetData(joyenv,tempnumber,' ',sizeof(tempnumber));
joydata->hats = atoi(tempnumber);
/* Now get the number of balls */
while (*joyenv==' ' && *joyenv!=0) joyenv++; /* jump spaces... */
joyenv+=joyGetData(joyenv,tempnumber,' ',sizeof(tempnumber));
joydata->balls = atoi(tempnumber);
return 1;
}



/************************************************************************/
/* Get a text from in the string starting in joyenv until it finds		*/
/* the stopchar or maxchars is reached. The result is placed in name.	*/
/************************************************************************/
int joyGetData(char *joyenv, char *name, char stopchar, size_t maxchars)
{
char *nameptr;			/* Pointer to the selected character */
int chcnt=0;			/* Count how many characters where copied */

nameptr=name;
while (*joyenv!=stopchar && *joyenv!=0)
	{
	if (nameptr<(name+(maxchars-1)))
		{
		*nameptr = *joyenv; /* Only copy if smaller than maximum */
		nameptr++;
		}
	chcnt++;
	joyenv++;
	}
if (*joyenv==stopchar)
	{
	joyenv++; /* Jump stopchar */
	chcnt++;
	}
*nameptr = 0; /* Mark last byte */
return chcnt;
}

#endif /* SDL_JOYSTICK_OS2 */