/*

    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);

	}

}