sdl_sysjoystick.c

SDL库 在进行视频显示程序spcaview安装时必须的库文件

#endif

	if ( fd < 0 ) {
		SDL_SetError("Unable to open %s\n",
		             SDL_joylist[joystick->index]);
		return(-1);
	}
	joystick->hwdata = (struct joystick_hwdata *)
	                   SDL_malloc(sizeof(*joystick->hwdata));
	if ( joystick->hwdata == NULL ) {
		SDL_OutOfMemory();
		close(fd);
		return(-1);
	}
	SDL_memset(joystick->hwdata, 0, sizeof(*joystick->hwdata));
	joystick->hwdata->fd = fd;

	/* Set the joystick to non-blocking read mode */
	fcntl(fd, F_SETFL, O_NONBLOCK);

	/* Get the number of buttons and axes on the joystick */
#ifndef NO_LOGICAL_JOYSTICKS
	if (realjoy)
		ConfigLogicalJoystick(joystick);
	else
#endif
#if SDL_INPUT_LINUXEV
	if ( ! EV_ConfigJoystick(joystick, fd) )
#endif
		JS_ConfigJoystick(joystick, fd);

	return(0);
}

#ifndef NO_LOGICAL_JOYSTICKS

static SDL_Joystick* FindLogicalJoystick(
   SDL_Joystick *joystick, struct joystick_logical_mapping* v)
{
        SDL_Joystick *logicaljoy;
        register int i;

        i = joystick->index;
        logicaljoy = NULL;

        /* get the fake joystick that will receive the event
         */
        for(;;) {

           if (SDL_joylist[i].logicalno == v->njoy) {
              logicaljoy = SDL_joylist[i].joy;
              break;
           }

           if (SDL_joylist[i].next == 0)
              break;

           i = SDL_joylist[i].next;

        }

        return logicaljoy;
}

static int LogicalJoystickButton(
   SDL_Joystick *joystick, Uint8 button, Uint8 state){
        struct joystick_logical_mapping* buttons;
        SDL_Joystick *logicaljoy = NULL;

        /* if there's no map then this is just a regular joystick
         */
        if (SDL_joylist[joystick->index].map == NULL)
           return 0;

        /* get the logical joystick that will receive the event
         */
        buttons = SDL_joylist[joystick->index].map->buttonmap+button;
        logicaljoy = FindLogicalJoystick(joystick, buttons);

        if (logicaljoy == NULL)
           return 1;

        SDL_PrivateJoystickButton(logicaljoy, buttons->nthing, state);

        return 1;
}

static int LogicalJoystickAxis(
	SDL_Joystick *joystick, Uint8 axis, Sint16 value)
{
        struct joystick_logical_mapping* axes;
        SDL_Joystick *logicaljoy = NULL;

        /* if there's no map then this is just a regular joystick
         */
        if (SDL_joylist[joystick->index].map == NULL)
           return 0;

        /* get the logical joystick that will receive the event
         */
        axes = SDL_joylist[joystick->index].map->axismap+axis;
        logicaljoy = FindLogicalJoystick(joystick, axes);

        if (logicaljoy == NULL)
           return 1;

        SDL_PrivateJoystickAxis(logicaljoy, axes->nthing, value);

        return 1;
}
#endif /* USE_LOGICAL_JOYSTICKS */

static __inline__
void HandleHat(SDL_Joystick *stick, Uint8 hat, int axis, int value)
{
	struct hwdata_hat *the_hat;
	const Uint8 position_map[3][3] = {
		{ SDL_HAT_LEFTUP, SDL_HAT_UP, SDL_HAT_RIGHTUP },
		{ SDL_HAT_LEFT, SDL_HAT_CENTERED, SDL_HAT_RIGHT },
		{ SDL_HAT_LEFTDOWN, SDL_HAT_DOWN, SDL_HAT_RIGHTDOWN }
	};
	SDL_logical_joydecl(SDL_Joystick *logicaljoy = NULL);
	SDL_logical_joydecl(struct joystick_logical_mapping* hats = NULL);

	the_hat = &stick->hwdata->hats[hat];
	if ( value < 0 ) {
		value = 0;
	} else
	if ( value == 0 ) {
		value = 1;
	} else
	if ( value > 0 ) {
		value = 2;
	}
	if ( value != the_hat->axis[axis] ) {
		the_hat->axis[axis] = value;

#ifndef NO_LOGICAL_JOYSTICKS
		/* if there's no map then this is just a regular joystick
		*/
		if (SDL_joylist[stick->index].map != NULL) {

			/* get the fake joystick that will receive the event
			*/
			hats = SDL_joylist[stick->index].map->hatmap+hat;
			logicaljoy = FindLogicalJoystick(stick, hats);
		}

		if (logicaljoy) {
			stick = logicaljoy;
			hat = hats->nthing;
		}
#endif /* USE_LOGICAL_JOYSTICKS */

		SDL_PrivateJoystickHat(stick, hat,
			position_map[the_hat->axis[1]][the_hat->axis[0]]);
	}
}

static __inline__
void HandleBall(SDL_Joystick *stick, Uint8 ball, int axis, int value)
{
	stick->hwdata->balls[ball].axis[axis] += value;
}

/* 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.
 */
static __inline__ void JS_HandleEvents(SDL_Joystick *joystick)
{
	struct js_event events[32];
	int i, len;
	Uint8 other_axis;

#ifndef NO_LOGICAL_JOYSTICKS
	if (SDL_joylist[joystick->index].fname == NULL) {
		SDL_joylist_head(i, joystick->index);
		JS_HandleEvents(SDL_joylist[i].joy);
		return;
	}
#endif

	while ((len=read(joystick->hwdata->fd, events, (sizeof events))) > 0) {
		len /= sizeof(events[0]);
		for ( i=0; i<len; ++i ) {
			switch (events[i].type & ~JS_EVENT_INIT) {
			    case JS_EVENT_AXIS:
				if ( events[i].number < joystick->naxes ) {
#ifndef NO_LOGICAL_JOYSTICKS
					if (!LogicalJoystickAxis(joystick,
				           events[i].number, events[i].value))
#endif
					SDL_PrivateJoystickAxis(joystick,
				           events[i].number, events[i].value);
					break;
				}
				events[i].number -= joystick->naxes;
				other_axis = (events[i].number / 2);
				if ( other_axis < joystick->nhats ) {
					HandleHat(joystick, other_axis,
						events[i].number%2,
						events[i].value);
					break;
				}
				events[i].number -= joystick->nhats*2;
				other_axis = (events[i].number / 2);
				if ( other_axis < joystick->nballs ) {
					HandleBall(joystick, other_axis,
						events[i].number%2,
						events[i].value);
					break;
				}
				break;
			    case JS_EVENT_BUTTON:
#ifndef NO_LOGICAL_JOYSTICKS
				if (!LogicalJoystickButton(joystick,
				           events[i].number, events[i].value))
#endif
				SDL_PrivateJoystickButton(joystick,
				           events[i].number, events[i].value);
				break;
			    default:
				/* ?? */
				break;
			}
		}
	}
}
#if SDL_INPUT_LINUXEV
static __inline__ int EV_AxisCorrect(SDL_Joystick *joystick, int which, int value)
{
	struct axis_correct *correct;

	correct = &joystick->hwdata->abs_correct[which];
	if ( correct->used ) {
		if ( value > correct->coef[0] ) {
			if ( value < correct->coef[1] ) {
				return 0;
			}
			value -= correct->coef[1];
		} else {
			value -= correct->coef[0];
		}
		value *= correct->coef[2];
		value >>= 14;
	}

	/* Clamp and return */
	if ( value < -32768 ) return -32768;
	if ( value >  32767 ) return  32767;

	return value;
}

static __inline__ void EV_HandleEvents(SDL_Joystick *joystick)
{
	struct input_event events[32];
	int i, len;
	int code;

#ifndef NO_LOGICAL_JOYSTICKS
	if (SDL_joylist[joystick->index].fname == NULL) {
		SDL_joylist_head(i, joystick->index);
		return EV_HandleEvents(SDL_joylist[i].joy);
	}
#endif

	while ((len=read(joystick->hwdata->fd, events, (sizeof events))) > 0) {
		len /= sizeof(events[0]);
		for ( i=0; i<len; ++i ) {
			code = events[i].code;
			switch (events[i].type) {
			    case EV_KEY:
				if ( code >= BTN_MISC ) {
					code -= BTN_MISC;
#ifndef NO_LOGICAL_JOYSTICKS
					if (!LogicalJoystickButton(joystick,
				           joystick->hwdata->key_map[code],
					   events[i].value))
#endif
					SDL_PrivateJoystickButton(joystick,
				           joystick->hwdata->key_map[code],
					   events[i].value);
				}
				break;
			    case EV_ABS:
				switch (code) {
				    case ABS_HAT0X:
				    case ABS_HAT0Y:
				    case ABS_HAT1X:
				    case ABS_HAT1Y:
				    case ABS_HAT2X:
				    case ABS_HAT2Y:
				    case ABS_HAT3X:
				    case ABS_HAT3Y:
					code -= ABS_HAT0X;
					HandleHat(joystick, code/2, code%2,
							events[i].value);
					break;
				    default:
					events[i].value = EV_AxisCorrect(joystick, code, events[i].value);
#ifndef NO_LOGICAL_JOYSTICKS
					if (!LogicalJoystickAxis(joystick,
				           joystick->hwdata->abs_map[code],
					   events[i].value))
#endif
					SDL_PrivateJoystickAxis(joystick,
				           joystick->hwdata->abs_map[code],
					   events[i].value);
					break;
				}
				break;
			    case EV_REL:
				switch (code) {
				    case REL_X:
				    case REL_Y:
					code -= REL_X;
					HandleBall(joystick, code/2, code%2,
							events[i].value);
					break;
				    default:
					break;
				}
				break;
			    default:
				break;
			}
		}
	}
}
#endif /* SDL_INPUT_LINUXEV */

void SDL_SYS_JoystickUpdate(SDL_Joystick *joystick)
{
	int i;
	
#if SDL_INPUT_LINUXEV
	if ( joystick->hwdata->is_hid )
		EV_HandleEvents(joystick);
	else
#endif
		JS_HandleEvents(joystick);

	/* Deliver ball motion updates */
	for ( i=0; i<joystick->nballs; ++i ) {
		int xrel, yrel;

		xrel = joystick->hwdata->balls[i].axis[0];
		yrel = joystick->hwdata->balls[i].axis[1];
		if ( xrel || yrel ) {
			joystick->hwdata->balls[i].axis[0] = 0;
			joystick->hwdata->balls[i].axis[1] = 0;
			SDL_PrivateJoystickBall(joystick, (Uint8)i, xrel, yrel);
		}
	}
}

/* Function to close a joystick after use */
void SDL_SYS_JoystickClose(SDL_Joystick *joystick)
{
#ifndef NO_LOGICAL_JOYSTICKS
	register int i;
	if (SDL_joylist[joystick->index].fname == NULL) {
		SDL_joylist_head(i, joystick->index);
		SDL_JoystickClose(SDL_joylist[i].joy);
	}
#endif

	if ( joystick->hwdata ) {
#ifndef NO_LOGICAL_JOYSTICKS
		if (SDL_joylist[joystick->index].fname != NULL)
#endif
		close(joystick->hwdata->fd);
		if ( joystick->hwdata->hats ) {
			SDL_free(joystick->hwdata->hats);
		}
		if ( joystick->hwdata->balls ) {
			SDL_free(joystick->hwdata->balls);
		}
		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_joylist[i].fname; ++i ) {
		SDL_free(SDL_joylist[i].fname);
	}
	SDL_joylist[0].fname = NULL;
}

#endif /* SDL_JOYSTICK_LINUX */