sdl_sysjoystick.c

SDL库 在进行视频显示程序spcaview安装时必须的库文件

		"/dev/input/event%d",
#endif
		"/dev/input/js%d",
		"/dev/js%d"
	};
	int numjoysticks;
	int i, j;
	int fd;
	char path[PATH_MAX];
	dev_t dev_nums[MAX_JOYSTICKS];  /* major/minor device numbers */
	struct stat sb;
	int n, duplicate;

	numjoysticks = 0;

	/* First see if the user specified a joystick to use */
	if ( SDL_getenv("SDL_JOYSTICK_DEVICE") != NULL ) {
		SDL_strlcpy(path, SDL_getenv("SDL_JOYSTICK_DEVICE"), sizeof(path));
		if ( stat(path, &sb) == 0 ) {
			fd = open(path, O_RDONLY, 0);
			if ( fd >= 0 ) {
				/* Assume the user knows what they're doing. */
				SDL_joylist[numjoysticks].fname = SDL_strdup(path);
				if ( SDL_joylist[numjoysticks].fname ) {
					dev_nums[numjoysticks] = sb.st_rdev;
					++numjoysticks;
				}
				close(fd);
			}
		}
	}

	for ( i=0; i<SDL_arraysize(joydev_pattern); ++i ) {
		for ( j=0; j < MAX_JOYSTICKS; ++j ) {
			SDL_snprintf(path, SDL_arraysize(path), joydev_pattern[i], j);

			/* rcg06302000 replaced access(F_OK) call with stat().
			 * stat() will fail if the file doesn't exist, so it's
			 * equivalent behaviour.
			 */
			if ( stat(path, &sb) == 0 ) {
				/* Check to make sure it's not already in list.
				 * This happens when we see a stick via symlink.
				 */
				duplicate = 0;
				for (n=0; (n<numjoysticks) && !duplicate; ++n) {
					if ( sb.st_rdev == dev_nums[n] ) {
						duplicate = 1;
					}
				}
				if (duplicate) {
					continue;
				}

				fd = open(path, O_RDONLY, 0);
				if ( fd < 0 ) {
					continue;
				}
#if SDL_INPUT_LINUXEV
#ifdef DEBUG_INPUT_EVENTS
				printf("Checking %s\n", path);
#endif
				if ( (i == 0) && ! EV_IsJoystick(fd) ) {
					close(fd);
					continue;
				}
#endif
				close(fd);

				/* We're fine, add this joystick */
				SDL_joylist[numjoysticks].fname = SDL_strdup(path);
				if ( SDL_joylist[numjoysticks].fname ) {
					dev_nums[numjoysticks] = sb.st_rdev;
					++numjoysticks;
				}
			}
		}

#if SDL_INPUT_LINUXEV
		/* This is a special case...
		   If the event devices are valid then the joystick devices
		   will be duplicates but without extra information about their
		   hats or balls. Unfortunately, the event devices can't
		   currently be calibrated, so it's a win-lose situation.
		   So : /dev/input/eventX = /dev/input/jsY = /dev/jsY
		*/
		if ( (i == 0) && (numjoysticks > 0) )
			break;
#endif
	}
#ifndef NO_LOGICAL_JOYSTICKS
	numjoysticks += CountLogicalJoysticks(numjoysticks);
#endif

	return(numjoysticks);
}

/* Function to get the device-dependent name of a joystick */
const char *SDL_SYS_JoystickName(int index)
{
	int fd;
	static char namebuf[128];
	char *name;
	SDL_logical_joydecl(int oindex = index);

#ifndef NO_LOGICAL_JOYSTICKS
	SDL_joylist_head(index, index);
#endif
	name = NULL;
	fd = open(SDL_joylist[index].fname, O_RDONLY, 0);
	if ( fd >= 0 ) {
		if ( 
#if SDL_INPUT_LINUXEV
		     (ioctl(fd, EVIOCGNAME(sizeof(namebuf)), namebuf) <= 0) &&
#endif
		     (ioctl(fd, JSIOCGNAME(sizeof(namebuf)), namebuf) <= 0) ) {
			name = SDL_joylist[index].fname;
		} else {
			name = namebuf;
		}
		close(fd);


#ifndef NO_LOGICAL_JOYSTICKS
		if (SDL_joylist[oindex].prev || SDL_joylist[oindex].next || index!=oindex)
		{
       		   LogicalSuffix(SDL_joylist[oindex].logicalno, namebuf, 128);
		}
#endif
	}
	return name;
}

static int allocate_hatdata(SDL_Joystick *joystick)
{
	int i;

	joystick->hwdata->hats = (struct hwdata_hat *)SDL_malloc(
		joystick->nhats * sizeof(struct hwdata_hat));
	if ( joystick->hwdata->hats == NULL ) {
		return(-1);
	}
	for ( i=0; i<joystick->nhats; ++i ) {
		joystick->hwdata->hats[i].axis[0] = 1;
		joystick->hwdata->hats[i].axis[1] = 1;
	}
	return(0);
}

static int allocate_balldata(SDL_Joystick *joystick)
{
	int i;

	joystick->hwdata->balls = (struct hwdata_ball *)SDL_malloc(
		joystick->nballs * sizeof(struct hwdata_ball));
	if ( joystick->hwdata->balls == NULL ) {
		return(-1);
	}
	for ( i=0; i<joystick->nballs; ++i ) {
		joystick->hwdata->balls[i].axis[0] = 0;
		joystick->hwdata->balls[i].axis[1] = 0;
	}
	return(0);
}

static SDL_bool JS_ConfigJoystick(SDL_Joystick *joystick, int fd)
{
	SDL_bool handled;
	unsigned char n;
	int old_axes, tmp_naxes, tmp_nhats, tmp_nballs;
	const char *name;
	char *env, env_name[128];
	int i;

	handled = SDL_FALSE;

	/* Default joystick device settings */
	if ( ioctl(fd, JSIOCGAXES, &n) < 0 ) {
		joystick->naxes = 2;
	} else {
		joystick->naxes = n;
	}
	if ( ioctl(fd, JSIOCGBUTTONS, &n) < 0 ) {
		joystick->nbuttons = 2;
	} else {
		joystick->nbuttons = n;
	}

	name = SDL_SYS_JoystickName(joystick->index);
	old_axes = joystick->naxes;

	/* Generic analog joystick support */
	if ( SDL_strstr(name, "Analog") == name && SDL_strstr(name, "-hat") ) {
		if ( SDL_sscanf(name,"Analog %d-axis %*d-button %d-hat",
			&tmp_naxes, &tmp_nhats) == 2 ) {

			joystick->naxes = tmp_naxes;
			joystick->nhats = tmp_nhats;

			handled = SDL_TRUE;
		}
	}

	/* Special joystick support */
	for ( i=0; i < SDL_arraysize(special_joysticks); ++i ) {
		if ( SDL_strcmp(name, special_joysticks[i].name) == 0 ) {

			joystick->naxes = special_joysticks[i].naxes;
			joystick->nhats = special_joysticks[i].nhats;
			joystick->nballs = special_joysticks[i].nballs;

			handled = SDL_TRUE;
			break;
		}
	}

	/* User environment joystick support */
	if ( (env = SDL_getenv("SDL_LINUX_JOYSTICK")) ) {
		*env_name = '\0';
		if ( *env == '\'' && SDL_sscanf(env, "'%[^']s'", env_name) == 1 )
			env += SDL_strlen(env_name)+2;
		else if ( SDL_sscanf(env, "%s", env_name) == 1 )
			env += SDL_strlen(env_name);

		if ( SDL_strcmp(name, env_name) == 0 ) {

			if ( SDL_sscanf(env, "%d %d %d", &tmp_naxes, &tmp_nhats,
				&tmp_nballs) == 3 ) {

				joystick->naxes = tmp_naxes;
				joystick->nhats = tmp_nhats;
				joystick->nballs = tmp_nballs;

				handled = SDL_TRUE;
			}
		}
	}

	/* Remap hats and balls */
	if (handled) {
		if ( joystick->nhats > 0 ) {
			if ( allocate_hatdata(joystick) < 0 ) {
				joystick->nhats = 0;
			}
		}
		if ( joystick->nballs > 0 ) {
			if ( allocate_balldata(joystick) < 0 ) {
				joystick->nballs = 0;
			}
		}
	}

	return(handled);
}

#if SDL_INPUT_LINUXEV

static SDL_bool EV_ConfigJoystick(SDL_Joystick *joystick, int fd)
{
	int i, t;
	unsigned long keybit[40];
	unsigned long absbit[40];
	unsigned long relbit[40];

	/* See if this device uses the new unified event API */
	if ( (ioctl(fd, EVIOCGBIT(EV_KEY, sizeof(keybit)), keybit) >= 0) &&
	     (ioctl(fd, EVIOCGBIT(EV_ABS, sizeof(absbit)), absbit) >= 0) &&
	     (ioctl(fd, EVIOCGBIT(EV_REL, sizeof(relbit)), relbit) >= 0) ) {
		joystick->hwdata->is_hid = SDL_TRUE;

		/* Get the number of buttons, axes, and other thingamajigs */
		for ( i=BTN_JOYSTICK; i < KEY_MAX; ++i ) {
			if ( test_bit(i, keybit) ) {
#ifdef DEBUG_INPUT_EVENTS
				printf("Joystick has button: 0x%x\n", i);
#endif
				joystick->hwdata->key_map[i-BTN_MISC] =
						joystick->nbuttons;
				++joystick->nbuttons;
			}
		}
		for ( i=BTN_MISC; i < BTN_JOYSTICK; ++i ) {
			if ( test_bit(i, keybit) ) {
#ifdef DEBUG_INPUT_EVENTS
				printf("Joystick has button: 0x%x\n", i);
#endif
				joystick->hwdata->key_map[i-BTN_MISC] =
						joystick->nbuttons;
				++joystick->nbuttons;
			}
		}
		for ( i=0; i<ABS_MAX; ++i ) {
			/* Skip hats */
			if ( i == ABS_HAT0X ) {
				i = ABS_HAT3Y;
				continue;
			}
			if ( test_bit(i, absbit) ) {
				int values[5];

				if ( ioctl(fd, EVIOCGABS(i), values) < 0 )
					continue;
#ifdef DEBUG_INPUT_EVENTS
				printf("Joystick has absolute axis: %x\n", i);
				printf("Values = { %d, %d, %d, %d, %d }\n",
					values[0], values[1],
					values[2], values[3], values[4]);
#endif /* DEBUG_INPUT_EVENTS */
				joystick->hwdata->abs_map[i] = joystick->naxes;
				if ( values[1] == values[2] ) {
				    joystick->hwdata->abs_correct[i].used = 0;
				} else {
				    joystick->hwdata->abs_correct[i].used = 1;
				    joystick->hwdata->abs_correct[i].coef[0] =
					(values[2] + values[1]) / 2 - values[4];
				    joystick->hwdata->abs_correct[i].coef[1] =
					(values[2] + values[1]) / 2 + values[4];
				    t = ((values[2] - values[1]) / 2 - 2 * values[4]);
				    if ( t != 0 ) {
					joystick->hwdata->abs_correct[i].coef[2] = (1 << 29) / t;
				    } else {
					joystick->hwdata->abs_correct[i].coef[2] = 0;
				    }
				}
				++joystick->naxes;
			}
		}
		for ( i=ABS_HAT0X; i <= ABS_HAT3Y; i += 2 ) {
			if ( test_bit(i, absbit) || test_bit(i+1, absbit) ) {
#ifdef DEBUG_INPUT_EVENTS
				printf("Joystick has hat %d\n",(i-ABS_HAT0X)/2);
#endif
				++joystick->nhats;
			}
		}
		if ( test_bit(REL_X, relbit) || test_bit(REL_Y, relbit) ) {
			++joystick->nballs;
		}

		/* Allocate data to keep track of these thingamajigs */
		if ( joystick->nhats > 0 ) {
			if ( allocate_hatdata(joystick) < 0 ) {
				joystick->nhats = 0;
			}
		}
		if ( joystick->nballs > 0 ) {
			if ( allocate_balldata(joystick) < 0 ) {
				joystick->nballs = 0;
			}
		}
	}
	return(joystick->hwdata->is_hid);
}

#endif /* SDL_INPUT_LINUXEV */

#ifndef NO_LOGICAL_JOYSTICKS
static void ConfigLogicalJoystick(SDL_Joystick *joystick)
{
        struct joystick_logical_layout* layout;
                                                                                
        layout = SDL_joylist[joystick->index].map->layout +
                SDL_joylist[joystick->index].logicalno;
                                                                                
        joystick->nbuttons = layout->nbuttons;
        joystick->nhats = layout->nhats;
        joystick->naxes = layout->naxes;
        joystick->nballs = layout->nballs;
}
#endif


/* 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 fd;
	SDL_logical_joydecl(int realindex);
	SDL_logical_joydecl(SDL_Joystick *realjoy = NULL);

	/* Open the joystick and set the joystick file descriptor */
#ifndef NO_LOGICAL_JOYSTICKS
	if (SDL_joylist[joystick->index].fname == NULL) {
		SDL_joylist_head(realindex, joystick->index);
		realjoy = SDL_JoystickOpen(realindex);

		if (realjoy == NULL)
			return(-1);
                                                                                
		fd = realjoy->hwdata->fd;

	} else {
		fd = open(SDL_joylist[joystick->index].fname, O_RDONLY, 0);
	}
	SDL_joylist[joystick->index].joy = joystick;
#else
	fd = open(SDL_joylist[joystick->index].fname, O_RDONLY, 0);