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      1 /*
      2   Simple DirectMedia Layer
      3   Copyright (C) 1997-2014 Sam Lantinga <slouken (at) libsdl.org>
      4 
      5   This software is provided 'as-is', without any express or implied
      6   warranty.  In no event will the authors be held liable for any damages
      7   arising from the use of this software.
      8 
      9   Permission is granted to anyone to use this software for any purpose,
     10   including commercial applications, and to alter it and redistribute it
     11   freely, subject to the following restrictions:
     12 
     13   1. The origin of this software must not be misrepresented; you must not
     14      claim that you wrote the original software. If you use this software
     15      in a product, an acknowledgment in the product documentation would be
     16      appreciated but is not required.
     17   2. Altered source versions must be plainly marked as such, and must not be
     18      misrepresented as being the original software.
     19   3. This notice may not be removed or altered from any source distribution.
     20 */
     21 
     22 /**
     23  *  \file SDL_joystick.h
     24  *
     25  *  Include file for SDL joystick event handling
     26  *
     27  * The term "device_index" identifies currently plugged in joystick devices between 0 and SDL_NumJoysticks, with the exact joystick
     28  *   behind a device_index changing as joysticks are plugged and unplugged.
     29  *
     30  * The term "instance_id" is the current instantiation of a joystick device in the system, if the joystick is removed and then re-inserted
     31  *   then it will get a new instance_id, instance_id's are monotonically increasing identifiers of a joystick plugged in.
     32  *
     33  * The term JoystickGUID is a stable 128-bit identifier for a joystick device that does not change over time, it identifies class of
     34  *   the device (a X360 wired controller for example). This identifier is platform dependent.
     35  *
     36  *
     37  */
     38 
     39 #ifndef _SDL_joystick_h
     40 #define _SDL_joystick_h
     41 
     42 #include "SDL_stdinc.h"
     43 #include "SDL_error.h"
     44 
     45 #include "begin_code.h"
     46 /* Set up for C function definitions, even when using C++ */
     47 #ifdef __cplusplus
     48 extern "C" {
     49 #endif
     50 
     51 /**
     52  *  \file SDL_joystick.h
     53  *
     54  *  In order to use these functions, SDL_Init() must have been called
     55  *  with the ::SDL_INIT_JOYSTICK flag.  This causes SDL to scan the system
     56  *  for joysticks, and load appropriate drivers.
     57  *
     58  *  If you would like to receive joystick updates while the application
     59  *  is in the background, you should set the following hint before calling
     60  *  SDL_Init(): SDL_HINT_JOYSTICK_ALLOW_BACKGROUND_EVENTS
     61  */
     62 
     63 /* The joystick structure used to identify an SDL joystick */
     64 struct _SDL_Joystick;
     65 typedef struct _SDL_Joystick SDL_Joystick;
     66 
     67 /* A structure that encodes the stable unique id for a joystick device */
     68 typedef struct {
     69     Uint8 data[16];
     70 } SDL_JoystickGUID;
     71 
     72 typedef Sint32 SDL_JoystickID;
     73 
     74 
     75 /* Function prototypes */
     76 /**
     77  *  Count the number of joysticks attached to the system right now
     78  */
     79 extern DECLSPEC int SDLCALL SDL_NumJoysticks(void);
     80 
     81 /**
     82  *  Get the implementation dependent name of a joystick.
     83  *  This can be called before any joysticks are opened.
     84  *  If no name can be found, this function returns NULL.
     85  */
     86 extern DECLSPEC const char *SDLCALL SDL_JoystickNameForIndex(int device_index);
     87 
     88 /**
     89  *  Open a joystick for use.
     90  *  The index passed as an argument refers tothe N'th joystick on the system.
     91  *  This index is the value which will identify this joystick in future joystick
     92  *  events.
     93  *
     94  *  \return A joystick identifier, or NULL if an error occurred.
     95  */
     96 extern DECLSPEC SDL_Joystick *SDLCALL SDL_JoystickOpen(int device_index);
     97 
     98 /**
     99  *  Return the name for this currently opened joystick.
    100  *  If no name can be found, this function returns NULL.
    101  */
    102 extern DECLSPEC const char *SDLCALL SDL_JoystickName(SDL_Joystick * joystick);
    103 
    104 /**
    105  *  Return the GUID for the joystick at this index
    106  */
    107 extern DECLSPEC SDL_JoystickGUID SDLCALL SDL_JoystickGetDeviceGUID(int device_index);
    108 
    109 /**
    110  *  Return the GUID for this opened joystick
    111  */
    112 extern DECLSPEC SDL_JoystickGUID SDLCALL SDL_JoystickGetGUID(SDL_Joystick * joystick);
    113 
    114 /**
    115  *  Return a string representation for this guid. pszGUID must point to at least 33 bytes
    116  *  (32 for the string plus a NULL terminator).
    117  */
    118 extern DECLSPEC void SDLCALL SDL_JoystickGetGUIDString(SDL_JoystickGUID guid, char *pszGUID, int cbGUID);
    119 
    120 /**
    121  *  convert a string into a joystick formatted guid
    122  */
    123 extern DECLSPEC SDL_JoystickGUID SDLCALL SDL_JoystickGetGUIDFromString(const char *pchGUID);
    124 
    125 /**
    126  *  Returns SDL_TRUE if the joystick has been opened and currently connected, or SDL_FALSE if it has not.
    127  */
    128 extern DECLSPEC SDL_bool SDLCALL SDL_JoystickGetAttached(SDL_Joystick * joystick);
    129 
    130 /**
    131  *  Get the instance ID of an opened joystick or -1 if the joystick is invalid.
    132  */
    133 extern DECLSPEC SDL_JoystickID SDLCALL SDL_JoystickInstanceID(SDL_Joystick * joystick);
    134 
    135 /**
    136  *  Get the number of general axis controls on a joystick.
    137  */
    138 extern DECLSPEC int SDLCALL SDL_JoystickNumAxes(SDL_Joystick * joystick);
    139 
    140 /**
    141  *  Get the number of trackballs on a joystick.
    142  *
    143  *  Joystick trackballs have only relative motion events associated
    144  *  with them and their state cannot be polled.
    145  */
    146 extern DECLSPEC int SDLCALL SDL_JoystickNumBalls(SDL_Joystick * joystick);
    147 
    148 /**
    149  *  Get the number of POV hats on a joystick.
    150  */
    151 extern DECLSPEC int SDLCALL SDL_JoystickNumHats(SDL_Joystick * joystick);
    152 
    153 /**
    154  *  Get the number of buttons on a joystick.
    155  */
    156 extern DECLSPEC int SDLCALL SDL_JoystickNumButtons(SDL_Joystick * joystick);
    157 
    158 /**
    159  *  Update the current state of the open joysticks.
    160  *
    161  *  This is called automatically by the event loop if any joystick
    162  *  events are enabled.
    163  */
    164 extern DECLSPEC void SDLCALL SDL_JoystickUpdate(void);
    165 
    166 /**
    167  *  Enable/disable joystick event polling.
    168  *
    169  *  If joystick events are disabled, you must call SDL_JoystickUpdate()
    170  *  yourself and check the state of the joystick when you want joystick
    171  *  information.
    172  *
    173  *  The state can be one of ::SDL_QUERY, ::SDL_ENABLE or ::SDL_IGNORE.
    174  */
    175 extern DECLSPEC int SDLCALL SDL_JoystickEventState(int state);
    176 
    177 /**
    178  *  Get the current state of an axis control on a joystick.
    179  *
    180  *  The state is a value ranging from -32768 to 32767.
    181  *
    182  *  The axis indices start at index 0.
    183  */
    184 extern DECLSPEC Sint16 SDLCALL SDL_JoystickGetAxis(SDL_Joystick * joystick,
    185                                                    int axis);
    186 
    187 /**
    188  *  \name Hat positions
    189  */
    190 /* @{ */
    191 #define SDL_HAT_CENTERED    0x00
    192 #define SDL_HAT_UP      0x01
    193 #define SDL_HAT_RIGHT       0x02
    194 #define SDL_HAT_DOWN        0x04
    195 #define SDL_HAT_LEFT        0x08
    196 #define SDL_HAT_RIGHTUP     (SDL_HAT_RIGHT|SDL_HAT_UP)
    197 #define SDL_HAT_RIGHTDOWN   (SDL_HAT_RIGHT|SDL_HAT_DOWN)
    198 #define SDL_HAT_LEFTUP      (SDL_HAT_LEFT|SDL_HAT_UP)
    199 #define SDL_HAT_LEFTDOWN    (SDL_HAT_LEFT|SDL_HAT_DOWN)
    200 /* @} */
    201 
    202 /**
    203  *  Get the current state of a POV hat on a joystick.
    204  *
    205  *  The hat indices start at index 0.
    206  *
    207  *  \return The return value is one of the following positions:
    208  *           - ::SDL_HAT_CENTERED
    209  *           - ::SDL_HAT_UP
    210  *           - ::SDL_HAT_RIGHT
    211  *           - ::SDL_HAT_DOWN
    212  *           - ::SDL_HAT_LEFT
    213  *           - ::SDL_HAT_RIGHTUP
    214  *           - ::SDL_HAT_RIGHTDOWN
    215  *           - ::SDL_HAT_LEFTUP
    216  *           - ::SDL_HAT_LEFTDOWN
    217  */
    218 extern DECLSPEC Uint8 SDLCALL SDL_JoystickGetHat(SDL_Joystick * joystick,
    219                                                  int hat);
    220 
    221 /**
    222  *  Get the ball axis change since the last poll.
    223  *
    224  *  \return 0, or -1 if you passed it invalid parameters.
    225  *
    226  *  The ball indices start at index 0.
    227  */
    228 extern DECLSPEC int SDLCALL SDL_JoystickGetBall(SDL_Joystick * joystick,
    229                                                 int ball, int *dx, int *dy);
    230 
    231 /**
    232  *  Get the current state of a button on a joystick.
    233  *
    234  *  The button indices start at index 0.
    235  */
    236 extern DECLSPEC Uint8 SDLCALL SDL_JoystickGetButton(SDL_Joystick * joystick,
    237                                                     int button);
    238 
    239 /**
    240  *  Close a joystick previously opened with SDL_JoystickOpen().
    241  */
    242 extern DECLSPEC void SDLCALL SDL_JoystickClose(SDL_Joystick * joystick);
    243 
    244 
    245 /* Ends C function definitions when using C++ */
    246 #ifdef __cplusplus
    247 }
    248 #endif
    249 #include "close_code.h"
    250 
    251 #endif /* _SDL_joystick_h */
    252 
    253 /* vi: set ts=4 sw=4 expandtab: */
    254