include/SDL_joystick.h
author Sam Lantinga <slouken@libsdl.org>
Wed, 06 Mar 2013 11:59:21 -0800
changeset 6974 11a03a79dfe8
parent 6949 4de584a3a027
child 7191 75360622e65f
permissions -rw-r--r--
The joystick events contain a joystick instance ID, which is a signed value, with -1 being invalid.
     1 /*
     2   Simple DirectMedia Layer
     3   Copyright (C) 1997-2013 Sam Lantinga <slouken@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 /* *INDENT-OFF* */
    49 extern "C" {
    50 /* *INDENT-ON* */
    51 #endif
    52 
    53 /**
    54  *  \file SDL_joystick.h
    55  *
    56  *  In order to use these functions, SDL_Init() must have been called
    57  *  with the ::SDL_INIT_JOYSTICK flag.  This causes SDL to scan the system
    58  *  for joysticks, and load appropriate drivers.
    59  */
    60 
    61 /* The joystick structure used to identify an SDL joystick */
    62 struct _SDL_Joystick;
    63 typedef struct _SDL_Joystick SDL_Joystick;
    64 
    65 /* A structure that encodes the stable unique id for a joystick device */
    66 typedef struct {
    67 	Uint8 data[16];
    68 } SDL_JoystickGUID;
    69 
    70 typedef Sint32 SDL_JoystickID;
    71 
    72 
    73 /* Function prototypes */
    74 /**
    75  *  Count the number of joysticks attached to the system right now
    76  */
    77 extern DECLSPEC int SDLCALL SDL_NumJoysticks(void);
    78 
    79 /**
    80  *  Get the implementation dependent name of a joystick.
    81  *  This can be called before any joysticks are opened.
    82  *  If no name can be found, this function returns NULL.
    83  */
    84 extern DECLSPEC const char *SDLCALL SDL_JoystickNameForIndex(int device_index);
    85 
    86 /**
    87  *  Open a joystick for use.  
    88  *  The index passed as an argument refers tothe N'th joystick on the system.  
    89  *  This index is the value which will identify this joystick in future joystick
    90  *  events.
    91  *  
    92  *  \return A joystick identifier, or NULL if an error occurred.
    93  */
    94 extern DECLSPEC SDL_Joystick *SDLCALL SDL_JoystickOpen(int device_index);
    95 
    96 /**
    97  *  Return the name for this currently opened joystick.
    98  *  If no name can be found, this function returns NULL.
    99  */
   100 extern DECLSPEC const char *SDLCALL SDL_JoystickName(SDL_Joystick * joystick);
   101 	
   102 /**
   103  *  Return the GUID for the joystick at this index
   104  */
   105 extern DECLSPEC SDL_JoystickGUID SDLCALL SDL_JoystickGetDeviceGUID(int device_index);
   106 
   107 /**
   108  *  Return the GUID for this opened joystick
   109  */
   110 extern DECLSPEC SDL_JoystickGUID SDLCALL SDL_JoystickGetGUID(SDL_Joystick * joystick);
   111 
   112 /**
   113  *  Return a string representation for this guid. pszGUID must point to at least 33 bytes
   114  *  (32 for the string plus a NULL terminator).
   115  */
   116 extern DECLSPEC void SDL_JoystickGetGUIDString(SDL_JoystickGUID guid, char *pszGUID, int cbGUID);
   117 
   118 /**
   119  *  convert a string into a joystick formatted guid
   120  */
   121 extern DECLSPEC SDL_JoystickGUID SDLCALL SDL_JoystickGetGUIDFromString(const char *pchGUID);
   122 
   123 /**
   124  *  Returns SDL_TRUE if the joystick has been opened and currently connected, or SDL_FALSE if it has not.
   125  */
   126 extern DECLSPEC SDL_bool SDLCALL SDL_JoystickGetAttached(SDL_Joystick * joystick);
   127 
   128 /**
   129  *  Get the instance ID of an opened joystick or -1 if the joystick is invalid.
   130  */
   131 extern DECLSPEC SDL_JoystickID SDLCALL SDL_JoystickInstanceID(SDL_Joystick * joystick);
   132 
   133 /**
   134  *  Get the number of general axis controls on a joystick.
   135  */
   136 extern DECLSPEC int SDLCALL SDL_JoystickNumAxes(SDL_Joystick * joystick);
   137 
   138 /**
   139  *  Get the number of trackballs on a joystick.
   140  *  
   141  *  Joystick trackballs have only relative motion events associated
   142  *  with them and their state cannot be polled.
   143  */
   144 extern DECLSPEC int SDLCALL SDL_JoystickNumBalls(SDL_Joystick * joystick);
   145 
   146 /**
   147  *  Get the number of POV hats on a joystick.
   148  */
   149 extern DECLSPEC int SDLCALL SDL_JoystickNumHats(SDL_Joystick * joystick);
   150 
   151 /**
   152  *  Get the number of buttons on a joystick.
   153  */
   154 extern DECLSPEC int SDLCALL SDL_JoystickNumButtons(SDL_Joystick * joystick);
   155 
   156 /**
   157  *  Update the current state of the open joysticks.
   158  *  
   159  *  This is called automatically by the event loop if any joystick
   160  *  events are enabled.
   161  */
   162 extern DECLSPEC void SDLCALL SDL_JoystickUpdate(void);
   163 
   164 /**
   165  *  Enable/disable joystick event polling.
   166  *  
   167  *  If joystick events are disabled, you must call SDL_JoystickUpdate()
   168  *  yourself and check the state of the joystick when you want joystick
   169  *  information.
   170  *  
   171  *  The state can be one of ::SDL_QUERY, ::SDL_ENABLE or ::SDL_IGNORE.
   172  */
   173 extern DECLSPEC int SDLCALL SDL_JoystickEventState(int state);
   174 
   175 /**
   176  *  Get the current state of an axis control on a joystick.
   177  *  
   178  *  The state is a value ranging from -32768 to 32767.
   179  *  
   180  *  The axis indices start at index 0.
   181  */
   182 extern DECLSPEC Sint16 SDLCALL SDL_JoystickGetAxis(SDL_Joystick * joystick,
   183                                                    int axis);
   184 
   185 /**
   186  *  \name Hat positions
   187  */
   188 /*@{*/
   189 #define SDL_HAT_CENTERED	0x00
   190 #define SDL_HAT_UP		0x01
   191 #define SDL_HAT_RIGHT		0x02
   192 #define SDL_HAT_DOWN		0x04
   193 #define SDL_HAT_LEFT		0x08
   194 #define SDL_HAT_RIGHTUP		(SDL_HAT_RIGHT|SDL_HAT_UP)
   195 #define SDL_HAT_RIGHTDOWN	(SDL_HAT_RIGHT|SDL_HAT_DOWN)
   196 #define SDL_HAT_LEFTUP		(SDL_HAT_LEFT|SDL_HAT_UP)
   197 #define SDL_HAT_LEFTDOWN	(SDL_HAT_LEFT|SDL_HAT_DOWN)
   198 /*@}*/
   199 
   200 /**
   201  *  Get the current state of a POV hat on a joystick.
   202  *
   203  *  The hat indices start at index 0.
   204  *  
   205  *  \return The return value is one of the following positions:
   206  *           - ::SDL_HAT_CENTERED
   207  *           - ::SDL_HAT_UP
   208  *           - ::SDL_HAT_RIGHT
   209  *           - ::SDL_HAT_DOWN
   210  *           - ::SDL_HAT_LEFT
   211  *           - ::SDL_HAT_RIGHTUP
   212  *           - ::SDL_HAT_RIGHTDOWN
   213  *           - ::SDL_HAT_LEFTUP
   214  *           - ::SDL_HAT_LEFTDOWN
   215  */
   216 extern DECLSPEC Uint8 SDLCALL SDL_JoystickGetHat(SDL_Joystick * joystick,
   217                                                  int hat);
   218 
   219 /**
   220  *  Get the ball axis change since the last poll.
   221  *  
   222  *  \return 0, or -1 if you passed it invalid parameters.
   223  *  
   224  *  The ball indices start at index 0.
   225  */
   226 extern DECLSPEC int SDLCALL SDL_JoystickGetBall(SDL_Joystick * joystick,
   227                                                 int ball, int *dx, int *dy);
   228 
   229 /**
   230  *  Get the current state of a button on a joystick.
   231  *  
   232  *  The button indices start at index 0.
   233  */
   234 extern DECLSPEC Uint8 SDLCALL SDL_JoystickGetButton(SDL_Joystick * joystick,
   235                                                     int button);
   236 
   237 /**
   238  *  Close a joystick previously opened with SDL_JoystickOpen().
   239  */
   240 extern DECLSPEC void SDLCALL SDL_JoystickClose(SDL_Joystick * joystick);
   241 
   242 
   243 /* Ends C function definitions when using C++ */
   244 #ifdef __cplusplus
   245 /* *INDENT-OFF* */
   246 }
   247 /* *INDENT-ON* */
   248 #endif
   249 #include "close_code.h"
   250 
   251 #endif /* _SDL_joystick_h */
   252 
   253 /* vi: set ts=4 sw=4 expandtab: */