SDL_joystick.h

00001 /*
00002   Simple DirectMedia Layer
00003   Copyright (C) 1997-2014 Sam Lantinga <slouken@libsdl.org>
00004 
00005   This software is provided 'as-is', without any express or implied
00006   warranty.  In no event will the authors be held liable for any damages
00007   arising from the use of this software.
00008 
00009   Permission is granted to anyone to use this software for any purpose,
00010   including commercial applications, and to alter it and redistribute it
00011   freely, subject to the following restrictions:
00012 
00013   1. The origin of this software must not be misrepresented; you must not
00014      claim that you wrote the original software. If you use this software
00015      in a product, an acknowledgment in the product documentation would be
00016      appreciated but is not required.
00017   2. Altered source versions must be plainly marked as such, and must not be
00018      misrepresented as being the original software.
00019   3. This notice may not be removed or altered from any source distribution.
00020 */
00021 
00022 /**
00023  *  \file SDL_joystick.h
00024  *
00025  *  Include file for SDL joystick event handling
00026  *
00027  * The term "device_index" identifies currently plugged in joystick devices between 0 and SDL_NumJoysticks, with the exact joystick
00028  *   behind a device_index changing as joysticks are plugged and unplugged.
00029  *
00030  * The term "instance_id" is the current instantiation of a joystick device in the system, if the joystick is removed and then re-inserted
00031  *   then it will get a new instance_id, instance_id's are monotonically increasing identifiers of a joystick plugged in.
00032  *
00033  * The term JoystickGUID is a stable 128-bit identifier for a joystick device that does not change over time, it identifies class of
00034  *   the device (a X360 wired controller for example). This identifier is platform dependent.
00035  *
00036  *
00037  */
00038 
00039 #ifndef _SDL_joystick_h
00040 #define _SDL_joystick_h
00041 
00042 #include "SDL_stdinc.h"
00043 #include "SDL_error.h"
00044 
00045 #include "begin_code.h"
00046 /* Set up for C function definitions, even when using C++ */
00047 #ifdef __cplusplus
00048 extern "C" {
00049 #endif
00050 
00051 /**
00052  *  \file SDL_joystick.h
00053  *
00054  *  In order to use these functions, SDL_Init() must have been called
00055  *  with the ::SDL_INIT_JOYSTICK flag.  This causes SDL to scan the system
00056  *  for joysticks, and load appropriate drivers.
00057  *
00058  *  If you would like to receive joystick updates while the application
00059  *  is in the background, you should set the following hint before calling
00060  *  SDL_Init(): SDL_HINT_JOYSTICK_ALLOW_BACKGROUND_EVENTS
00061  */
00062 
00063 /* The joystick structure used to identify an SDL joystick */
00064 struct _SDL_Joystick;
00065 typedef struct _SDL_Joystick SDL_Joystick;
00066 
00067 /* A structure that encodes the stable unique id for a joystick device */
00068 typedef struct {
00069     Uint8 data[16];
00070 } SDL_JoystickGUID;
00071 
00072 typedef Sint32 SDL_JoystickID;
00073 
00074 
00075 /* Function prototypes */
00076 /**
00077  *  Count the number of joysticks attached to the system right now
00078  */
00079 extern DECLSPEC int SDLCALL SDL_NumJoysticks(void);
00080 
00081 /**
00082  *  Get the implementation dependent name of a joystick.
00083  *  This can be called before any joysticks are opened.
00084  *  If no name can be found, this function returns NULL.
00085  */
00086 extern DECLSPEC const char *SDLCALL SDL_JoystickNameForIndex(int device_index);
00087 
00088 /**
00089  *  Open a joystick for use.
00090  *  The index passed as an argument refers tothe N'th joystick on the system.
00091  *  This index is the value which will identify this joystick in future joystick
00092  *  events.
00093  *
00094  *  \return A joystick identifier, or NULL if an error occurred.
00095  */
00096 extern DECLSPEC SDL_Joystick *SDLCALL SDL_JoystickOpen(int device_index);
00097 
00098 /**
00099  *  Return the name for this currently opened joystick.
00100  *  If no name can be found, this function returns NULL.
00101  */
00102 extern DECLSPEC const char *SDLCALL SDL_JoystickName(SDL_Joystick * joystick);
00103 
00104 /**
00105  *  Return the GUID for the joystick at this index
00106  */
00107 extern DECLSPEC SDL_JoystickGUID SDLCALL SDL_JoystickGetDeviceGUID(int device_index);
00108 
00109 /**
00110  *  Return the GUID for this opened joystick
00111  */
00112 extern DECLSPEC SDL_JoystickGUID SDLCALL SDL_JoystickGetGUID(SDL_Joystick * joystick);
00113 
00114 /**
00115  *  Return a string representation for this guid. pszGUID must point to at least 33 bytes
00116  *  (32 for the string plus a NULL terminator).
00117  */
00118 extern DECLSPEC void SDLCALL SDL_JoystickGetGUIDString(SDL_JoystickGUID guid, char *pszGUID, int cbGUID);
00119 
00120 /**
00121  *  convert a string into a joystick formatted guid
00122  */
00123 extern DECLSPEC SDL_JoystickGUID SDLCALL SDL_JoystickGetGUIDFromString(const char *pchGUID);
00124 
00125 /**
00126  *  Returns SDL_TRUE if the joystick has been opened and currently connected, or SDL_FALSE if it has not.
00127  */
00128 extern DECLSPEC SDL_bool SDLCALL SDL_JoystickGetAttached(SDL_Joystick * joystick);
00129 
00130 /**
00131  *  Get the instance ID of an opened joystick or -1 if the joystick is invalid.
00132  */
00133 extern DECLSPEC SDL_JoystickID SDLCALL SDL_JoystickInstanceID(SDL_Joystick * joystick);
00134 
00135 /**
00136  *  Get the number of general axis controls on a joystick.
00137  */
00138 extern DECLSPEC int SDLCALL SDL_JoystickNumAxes(SDL_Joystick * joystick);
00139 
00140 /**
00141  *  Get the number of trackballs on a joystick.
00142  *
00143  *  Joystick trackballs have only relative motion events associated
00144  *  with them and their state cannot be polled.
00145  */
00146 extern DECLSPEC int SDLCALL SDL_JoystickNumBalls(SDL_Joystick * joystick);
00147 
00148 /**
00149  *  Get the number of POV hats on a joystick.
00150  */
00151 extern DECLSPEC int SDLCALL SDL_JoystickNumHats(SDL_Joystick * joystick);
00152 
00153 /**
00154  *  Get the number of buttons on a joystick.
00155  */
00156 extern DECLSPEC int SDLCALL SDL_JoystickNumButtons(SDL_Joystick * joystick);
00157 
00158 /**
00159  *  Update the current state of the open joysticks.
00160  *
00161  *  This is called automatically by the event loop if any joystick
00162  *  events are enabled.
00163  */
00164 extern DECLSPEC void SDLCALL SDL_JoystickUpdate(void);
00165 
00166 /**
00167  *  Enable/disable joystick event polling.
00168  *
00169  *  If joystick events are disabled, you must call SDL_JoystickUpdate()
00170  *  yourself and check the state of the joystick when you want joystick
00171  *  information.
00172  *
00173  *  The state can be one of ::SDL_QUERY, ::SDL_ENABLE or ::SDL_IGNORE.
00174  */
00175 extern DECLSPEC int SDLCALL SDL_JoystickEventState(int state);
00176 
00177 /**
00178  *  Get the current state of an axis control on a joystick.
00179  *
00180  *  The state is a value ranging from -32768 to 32767.
00181  *
00182  *  The axis indices start at index 0.
00183  */
00184 extern DECLSPEC Sint16 SDLCALL SDL_JoystickGetAxis(SDL_Joystick * joystick,
00185                                                    int axis);
00186 
00187 /**
00188  *  \name Hat positions
00189  */
00190 /* @{ */
00191 #define SDL_HAT_CENTERED    0x00
00192 #define SDL_HAT_UP      0x01
00193 #define SDL_HAT_RIGHT       0x02
00194 #define SDL_HAT_DOWN        0x04
00195 #define SDL_HAT_LEFT        0x08
00196 #define SDL_HAT_RIGHTUP     (SDL_HAT_RIGHT|SDL_HAT_UP)
00197 #define SDL_HAT_RIGHTDOWN   (SDL_HAT_RIGHT|SDL_HAT_DOWN)
00198 #define SDL_HAT_LEFTUP      (SDL_HAT_LEFT|SDL_HAT_UP)
00199 #define SDL_HAT_LEFTDOWN    (SDL_HAT_LEFT|SDL_HAT_DOWN)
00200 /* @} */
00201 
00202 /**
00203  *  Get the current state of a POV hat on a joystick.
00204  *
00205  *  The hat indices start at index 0.
00206  *
00207  *  \return The return value is one of the following positions:
00208  *           - ::SDL_HAT_CENTERED
00209  *           - ::SDL_HAT_UP
00210  *           - ::SDL_HAT_RIGHT
00211  *           - ::SDL_HAT_DOWN
00212  *           - ::SDL_HAT_LEFT
00213  *           - ::SDL_HAT_RIGHTUP
00214  *           - ::SDL_HAT_RIGHTDOWN
00215  *           - ::SDL_HAT_LEFTUP
00216  *           - ::SDL_HAT_LEFTDOWN
00217  */
00218 extern DECLSPEC Uint8 SDLCALL SDL_JoystickGetHat(SDL_Joystick * joystick,
00219                                                  int hat);
00220 
00221 /**
00222  *  Get the ball axis change since the last poll.
00223  *
00224  *  \return 0, or -1 if you passed it invalid parameters.
00225  *
00226  *  The ball indices start at index 0.
00227  */
00228 extern DECLSPEC int SDLCALL SDL_JoystickGetBall(SDL_Joystick * joystick,
00229                                                 int ball, int *dx, int *dy);
00230 
00231 /**
00232  *  Get the current state of a button on a joystick.
00233  *
00234  *  The button indices start at index 0.
00235  */
00236 extern DECLSPEC Uint8 SDLCALL SDL_JoystickGetButton(SDL_Joystick * joystick,
00237                                                     int button);
00238 
00239 /**
00240  *  Close a joystick previously opened with SDL_JoystickOpen().
00241  */
00242 extern DECLSPEC void SDLCALL SDL_JoystickClose(SDL_Joystick * joystick);
00243 
00244 
00245 /* Ends C function definitions when using C++ */
00246 #ifdef __cplusplus
00247 }
00248 #endif
00249 #include "close_code.h"
00250 
00251 #endif /* _SDL_joystick_h */
00252 
00253 /* vi: set ts=4 sw=4 expandtab: */