include/SDL_joystick.h
author Sam Lantinga <slouken@libsdl.org>
Wed, 30 Sep 2015 15:39:30 -0700
changeset 9884 26b595dea221
parent 9806 2deeef7b793c
child 9916 9429bc102632
permissions -rw-r--r--
SDL - added new SDL_JoystickCurrentPowerLevel() API that returns the battery level of the selected joystick. Currently only implemented for XInput devices, other platforms are a TODO.

CR: Sam
     1 /*
     2   Simple DirectMedia Layer
     3   Copyright (C) 1997-2015 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 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 typedef enum
    75 {
    76     SDL_JOYSTICK_POWER_UNKNOWN = -1,
    77     SDL_JOYSTICK_POWER_EMPTY,
    78     SDL_JOYSTICK_POWER_LOW,
    79     SDL_JOYSTICK_POWER_MEDIUM,
    80     SDL_JOYSTICK_POWER_FULL,
    81     SDL_JOYSTICK_POWER_WIRED,
    82     SDL_JOYSTICK_POWER_MAX
    83 } SDL_JoystickPowerLevel;
    84 
    85 /* Function prototypes */
    86 /**
    87  *  Count the number of joysticks attached to the system right now
    88  */
    89 extern DECLSPEC int SDLCALL SDL_NumJoysticks(void);
    90 
    91 /**
    92  *  Get the implementation dependent name of a joystick.
    93  *  This can be called before any joysticks are opened.
    94  *  If no name can be found, this function returns NULL.
    95  */
    96 extern DECLSPEC const char *SDLCALL SDL_JoystickNameForIndex(int device_index);
    97 
    98 /**
    99  *  Open a joystick for use.
   100  *  The index passed as an argument refers to the N'th joystick on the system.
   101  *  This index is not the value which will identify this joystick in future
   102  *  joystick events.  The joystick's instance id (::SDL_JoystickID) will be used
   103  *  there instead.
   104  *
   105  *  \return A joystick identifier, or NULL if an error occurred.
   106  */
   107 extern DECLSPEC SDL_Joystick *SDLCALL SDL_JoystickOpen(int device_index);
   108 
   109 /**
   110  *  Return the name for this currently opened joystick.
   111  *  If no name can be found, this function returns NULL.
   112  */
   113 extern DECLSPEC const char *SDLCALL SDL_JoystickName(SDL_Joystick * joystick);
   114 
   115 /**
   116  *  Return the GUID for the joystick at this index
   117  */
   118 extern DECLSPEC SDL_JoystickGUID SDLCALL SDL_JoystickGetDeviceGUID(int device_index);
   119 
   120 /**
   121  *  Return the GUID for this opened joystick
   122  */
   123 extern DECLSPEC SDL_JoystickGUID SDLCALL SDL_JoystickGetGUID(SDL_Joystick * joystick);
   124 
   125 /**
   126  *  Return a string representation for this guid. pszGUID must point to at least 33 bytes
   127  *  (32 for the string plus a NULL terminator).
   128  */
   129 extern DECLSPEC void SDLCALL SDL_JoystickGetGUIDString(SDL_JoystickGUID guid, char *pszGUID, int cbGUID);
   130 
   131 /**
   132  *  convert a string into a joystick formatted guid
   133  */
   134 extern DECLSPEC SDL_JoystickGUID SDLCALL SDL_JoystickGetGUIDFromString(const char *pchGUID);
   135 
   136 /**
   137  *  Returns SDL_TRUE if the joystick has been opened and currently connected, or SDL_FALSE if it has not.
   138  */
   139 extern DECLSPEC SDL_bool SDLCALL SDL_JoystickGetAttached(SDL_Joystick * joystick);
   140 
   141 /**
   142  *  Get the instance ID of an opened joystick or -1 if the joystick is invalid.
   143  */
   144 extern DECLSPEC SDL_JoystickID SDLCALL SDL_JoystickInstanceID(SDL_Joystick * joystick);
   145 
   146 /**
   147  *  Get the number of general axis controls on a joystick.
   148  */
   149 extern DECLSPEC int SDLCALL SDL_JoystickNumAxes(SDL_Joystick * joystick);
   150 
   151 /**
   152  *  Get the number of trackballs on a joystick.
   153  *
   154  *  Joystick trackballs have only relative motion events associated
   155  *  with them and their state cannot be polled.
   156  */
   157 extern DECLSPEC int SDLCALL SDL_JoystickNumBalls(SDL_Joystick * joystick);
   158 
   159 /**
   160  *  Get the number of POV hats on a joystick.
   161  */
   162 extern DECLSPEC int SDLCALL SDL_JoystickNumHats(SDL_Joystick * joystick);
   163 
   164 /**
   165  *  Get the number of buttons on a joystick.
   166  */
   167 extern DECLSPEC int SDLCALL SDL_JoystickNumButtons(SDL_Joystick * joystick);
   168 
   169 /**
   170  *  Update the current state of the open joysticks.
   171  *
   172  *  This is called automatically by the event loop if any joystick
   173  *  events are enabled.
   174  */
   175 extern DECLSPEC void SDLCALL SDL_JoystickUpdate(void);
   176 
   177 /**
   178  *  Enable/disable joystick event polling.
   179  *
   180  *  If joystick events are disabled, you must call SDL_JoystickUpdate()
   181  *  yourself and check the state of the joystick when you want joystick
   182  *  information.
   183  *
   184  *  The state can be one of ::SDL_QUERY, ::SDL_ENABLE or ::SDL_IGNORE.
   185  */
   186 extern DECLSPEC int SDLCALL SDL_JoystickEventState(int state);
   187 
   188 /**
   189  *  Get the current state of an axis control on a joystick.
   190  *
   191  *  The state is a value ranging from -32768 to 32767.
   192  *
   193  *  The axis indices start at index 0.
   194  */
   195 extern DECLSPEC Sint16 SDLCALL SDL_JoystickGetAxis(SDL_Joystick * joystick,
   196                                                    int axis);
   197 
   198 /**
   199  *  \name Hat positions
   200  */
   201 /* @{ */
   202 #define SDL_HAT_CENTERED    0x00
   203 #define SDL_HAT_UP          0x01
   204 #define SDL_HAT_RIGHT       0x02
   205 #define SDL_HAT_DOWN        0x04
   206 #define SDL_HAT_LEFT        0x08
   207 #define SDL_HAT_RIGHTUP     (SDL_HAT_RIGHT|SDL_HAT_UP)
   208 #define SDL_HAT_RIGHTDOWN   (SDL_HAT_RIGHT|SDL_HAT_DOWN)
   209 #define SDL_HAT_LEFTUP      (SDL_HAT_LEFT|SDL_HAT_UP)
   210 #define SDL_HAT_LEFTDOWN    (SDL_HAT_LEFT|SDL_HAT_DOWN)
   211 /* @} */
   212 
   213 /**
   214  *  Get the current state of a POV hat on a joystick.
   215  *
   216  *  The hat indices start at index 0.
   217  *
   218  *  \return The return value is one of the following positions:
   219  *           - ::SDL_HAT_CENTERED
   220  *           - ::SDL_HAT_UP
   221  *           - ::SDL_HAT_RIGHT
   222  *           - ::SDL_HAT_DOWN
   223  *           - ::SDL_HAT_LEFT
   224  *           - ::SDL_HAT_RIGHTUP
   225  *           - ::SDL_HAT_RIGHTDOWN
   226  *           - ::SDL_HAT_LEFTUP
   227  *           - ::SDL_HAT_LEFTDOWN
   228  */
   229 extern DECLSPEC Uint8 SDLCALL SDL_JoystickGetHat(SDL_Joystick * joystick,
   230                                                  int hat);
   231 
   232 /**
   233  *  Get the ball axis change since the last poll.
   234  *
   235  *  \return 0, or -1 if you passed it invalid parameters.
   236  *
   237  *  The ball indices start at index 0.
   238  */
   239 extern DECLSPEC int SDLCALL SDL_JoystickGetBall(SDL_Joystick * joystick,
   240                                                 int ball, int *dx, int *dy);
   241 
   242 /**
   243  *  Get the current state of a button on a joystick.
   244  *
   245  *  The button indices start at index 0.
   246  */
   247 extern DECLSPEC Uint8 SDLCALL SDL_JoystickGetButton(SDL_Joystick * joystick,
   248                                                     int button);
   249 
   250 /**
   251  *  Close a joystick previously opened with SDL_JoystickOpen().
   252  */
   253 extern DECLSPEC void SDLCALL SDL_JoystickClose(SDL_Joystick * joystick);
   254 
   255 /**
   256 *  Return the battery level of this joystick
   257 */
   258 extern DECLSPEC SDL_JoystickPowerLevel SDLCALL SDL_JoystickCurrentPowerLevel(SDL_Joystick * joystick);
   259 
   260 
   261 /* Ends C function definitions when using C++ */
   262 #ifdef __cplusplus
   263 }
   264 #endif
   265 #include "close_code.h"
   266 
   267 #endif /* _SDL_joystick_h */
   268 
   269 /* vi: set ts=4 sw=4 expandtab: */