include/SDL_joystick.h
author Sam Lantinga <slouken@libsdl.org>
Wed, 04 Jan 2017 10:28:07 -0800
changeset 10752 c9d3ff50dfcf
parent 10737 3406a0f8b041
child 10855 fc18eb831c08
permissions -rw-r--r--
Added SDL_JoystickGetAxisInitialState() to get a joystick axis' initial value.
This is useful for controller mapping programs to determine an axis' zero state
     1 /*
     2   Simple DirectMedia Layer
     3   Copyright (C) 1997-2017 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 /**
    64  * The joystick structure used to identify an SDL joystick
    65  */
    66 struct _SDL_Joystick;
    67 typedef struct _SDL_Joystick SDL_Joystick;
    68 
    69 /* A structure that encodes the stable unique id for a joystick device */
    70 typedef struct {
    71     Uint8 data[16];
    72 } SDL_JoystickGUID;
    73 
    74 typedef Sint32 SDL_JoystickID;
    75 
    76 typedef enum
    77 {
    78     SDL_JOYSTICK_POWER_UNKNOWN = -1,
    79     SDL_JOYSTICK_POWER_EMPTY,
    80     SDL_JOYSTICK_POWER_LOW,
    81     SDL_JOYSTICK_POWER_MEDIUM,
    82     SDL_JOYSTICK_POWER_FULL,
    83     SDL_JOYSTICK_POWER_WIRED,
    84     SDL_JOYSTICK_POWER_MAX
    85 } SDL_JoystickPowerLevel;
    86 
    87 /* Function prototypes */
    88 /**
    89  *  Count the number of joysticks attached to the system right now
    90  */
    91 extern DECLSPEC int SDLCALL SDL_NumJoysticks(void);
    92 
    93 /**
    94  *  Get the implementation dependent name of a joystick.
    95  *  This can be called before any joysticks are opened.
    96  *  If no name can be found, this function returns NULL.
    97  */
    98 extern DECLSPEC const char *SDLCALL SDL_JoystickNameForIndex(int device_index);
    99 
   100 /**
   101  *  Return the GUID for the joystick at this index
   102  *  This can be called before any joysticks are opened.
   103  */
   104 extern DECLSPEC SDL_JoystickGUID SDLCALL SDL_JoystickGetDeviceGUID(int device_index);
   105 
   106 /**
   107  *  Get the USB vendor ID of a joystick, if available.
   108  *  This can be called before any joysticks are opened.
   109  *  If the vendor ID isn't available this function returns 0.
   110  */
   111 extern DECLSPEC Uint16 SDLCALL SDL_JoystickGetDeviceVendor(int device_index);
   112 
   113 /**
   114  *  Get the USB product ID of a joystick, if available.
   115  *  This can be called before any joysticks are opened.
   116  *  If the product ID isn't available this function returns 0.
   117  */
   118 extern DECLSPEC Uint16 SDLCALL SDL_JoystickGetDeviceProduct(int device_index);
   119 
   120 /**
   121  *  Get the product version of a joystick, if available.
   122  *  This can be called before any joysticks are opened.
   123  *  If the product version isn't available this function returns 0.
   124  */
   125 extern DECLSPEC Uint16 SDLCALL SDL_JoystickGetDeviceProductVersion(int device_index);
   126 
   127 /**
   128  *  Open a joystick for use.
   129  *  The index passed as an argument refers to the N'th joystick on the system.
   130  *  This index is not the value which will identify this joystick in future
   131  *  joystick events.  The joystick's instance id (::SDL_JoystickID) will be used
   132  *  there instead.
   133  *
   134  *  \return A joystick identifier, or NULL if an error occurred.
   135  */
   136 extern DECLSPEC SDL_Joystick *SDLCALL SDL_JoystickOpen(int device_index);
   137 
   138 /**
   139  * Return the SDL_Joystick associated with an instance id.
   140  */
   141 extern DECLSPEC SDL_Joystick *SDLCALL SDL_JoystickFromInstanceID(SDL_JoystickID joyid);
   142 
   143 /**
   144  *  Return the name for this currently opened joystick.
   145  *  If no name can be found, this function returns NULL.
   146  */
   147 extern DECLSPEC const char *SDLCALL SDL_JoystickName(SDL_Joystick * joystick);
   148 
   149 /**
   150  *  Return the GUID for this opened joystick
   151  */
   152 extern DECLSPEC SDL_JoystickGUID SDLCALL SDL_JoystickGetGUID(SDL_Joystick * joystick);
   153 
   154 /**
   155  *  Get the USB vendor ID of an opened joystick, if available.
   156  *  If the vendor ID isn't available this function returns 0.
   157  */
   158 extern DECLSPEC Uint16 SDLCALL SDL_JoystickGetVendor(SDL_Joystick * joystick);
   159 
   160 /**
   161  *  Get the USB product ID of an opened joystick, if available.
   162  *  If the product ID isn't available this function returns 0.
   163  */
   164 extern DECLSPEC Uint16 SDLCALL SDL_JoystickGetProduct(SDL_Joystick * joystick);
   165 
   166 /**
   167  *  Get the product version of an opened joystick, if available.
   168  *  If the product version isn't available this function returns 0.
   169  */
   170 extern DECLSPEC Uint16 SDLCALL SDL_JoystickGetProductVersion(SDL_Joystick * joystick);
   171 
   172 /**
   173  *  Return a string representation for this guid. pszGUID must point to at least 33 bytes
   174  *  (32 for the string plus a NULL terminator).
   175  */
   176 extern DECLSPEC void SDLCALL SDL_JoystickGetGUIDString(SDL_JoystickGUID guid, char *pszGUID, int cbGUID);
   177 
   178 /**
   179  *  Convert a string into a joystick guid
   180  */
   181 extern DECLSPEC SDL_JoystickGUID SDLCALL SDL_JoystickGetGUIDFromString(const char *pchGUID);
   182 
   183 /**
   184  *  Returns SDL_TRUE if the joystick has been opened and currently connected, or SDL_FALSE if it has not.
   185  */
   186 extern DECLSPEC SDL_bool SDLCALL SDL_JoystickGetAttached(SDL_Joystick * joystick);
   187 
   188 /**
   189  *  Get the instance ID of an opened joystick or -1 if the joystick is invalid.
   190  */
   191 extern DECLSPEC SDL_JoystickID SDLCALL SDL_JoystickInstanceID(SDL_Joystick * joystick);
   192 
   193 /**
   194  *  Get the number of general axis controls on a joystick.
   195  */
   196 extern DECLSPEC int SDLCALL SDL_JoystickNumAxes(SDL_Joystick * joystick);
   197 
   198 /**
   199  *  Get the number of trackballs on a joystick.
   200  *
   201  *  Joystick trackballs have only relative motion events associated
   202  *  with them and their state cannot be polled.
   203  */
   204 extern DECLSPEC int SDLCALL SDL_JoystickNumBalls(SDL_Joystick * joystick);
   205 
   206 /**
   207  *  Get the number of POV hats on a joystick.
   208  */
   209 extern DECLSPEC int SDLCALL SDL_JoystickNumHats(SDL_Joystick * joystick);
   210 
   211 /**
   212  *  Get the number of buttons on a joystick.
   213  */
   214 extern DECLSPEC int SDLCALL SDL_JoystickNumButtons(SDL_Joystick * joystick);
   215 
   216 /**
   217  *  Update the current state of the open joysticks.
   218  *
   219  *  This is called automatically by the event loop if any joystick
   220  *  events are enabled.
   221  */
   222 extern DECLSPEC void SDLCALL SDL_JoystickUpdate(void);
   223 
   224 /**
   225  *  Enable/disable joystick event polling.
   226  *
   227  *  If joystick events are disabled, you must call SDL_JoystickUpdate()
   228  *  yourself and check the state of the joystick when you want joystick
   229  *  information.
   230  *
   231  *  The state can be one of ::SDL_QUERY, ::SDL_ENABLE or ::SDL_IGNORE.
   232  */
   233 extern DECLSPEC int SDLCALL SDL_JoystickEventState(int state);
   234 
   235 #define SDL_JOYSTICK_AXIS_MAX   32767
   236 #define SDL_JOYSTICK_AXIS_MIN   -32768
   237 /**
   238  *  Get the current state of an axis control on a joystick.
   239  *
   240  *  The state is a value ranging from -32768 to 32767.
   241  *
   242  *  The axis indices start at index 0.
   243  */
   244 extern DECLSPEC Sint16 SDLCALL SDL_JoystickGetAxis(SDL_Joystick * joystick,
   245                                                    int axis);
   246 
   247 /**
   248  *  Get the initial state of an axis control on a joystick.
   249  *
   250  *  The state is a value ranging from -32768 to 32767.
   251  *
   252  *  The axis indices start at index 0.
   253  *
   254  *  \return SDL_TRUE if this axis has any initial value, or SDL_FALSE if not.
   255  */
   256 extern DECLSPEC SDL_bool SDLCALL SDL_JoystickGetAxisInitialState(SDL_Joystick * joystick,
   257                                                    int axis, Sint16 *state);
   258 
   259 /**
   260  *  \name Hat positions
   261  */
   262 /* @{ */
   263 #define SDL_HAT_CENTERED    0x00
   264 #define SDL_HAT_UP          0x01
   265 #define SDL_HAT_RIGHT       0x02
   266 #define SDL_HAT_DOWN        0x04
   267 #define SDL_HAT_LEFT        0x08
   268 #define SDL_HAT_RIGHTUP     (SDL_HAT_RIGHT|SDL_HAT_UP)
   269 #define SDL_HAT_RIGHTDOWN   (SDL_HAT_RIGHT|SDL_HAT_DOWN)
   270 #define SDL_HAT_LEFTUP      (SDL_HAT_LEFT|SDL_HAT_UP)
   271 #define SDL_HAT_LEFTDOWN    (SDL_HAT_LEFT|SDL_HAT_DOWN)
   272 /* @} */
   273 
   274 /**
   275  *  Get the current state of a POV hat on a joystick.
   276  *
   277  *  The hat indices start at index 0.
   278  *
   279  *  \return The return value is one of the following positions:
   280  *           - ::SDL_HAT_CENTERED
   281  *           - ::SDL_HAT_UP
   282  *           - ::SDL_HAT_RIGHT
   283  *           - ::SDL_HAT_DOWN
   284  *           - ::SDL_HAT_LEFT
   285  *           - ::SDL_HAT_RIGHTUP
   286  *           - ::SDL_HAT_RIGHTDOWN
   287  *           - ::SDL_HAT_LEFTUP
   288  *           - ::SDL_HAT_LEFTDOWN
   289  */
   290 extern DECLSPEC Uint8 SDLCALL SDL_JoystickGetHat(SDL_Joystick * joystick,
   291                                                  int hat);
   292 
   293 /**
   294  *  Get the ball axis change since the last poll.
   295  *
   296  *  \return 0, or -1 if you passed it invalid parameters.
   297  *
   298  *  The ball indices start at index 0.
   299  */
   300 extern DECLSPEC int SDLCALL SDL_JoystickGetBall(SDL_Joystick * joystick,
   301                                                 int ball, int *dx, int *dy);
   302 
   303 /**
   304  *  Get the current state of a button on a joystick.
   305  *
   306  *  The button indices start at index 0.
   307  */
   308 extern DECLSPEC Uint8 SDLCALL SDL_JoystickGetButton(SDL_Joystick * joystick,
   309                                                     int button);
   310 
   311 /**
   312  *  Close a joystick previously opened with SDL_JoystickOpen().
   313  */
   314 extern DECLSPEC void SDLCALL SDL_JoystickClose(SDL_Joystick * joystick);
   315 
   316 /**
   317  *  Return the battery level of this joystick
   318  */
   319 extern DECLSPEC SDL_JoystickPowerLevel SDLCALL SDL_JoystickCurrentPowerLevel(SDL_Joystick * joystick);
   320 
   321 /* Ends C function definitions when using C++ */
   322 #ifdef __cplusplus
   323 }
   324 #endif
   325 #include "close_code.h"
   326 
   327 #endif /* SDL_joystick_h_ */
   328 
   329 /* vi: set ts=4 sw=4 expandtab: */