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1 /*
2   Simple DirectMedia Layer
3   Copyright (C) 1997-2016 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 SDL_Joystick associated with an instance id.
111  */
112 extern DECLSPEC SDL_Joystick *SDLCALL SDL_JoystickFromInstanceID(SDL_JoystickID joyid);
113 
114 /**
115  *  Return the name for this currently opened joystick.
116  *  If no name can be found, this function returns NULL.
117  */
118 extern DECLSPEC const char *SDLCALL SDL_JoystickName(SDL_Joystick * joystick);
119 
120 /**
121  *  Return the GUID for the joystick at this index
122  */
123 extern DECLSPEC SDL_JoystickGUID SDLCALL SDL_JoystickGetDeviceGUID(int device_index);
124 
125 /**
126  *  Return the GUID for this opened joystick
127  */
128 extern DECLSPEC SDL_JoystickGUID SDLCALL SDL_JoystickGetGUID(SDL_Joystick * joystick);
129 
130 /**
131  *  Return a string representation for this guid. pszGUID must point to at least 33 bytes
132  *  (32 for the string plus a NULL terminator).
133  */
134 extern DECLSPEC void SDLCALL SDL_JoystickGetGUIDString(SDL_JoystickGUID guid, char *pszGUID, int cbGUID);
135 
136 /**
137  *  convert a string into a joystick formatted guid
138  */
139 extern DECLSPEC SDL_JoystickGUID SDLCALL SDL_JoystickGetGUIDFromString(const char *pchGUID);
140 
141 /**
142  *  Returns SDL_TRUE if the joystick has been opened and currently connected, or SDL_FALSE if it has not.
143  */
144 extern DECLSPEC SDL_bool SDLCALL SDL_JoystickGetAttached(SDL_Joystick * joystick);
145 
146 /**
147  *  Get the instance ID of an opened joystick or -1 if the joystick is invalid.
148  */
149 extern DECLSPEC SDL_JoystickID SDLCALL SDL_JoystickInstanceID(SDL_Joystick * joystick);
150 
151 /**
152  *  Get the number of general axis controls on a joystick.
153  */
154 extern DECLSPEC int SDLCALL SDL_JoystickNumAxes(SDL_Joystick * joystick);
155 
156 /**
157  *  Get the number of trackballs on a joystick.
158  *
159  *  Joystick trackballs have only relative motion events associated
160  *  with them and their state cannot be polled.
161  */
162 extern DECLSPEC int SDLCALL SDL_JoystickNumBalls(SDL_Joystick * joystick);
163 
164 /**
165  *  Get the number of POV hats on a joystick.
166  */
167 extern DECLSPEC int SDLCALL SDL_JoystickNumHats(SDL_Joystick * joystick);
168 
169 /**
170  *  Get the number of buttons on a joystick.
171  */
172 extern DECLSPEC int SDLCALL SDL_JoystickNumButtons(SDL_Joystick * joystick);
173 
174 /**
175  *  Update the current state of the open joysticks.
176  *
177  *  This is called automatically by the event loop if any joystick
178  *  events are enabled.
179  */
180 extern DECLSPEC void SDLCALL SDL_JoystickUpdate(void);
181 
182 /**
183  *  Enable/disable joystick event polling.
184  *
185  *  If joystick events are disabled, you must call SDL_JoystickUpdate()
186  *  yourself and check the state of the joystick when you want joystick
187  *  information.
188  *
189  *  The state can be one of ::SDL_QUERY, ::SDL_ENABLE or ::SDL_IGNORE.
190  */
191 extern DECLSPEC int SDLCALL SDL_JoystickEventState(int state);
192 
193 /**
194  *  Get the current state of an axis control on a joystick.
195  *
196  *  The state is a value ranging from -32768 to 32767.
197  *
198  *  The axis indices start at index 0.
199  */
200 extern DECLSPEC Sint16 SDLCALL SDL_JoystickGetAxis(SDL_Joystick * joystick,
201                                                    int axis);
202 
203 /**
204  *  \name Hat positions
205  */
206 /* @{ */
207 #define SDL_HAT_CENTERED    0x00
208 #define SDL_HAT_UP          0x01
209 #define SDL_HAT_RIGHT       0x02
210 #define SDL_HAT_DOWN        0x04
211 #define SDL_HAT_LEFT        0x08
212 #define SDL_HAT_RIGHTUP     (SDL_HAT_RIGHT|SDL_HAT_UP)
213 #define SDL_HAT_RIGHTDOWN   (SDL_HAT_RIGHT|SDL_HAT_DOWN)
214 #define SDL_HAT_LEFTUP      (SDL_HAT_LEFT|SDL_HAT_UP)
215 #define SDL_HAT_LEFTDOWN    (SDL_HAT_LEFT|SDL_HAT_DOWN)
216 /* @} */
217 
218 /**
219  *  Get the current state of a POV hat on a joystick.
220  *
221  *  The hat indices start at index 0.
222  *
223  *  \return The return value is one of the following positions:
224  *           - ::SDL_HAT_CENTERED
225  *           - ::SDL_HAT_UP
226  *           - ::SDL_HAT_RIGHT
227  *           - ::SDL_HAT_DOWN
228  *           - ::SDL_HAT_LEFT
229  *           - ::SDL_HAT_RIGHTUP
230  *           - ::SDL_HAT_RIGHTDOWN
231  *           - ::SDL_HAT_LEFTUP
232  *           - ::SDL_HAT_LEFTDOWN
233  */
234 extern DECLSPEC Uint8 SDLCALL SDL_JoystickGetHat(SDL_Joystick * joystick,
235                                                  int hat);
236 
237 /**
238  *  Get the ball axis change since the last poll.
239  *
240  *  \return 0, or -1 if you passed it invalid parameters.
241  *
242  *  The ball indices start at index 0.
243  */
244 extern DECLSPEC int SDLCALL SDL_JoystickGetBall(SDL_Joystick * joystick,
245                                                 int ball, int *dx, int *dy);
246 
247 /**
248  *  Get the current state of a button on a joystick.
249  *
250  *  The button indices start at index 0.
251  */
252 extern DECLSPEC Uint8 SDLCALL SDL_JoystickGetButton(SDL_Joystick * joystick,
253                                                     int button);
254 
255 /**
256  *  Close a joystick previously opened with SDL_JoystickOpen().
257  */
258 extern DECLSPEC void SDLCALL SDL_JoystickClose(SDL_Joystick * joystick);
259 
260 /**
261  *  Return the battery level of this joystick
262  */
263 extern DECLSPEC SDL_JoystickPowerLevel SDLCALL SDL_JoystickCurrentPowerLevel(SDL_Joystick * joystick);
264 
265 /* Ends C function definitions when using C++ */
266 #ifdef __cplusplus
267 }
268 #endif
269 #include "close_code.h"
270 
271 #endif /* _SDL_joystick_h */
272 
273 /* vi: set ts=4 sw=4 expandtab: */
274