1/*
2 Simple DirectMedia Layer
3 Copyright (C) 1997-2018 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_sensor.h
24 *
25 * Include file for SDL sensor event handling
26 *
27 */
28
29#ifndef _SDL_sensor_h
30#define _SDL_sensor_h
31
32#include "SDL_stdinc.h"
33#include "SDL_error.h"
34
35#include "begin_code.h"
36/* Set up for C function definitions, even when using C++ */
37#ifdef __cplusplus
38/* *INDENT-OFF* */
39extern "C" {
40/* *INDENT-ON* */
41#endif
42
43/**
44 * \brief SDL_sensor.h
45 *
46 * In order to use these functions, SDL_Init() must have been called
47 * with the ::SDL_INIT_SENSOR flag. This causes SDL to scan the system
48 * for sensors, and load appropriate drivers.
49 */
50
51struct _SDL_Sensor;
52typedef struct _SDL_Sensor SDL_Sensor;
53
54/**
55 * This is a unique ID for a sensor for the time it is connected to the system,
56 * and is never reused for the lifetime of the application.
57 *
58 * The ID value starts at 0 and increments from there. The value -1 is an invalid ID.
59 */
60typedef Sint32 SDL_SensorID;
61
62/* The different sensors defined by SDL
63 *
64 * Additional sensors may be available, using platform dependent semantics.
65 *
66 * Hare are the additional Android sensors:
67 * https://developer.android.com/reference/android/hardware/SensorEvent.html#values
68 */
69typedef enum
70{
71 SDL_SENSOR_INVALID = -1, /**< Returned for an invalid sensor */
72 SDL_SENSOR_UNKNOWN, /**< Unknown sensor type */
73 SDL_SENSOR_ACCEL, /**< Accelerometer */
74 SDL_SENSOR_GYRO /**< Gyroscope */
75} SDL_SensorType;
76
77/**
78 * Accelerometer sensor
79 *
80 * The accelerometer returns the current acceleration in SI meters per
81 * second squared. This includes gravity, so a device at rest will have
82 * an acceleration of SDL_STANDARD_GRAVITY straight down.
83 *
84 * values[0]: Acceleration on the x axis
85 * values[1]: Acceleration on the y axis
86 * values[2]: Acceleration on the z axis
87 *
88 * For phones held in portrait mode, the axes are defined as follows:
89 * -X ... +X : left ... right
90 * -Y ... +Y : bottom ... top
91 * -Z ... +Z : farther ... closer
92 *
93 * The axis data is not changed when the phone is rotated.
94 *
95 * \sa SDL_GetDisplayOrientation()
96 */
97#define SDL_STANDARD_GRAVITY 9.80665f
98
99/**
100 * Gyroscope sensor
101 *
102 * The gyroscope returns the current rate of rotation in radians per second.
103 * The rotation is positive in the counter-clockwise direction. That is,
104 * an observer looking from a positive location on one of the axes would
105 * see positive rotation on that axis when it appeared to be rotating
106 * counter-clockwise.
107 *
108 * values[0]: Angular speed around the x axis
109 * values[1]: Angular speed around the y axis
110 * values[2]: Angular speed around the z axis
111 *
112 * For phones held in portrait mode, the axes are defined as follows:
113 * -X ... +X : left ... right
114 * -Y ... +Y : bottom ... top
115 * -Z ... +Z : farther ... closer
116 *
117 * The axis data is not changed when the phone is rotated.
118 *
119 * \sa SDL_GetDisplayOrientation()
120 */
121
122/* Function prototypes */
123
124/**
125 * \brief Count the number of sensors attached to the system right now
126 */
127extern DECLSPEC int SDLCALL SDL_NumSensors(void);
128
129/**
130 * \brief Get the implementation dependent name of a sensor.
131 *
132 * This can be called before any sensors are opened.
133 *
134 * \return The sensor name, or NULL if device_index is out of range.
135 */
136extern DECLSPEC const char *SDLCALL SDL_SensorGetDeviceName(int device_index);
137
138/**
139 * \brief Get the type of a sensor.
140 *
141 * This can be called before any sensors are opened.
142 *
143 * \return The sensor type, or SDL_SENSOR_INVALID if device_index is out of range.
144 */
145extern DECLSPEC SDL_SensorType SDLCALL SDL_SensorGetDeviceType(int device_index);
146
147/**
148 * \brief Get the platform dependent type of a sensor.
149 *
150 * This can be called before any sensors are opened.
151 *
152 * \return The sensor platform dependent type, or -1 if device_index is out of range.
153 */
154extern DECLSPEC int SDLCALL SDL_SensorGetDeviceNonPortableType(int device_index);
155
156/**
157 * \brief Get the instance ID of a sensor.
158 *
159 * This can be called before any sensors are opened.
160 *
161 * \return The sensor instance ID, or -1 if device_index is out of range.
162 */
163extern DECLSPEC SDL_SensorID SDLCALL SDL_SensorGetDeviceInstanceID(int device_index);
164
165/**
166 * \brief Open a sensor for use.
167 *
168 * The index passed as an argument refers to the N'th sensor on the system.
169 *
170 * \return A sensor identifier, or NULL if an error occurred.
171 */
172extern DECLSPEC SDL_Sensor *SDLCALL SDL_SensorOpen(int device_index);
173
174/**
175 * Return the SDL_Sensor associated with an instance id.
176 */
177extern DECLSPEC SDL_Sensor *SDLCALL SDL_SensorFromInstanceID(SDL_SensorID instance_id);
178
179/**
180 * \brief Get the implementation dependent name of a sensor.
181 *
182 * \return The sensor name, or NULL if the sensor is NULL.
183 */
184extern DECLSPEC const char *SDLCALL SDL_SensorGetName(SDL_Sensor *sensor);
185
186/**
187 * \brief Get the type of a sensor.
188 *
189 * This can be called before any sensors are opened.
190 *
191 * \return The sensor type, or SDL_SENSOR_INVALID if the sensor is NULL.
192 */
193extern DECLSPEC SDL_SensorType SDLCALL SDL_SensorGetType(SDL_Sensor *sensor);
194
195/**
196 * \brief Get the platform dependent type of a sensor.
197 *
198 * This can be called before any sensors are opened.
199 *
200 * \return The sensor platform dependent type, or -1 if the sensor is NULL.
201 */
202extern DECLSPEC int SDLCALL SDL_SensorGetNonPortableType(SDL_Sensor *sensor);
203
204/**
205 * \brief Get the instance ID of a sensor.
206 *
207 * This can be called before any sensors are opened.
208 *
209 * \return The sensor instance ID, or -1 if the sensor is NULL.
210 */
211extern DECLSPEC SDL_SensorID SDLCALL SDL_SensorGetInstanceID(SDL_Sensor *sensor);
212
213/**
214 * Get the current state of an opened sensor.
215 *
216 * The number of values and interpretation of the data is sensor dependent.
217 *
218 * \param sensor The sensor to query
219 * \param data A pointer filled with the current sensor state
220 * \param num_values The number of values to write to data
221 *
222 * \return 0 or -1 if an error occurred.
223 */
224extern DECLSPEC int SDLCALL SDL_SensorGetData(SDL_Sensor * sensor, float *data, int num_values);
225
226/**
227 * Close a sensor previously opened with SDL_SensorOpen()
228 */
229extern DECLSPEC void SDLCALL SDL_SensorClose(SDL_Sensor * sensor);
230
231/**
232 * Update the current state of the open sensors.
233 *
234 * This is called automatically by the event loop if sensor events are enabled.
235 *
236 * This needs to be called from the thread that initialized the sensor subsystem.
237 */
238extern DECLSPEC void SDLCALL SDL_SensorUpdate(void);
239
240
241/* Ends C function definitions when using C++ */
242#ifdef __cplusplus
243/* *INDENT-OFF* */
244}
245/* *INDENT-ON* */
246#endif
247#include "close_code.h"
248
249#endif /* _SDL_sensor_h */
250
251/* vi: set ts=4 sw=4 expandtab: */
252