SDL/include/SDL_joystick.h

/*
  Simple DirectMedia Layer
  Copyright (C) 1997-2021 Sam Lantinga <slouken@libsdl.org>

  This software is provided 'as-is', without any express or implied
  warranty.  In no event will the authors be held liable for any damages
  arising from the use of this software.

  Permission is granted to anyone to use this software for any purpose,
  including commercial applications, and to alter it and redistribute it
  freely, subject to the following restrictions:

  1. The origin of this software must not be misrepresented; you must not
     claim that you wrote the original software. If you use this software
     in a product, an acknowledgment in the product documentation would be
     appreciated but is not required.
  2. Altered source versions must be plainly marked as such, and must not be
     misrepresented as being the original software.
  3. This notice may not be removed or altered from any source distribution.
*/

/**
 *  \file SDL_joystick.h
 *
 *  Include file for SDL joystick event handling
 *
 * The term "device_index" identifies currently plugged in joystick devices between 0 and SDL_NumJoysticks(), with the exact joystick
 *   behind a device_index changing as joysticks are plugged and unplugged.
 *
 * The term "instance_id" is the current instantiation of a joystick device in the system, if the joystick is removed and then re-inserted
 *   then it will get a new instance_id, instance_id's are monotonically increasing identifiers of a joystick plugged in.
 *
 * The term "player_index" is the number assigned to a player on a specific
 *   controller. For XInput controllers this returns the XInput user index.
 *   Many joysticks will not be able to supply this information.
 *
 * The term JoystickGUID is a stable 128-bit identifier for a joystick device that does not change over time, it identifies class of
 *   the device (a X360 wired controller for example). This identifier is platform dependent.
 */

#ifndef SDL_joystick_h_
#define SDL_joystick_h_

#include "SDL_stdinc.h"
#include "SDL_error.h"

#include "begin_code.h"
/* Set up for C function definitions, even when using C++ */
#ifdef __cplusplus
extern "C" {
#endif

/**
 *  \file SDL_joystick.h
 *
 *  In order to use these functions, SDL_Init() must have been called
 *  with the ::SDL_INIT_JOYSTICK flag.  This causes SDL to scan the system
 *  for joysticks, and load appropriate drivers.
 *
 *  If you would like to receive joystick updates while the application
 *  is in the background, you should set the following hint before calling
 *  SDL_Init(): SDL_HINT_JOYSTICK_ALLOW_BACKGROUND_EVENTS
 */

/**
 * The joystick structure used to identify an SDL joystick
 */
struct _SDL_Joystick;
typedef struct _SDL_Joystick SDL_Joystick;

/* A structure that encodes the stable unique id for a joystick device */
typedef struct {
    Uint8 data[16];
} SDL_JoystickGUID;

/**
 * This is a unique ID for a joystick for the time it is connected to the system,
 * and is never reused for the lifetime of the application. If the joystick is
 * disconnected and reconnected, it will get a new ID.
 *
 * The ID value starts at 0 and increments from there. The value -1 is an invalid ID.
 */
typedef Sint32 SDL_JoystickID;

typedef enum
{
    SDL_JOYSTICK_TYPE_UNKNOWN,
    SDL_JOYSTICK_TYPE_GAMECONTROLLER,
    SDL_JOYSTICK_TYPE_WHEEL,
    SDL_JOYSTICK_TYPE_ARCADE_STICK,
    SDL_JOYSTICK_TYPE_FLIGHT_STICK,
    SDL_JOYSTICK_TYPE_DANCE_PAD,
    SDL_JOYSTICK_TYPE_GUITAR,
    SDL_JOYSTICK_TYPE_DRUM_KIT,
    SDL_JOYSTICK_TYPE_ARCADE_PAD,
    SDL_JOYSTICK_TYPE_THROTTLE
} SDL_JoystickType;

typedef enum
{
    SDL_JOYSTICK_POWER_UNKNOWN = -1,
    SDL_JOYSTICK_POWER_EMPTY,   /* <= 5% */
    SDL_JOYSTICK_POWER_LOW,     /* <= 20% */
    SDL_JOYSTICK_POWER_MEDIUM,  /* <= 70% */
    SDL_JOYSTICK_POWER_FULL,    /* <= 100% */
    SDL_JOYSTICK_POWER_WIRED,
    SDL_JOYSTICK_POWER_MAX
} SDL_JoystickPowerLevel;

/* Set max recognized G-force from accelerometer
   See src/joystick/uikit/SDL_sysjoystick.m for notes on why this is needed
 */
#define SDL_IPHONE_MAX_GFORCE 5.0


/* Function prototypes */

/**
 * Locking for multi-threaded access to the joystick API
 *
 * If you are using the joystick API or handling events from multiple threads
 * you should use these locking functions to protect access to the joysticks.
 *
 * In particular, you are guaranteed that the joystick list won't change, so
 * the API functions that take a joystick index will be valid, and joystick
 * and game controller events will not be delivered.
 *
 * \since This function is available since SDL 2.0.7.
 */
extern DECLSPEC void SDLCALL SDL_LockJoysticks(void);


/**
 * Unlocking for multi-threaded access to the joystick API
 *
 * If you are using the joystick API or handling events from multiple threads
 * you should use these locking functions to protect access to the joysticks.
 *
 * In particular, you are guaranteed that the joystick list won't change, so
 * the API functions that take a joystick index will be valid, and joystick
 * and game controller events will not be delivered.
 *
 * \since This function is available since SDL 2.0.7.
 */
extern DECLSPEC void SDLCALL SDL_UnlockJoysticks(void);

/**
 * Count the number of joysticks attached to the system.
 *
 * \returns the number of attached joysticks on success or a negative error
 *          code on failure; call SDL_GetError() for more information.
 *
 * \since This function is available since SDL 2.0.0.
 *
 * \sa SDL_JoystickName
 * \sa SDL_JoystickOpen
 */
extern DECLSPEC int SDLCALL SDL_NumJoysticks(void);

/**
 * Get the implementation dependent name of a joystick.
 *
 * This can be called before any joysticks are opened.
 *
 * \param device_index the index of the joystick to query (the N'th joystick
 *                     on the system)
 * \returns the name of the selected joystick. If no name can be found, this
 *          function returns NULL; call SDL_GetError() for more information.
 *
 * \since This function is available since SDL 2.0.0.
 *
 * \sa SDL_JoystickName
 * \sa SDL_JoystickOpen
 */
extern DECLSPEC const char *SDLCALL SDL_JoystickNameForIndex(int device_index);

/**
 * Get the player index of a joystick, or -1 if it's not available This can be
 * called before any joysticks are opened.
 *
 * \since This function is available since SDL 2.0.9.
 */
extern DECLSPEC int SDLCALL SDL_JoystickGetDevicePlayerIndex(int device_index);

/**
 * Get the implementation-dependent GUID for the joystick at a given device
 * index.
 *
 * This function can be called before any joysticks are opened.
 *
 * \param device_index the index of the joystick to query (the N'th joystick
 *                     on the system
 * \returns the GUID of the selected joystick. If called on an invalid index,
 *          this function returns a zero GUID
 *
 * \since This function is available since SDL 2.0.0.
 *
 * \sa SDL_JoystickGetGUID
 * \sa SDL_JoystickGetGUIDString
 */
extern DECLSPEC SDL_JoystickGUID SDLCALL SDL_JoystickGetDeviceGUID(int device_index);

/**
 * Get the USB vendor ID of a joystick, if available.
 *
 * This can be called before any joysticks are opened. If the vendor ID isn't
 * available this function returns 0.
 *
 * \param device_index the index of the joystick to query (the N'th joystick
 *                     on the system
 * \returns the USB vendor ID of the selected joystick. If called on an
 *          invalid index, this function returns zero
 *
 * \since This function is available since SDL 2.0.6.
 */
extern DECLSPEC Uint16 SDLCALL SDL_JoystickGetDeviceVendor(int device_index);

/**
 * Get the USB product ID of a joystick, if available.
 *
 * This can be called before any joysticks are opened. If the product ID isn't
 * available this function returns 0.
 *
 * \param device_index the index of the joystick to query (the N'th joystick
 *                     on the system
 * \returns the USB product ID of the selected joystick. If called on an
 *          invalid index, this function returns zero
 *
 * \since This function is available since SDL 2.0.6.
 */
extern DECLSPEC Uint16 SDLCALL SDL_JoystickGetDeviceProduct(int device_index);

/**
 * Get the product version of a joystick, if available.
 *
 * This can be called before any joysticks are opened. If the product version
 * isn't available this function returns 0.
 *
 * \param device_index the index of the joystick to query (the N'th joystick
 *                     on the system
 * \returns the product version of the selected joystick. If called on an
 *          invalid index, this function returns zero
 *
 * \since This function is available since SDL 2.0.6.
 */
extern DECLSPEC Uint16 SDLCALL SDL_JoystickGetDeviceProductVersion(int device_index);

/**
 * Get the type of a joystick, if available.
 *
 * This can be called before any joysticks are opened.
 *
 * \param device_index the index of the joystick to query (the N'th joystick
 *                     on the system
 * \returns the SDL_JoystickType of the selected joystick. If called on an
 *          invalid index, this function returns `SDL_JOYSTICK_TYPE_UNKNOWN`
 *
 * \since This function is available since SDL 2.0.6.
 */
extern DECLSPEC SDL_JoystickType SDLCALL SDL_JoystickGetDeviceType(int device_index);

/**
 * Get the instance ID of a joystick.
 *
 * This can be called before any joysticks are opened. If the index is out of
 * range, this function will return -1.
 *
 * \param device_index the index of the joystick to query (the N'th joystick
 *                     on the system
 * \returns the instance id of the selected joystick. If called on an invalid
 *          index, this function returns zero
 *
 * \since This function is available since SDL 2.0.6.
 */
extern DECLSPEC SDL_JoystickID SDLCALL SDL_JoystickGetDeviceInstanceID(int device_index);

/**
 * Open a joystick for use.
 *
 * The `device_index` argument refers to the N'th joystick presently
 * recognized by SDL on the system. It is **NOT** the same as the instance ID
 * used to identify the joystick in future events. See
 * SDL_JoystickInstanceID() for more details about instance IDs.
 *
 * The joystick subsystem must be initialized before a joystick can be opened
 * for use.
 *
 * \param device_index the index of the joystick to query
 * \returns a joystick identifier or NULL if an error occurred; call
 *          SDL_GetError() for more information.
 *
 * \since This function is available since SDL 2.0.0.
 *
 * \sa SDL_JoystickClose
 * \sa SDL_JoystickInstanceID
 */
extern DECLSPEC SDL_Joystick *SDLCALL SDL_JoystickOpen(int device_index);

/**
 * Get the SDL_Joystick associated with an instance id.
 *
 * \param instance_id the instance id to get the SDL_Joystick for
 * \returns an SDL_Joystick on success or NULL on failure; call SDL_GetError()
 *          for more information.
 *
 * \since This function is available since SDL 2.0.4.
 */
extern DECLSPEC SDL_Joystick *SDLCALL SDL_JoystickFromInstanceID(SDL_JoystickID instance_id);

/**
 * Get the SDL_Joystick associated with a player index.
 *
 * \param player_index the player index to get the SDL_Joystick for
 * \returns an SDL_Joystick on success or NULL on failure; call SDL_GetError()
 *          for more information.
 *
 * \since This function is available since SDL 2.0.12.
 */
extern DECLSPEC SDL_Joystick *SDLCALL SDL_JoystickFromPlayerIndex(int player_index);

/**
 * Attach a new virtual joystick.
 *
 * \returns the joystick's device index, or -1 if an error occurred.
 *
 * \since This function is available since SDL 2.0.14.
 */
extern DECLSPEC int SDLCALL SDL_JoystickAttachVirtual(SDL_JoystickType type,
                                                      int naxes,
                                                      int nbuttons,
                                                      int nhats);

/**
 * Detach a virtual joystick.
 *
 * \param device_index a value previously returned from
 *                     SDL_JoystickAttachVirtual()
 * \returns 0 on success, or -1 if an error occurred.
 *
 * \since This function is available since SDL 2.0.14.
 */
extern DECLSPEC int SDLCALL SDL_JoystickDetachVirtual(int device_index);

/**
 * Query whether or not the joystick at a given device index is virtual.
 *
 * \param device_index a joystick device index.
 * \returns SDL_TRUE if the joystick is virtual, SDL_FALSE otherwise.
 *
 * \since This function is available since SDL 2.0.14.
 */
extern DECLSPEC SDL_bool SDLCALL SDL_JoystickIsVirtual(int device_index);

/**
 * Set values on an opened, virtual-joystick's axis.
 *
 * Please note that values set here will not be applied until the next call to
 * SDL_JoystickUpdate, which can either be called directly, or can be called
 * indirectly through various other SDL APIs, including, but not limited to
 * the following: SDL_PollEvent, SDL_PumpEvents, SDL_WaitEventTimeout,
 * SDL_WaitEvent.
 *
 * \param joystick the virtual joystick on which to set state.
 * \param axis the specific axis on the virtual joystick to set.
 * \param value the new value for the specified axis.
 * \returns 0 on success, -1 on error.
 *
 * \since This function is available since SDL 2.0.14.
 */
extern DECLSPEC int SDLCALL SDL_JoystickSetVirtualAxis(SDL_Joystick *joystick, int axis, Sint16 value);

/**
 * Set values on an opened, virtual-joystick's button.
 *
 * Please note that values set here will not be applied until the next call to
 * SDL_JoystickUpdate, which can either be called directly, or can be called
 * indirectly through various other SDL APIs, including, but not limited to
 * the following: SDL_PollEvent, SDL_PumpEvents, SDL_WaitEventTimeout,
 * SDL_WaitEvent.
 *
 * \param joystick the virtual joystick on which to set state.
 * \param button the specific button on the virtual joystick to set.
 * \param value the new value for the specified button.
 * \returns 0 on success, -1 on error.
 *
 * \since This function is available since SDL 2.0.14.
 */
extern DECLSPEC int SDLCALL SDL_JoystickSetVirtualButton(SDL_Joystick *joystick, int button, Uint8 value);

/**
 * Set values on an opened, virtual-joystick's hat.
 *
 * Please note that values set here will not be applied until the next call to
 * SDL_JoystickUpdate, which can either be called directly, or can be called
 * indirectly through various other SDL APIs, including, but not limited to
 * the following: SDL_PollEvent, SDL_PumpEvents, SDL_WaitEventTimeout,
 * SDL_WaitEvent.
 *
 * \param joystick the virtual joystick on which to set state.
 * \param hat the specific hat on the virtual joystick to set.
 * \param value the new value for the specified hat.
 * \returns 0 on success, -1 on error.
 *
 * \since This function is available since SDL 2.0.14.
 */
extern DECLSPEC int SDLCALL SDL_JoystickSetVirtualHat(SDL_Joystick *joystick, int hat, Uint8 value);

/**
 * Get the implementation dependent name of a joystick.
 *
 * \param joystick the SDL_Joystick obtained from SDL_JoystickOpen()
 * \returns the name of the selected joystick. If no name can be found, this
 *          function returns NULL; call SDL_GetError() for more information.
 *
 * \since This function is available since SDL 2.0.0.
 *
 * \sa SDL_JoystickNameForIndex
 * \sa SDL_JoystickOpen
 */
extern DECLSPEC const char *SDLCALL SDL_JoystickName(SDL_Joystick *joystick);

/**
 * Get the player index of an opened joystick.
 *
 * For XInput controllers this returns the XInput user index. Many joysticks
 * will not be able to supply this information.
 *
 * \param joystick the SDL_Joystick obtained from SDL_JoystickOpen()
 * \returns the player index, or -1 if it's not available.
 *
 * \since This function is available since SDL 2.0.9.
 */
extern DECLSPEC int SDLCALL SDL_JoystickGetPlayerIndex(SDL_Joystick *joystick);

/**
 * Set the player index of an opened joystick.
 *
 * \param joystick the SDL_Joystick obtained from SDL_JoystickOpen()
 * \param player_index the player index to set.
 *
 * \since This function is available since SDL 2.0.12.
 */
extern DECLSPEC void SDLCALL SDL_JoystickSetPlayerIndex(SDL_Joystick *joystick, int player_index);

/**
 * Get the implementation-dependent GUID for the joystick.
 *
 * This function requires an open joystick.
 *
 * \param joystick the SDL_Joystick obtained from SDL_JoystickOpen()
 * \returns the GUID of the given joystick. If called on an invalid index,
 *          this function returns a zero GUID; call SDL_GetError() for more
 *          information.
 *
 * \since This function is available since SDL 2.0.0.
 *
 * \sa SDL_JoystickGetDeviceGUID
 * \sa SDL_JoystickGetGUIDString
 */
extern DECLSPEC SDL_JoystickGUID SDLCALL SDL_JoystickGetGUID(SDL_Joystick *joystick);

/**
 * Get the USB vendor ID of an opened joystick, if available.
 *
 * If the vendor ID isn't available this function returns 0.
 *
 * \param joystick the SDL_Joystick obtained from SDL_JoystickOpen()
 * \returns the USB vendor ID of the selected joystick, or 0 if unavailable.
 *
 * \since This function is available since SDL 2.0.6.
 */
extern DECLSPEC Uint16 SDLCALL SDL_JoystickGetVendor(SDL_Joystick *joystick);

/**
 * Get the USB product ID of an opened joystick, if available.
 *
 * If the product ID isn't available this function returns 0.
 *
 * \param joystick the SDL_Joystick obtained from SDL_JoystickOpen()
 * \returns the USB product ID of the selected joystick, or 0 if unavailable.
 *
 * \since This function is available since SDL 2.0.6.
 */
extern DECLSPEC Uint16 SDLCALL SDL_JoystickGetProduct(SDL_Joystick *joystick);

/**
 * Get the product version of an opened joystick, if available.
 *
 * If the product version isn't available this function returns 0.
 *
 * \param joystick the SDL_Joystick obtained from SDL_JoystickOpen()
 * \returns the product version of the selected joystick, or 0 if unavailable.
 *
 * \since This function is available since SDL 2.0.6.
 */
extern DECLSPEC Uint16 SDLCALL SDL_JoystickGetProductVersion(SDL_Joystick *joystick);

/**
 * Get the serial number of an opened joystick, if available.
 *
 * Returns the serial number of the joystick, or NULL if it is not available.
 *
 * \param joystick the SDL_Joystick obtained from SDL_JoystickOpen()
 * \returns the serial number of the selected joystick, or NULL if
 *          unavailable.
 *
 * \since This function is available since SDL 2.0.14.
 */
extern DECLSPEC const char * SDLCALL SDL_JoystickGetSerial(SDL_Joystick *joystick);

/**
 * Get the type of an opened joystick.
 *
 * \param joystick the SDL_Joystick obtained from SDL_JoystickOpen()
 * \returns the SDL_JoystickType of the selected joystick.
 *
 * \since This function is available since SDL 2.0.6.
 */
extern DECLSPEC SDL_JoystickType SDLCALL SDL_JoystickGetType(SDL_Joystick *joystick);

/**
 * Get an ASCII string representation for a given SDL_JoystickGUID.
 *
 * You should supply at least 33 bytes for pszGUID.
 *
 * \param guid the SDL_JoystickGUID you wish to convert to string
 * \param pszGUID buffer in which to write the ASCII string
 * \param cbGUID the size of pszGUID
 *
 * \since This function is available since SDL 2.0.0.
 *
 * \sa SDL_JoystickGetDeviceGUID
 * \sa SDL_JoystickGetGUID
 * \sa SDL_JoystickGetGUIDFromString
 */
extern DECLSPEC void SDLCALL SDL_JoystickGetGUIDString(SDL_JoystickGUID guid, char *pszGUID, int cbGUID);

/**
 * Convert a GUID string into a SDL_JoystickGUID structure.
 *
 * Performs no error checking. If this function is given a string containing
 * an invalid GUID, the function will silently succeed, but the GUID generated
 * will not be useful.
 *
 * \param pchGUID string containing an ASCII representation of a GUID
 * \returns a SDL_JoystickGUID structure.
 *
 * \since This function is available since SDL 2.0.0.
 *
 * \sa SDL_JoystickGetGUIDString
 */
extern DECLSPEC SDL_JoystickGUID SDLCALL SDL_JoystickGetGUIDFromString(const char *pchGUID);

/**
 * Get the status of a specified joystick.
 *
 * \param joystick the joystick to query
 * \returns SDL_TRUE if the joystick has been opened, SDL_FALSE if it has not;
 *          call SDL_GetError() for more information.
 *
 * \since This function is available since SDL 2.0.0.
 *
 * \sa SDL_JoystickClose
 * \sa SDL_JoystickOpen
 */
extern DECLSPEC SDL_bool SDLCALL SDL_JoystickGetAttached(SDL_Joystick *joystick);

/**
 * Get the instance ID of an opened joystick.
 *
 * \param joystick an SDL_Joystick structure containing joystick information
 * \returns the instance ID of the specified joystick on success or a negative
 *          error code on failure; call SDL_GetError() for more information.
 *
 * \since This function is available since SDL 2.0.0.
 *
 * \sa SDL_JoystickOpen
 */
extern DECLSPEC SDL_JoystickID SDLCALL SDL_JoystickInstanceID(SDL_Joystick *joystick);

/**
 * Get the number of general axis controls on a joystick.
 *
 * Often, the directional pad on a game controller will either look like 4
 * separate buttons or a POV hat, and not axes, but all of this is up to the
 * device and platform.
 *
 * \param joystick an SDL_Joystick structure containing joystick information
 * \returns the number of axis controls/number of axes on success or a
 *          negative error code on failure; call SDL_GetError() for more
 *          information.
 *
 * \since This function is available since SDL 2.0.0.
 *
 * \sa SDL_JoystickGetAxis
 * \sa SDL_JoystickOpen
 */
extern DECLSPEC int SDLCALL SDL_JoystickNumAxes(SDL_Joystick *joystick);

/**
 * Get the number of trackballs on a joystick.
 *
 * Joystick trackballs have only relative motion events associated with them
 * and their state cannot be polled.
 *
 * Most joysticks do not have trackballs.
 *
 * \param joystick an SDL_Joystick structure containing joystick information
 * \returns the number of trackballs on success or a negative error code on
 *          failure; call SDL_GetError() for more information.
 *
 * \since This function is available since SDL 2.0.0.
 *
 * \sa SDL_JoystickGetBall
 */
extern DECLSPEC int SDLCALL SDL_JoystickNumBalls(SDL_Joystick *joystick);

/**
 * Get the number of POV hats on a joystick.
 *
 * \param joystick an SDL_Joystick structure containing joystick information
 * \returns the number of POV hats on success or a negative error code on
 *          failure; call SDL_GetError() for more information.
 *
 * \since This function is available since SDL 2.0.0.
 *
 * \sa SDL_JoystickGetHat
 * \sa SDL_JoystickOpen
 */
extern DECLSPEC int SDLCALL SDL_JoystickNumHats(SDL_Joystick *joystick);

/**
 * Get the number of buttons on a joystick.
 *
 * \param joystick an SDL_Joystick structure containing joystick information
 * \returns the number of buttons on success or a negative error code on
 *          failure; call SDL_GetError() for more information.
 *
 * \since This function is available since SDL 2.0.0.
 *
 * \sa SDL_JoystickGetButton
 * \sa SDL_JoystickOpen
 */
extern DECLSPEC int SDLCALL SDL_JoystickNumButtons(SDL_Joystick *joystick);

/**
 * Update the current state of the open joysticks.
 *
 * This is called automatically by the event loop if any joystick events are
 * enabled.
 *
 * \since This function is available since SDL 2.0.0.
 *
 * \sa SDL_JoystickEventState
 */
extern DECLSPEC void SDLCALL SDL_JoystickUpdate(void);

/**
 * Enable/disable joystick event polling.
 *
 * If joystick events are disabled, you must call SDL_JoystickUpdate()
 * yourself and manually check the state of the joystick when you want
 * joystick information.
 *
 * It is recommended that you leave joystick event handling enabled.
 *
 * **WARNING**: Calling this function may delete all events currently in SDL's
 * event queue.
 *
 * \param state can be one of `SDL_QUERY`, `SDL_IGNORE`, or `SDL_ENABLE`
 * \returns 1 if enabled, 0 if disabled, or a negative error code on failure;
 *          call SDL_GetError() for more information.
 *
 *          If `state` is `SDL_QUERY` then the current state is returned,
 *          otherwise the new processing state is returned.
 *
 * \since This function is available since SDL 2.0.0.
 *
 * \sa SDL_GameControllerEventState
 */
extern DECLSPEC int SDLCALL SDL_JoystickEventState(int state);

#define SDL_JOYSTICK_AXIS_MAX   32767
#define SDL_JOYSTICK_AXIS_MIN   -32768

/**
 * Get the current state of an axis control on a joystick.
 *
 * SDL makes no promises about what part of the joystick any given axis refers
 * to. Your game should have some sort of configuration UI to let users
 * specify what each axis should be bound to. Alternately, SDL's higher-level
 * Game Controller API makes a great effort to apply order to this lower-level
 * interface, so you know that a specific axis is the "left thumb stick," etc.
 *
 * The value returned by SDL_JoystickGetAxis() is a signed integer (-32768 to
 * 32767) representing the current position of the axis. It may be necessary
 * to impose certain tolerances on these values to account for jitter.
 *
 * \param joystick an SDL_Joystick structure containing joystick information
 * \param axis the axis to query; the axis indices start at index 0
 * \returns a 16-bit signed integer representing the current position of the
 *          axis or 0 on failure; call SDL_GetError() for more information.
 *
 * \since This function is available since SDL 2.0.0.
 *
 * \sa SDL_JoystickNumAxes
 */
extern DECLSPEC Sint16 SDLCALL SDL_JoystickGetAxis(SDL_Joystick *joystick,
                                                   int axis);

/**
 * Get the initial state of an axis control on a joystick.
 *
 * The state is a value ranging from -32768 to 32767.
 *
 * The axis indices start at index 0.
 *
 * \param joystick an SDL_Joystick structure containing joystick information
 * \param axis the axis to query; the axis indices start at index 0
 * \param state Upon return, the initial value is supplied here.
 * \return SDL_TRUE if this axis has any initial value, or SDL_FALSE if not.
 *
 * \since This function is available since SDL 2.0.6.
 */
extern DECLSPEC SDL_bool SDLCALL SDL_JoystickGetAxisInitialState(SDL_Joystick *joystick,
                                                   int axis, Sint16 *state);

/**
 *  \name Hat positions
 */
/* @{ */
#define SDL_HAT_CENTERED    0x00
#define SDL_HAT_UP          0x01
#define SDL_HAT_RIGHT       0x02
#define SDL_HAT_DOWN        0x04
#define SDL_HAT_LEFT        0x08
#define SDL_HAT_RIGHTUP     (SDL_HAT_RIGHT|SDL_HAT_UP)
#define SDL_HAT_RIGHTDOWN   (SDL_HAT_RIGHT|SDL_HAT_DOWN)
#define SDL_HAT_LEFTUP      (SDL_HAT_LEFT|SDL_HAT_UP)
#define SDL_HAT_LEFTDOWN    (SDL_HAT_LEFT|SDL_HAT_DOWN)
/* @} */

/**
 * Get the current state of a POV hat on a joystick.
 *
 * The returned value will be one of the following positions:
 *
 * - `SDL_HAT_CENTERED`
 * - `SDL_HAT_UP`
 * - `SDL_HAT_RIGHT`
 * - `SDL_HAT_DOWN`
 * - `SDL_HAT_LEFT`
 * - `SDL_HAT_RIGHTUP`
 * - `SDL_HAT_RIGHTDOWN`
 * - `SDL_HAT_LEFTUP`
 * - `SDL_HAT_LEFTDOWN`
 *
 * \param joystick an SDL_Joystick structure containing joystick information
 * \param hat the hat index to get the state from; indices start at index 0
 * \returns the current hat position.
 *
 * \since This function is available since SDL 2.0.0.
 *
 * \sa SDL_JoystickNumHats
 */
extern DECLSPEC Uint8 SDLCALL SDL_JoystickGetHat(SDL_Joystick *joystick,
                                                 int hat);

/**
 * Get the ball axis change since the last poll.
 *
 * Trackballs can only return relative motion since the last call to
 * SDL_JoystickGetBall(), these motion deltas are placed into `dx` and `dy`.
 *
 * Most joysticks do not have trackballs.
 *
 * \param joystick the SDL_Joystick to query
 * \param ball the ball index to query; ball indices start at index 0
 * \param dx stores the difference in the x axis position since the last poll
 * \param dy stores the difference in the y axis position since the last poll
 * \returns 0 on success or a negative error code on failure; call
 *          SDL_GetError() for more information.
 *
 * \since This function is available since SDL 2.0.0.
 *
 * \sa SDL_JoystickNumBalls
 */
extern DECLSPEC int SDLCALL SDL_JoystickGetBall(SDL_Joystick *joystick,
                                                int ball, int *dx, int *dy);

/**
 * Get the current state of a button on a joystick.
 *
 * \param joystick an SDL_Joystick structure containing joystick information
 * \param button the button index to get the state from; indices start at
 *               index 0
 * \returns 1 if the specified button is pressed, 0 otherwise.
 *
 * \since This function is available since SDL 2.0.0.
 *
 * \sa SDL_JoystickNumButtons
 */
extern DECLSPEC Uint8 SDLCALL SDL_JoystickGetButton(SDL_Joystick *joystick,
                                                    int button);

/**
 * Start a rumble effect.
 *
 * Each call to this function cancels any previous rumble effect, and calling
 * it with 0 intensity stops any rumbling.
 *
 * \param joystick The joystick to vibrate
 * \param low_frequency_rumble The intensity of the low frequency (left)
 *                             rumble motor, from 0 to 0xFFFF
 * \param high_frequency_rumble The intensity of the high frequency (right)
 *                              rumble motor, from 0 to 0xFFFF
 * \param duration_ms The duration of the rumble effect, in milliseconds
 * \returns 0, or -1 if rumble isn't supported on this joystick
 *
 * \since This function is available since SDL 2.0.9.
 *
 * \sa SDL_JoystickHasRumble
 */
extern DECLSPEC int SDLCALL SDL_JoystickRumble(SDL_Joystick *joystick, Uint16 low_frequency_rumble, Uint16 high_frequency_rumble, Uint32 duration_ms);

/**
 * Start a rumble effect in the joystick's triggers
 *
 * Each call to this function cancels any previous trigger rumble effect, and
 * calling it with 0 intensity stops any rumbling.
 *
 * Note that this function is for _trigger_ rumble; the first joystick to
 * support this was the PlayStation 5's DualShock 5 controller. If you want
 * the (more common) whole-controller rumble, use SDL_JoystickRumble()
 * instead.
 *
 * \param joystick The joystick to vibrate
 * \param left_rumble The intensity of the left trigger rumble motor, from 0
 *                    to 0xFFFF
 * \param right_rumble The intensity of the right trigger rumble motor, from 0
 *                     to 0xFFFF
 * \param duration_ms The duration of the rumble effect, in milliseconds
 * \returns 0, or -1 if trigger rumble isn't supported on this joystick
 *
 * \since This function is available since SDL 2.0.14.
 *
 * \sa SDL_JoystickHasRumbleTriggers
 */
extern DECLSPEC int SDLCALL SDL_JoystickRumbleTriggers(SDL_Joystick *joystick, Uint16 left_rumble, Uint16 right_rumble, Uint32 duration_ms);

/**
 * Query whether a joystick has an LED.
 *
 * An example of a joystick LED is the light on the back of a PlayStation 4's
 * DualShock 4 controller.
 *
 * \param joystick The joystick to query
 * \return SDL_TRUE if the joystick has a modifiable LED, SDL_FALSE otherwise.
 *
 * \since This function is available since SDL 2.0.14.
 */
extern DECLSPEC SDL_bool SDLCALL SDL_JoystickHasLED(SDL_Joystick *joystick);

/**
 * Query whether a joystick has rumble support.
 *
 * \param joystick The joystick to query
 * \return SDL_TRUE if the joystick has rumble, SDL_FALSE otherwise.
 *
 * \since This function is available since SDL 2.0.18.
 *
 * \sa SDL_JoystickRumble
 */
extern DECLSPEC SDL_bool SDLCALL SDL_JoystickHasRumble(SDL_Joystick *joystick);

/**
 * Query whether a joystick has rumble support on triggers.
 *
 * \param joystick The joystick to query
 * \return SDL_TRUE if the joystick has trigger rumble, SDL_FALSE otherwise.
 *
 * \since This function is available since SDL 2.0.18.
 *
 * \sa SDL_JoystickRumbleTriggers
 */
extern DECLSPEC SDL_bool SDLCALL SDL_JoystickHasRumbleTriggers(SDL_Joystick *joystick);

/**
 * Update a joystick's LED color.
 *
 * An example of a joystick LED is the light on the back of a PlayStation 4's
 * DualShock 4 controller.
 *
 * \param joystick The joystick to update
 * \param red The intensity of the red LED
 * \param green The intensity of the green LED
 * \param blue The intensity of the blue LED
 * \returns 0 on success, -1 if this joystick does not have a modifiable LED
 *
 * \since This function is available since SDL 2.0.14.
 */
extern DECLSPEC int SDLCALL SDL_JoystickSetLED(SDL_Joystick *joystick, Uint8 red, Uint8 green, Uint8 blue);

/**
 * Send a joystick specific effect packet
 *
 * \param joystick The joystick to affect
 * \param data The data to send to the joystick
 * \param size The size of the data to send to the joystick
 * \returns 0, or -1 if this joystick or driver doesn't support effect packets
 *
 * \since This function is available since SDL 2.0.16.
 */
extern DECLSPEC int SDLCALL SDL_JoystickSendEffect(SDL_Joystick *joystick, const void *data, int size);

/**
 * Close a joystick previously opened with SDL_JoystickOpen().
 *
 * \param joystick The joystick device to close
 *
 * \since This function is available since SDL 2.0.0.
 *
 * \sa SDL_JoystickOpen
 */
extern DECLSPEC void SDLCALL SDL_JoystickClose(SDL_Joystick *joystick);

/**
 * Get the battery level of a joystick as SDL_JoystickPowerLevel.
 *
 * \param joystick the SDL_Joystick to query
 * \returns the current battery level as SDL_JoystickPowerLevel on success or
 *          `SDL_JOYSTICK_POWER_UNKNOWN` if it is unknown
 *
 * \since This function is available since SDL 2.0.4.
 */
extern DECLSPEC SDL_JoystickPowerLevel SDLCALL SDL_JoystickCurrentPowerLevel(SDL_Joystick *joystick);

/* Ends C function definitions when using C++ */
#ifdef __cplusplus
}
#endif
#include "close_code.h"

#endif /* SDL_joystick_h_ */

/* vi: set ts=4 sw=4 expandtab: */