1
0
mirror of https://github.com/Relintai/sdl2_frt.git synced 2024-12-29 20:27:12 +01:00
sdl2_frt/include/SDL_gamecontroller.h
Sam Lantinga 2be75c6a61 Fixed bug 5028 - Virtual Joysticks (new joystick backend)
David Ludwig

I have created a new driver for SDL's Joystick and Game-Controller subsystem: a Virtual driver.  This driver allows one to create a software-based joystick, which to SDL applications will look and react like a real joystick, but whose state can be set programmatically.  A primary use case for this is to help enable developers to add touch-screen joysticks to their apps.

The driver comes with a set of new, public APIs, with functions to attach and detach joysticks, set virtual-joystick state, and to determine if a joystick is a virtual-one.

Use of virtual joysticks goes as such:

1. Attach one or more virtual joysticks by calling SDL_JoystickAttachVirtual.  If successful, this returns the virtual-device's joystick-index.
2. Open the virtual joysticks (using indicies returned by SDL_JoystickAttachVirtual).
3. Call any of the SDL_JoystickSetVirtual* functions when joystick-state changes.  Please note that virtual-joystick state will only get applied on the next call to SDL_JoystickUpdate, or when pumping or polling for SDL events (via SDL_PumpEvents or SDL_PollEvent).


Here is a listing of the new, public APIs, at present and subject to change:

------------------------------------------------------------

/**
 * Attaches a new virtual joystick.
 * Returns the joystick's device index, or -1 if an error occurred.
 */
extern DECLSPEC int SDLCALL SDL_JoystickAttachVirtual(SDL_JoystickType type, int naxes, int nballs, int nbuttons, int nhats);

/**
 * Detaches a virtual joystick
 * Returns 0 on success, or -1 if an error occurred.
 */
extern DECLSPEC int SDLCALL SDL_JoystickDetachVirtual(int device_index);

/**
 * Indicates whether or not a virtual-joystick is at a given device index.
 */
extern DECLSPEC SDL_bool SDLCALL SDL_JoystickIsVirtual(int device_index);

/**
 * Set values on an opened, virtual-joystick's controls.
 * Returns 0 on success, -1 on error.
 */
extern DECLSPEC int SDLCALL SDL_JoystickSetVirtualAxis(SDL_Joystick * joystick, int axis, Sint16 value);
extern DECLSPEC int SDLCALL SDL_JoystickSetVirtualBall(SDL_Joystick * joystick, int ball, Sint16 xrel, Sint16 yrel);
extern DECLSPEC int SDLCALL SDL_JoystickSetVirtualButton(SDL_Joystick * joystick, int button, Uint8 value);
extern DECLSPEC int SDLCALL SDL_JoystickSetVirtualHat(SDL_Joystick * joystick, int hat, Uint8 value);

------------------------------------------------------------

Miscellaneous notes on the initial patch, which are also subject to change:

1. no test code is present in SDL, yet.  This should, perhaps, change.  Initial development was done with an ImGui-based app, which potentially is too thick for use in SDL-official.  If tests are to be added, what kind of tests?  Automated?  Graphical?

2. virtual game controllers can be created by calling SDL_JoystickAttachVirtual with a joystick-type of SDL_JOYSTICK_TYPE_GAME_CONTROLLER, with naxes (num axes) set to SDL_CONTROLLER_AXIS_MAX, and with nbuttons (num buttons) set to SDL_CONTROLLER_BUTTON_MAX.  When updating their state, values of type SDL_GameControllerAxis or SDL_GameControllerButton can be casted to an int and used for the control-index (in calls to SDL_JoystickSetVirtual* functions).

3. virtual joysticks' guids are mostly all-zeros with the exception of the last two bytes, the first of which is a 'v', to indicate that the guid is a virtual one, and the second of which is a SDL_JoystickType that has been converted into a Uint8.

4. virtual joysticks are ONLY turned into virtual game-controllers if and when their joystick-type is set to SDL_JOYSTICK_TYPE_GAMECONTROLLER.  This is controlled by having SDL's default list of game-controllers have a single entry for a virtual game controller (of guid, "00000000000000000000000000007601", which is subject to the guid-encoding described above).

5. regarding having to call SDL_JoystickUpdate, either directly or indirectly via SDL_PumpEvents or SDL_PollEvents, before new virtual-joystick state becomes active (as specified via SDL_JoystickSetVirtual* function-calls), this was done to match behavior found in SDL's other joystick drivers, almost all of which will only update SDL-state during SDL_JoystickUpdate.

6. the initial patch is based off of SDL 2.0.12

7. the virtual joystick subsystem is disabled by default.  It should be possible to enable it by building with SDL_JOYSTICK_VIRTUAL=1



Questions, comments, suggestions, or bug reports very welcome!
2020-03-13 19:08:45 -07:00

422 lines
14 KiB
C

/*
Simple DirectMedia Layer
Copyright (C) 1997-2020 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_gamecontroller.h
*
* Include file for SDL game controller event handling
*/
#ifndef SDL_gamecontroller_h_
#define SDL_gamecontroller_h_
#include "SDL_stdinc.h"
#include "SDL_error.h"
#include "SDL_rwops.h"
#include "SDL_joystick.h"
#include "begin_code.h"
/* Set up for C function definitions, even when using C++ */
#ifdef __cplusplus
extern "C" {
#endif
/**
* \file SDL_gamecontroller.h
*
* In order to use these functions, SDL_Init() must have been called
* with the ::SDL_INIT_GAMECONTROLLER flag. This causes SDL to scan the system
* for game controllers, and load appropriate drivers.
*
* If you would like to receive controller 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 gamecontroller structure used to identify an SDL game controller
*/
struct _SDL_GameController;
typedef struct _SDL_GameController SDL_GameController;
typedef enum
{
SDL_CONTROLLER_TYPE_UNKNOWN = 0,
SDL_CONTROLLER_TYPE_XBOX360,
SDL_CONTROLLER_TYPE_XBOXONE,
SDL_CONTROLLER_TYPE_PS3,
SDL_CONTROLLER_TYPE_PS4,
SDL_CONTROLLER_TYPE_NINTENDO_SWITCH_PRO,
SDL_CONTROLLER_TYPE_VIRTUAL
} SDL_GameControllerType;
typedef enum
{
SDL_CONTROLLER_BINDTYPE_NONE = 0,
SDL_CONTROLLER_BINDTYPE_BUTTON,
SDL_CONTROLLER_BINDTYPE_AXIS,
SDL_CONTROLLER_BINDTYPE_HAT
} SDL_GameControllerBindType;
/**
* Get the SDL joystick layer binding for this controller button/axis mapping
*/
typedef struct SDL_GameControllerButtonBind
{
SDL_GameControllerBindType bindType;
union
{
int button;
int axis;
struct {
int hat;
int hat_mask;
} hat;
} value;
} SDL_GameControllerButtonBind;
/**
* To count the number of game controllers in the system for the following:
* int nJoysticks = SDL_NumJoysticks();
* int nGameControllers = 0;
* for (int i = 0; i < nJoysticks; i++) {
* if (SDL_IsGameController(i)) {
* nGameControllers++;
* }
* }
*
* Using the SDL_HINT_GAMECONTROLLERCONFIG hint or the SDL_GameControllerAddMapping() you can add support for controllers SDL is unaware of or cause an existing controller to have a different binding. The format is:
* guid,name,mappings
*
* Where GUID is the string value from SDL_JoystickGetGUIDString(), name is the human readable string for the device and mappings are controller mappings to joystick ones.
* Under Windows there is a reserved GUID of "xinput" that covers any XInput devices.
* The mapping format for joystick is:
* bX - a joystick button, index X
* hX.Y - hat X with value Y
* aX - axis X of the joystick
* Buttons can be used as a controller axis and vice versa.
*
* This string shows an example of a valid mapping for a controller
* "03000000341a00003608000000000000,PS3 Controller,a:b1,b:b2,y:b3,x:b0,start:b9,guide:b12,back:b8,dpup:h0.1,dpleft:h0.8,dpdown:h0.4,dpright:h0.2,leftshoulder:b4,rightshoulder:b5,leftstick:b10,rightstick:b11,leftx:a0,lefty:a1,rightx:a2,righty:a3,lefttrigger:b6,righttrigger:b7",
*
*/
/**
* Load a set of mappings from a seekable SDL data stream (memory or file), filtered by the current SDL_GetPlatform()
* A community sourced database of controllers is available at https://raw.github.com/gabomdq/SDL_GameControllerDB/master/gamecontrollerdb.txt
*
* If \c freerw is non-zero, the stream will be closed after being read.
*
* \return number of mappings added, -1 on error
*/
extern DECLSPEC int SDLCALL SDL_GameControllerAddMappingsFromRW(SDL_RWops * rw, int freerw);
/**
* Load a set of mappings from a file, filtered by the current SDL_GetPlatform()
*
* Convenience macro.
*/
#define SDL_GameControllerAddMappingsFromFile(file) SDL_GameControllerAddMappingsFromRW(SDL_RWFromFile(file, "rb"), 1)
/**
* Add or update an existing mapping configuration
*
* \return 1 if mapping is added, 0 if updated, -1 on error
*/
extern DECLSPEC int SDLCALL SDL_GameControllerAddMapping(const char* mappingString);
/**
* Get the number of mappings installed
*
* \return the number of mappings
*/
extern DECLSPEC int SDLCALL SDL_GameControllerNumMappings(void);
/**
* Get the mapping at a particular index.
*
* \return the mapping string. Must be freed with SDL_free(). Returns NULL if the index is out of range.
*/
extern DECLSPEC char * SDLCALL SDL_GameControllerMappingForIndex(int mapping_index);
/**
* Get a mapping string for a GUID
*
* \return the mapping string. Must be freed with SDL_free(). Returns NULL if no mapping is available
*/
extern DECLSPEC char * SDLCALL SDL_GameControllerMappingForGUID(SDL_JoystickGUID guid);
/**
* Get a mapping string for an open GameController
*
* \return the mapping string. Must be freed with SDL_free(). Returns NULL if no mapping is available
*/
extern DECLSPEC char * SDLCALL SDL_GameControllerMapping(SDL_GameController * gamecontroller);
/**
* Is the joystick on this index supported by the game controller interface?
*/
extern DECLSPEC SDL_bool SDLCALL SDL_IsGameController(int joystick_index);
/**
* Get the implementation dependent name of a game controller.
* This can be called before any controllers are opened.
* If no name can be found, this function returns NULL.
*/
extern DECLSPEC const char *SDLCALL SDL_GameControllerNameForIndex(int joystick_index);
/**
* Get the type of a game controller.
* This can be called before any controllers are opened.
*/
extern DECLSPEC SDL_GameControllerType SDLCALL SDL_GameControllerTypeForIndex(int joystick_index);
/**
* Get the mapping of a game controller.
* This can be called before any controllers are opened.
*
* \return the mapping string. Must be freed with SDL_free(). Returns NULL if no mapping is available
*/
extern DECLSPEC char *SDLCALL SDL_GameControllerMappingForDeviceIndex(int joystick_index);
/**
* Open a game controller for use.
* The index passed as an argument refers to the N'th game controller on the system.
* This index is not the value which will identify this controller in future
* controller events. The joystick's instance id (::SDL_JoystickID) will be
* used there instead.
*
* \return A controller identifier, or NULL if an error occurred.
*/
extern DECLSPEC SDL_GameController *SDLCALL SDL_GameControllerOpen(int joystick_index);
/**
* Return the SDL_GameController associated with an instance id.
*/
extern DECLSPEC SDL_GameController *SDLCALL SDL_GameControllerFromInstanceID(SDL_JoystickID joyid);
/**
* Return the SDL_GameController associated with a player index.
*/
extern DECLSPEC SDL_GameController *SDLCALL SDL_GameControllerFromPlayerIndex(int player_index);
/**
* Return the name for this currently opened controller
*/
extern DECLSPEC const char *SDLCALL SDL_GameControllerName(SDL_GameController *gamecontroller);
/**
* Return the type of this currently opened controller
*/
extern DECLSPEC SDL_GameControllerType SDLCALL SDL_GameControllerGetType(SDL_GameController *gamecontroller);
/**
* Get the player index of an opened game controller, or -1 if it's not available
*
* For XInput controllers this returns the XInput user index.
*/
extern DECLSPEC int SDLCALL SDL_GameControllerGetPlayerIndex(SDL_GameController *gamecontroller);
/**
* Set the player index of an opened game controller
*/
extern DECLSPEC void SDLCALL SDL_GameControllerSetPlayerIndex(SDL_GameController *gamecontroller, int player_index);
/**
* Get the USB vendor ID of an opened controller, if available.
* If the vendor ID isn't available this function returns 0.
*/
extern DECLSPEC Uint16 SDLCALL SDL_GameControllerGetVendor(SDL_GameController * gamecontroller);
/**
* Get the USB product ID of an opened controller, if available.
* If the product ID isn't available this function returns 0.
*/
extern DECLSPEC Uint16 SDLCALL SDL_GameControllerGetProduct(SDL_GameController * gamecontroller);
/**
* Get the product version of an opened controller, if available.
* If the product version isn't available this function returns 0.
*/
extern DECLSPEC Uint16 SDLCALL SDL_GameControllerGetProductVersion(SDL_GameController * gamecontroller);
/**
* Returns SDL_TRUE if the controller has been opened and currently connected,
* or SDL_FALSE if it has not.
*/
extern DECLSPEC SDL_bool SDLCALL SDL_GameControllerGetAttached(SDL_GameController *gamecontroller);
/**
* Get the underlying joystick object used by a controller
*/
extern DECLSPEC SDL_Joystick *SDLCALL SDL_GameControllerGetJoystick(SDL_GameController *gamecontroller);
/**
* Enable/disable controller event polling.
*
* If controller events are disabled, you must call SDL_GameControllerUpdate()
* yourself and check the state of the controller when you want controller
* information.
*
* The state can be one of ::SDL_QUERY, ::SDL_ENABLE or ::SDL_IGNORE.
*/
extern DECLSPEC int SDLCALL SDL_GameControllerEventState(int state);
/**
* Update the current state of the open game controllers.
*
* This is called automatically by the event loop if any game controller
* events are enabled.
*/
extern DECLSPEC void SDLCALL SDL_GameControllerUpdate(void);
/**
* The list of axes available from a controller
*
* Thumbstick axis values range from SDL_JOYSTICK_AXIS_MIN to SDL_JOYSTICK_AXIS_MAX,
* and are centered within ~8000 of zero, though advanced UI will allow users to set
* or autodetect the dead zone, which varies between controllers.
*
* Trigger axis values range from 0 to SDL_JOYSTICK_AXIS_MAX.
*/
typedef enum
{
SDL_CONTROLLER_AXIS_INVALID = -1,
SDL_CONTROLLER_AXIS_LEFTX,
SDL_CONTROLLER_AXIS_LEFTY,
SDL_CONTROLLER_AXIS_RIGHTX,
SDL_CONTROLLER_AXIS_RIGHTY,
SDL_CONTROLLER_AXIS_TRIGGERLEFT,
SDL_CONTROLLER_AXIS_TRIGGERRIGHT,
SDL_CONTROLLER_AXIS_MAX
} SDL_GameControllerAxis;
/**
* turn this string into a axis mapping
*/
extern DECLSPEC SDL_GameControllerAxis SDLCALL SDL_GameControllerGetAxisFromString(const char *pchString);
/**
* turn this axis enum into a string mapping
*/
extern DECLSPEC const char* SDLCALL SDL_GameControllerGetStringForAxis(SDL_GameControllerAxis axis);
/**
* Get the SDL joystick layer binding for this controller button mapping
*/
extern DECLSPEC SDL_GameControllerButtonBind SDLCALL
SDL_GameControllerGetBindForAxis(SDL_GameController *gamecontroller,
SDL_GameControllerAxis axis);
/**
* Get the current state of an axis control on a game controller.
*
* The state is a value ranging from -32768 to 32767 (except for the triggers,
* which range from 0 to 32767).
*
* The axis indices start at index 0.
*/
extern DECLSPEC Sint16 SDLCALL
SDL_GameControllerGetAxis(SDL_GameController *gamecontroller,
SDL_GameControllerAxis axis);
/**
* The list of buttons available from a controller
*/
typedef enum
{
SDL_CONTROLLER_BUTTON_INVALID = -1,
SDL_CONTROLLER_BUTTON_A,
SDL_CONTROLLER_BUTTON_B,
SDL_CONTROLLER_BUTTON_X,
SDL_CONTROLLER_BUTTON_Y,
SDL_CONTROLLER_BUTTON_BACK,
SDL_CONTROLLER_BUTTON_GUIDE,
SDL_CONTROLLER_BUTTON_START,
SDL_CONTROLLER_BUTTON_LEFTSTICK,
SDL_CONTROLLER_BUTTON_RIGHTSTICK,
SDL_CONTROLLER_BUTTON_LEFTSHOULDER,
SDL_CONTROLLER_BUTTON_RIGHTSHOULDER,
SDL_CONTROLLER_BUTTON_DPAD_UP,
SDL_CONTROLLER_BUTTON_DPAD_DOWN,
SDL_CONTROLLER_BUTTON_DPAD_LEFT,
SDL_CONTROLLER_BUTTON_DPAD_RIGHT,
SDL_CONTROLLER_BUTTON_MAX
} SDL_GameControllerButton;
/**
* turn this string into a button mapping
*/
extern DECLSPEC SDL_GameControllerButton SDLCALL SDL_GameControllerGetButtonFromString(const char *pchString);
/**
* turn this button enum into a string mapping
*/
extern DECLSPEC const char* SDLCALL SDL_GameControllerGetStringForButton(SDL_GameControllerButton button);
/**
* Get the SDL joystick layer binding for this controller button mapping
*/
extern DECLSPEC SDL_GameControllerButtonBind SDLCALL
SDL_GameControllerGetBindForButton(SDL_GameController *gamecontroller,
SDL_GameControllerButton button);
/**
* Get the current state of a button on a game controller.
*
* The button indices start at index 0.
*/
extern DECLSPEC Uint8 SDLCALL SDL_GameControllerGetButton(SDL_GameController *gamecontroller,
SDL_GameControllerButton button);
/**
* Trigger a rumble effect
* Each call to this function cancels any previous rumble effect, and calling it with 0 intensity stops any rumbling.
*
* \param gamecontroller The controller 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
*
* \return 0, or -1 if rumble isn't supported on this joystick
*/
extern DECLSPEC int SDLCALL SDL_GameControllerRumble(SDL_GameController *gamecontroller, Uint16 low_frequency_rumble, Uint16 high_frequency_rumble, Uint32 duration_ms);
/**
* Close a controller previously opened with SDL_GameControllerOpen().
*/
extern DECLSPEC void SDLCALL SDL_GameControllerClose(SDL_GameController *gamecontroller);
/* Ends C function definitions when using C++ */
#ifdef __cplusplus
}
#endif
#include "close_code.h"
#endif /* SDL_gamecontroller_h_ */
/* vi: set ts=4 sw=4 expandtab: */