view include/SDL_joystick.h @ 4167:a6f635e5eaa6 SDL-1.2

Fixed bug #611 From Tim Angus 2008-08-12 11:18:06 I'm one of the maintainers of ioquake3.org, an updated version of the Quake 3 engine. Relatively recently, we moved ioq3 to use SDL as a replacement for 95% of the platform specific code that was there. On the whole it's doing a great job but unfortunately since the move we've been getting complaints about the quality of the mouse input on the Windows platform to the point where for many the game is unplayable. Put in other terms, the current stable SDL 1.2 is basically not fit for purpose if you need high quality mouse input as you do in a first person shooter. Over the weekend I decided to pull my finger out and actually figure out what's going on. There are basically two major problems. Firstly, when using the "windib" driver, mouse input is gathered via the WM_MOUSEMOVE message. Googling for this indicates that often this is known to result in "spurious" and/or "missing" mouse movement events; this is the primary cause of the poor mouse input. The second problem is that the "directx" driver does not work at all in combination with OpenGL meaning that you can't use DirectInput if your application also uses OpenGL. In other words you're locked into using the "windib" driver and its poor mouse input. In order to address these problems I've done the following: * Remove WM_MOUSEMOVE based motion event generation and replace with calls to GetCursorPos which seems much more reliable. In order to achieve this I've moved mouse motion out into a separate function that is called once per DIB_PumpEvents. * Remove the restriction on the "directx" driver being inoperable in combination with OpenGL. There is a bug for this issues that I've hijacked to a certain extent (http://bugzilla.libsdl.org/show_bug.cgi?id=265). I'm the first to admit I don't really understand why this restriction is there in the first place. The commit message for the bug fix that introduced this restriction (r581) isn't very elaborate and I couldn't see any other bug tracking the issue. If anyone has more information on the bug that was avoided by r581 it would be helpful as I/someone could then look into addressing the problem without disabling the "directx" driver. * I've also removed the restriction on not being allowed to use DirectInput in windowed mode. I couldn't see any reason for this, at least not from our perspective. I have my suspicions that it'll be something like matching up the cursor with the mouse coordinates... * I bumped up the DirectInput API used to version 7 in order to get access to mouse buttons 4-7. I've had to inject a little bit of the DX7 headers into SDL there as the MinGW ones aren't up to date in this respect.
author Sam Lantinga <slouken@libsdl.org>
date Thu, 02 Apr 2009 04:43:36 +0000
parents a1b03ba2fcd0
children 4c4113c2162c
line wrap: on
line source

/*
    SDL - Simple DirectMedia Layer
    Copyright (C) 1997-2009 Sam Lantinga

    This library is free software; you can redistribute it and/or
    modify it under the terms of the GNU Lesser General Public
    License as published by the Free Software Foundation; either
    version 2.1 of the License, or (at your option) any later version.

    This library is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
    Lesser General Public License for more details.

    You should have received a copy of the GNU Lesser General Public
    License along with this library; if not, write to the Free Software
    Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA

    Sam Lantinga
    slouken@libsdl.org
*/

/* Include file for SDL joystick event handling */

#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

/* 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.
*/

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


/* Function prototypes */
/*
 * Count the number of joysticks attached to the system
 */
extern DECLSPEC int SDLCALL SDL_NumJoysticks(void);

/*
 * Get the implementation dependent name of a joystick.
 * This can be called before any joysticks are opened.
 * If no name can be found, this function returns NULL.
 */
extern DECLSPEC const char * SDLCALL SDL_JoystickName(int device_index);

/*
 * Open a joystick for use - the index passed as an argument refers to
 * the N'th joystick on the system.  This index is the value which will
 * identify this joystick in future joystick events.
 *
 * This function returns a joystick identifier, or NULL if an error occurred.
 */
extern DECLSPEC SDL_Joystick * SDLCALL SDL_JoystickOpen(int device_index);

/*
 * Returns 1 if the joystick has been opened, or 0 if it has not.
 */
extern DECLSPEC int SDLCALL SDL_JoystickOpened(int device_index);

/*
 * Get the device index of an opened joystick.
 */
extern DECLSPEC int SDLCALL SDL_JoystickIndex(SDL_Joystick *joystick);

/*
 * Get the number of general axis controls on a joystick
 */
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.
 */
extern DECLSPEC int SDLCALL SDL_JoystickNumBalls(SDL_Joystick *joystick);

/*
 * Get the number of POV hats on a joystick
 */
extern DECLSPEC int SDLCALL SDL_JoystickNumHats(SDL_Joystick *joystick);

/*
 * Get the number of buttons on a joystick
 */
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.
 */
extern DECLSPEC void SDLCALL SDL_JoystickUpdate(void);

/*
 * Enable/disable joystick event polling.
 * If joystick events are disabled, you must call SDL_JoystickUpdate()
 * yourself and check the state of the joystick when you want joystick
 * information.
 * The state can be one of SDL_QUERY, SDL_ENABLE or SDL_IGNORE.
 */
extern DECLSPEC int SDLCALL SDL_JoystickEventState(int state);

/*
 * Get the current 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.
 */
extern DECLSPEC Sint16 SDLCALL SDL_JoystickGetAxis(SDL_Joystick *joystick, int axis);

/*
 * Get the current state of a POV hat on a joystick
 * The return value is one of the following 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)
/*
 * The hat indices start at index 0.
 */
extern DECLSPEC Uint8 SDLCALL SDL_JoystickGetHat(SDL_Joystick *joystick, int hat);

/*
 * Get the ball axis change since the last poll
 * This returns 0, or -1 if you passed it invalid parameters.
 * The ball indices start at index 0.
 */
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
 * The button indices start at index 0.
 */
extern DECLSPEC Uint8 SDLCALL SDL_JoystickGetButton(SDL_Joystick *joystick, int button);

/*
 * Close a joystick previously opened with SDL_JoystickOpen()
 */
extern DECLSPEC void SDLCALL SDL_JoystickClose(SDL_Joystick *joystick);


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

#endif /* _SDL_joystick_h */