view src/joystick/SDL_sysjoystick.h @ 3880:74e828c64315 SDL-1.2

Fixed bug #292 I might be on crack here. It looks like SDL_ConvertMono() in src/audio/SDL_audiocvt.c adds the left and right channels of a stereo stream together, and clamps the new mono channel if it would overflow. Shouldn't it be dividing by 2 to average the two sample points instead of clamping? Otherwise the mono sample point's volume doubles in the conversion. This would also make the conversion faster, as it replaces two branches per sample frame with a bitwise shift. --ryan.
author Sam Lantinga <slouken@libsdl.org>
date Sun, 24 Sep 2006 15:45:37 +0000
parents d910939febfa
children 782fd950bd46 c121d94672cb a1b03ba2fcd0
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/*
    SDL - Simple DirectMedia Layer
    Copyright (C) 1997-2006 Sam Lantinga

    This library is SDL_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 "SDL_config.h"

/* This is the system specific header for the SDL joystick API */

#include "SDL_joystick.h"

/* The SDL joystick structure */
struct _SDL_Joystick {
	Uint8 index;		/* Device index */
	const char *name;	/* Joystick name - system dependent */

	int naxes;		/* Number of axis controls on the joystick */
	Sint16 *axes;		/* Current axis states */

	int nhats;		/* Number of hats on the joystick */
	Uint8 *hats;		/* Current hat states */
	
	int nballs;		/* Number of trackballs on the joystick */
	struct balldelta {
		int dx;
		int dy;
	} *balls;		/* Current ball motion deltas */
	
	int nbuttons;		/* Number of buttons on the joystick */
	Uint8 *buttons;		/* Current button states */
	
	struct joystick_hwdata *hwdata;	/* Driver dependent information */

	int ref_count;		/* Reference count for multiple opens */
};

/* Function to scan the system for joysticks.
 * Joystick 0 should be the system default joystick.
 * This function should return the number of available joysticks, or -1
 * on an unrecoverable fatal error.
 */
extern int SDL_SYS_JoystickInit(void);

/* Function to get the device-dependent name of a joystick */
extern const char *SDL_SYS_JoystickName(int index);

/* Function to open a joystick for use.
   The joystick to open is specified by the index field of the joystick.
   This should fill the nbuttons and naxes fields of the joystick structure.
   It returns 0, or -1 if there is an error.
 */
extern int SDL_SYS_JoystickOpen(SDL_Joystick *joystick);

/* Function to update the state of a joystick - called as a device poll.
 * This function shouldn't update the joystick structure directly,
 * but instead should call SDL_PrivateJoystick*() to deliver events
 * and update joystick device state.
 */
extern void SDL_SYS_JoystickUpdate(SDL_Joystick *joystick);

/* Function to close a joystick after use */
extern void SDL_SYS_JoystickClose(SDL_Joystick *joystick);

/* Function to perform any system-specific joystick related cleanup */
extern void SDL_SYS_JoystickQuit(void);