view src/thread/pth/SDL_sysmutex.c @ 3496:78fc8ea578b2

Joe 2009-11-23 21:31:10 PST If type is ::SDL_HAPTIC_CARTESIAN, direction is encoded by three positions 367 * (X axis, Y axis and Z axis (with 3 axes)). ::SDL_HAPTIC_CARTESIAN uses 368 * the first three \c dir parameters. The cardinal directions would be: 369 * - North: 0,-1, 0 370 * - East: -1, 0, 0 371 * - South: 0, 1, 0 372 * - West: 1, 0, 0 typedef struct SDL_HapticDirection { Uint8 type; /**< The type of encoding. */ Uint16 dir[3]; /**< The encoded direction. */ } SDL_HapticDirection; An unsigned int can't store negative values and I don't see an alternate way to encode them in the docs or source. The best I have been able to come up with is using a negative magnitude for the effect but this will only get me 2 of the 4 quadrants in the plane for 2d effects. I looked at the win32 and linux implementations and I believe is is safe to use signed ints in the direction struct. I am unfamiliar with the darwin haptics API so I don't know if it is safe.
author Sam Lantinga <slouken@libsdl.org>
date Fri, 27 Nov 2009 19:29:27 +0000
parents 99210400e8b9
children
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/*
    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 "SDL_config.h"

/*
 *	GNU pth mutexes
 *
 *	Patrice Mandin
 */

#include <pth.h>

#include "SDL_mutex.h"
#include "SDL_sysmutex_c.h"

/* Create a mutex */
SDL_mutex *
SDL_CreateMutex(void)
{
    SDL_mutex *mutex;

    /* Allocate mutex memory */
    mutex = (SDL_mutex *) SDL_malloc(sizeof(*mutex));
    if (mutex) {
        /* Create the mutex, with initial value signaled */
        if (!pth_mutex_init(&(mutex->mutexpth_p))) {
            SDL_SetError("Couldn't create mutex");
            SDL_free(mutex);
            mutex = NULL;
        }
    } else {
        SDL_OutOfMemory();
    }
    return (mutex);
}

/* Free the mutex */
void
SDL_DestroyMutex(SDL_mutex * mutex)
{
    if (mutex) {
        SDL_free(mutex);
    }
}

/* Lock the mutex */
int
SDL_mutexP(SDL_mutex * mutex)
{
    if (mutex == NULL) {
        SDL_SetError("Passed a NULL mutex");
        return -1;
    }

    pth_mutex_acquire(&(mutex->mutexpth_p), FALSE, NULL);

    return (0);
}

/* Unlock the mutex */
int
SDL_mutexV(SDL_mutex * mutex)
{
    if (mutex == NULL) {
        SDL_SetError("Passed a NULL mutex");
        return -1;
    }

    pth_mutex_release(&(mutex->mutexpth_p));

    return (0);
}

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