Date: Sun, 18 Apr 2004 16:09:53 -0400 (EDT) From: David MacCormack Subject: [SDL] Linux joystick patch I recently got myself a PS2 -> USB converter (a super joybox 5). It accepts 4 PSX/PS2 controllers. It's implemented as a HID, which is nice because it doesn't require its own driver, but the problem is that it's implemented as a *single* HID -- that is, it shows up as a single joystick with 19 axes, 4 hats, and 48 buttons. This poses a problem for a number of apps which use SDL (stella, fce ultra, zsnes, to name a few) and see only a single (physical) joystick even though there are really 4 (logical) joysticks. There are a number of these types of devices on the market, and I've seen others post messages (in the zsnes forum, for example) with the same problem, so I came up with what I think is a pretty generic solution. I patched src/joystick/linux/SDL_sysjoystic.c to include support for logical joysticks; basically, it's a static array and supporting functions that map a single physical joystick to multiple logical joysticks. The attached patch has the new code. It's wrapped inside #ifndef statements so that you can get the old behavior if you want.

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

#include <stdio.h>
#include <stdlib.h>
#include <pth.h>

#include "SDL_error.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 *)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");
			free(mutex);
			mutex = NULL;
		}
	} else {
		SDL_OutOfMemory();
	}
	return(mutex);
}

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