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.

/* Test program to check SDL's CPU endian detection and byte swapping routines */

#include <stdio.h>

#include "SDL.h"
#include "SDL_endian.h"

int main(int argc, char *argv[])
{
	Uint16 value16 = 0xCDAB;
	Uint32 value32 = 0xEFBEADDE;
#if defined(__GNUC__) && defined(SDL_HAS_64BIT_TYPE)
	Uint64 value64 = 0xEFBEADDECDAB3412LL;
#endif

	printf("This is a %s endian machine.\n",
		(SDL_BYTEORDER == SDL_LIL_ENDIAN) ? "little" : "big");
	printf("Value 16 = 0x%X, swapped = 0x%X\n", value16, SDL_Swap16(value16));
	printf("Value 32 = 0x%X, swapped = 0x%X\n", value32, SDL_Swap32(value32));
#if defined(__GNUC__) && defined(SDL_HAS_64BIT_TYPE)
	printf("Value 64 = 0x%llX, swapped = 0x%llX\n", value64, SDL_Swap64(value64));
#endif
	return(0);
}