Sort controllers by the js* index on Linux

Also fixed the initial scan to directly scan devices instead of using
udev so they can be sorted, as intended.

Fixes https://github.com/libsdl-org/SDL/issues/4688
This commit is contained in:
Sam Lantinga 2022-04-05 21:00:07 -07:00
parent 0249df9d96
commit 7ea1b69dd4
1 changed files with 70 additions and 25 deletions

View File

@ -606,6 +606,26 @@ LINUX_InotifyJoystickDetect(void)
}
#endif /* HAVE_INOTIFY */
static int get_event_joystick_index(int event)
{
int joystick_index = -1;
int i, count;
struct dirent **entries;
char path[PATH_MAX];
SDL_snprintf(path, SDL_arraysize(path), "/sys/class/input/event%d/device", event);
count = scandir(path, &entries, NULL, alphasort);
for (i = 0; i < count; ++i) {
if (SDL_strncmp(entries[i]->d_name, "js", 2) == 0) {
joystick_index = SDL_atoi(entries[i]->d_name+2);
}
free(entries[i]); /* This should NOT be SDL_free() */
}
free(entries); /* This should NOT be SDL_free() */
return joystick_index;
}
/* Detect devices by reading /dev/input. In the inotify code path we
* have to do this the first time, to detect devices that already existed
* before we started; in the non-inotify code path we do this repeatedly
@ -618,10 +638,35 @@ filter_entries(const struct dirent *entry)
static int
sort_entries(const struct dirent **a, const struct dirent **b)
{
int numA = SDL_atoi((*a)->d_name+5);
int numB = SDL_atoi((*b)->d_name+5);
int numA, numB;
int offset;
if (SDL_classic_joysticks) {
offset = 2; /* strlen("js") */
numA = SDL_atoi((*a)->d_name+offset);
numB = SDL_atoi((*b)->d_name+offset);
} else {
offset = 5; /* strlen("event") */
numA = SDL_atoi((*a)->d_name+offset);
numB = SDL_atoi((*b)->d_name+offset);
/* See if we can get the joystick ordering */
{
int jsA = get_event_joystick_index(numA);
int jsB = get_event_joystick_index(numB);
if (jsA >= 0 && jsB >= 0) {
numA = jsA;
numB = jsB;
} else if (jsA >= 0) {
return -1;
} else if (jsB >= 0) {
return 1;
}
}
}
return (numA - numB);
}
static void
LINUX_FallbackJoystickDetect(void)
{
@ -684,29 +729,7 @@ LINUX_JoystickInit(void)
SDL_classic_joysticks = SDL_GetHintBoolean(SDL_HINT_LINUX_JOYSTICK_CLASSIC, SDL_FALSE);
#if SDL_USE_LIBUDEV
if (enumeration_method == ENUMERATION_UNSET) {
if (SDL_GetHintBoolean("SDL_JOYSTICK_DISABLE_UDEV", SDL_FALSE)) {
SDL_LogDebug(SDL_LOG_CATEGORY_INPUT,
"udev disabled by SDL_JOYSTICK_DISABLE_UDEV");
enumeration_method = ENUMERATION_FALLBACK;
} else if (access("/.flatpak-info", F_OK) == 0
|| access("/run/host/container-manager", F_OK) == 0) {
/* Explicitly check `/.flatpak-info` because, for old versions of
* Flatpak, this was the only available way to tell if we were in
* a Flatpak container. */
SDL_LogDebug(SDL_LOG_CATEGORY_INPUT,
"Container detected, disabling udev integration");
enumeration_method = ENUMERATION_FALLBACK;
} else {
SDL_LogDebug(SDL_LOG_CATEGORY_INPUT,
"Using udev for joystick device discovery");
enumeration_method = ENUMERATION_LIBUDEV;
}
}
#endif
enumeration_method = ENUMERATION_UNSET;
/* First see if the user specified one or more joysticks to use */
if (devices != NULL) {
@ -735,6 +758,28 @@ LINUX_JoystickInit(void)
LINUX_JoystickDetect();
#if SDL_USE_LIBUDEV
if (enumeration_method == ENUMERATION_UNSET) {
if (SDL_GetHintBoolean("SDL_JOYSTICK_DISABLE_UDEV", SDL_FALSE)) {
SDL_LogDebug(SDL_LOG_CATEGORY_INPUT,
"udev disabled by SDL_JOYSTICK_DISABLE_UDEV");
enumeration_method = ENUMERATION_FALLBACK;
} else if (access("/.flatpak-info", F_OK) == 0
|| access("/run/host/container-manager", F_OK) == 0) {
/* Explicitly check `/.flatpak-info` because, for old versions of
* Flatpak, this was the only available way to tell if we were in
* a Flatpak container. */
SDL_LogDebug(SDL_LOG_CATEGORY_INPUT,
"Container detected, disabling udev integration");
enumeration_method = ENUMERATION_FALLBACK;
} else {
SDL_LogDebug(SDL_LOG_CATEGORY_INPUT,
"Using udev for joystick device discovery");
enumeration_method = ENUMERATION_LIBUDEV;
}
}
if (enumeration_method == ENUMERATION_LIBUDEV) {
if (SDL_UDEV_Init() < 0) {
return SDL_SetError("Could not initialize UDEV");