Existing SDL applications may not know about the need to set a specific
hint to enable rumble on PS5 controllers, even though they may already
set the equivalent SDL_HINT_JOYSTICK_HIDAPI_PS4_RUMBLE hint for PS4
controller rumble support.
Rather than requiring those developers update their apps, let's use the
SDL_HINT_JOYSTICK_HIDAPI_PS4_RUMBLE value as an indication of the behavior
they are expected for all PlayStation controllers.
jibb
I'm testing with DualShock 4, DualSense, Switch Pro Controller, and PowerA Switch Controller.
I'm using the standard mapping file from here:
https://raw.github.com/gabomdq/SDL_GameControllerDB/master/gamecontrollerdb.txt
With SDL_HINT_GAMECONTROLLER_USE_BUTTON_LABELS turned off (set to "0") I expect the button positions to be the same on all devices, based on Xbox controller button naming (eg SDL_GameControllerGetButton(g, SDL_CONTROLLER_BUTTON_Y) gives me whether the North face button is pressed).
However, the Switch Pro Controller layout is wrong (matching labels rather than positions, so X and Y are swapped and A and B are swapped). And with the PowerA controller the East and West buttons are correct, but the North and South buttons are swapped instead.
Mathias Kaerlev
Also seeing this on 2.0.14. This is most likely a regression, since we weren't seeing this on an earlier SDL version.
I suspect it might be caused by this commit:
a569b21188 (diff-da9344d94c66b8c702a45e7649f412039f08bba83bd82de33f5c80ea9c8c39d5)
It seems like both the HIDAPI driver and SDL_gamecontroller.c will try to swap the buttons if the hint is set to 0, causing the button remap to cancel out.
RustyM
This is related to Bug 5034, but crashes under a somewhat different condition.
In the latest tip (changeset 13914) or with the SDL 2.0.12 source + David?s 5034 patch, unplugging and then replugging in certain controller types on macOS will crash. A mix of new controllers like Switch Pro, PS4 and Xbox One all work without issue. But if a controller without a rumble function, like many SNES retro USB gamepads, is mixed with a PS4 or Switch Pro controller it will crash.
File: joystick/darwin/SDL_sysjoystick.c
Function: static recDevice *FreeDevice(recDevice *removeDevice)
On line 159: while (device->pNext != removeDevice) {
Causes: Thread 1: EXC_BAD_ACCESS (code=1, address=0x188)
This can be reproduced in testgamecontroller" by starting the test program with both a ?retro? controller plugged in and a ?modern rumble? controller (Switch Pro/PS4). This may crash on launch, but it depends on which controller ends up as device 0. If it doesn?t crash, unplug the ?modern rumble? controller and plug it back in.
Some of the "retro" controllers I?ve seen this crash with:
- iBuffalo SNES Controller
- 8Bitdo SN30 Gamepad (in MacOS mode)
- Retrolink NES Controller
- HuiJia SNES Controller Adaptor
The issue appears macOS specific. Seen on 10.12.6 and 10.14.6. Not seen on Windows 10.
The while loop in FreeDevice() assumes that every device is not NULL.
recDevice *device = gpDeviceList;
while (device->pNext != removeDevice) {
device = device->pNext;
}
device->pNext = pDeviceNext;
So maybe we should check for NULL here? Or instead prevent adding NULL devices to the list in the first place? Checking device for NULL before entering the loop appears to work.
recDevice *device = gpDeviceList;
if (!device) {
while (device->pNext != removeDevice) {
device = device->pNext;
}
}
device->pNext = pDeviceNext;
Note that axes are changed to match the axes we're using with PlayStation controllers, since users will appreciate consistent behaviour across devices.
i.e. where the string is known guaranteed to be WCHAR*, in:
- SDL_dinputjoystick.c (WIN_IsXInputDevice): VARIANT->var is BSTR (WCHAR*)
- SDL_rawinputjoystick.c (RAWINPUT_AddDevice): string is WCHAR*
- SDL_windows_gaming_input.c (IEventHandler_CRawGameControllerVtbl_InvokeAdded):
string is WCHAR*
There should be more of these..
pj5085
I added some printf to verify the math being done. Of the three joysticks I have, it works correctly for at least two, and seems to work correctly for the third. I say "seems to" because, for the third joystick, the values never go through the AxisCorrect function, and thus never hit my printf statements, even though they did in the version I wrote my patch against. I'm not sure what's going on there, but it at least seems to be working correctly in as much as I can tell.
I note this result in particular, for an SNES Gamepad (min=0, max=255):
Joystick value 0 becomes -32768
Joystick value 127 becomes 0
Joystick value 255 becomes 32767
Without the code that forces a zero point, the 127 input value would become -129, so I think you see why I added that code to turn it into zero. However, I think Kai Krakow has a point about how SDL shouldn't assume that there should be a center.
Obviously in the majority of cases there actually should be a center, and the code that turns that 127 into an actual 0 is creating only a 0.2% error over 0.4% of this joystick's range. However, what if there is an axis that is some kind of special control, like a 4-position switch, and, for whatever reason, the joystick reports it as an axis with 4 possible values, 0 to 3? In that case, mutilating the two center values to the same value is much more of an error and and turns that 4-position switch into a 3-position switch. If any joystick does this with a 2-position switch, then this code would render that control entirely useless as it would report the same value with the switch in either position. Obviously the code could require that there be at least N possible values, to guess whether something is a proper axis or just some kind of switch, but the choice of N would be arbitrary and that's ugly.
I guess the real problem here is that my gamepad is just kind of broken. It should be reporting a range of -1 to +1 since that's what it actually does. Also, as Kai Krakow points out, it's probably not SDL's place to fix broken hardware. I'll add that, if SDL does fix broken hardware, it should probably actually know that it's broken rather than be merely guessing that it is.
So, to the extent that SDL is able to do stuff like this, perhaps it's something better left for the user to configure in some kind of config file.
pj5085
It occurred to me that my simple patch that comments out a few lines of code does not correctly remove the dead zone since the calculation presumably assumes the dead zone has been cut out of the range. Then, while looking into how to make it output the correct range of values, I realized SDL wasn't returning the correct range of values to begin with.
This line of code was already present:
printf("Values = { %d, %d, %d, %d, %d }\n", absinfo.value, absinfo.minimum, absinfo.maximum, absinfo.fuzz, absinfo.flat);
For my joystick this yeilds:
Values = { 0, -127, 127, 0, 15 }
Then this code calculates the coefficients:
In SDL1:
joystick->hwdata->abs_correct[i].coef[0] = (absinfo.maximum + absinfo.minimum) / 2 - absinfo.flat;
joystick->hwdata->abs_correct[i].coef[1] = (absinfo.maximum + absinfo.minimum) / 2 + absinfo.flat;
t = ((absinfo.maximum - absinfo.minimum) / 2 - 2 * absinfo.flat);
if ( t != 0 ) {
joystick->hwdata->abs_correct[i].coef[2] = (1 << 29) / t;
} else {
joystick->hwdata->abs_correct[i].coef[2] = 0;
}
In SDL2:
joystick->hwdata->abs_correct[i].coef[0] = (absinfo.maximum + absinfo.minimum) - 2 * absinfo.flat;
joystick->hwdata->abs_correct[i].coef[1] = (absinfo.maximum + absinfo.minimum) + 2 * absinfo.flat;
t = ((absinfo.maximum - absinfo.minimum) - 4 * absinfo.flat);
if (t != 0) {
joystick->hwdata->abs_correct[i].coef[2] = (1 << 28) / t;
} else {
joystick->hwdata->abs_correct[i].coef[2] = 0;
}
Neither calculates the correct coefficients for the code in the AxisCorrect function.
In SDL1:
if ( value > correct->coef[0] ) {
if ( value < correct->coef[1] ) {
return 0;
}
value -= correct->coef[1];
} else {
value -= correct->coef[0];
}
value *= correct->coef[2];
value >>= 14;
In SDL2:
value *= 2;
if (value > correct->coef[0]) {
if (value < correct->coef[1]) {
return 0;
}
value -= correct->coef[1];
} else {
value -= correct->coef[0];
}
In SDL1, the calculated coefficients are coef[0]=15, coef[1]=-15 and coef[2]=5534751. So with a full-scale input of 127, it calculates an output value of 37835, which is considerably out of range.
In SDL2, the calculated coefficients are coef[0]=30, coef[1]=-30, and coef[2]=1383687. So with a full-scale input of 127, it calculates the same output value of 37835.
I tested it with the 3 joysticks I have, and it produces out-of-range values for all of them.
Anyway, since dead zones are garbage, I just deleted all of that junk and wrote some code that takes the absinfo.minimum and absinfo.maximum values and uses them to scale the axis range to -32767 through +32767.
I also made it detect when a range doesn't have an integer center point, e.g. the center of -128 to + 127 is -0.5. In such cases, if either value to the side of the center is provided, it zeros it, but it otherwise doesn't implement any kind of dead zone. This seemed important with my gamepad which provides only the values of 0, 127, and 255, since without this hack it would never be centered.
Also, the previous minimum output value was -32768, but as that creates an output range that has no true center, I changed the minimum value to -32767.
I tested it with the 3 joystick devices I have and it seems to create correct values for all of them.
Sam Lantinga
Cameron Gutman
Ozkan Sezer
JibbSmart