Add support for the Home LED on NS Controllers

[ThiLelito]

With the addition of Input.set_joy_light() from #111681, I wondered if the LED around the Home Button in some Nintendo Switch controllers could be adjusted. I discovered they could not, because its implementation uses the SDL_SetJoystickLED function while the Home LED uses the SDL_JOYSTICK_HIDAPI_SWITCH_HOME_LED hint.

This PR aims to add support for this LED mentioned.

I only changed the drivers/sdl/joypad_sdl.cpp file:

• Added an if condition on close_joypad to check if it's a NS controller and turn the LED off if true:
  • Sets the SDL_JOYSTICK_HIDAPI_SWITCH_HOME_LED hint to "0.0";
• Added an if condition on has_joy_light to make NS controllers return true;
• Added logic to set up the brightness of the NS controller LED:
  • It gets the max rgb value of the Color provided;
  • Sets the SDL_JOYSTICK_HIDAPI_SWITCH_HOME_LED hint with the char * of the maximum value.

I've tested on Windows and it seems to work. I don't know if there are other controllers that use the same hint and are not mentioned in the if statements. If so, feel free to change or improve it.

[Nintorch]

Hello, thank you for your work! I feel like we can also change the behaviour of SDL to make the existing code work with Switch controllers, it doesn't look too hard to fix, see also:

godot/thirdparty/sdl/joystick/hidapi/SDL_hidapi_switch.c

Lines 1617 to 1628 in 741fb8a

	// Set the LED state
	if (HasHomeLED(ctx)) {
	if (ctx->m_eControllerType == k_eSwitchDeviceInfoControllerType_JoyConLeft ||
	ctx->m_eControllerType == k_eSwitchDeviceInfoControllerType_JoyConRight) {
	SDL_AddHintCallback(SDL_HINT_JOYSTICK_HIDAPI_JOYCON_HOME_LED,
	SDL_HomeLEDHintChanged, ctx);
	} else {
	SDL_AddHintCallback(SDL_HINT_JOYSTICK_HIDAPI_SWITCH_HOME_LED,
	SDL_HomeLEDHintChanged, ctx);
	}
	}
	}

godot/thirdparty/sdl/joystick/hidapi/SDL_hidapi_switch.c

Lines 734 to 753 in 741fb8a

	static void SDLCALL SDL_HomeLEDHintChanged(void *userdata, const char *name, const char *oldValue, const char *hint)
	{
	SDL_DriverSwitch_Context *ctx = (SDL_DriverSwitch_Context *)userdata;
	if (hint && *hint) {
	int value;
	if (SDL_strchr(hint, '.') != NULL) {
	value = (int)(100.0f * SDL_atof(hint));
	if (value > 255) {
	value = 255;
	}
	} else if (SDL_GetStringBoolean(hint, true)) {
	value = 100;
	} else {
	value = 0;
	}
	SetHomeLED(ctx, (Uint8)value);
	}
	}

Maybe we can make the Switch driver report having a SDL_PROP_JOYSTICK_CAP_MONO_LED_BOOLEAN capability, similarly to how PS4 controllers work:

godot/thirdparty/sdl/joystick/hidapi/SDL_hidapi_ps4.c

Lines 891 to 906 in 741fb8a

	static Uint32 HIDAPI_DriverPS4_GetJoystickCapabilities(SDL_HIDAPI_Device *device, SDL_Joystick *joystick)
	{
	SDL_DriverPS4_Context *ctx = (SDL_DriverPS4_Context *)device->context;
	Uint32 result = 0;
	if (ctx->enhanced_mode_available) {
	if (ctx->lightbar_supported) {
	result |= SDL_JOYSTICK_CAP_RGB_LED;
	}
	if (ctx->vibration_supported) {
	result |= SDL_JOYSTICK_CAP_RUMBLE;
	}
	}
	return result;
	}

godot/thirdparty/sdl/joystick/hidapi/SDL_hidapijoystick.c

Lines 802 to 816 in 741fb8a

	static void HIDAPI_UpdateJoystickProperties(SDL_HIDAPI_Device *device, SDL_Joystick *joystick)
	{
	SDL_PropertiesID props = SDL_GetJoystickProperties(joystick);
	Uint32 caps = device->driver->GetJoystickCapabilities(device, joystick);
	if (caps & SDL_JOYSTICK_CAP_MONO_LED) {
	SDL_SetBooleanProperty(props, SDL_PROP_JOYSTICK_CAP_MONO_LED_BOOLEAN, true);
	} else {
	SDL_SetBooleanProperty(props, SDL_PROP_JOYSTICK_CAP_MONO_LED_BOOLEAN, false);
	}
	if (caps & SDL_JOYSTICK_CAP_RGB_LED) {
	SDL_SetBooleanProperty(props, SDL_PROP_JOYSTICK_CAP_RGB_LED_BOOLEAN, true);
	} else {
	SDL_SetBooleanProperty(props, SDL_PROP_JOYSTICK_CAP_RGB_LED_BOOLEAN, false);
	}

What do you think? :)
Should we also ask the SDL developers what they think about it?

Another reason I suggest doing this inside SDL is because the current approach of changing the hint will (probably) modify the home LED of all connected Switch controllers, not just one that was used for set_joy_light, so it might feel like a bug.

[ThiLelito]

Hey, thanks for your response!

Maybe we can make the Switch driver report having a SDL_PROP_JOYSTICK_CAP_MONO_LED_BOOLEAN capability, similarly to how PS4 controllers work.
Should we also ask the SDL developers what they think about it?

I think that we could, it seems to be the best option now that you mentioned it.
I guess we should ask the developers aswell, as they are the ones mostly responsible for the SDL. They may have a better idea of how we can overcome this :)

Another reason I suggest doing this inside SDL is because the current approach of changing the hint will (probably) modify the home LED of all connected Switch controllers, not just one that was used for set_joy_light, so it might feel like a bug.

Now that you've mentioned it, yes, I can't really test it since I don't have two or more controllers with this capability but as the hint is changed without providing the joypad/gamepad, it probably changes every controllers LED lights.

Also thanks @AThousandShips for the suggested change, it really is better.

[ThiLelito]

As discussed and suggested by @Nintorch , I tried changing the Switch SDL file and it seems to work properly, I just can't test it on multiple controllers but it may work as intended now.

• I've removed the code previously added to joypad.sdl since they are not necessary anymore
• Done the implementation in SDL_hidapi_switch.c as discussed and it seems to work as intended. The only logical difference is that now it should work for independent controllers as it is now treated as a property instead of a hint.
• It should work to both the Pro Controller and the Right Joy-Con (I confess I am not sure of how the Joy-con Pair is detected, but as the Pair includes the Right Joy-con I've added it aswell)

I should note that from my tests, the Pro Controller Home LED has different levels of brightness instead of a continuous range. It isn't an issue but I feel like this should be known.

[Nintorch]

Looks good to me! May I ask if the code works if you connect both the Pro Controller and the right Joy Con and call set_joy_light() on one of them?

[ThiLelito]

AFAIK it should work as both Pro Controllers and Joy Cons use the same base file (SDL_hidapi_switch) and I've added them to the HIDAPI_DriverSwitch_GetJoystickCapabilities so they should work equally (and separately). Sadly I can't confirm 100% that it works since I can't test it as I only have the NS2 Joy Cons* (and a NS1 Pro Controller)

* The NS2 Joy Cons and NS2 Pro Controllers don't have this LED so they wouldn't work whatsoever.

[Nintorch]

Ohh, I see!
@slouken Hello, sorry for bothering you, may I ask if this change would be acceptable as a pull request for SDL repository?

[slouken]

Ohh, I see! @slouken Hello, sorry for bothering you, may I ask if this change would be acceptable as a pull request for SDL repository?

Feel free to make the pull request. I need to think about whether this makes sense, since the home LED is treated differently from a mono LED, but I can think about that later once you've proposed it.

[Nintorch]

@ThiLelito Would you like to make a PR for SDL or would you like me to make it for you, if you want? :)

[ThiLelito]

@Nintorch Feel free to make it :)

[Nintorch]

Tested locally, it works as expected! Great job! :D

(Off-topic, but before you made this PR I didn't even know Switch controllers had home LEDs :D )

[Alex2782]

The code looks good, not tested, but I trust @Nintorch 😃

[Repiteo]

Could you squash your commits? See our pull request guidelines for more information

[ThiLelito]

Could you squash your commits? See our pull request guidelines for more information

Done :)

[Gemini04126]

aww, it's not in 4.6? sad, because i can't get my mom's ps4 controllers to connect, lol

[Repiteo]

Thanks! Congratulations on your first merged contribution! 🎉