Xinput triggers mapped to analog sticks could pollute internal analog sticks state

[Kethen]

Game or games this happens in

all games, if triggers were mapped under xinput

What area of the game / PPSSPP

It seems that Xinput devices would not send trigger values unless it's over XINPUT_GAMEPAD_TRIGGER_THRESHOLD

ppsspp/Windows/XinputDevice.cpp

Line 240 in 2036f1c

if (NormalizedDeadzoneDiffers(prevState[pad].Gamepad.bLeftTrigger, state.Gamepad.bLeftTrigger, XINPUT_GAMEPAD_TRIGGER_THRESHOLD)) {

So it never sends anything under XINPUT_GAMEPAD_TRIGGER_THRESHOLD after a higher value was sent, leaving a stuck analog value > 30.f/255.0f ~ 0.1176 on internal state

The stuck value can then further affect analog normalizing on control mapper

What should happen

Idle trigger should not maintain an analog value

Maintaining a value could also be the cause of #16643

Perhaps when XINPUT_GAMEPAD_TRIGGER_THRESHOLD is not met, it should gradually send values until 0 so that control mapper can also drop back to under deadzone? Or maybe send clamp((x - 30.0f)/(255.0f - 30.0f), 0.0, 1.0) as trigger input and skip the check

Logs

No response

Platform

Windows

Mobile phone model or graphics card

Not relevant

PPSSPP version affected

v1.16.6 release, v1.16.6-290-g2036f1c36

Last working version

No response

Graphics backend (3D API)

Vulkan

Checklist

• Test in the latest git build in case it's already fixed.
• Search for other reports of the same issue.

[Kethen]

Since 633a6f6, it might make sense to just skip the deadzone checking for triggers as well

[hrydgard]

Fixed by #18407.