Gamepad Axis Events are Dirty Little Liars

Development Programming & Scripting C++
1

I am trying to support both mouse/keyboard and gamepad for a twin-stick-shooter style game. I’m scratching my head at gamepad axis events and how deceiving they are.

My axis events are mapped like so:
axisbinding.JPG

With my gamepads disconnected I receive gamepad axis events with a value of 0.0f every frame. With no gamepads connected, I’d expect this to either not get called or be NaN. I feel like I’m missing a key part of this story, do people dynamically bind/unbind axis based on gamepad connection polling?

2

0.0f events are received every frame no matter which input device you are using. You should use something like this


if (!FMath::IsNearlyEqual(Val, 0.f))
	{
3

Right. I’m doing some outright gamepad detection now:


if (UseGamepad)
{
    LastAimX = Val;
}

I guess I’m more interested in why this is the case from an architectural point of view. 0.0f is a valid axis value for a gamepad but that’s if and only if your gamepad is connected.

4

I don’t know if this has any bearing on your case, but I think you are only supposed to make one map pr. axis. The positive one, that is. Now, I would imagine, that the inputs would report both 1 and -1 and -1 and 1, depending on which way you go on the axis…

5

Thanks for mentioning that. It doesn’t affect the original issue, but it does make things cleaner and that makes me happy :smiley: