Change the default deadzone value for new actions from 0.5 to 0.2

[reptofrog]

This changes the default deadzone value for new actions from 0.5 to 0.2 as discussed in godotengine/godot-proposals#7069.

This does not change the built-in actions.

This is my first pull request, so there is chance I have done something wrong - please check.

• Bugsquad edit, closes: Decrease the default deadzone value for actions to better match real world use cases godot-proposals#7069

[AThousandShips]

You will probably need to add a compatibility note, but the CI will instruct for that

[AThousandShips]

Needs a compatibility addition, follow the instructions here

Like so:

GH-80299
--------
Validate extension JSON: Error: Field 'classes/InputMap/methods/add_action/arguments/1': default_value changed value in new API, from "0.5" to "0.2".

Default deadzone value was changed.

Unsure what the comment should be here, if any further instructions are needed

[AThousandShips]

Have you made sure this doesn't change input bindings from before this applied? I.e. make a binding with the default deadzone, and then open it with these changes

[reptofrog]

Have you made sure this doesn't change input bindings from before this applied? I.e. make a binding with the default deadzone, and then open it with these changes

Yes, I have tested for that, old actions are not changed.

[Calinou]

Tested locally, it works as expected:

This implies a small run-time behavior change, as actions created from a script in InputMap will now have a lower deadzone by default. I think this is acceptable (especially since creating new actions from code is uncommon), but it needs to be clearly documented in the release notes.

[Calinou]

Note that godotengine/godot-demo-projects#1024 changes the deadzone for all non-built-in inputs in demo projects to 0.2. Merging this PR would ensure we don't accidentally add new actions with a higher deadzone in demo projects 🙂

[Sauermann]

I consider these changes beneficial and think, that they should be included.
Since this PR adjusts the API, perhaps it should be merged early in the 4.4 dev-cycle.

The following two places in the code base should also be investigated, if changes are necessary:

godot/core/config/project_settings.cpp

Line 506 in 7d151c8

action["deadzone"] = Variant(0.5f);

godot/tests/core/input/test_input_event.h

Line 93 in 7d151c8

// Since deadzone is 0.5, action_strength grows linearly from 0.5 to 1.0.