Fix isVehicleOnGround

[FileEX]

Summary

This PR fixes the isVehicleOnGround function similarly to how #4317 fixed IsPedOnGround.

The current logic is very primitive. It simply checks the distance from the bottom of the bounding box to the ground. That’s why if a vehicle is, for example, lying on its roof, it returns false. It can also return false on slopes, and for a Monster Truck it always returns false, because its wheels aren’t included in the bounding box, which ends at the model’s edge.

The fixed isVehicleOnGround function now first does a simple check to see if any wheel is touching the ground. If so, the vehicle is considered on the ground. If not, it performs a basic OOB check and measures the distance to the ground. During testing, I never received a false negative.

Motivation

Fixed #471 and #2093

Test plan

Tested.

Spawn Monster Truck
crun isVehicleOnGround(me.vehicle) -- always false

Spawn Beagle
crun setVehicleDamageProof(me.vehicle, true)
crun me.vehicle.rotation = Vector3(0, 180, 0)
crun isVehicleOnGround(me.vehicle) -- false

Spawn some car
crun setVehicleHandling(me.vehicle, 'suspensionLowerLimit', -1)
crun isVehicleOnGround(me.vehicle) -- false

Checklist

• Your code should follow the coding guidelines.
• Smaller pull requests are easier to review. If your pull request is beefy, your pull request should be reviewable commit-by-commit.