SlimeDream/MovementController.cs

public partial class MovementController : Node
{
	[ExportGroup("Movement")]
	[Export] public float Acceleration     { get; set; } = 2.5f;
	[Export] public float MaxSpeed         { get; set; } = 3.0f;
	[Export] public float FrictionFloor    { get; set; } = 3.5f;
	[Export] public float FrictionAir      { get; set; } = 1.0f;
	[Export] public float SprintMultiplier { get; set; } = 2.0f;

	[ExportGroup("Jumping")]
	[Export] public float JumpVelocity { get; set; } = 4.0f;
	/// <summary> Time (in seconds) after pressing the jump button a jump may occur late. </summary>
	[Export] public float JumpEarlyTime { get; set; } = 0.2f;
	/// <summary> Time (in seconds) after leaving a jumpable surface when a jump may still occur. </summary>
	[Export] public float JumpCoyoteTime { get; set; } = 0.2f;

	public float TimeSinceJumpPressed { get; private set; } = float.PositiveInfinity;
	public float TimeSinceOnFloor     { get; private set; } = float.PositiveInfinity;

	private CharacterBody3D Player;
	public override void _Ready()
	{
		Player = GetParent<CharacterBody3D>();
	}

	public override void _UnhandledInput(InputEvent ev)
	{
		if (ev.IsActionPressed("move_jump")) {
			TimeSinceJumpPressed = 0.0f;
			GetViewport().SetInputAsHandled();
		}
	}

	public override void _PhysicsProcess(double delta)
	{
		var velocity    = Player.Velocity;
		var horVelocity = new Vector2(velocity.X, velocity.Z);

		var gravity = (float)ProjectSettings.GetSetting("physics/3d/default_gravity");
		velocity.Y -= gravity * (float)delta;

		var input  = Input.GetVector("move_left", "move_right", "move_forward", "move_back");
		var camera = GetViewport().GetCamera3D();
		var target = input.Rotated(camera.GlobalRotation.Y - Tau / 4) * MaxSpeed;

		var isOnFloor   = Player.IsOnFloor();
		var isMoving    = target.Dot(horVelocity) > 0.0f;
		var isSprinting = Input.IsActionPressed("move_sprint");

		var accel = isMoving  ? Acceleration
		          : isOnFloor ? FrictionFloor
		                      : FrictionAir;

		if (isSprinting) {
			target *= SprintMultiplier;
			accel  *= SprintMultiplier;
		}

		horVelocity = horVelocity.Lerp(target, accel * (float)delta);

		velocity.X = horVelocity.X;
		velocity.Z = horVelocity.Y;

		if (isOnFloor) TimeSinceOnFloor = 0.0f;
		else           TimeSinceOnFloor += (float)delta;

		if ((TimeSinceJumpPressed <= JumpEarlyTime) && (TimeSinceOnFloor <= JumpCoyoteTime)) {
			TimeSinceJumpPressed = TimeSinceOnFloor = float.PositiveInfinity;
			velocity.Y = JumpVelocity;
		} else
			TimeSinceJumpPressed += (float)delta;

		Player.Velocity = velocity;
		Player.MoveAndSlide();
	}

	public override void _Process(double delta)
	{
	}
}