MovementTests/systems/dash/DashSystem.cs

using Godot;

namespace Movementtests.systems;

public partial class DashSystem: Node3D
{
    public record DashLocation(bool HasHit, Vector3 TargetLocation, Vector3 CollisionPoint, Vector3 CollisionNormal);
    
    
    [Export(PropertyHint.Range, "0,0.2,0.01,or_greater")]
    public float DashSpeed { get; set; } = 0.1f;
    [Export(PropertyHint.Range, "0,1000,1,or_greater")]
    public float PostDashSpeed { get; set; } = 0f;
    
    public bool HasHit { get; set; }
    public Vector3 TargetLocation { get; set; }
    public Vector3 CollisionPoint { get; set; }
    public Vector3 CollisionNormal { get; set; }
    public Vector3 PlannedLocation { get; set; }
    
    public bool ShouldMantle { get; set; }
    public Vector3 PlannedMantleLocation { get; set; }
    public MantleSystem MantleSystem { get; set; }
        
    private HeadSystem _head;
    private ShapeCast3D _dashCast3D;
    private Camera3D _camera;
    private Vector3 _dashDirection = Vector3.Zero;
    
    private ShapeCast3D _dashCastDrop;
    private MeshInstance3D _dashDropIndicator;
    private MeshInstance3D _dashDropLocationIndicator;

    private MeshInstance3D _dashTarget;
    private CpuParticles3D _dashIndicator;
    private AnimationPlayer _dashIndicatorAnim;
    
    [Export]
    public PackedScene DashIndicatorScene { get; set; }

    [Signal]
    public delegate void DashStartedEventHandler();
    [Signal]
    public delegate void DashEndedEventHandler();
    [Signal]
    public delegate void DashProgressEventHandler(float progress);
    
    private Vector3 _globalDashPosition = Vector3.Zero;
    
    public float DashCastRadius { get; set; }

    public void Init(HeadSystem head, Camera3D camera)
    {
        _dashCast3D = GetNode<ShapeCast3D>("DashCast3D");
        var dashShape = _dashCast3D.GetShape() as SphereShape3D;
        DashCastRadius = dashShape!.Radius;
        
        _dashCastDrop = GetNode<ShapeCast3D>("DashCastDrop");
        _dashDropIndicator = GetNode<MeshInstance3D>("DashDropIndicator");
        _dashDropIndicator.Visible = false;
        _dashDropLocationIndicator = GetNode<MeshInstance3D>("DashDropLocationIndicator");
        _dashDropLocationIndicator.Visible = false;
        
        _head = head;
        _camera = camera;
        
        MantleSystem = GetNode<MantleSystem>("MantleSystem");
        MantleSystem.Init();
        
        _dashTarget = GetNode<MeshInstance3D>("DashTarget");
        _dashTarget.SetVisible(false);
        _dashIndicator = GetNode<CpuParticles3D>("DashIndicator");
        _dashIndicatorAnim = GetNode<AnimationPlayer>("DashIndicator/AnimationPlayer");
    }

    private DashLocation ComputeDashLocation()
    {
        var targetLocation = _dashCast3D.ToGlobal(_dashCast3D.TargetPosition);
        var hasHit = _dashCast3D.IsColliding();
        if (!hasHit)
        {
            return new DashLocation(false, targetLocation, Vector3.Zero, Vector3.Zero);
        }

        var collisionPoint = _dashCast3D.GetCollisionPoint(0);
        var collisionNormal = _dashCast3D.GetCollisionNormal(0);
        
        var fraction = _dashCast3D.GetClosestCollisionSafeFraction();
        var globalSweepPath = targetLocation - _dashCast3D.GlobalPosition;
        var locationAlongPath = _dashCast3D.GlobalPosition + globalSweepPath * fraction;
        return new DashLocation(true, locationAlongPath, collisionPoint, collisionNormal);
    }

    public void PrepareDash()
    {
        _dashCast3D.SetRotation(_head.GetGlobalLookRotation());

        (HasHit, PlannedLocation, CollisionPoint, CollisionNormal) = ComputeDashLocation();
        
        // TODO: Position mantle system to planned location, aligned with ground planned and facing the same way as the dash
        // Then query it being careful when dashing underneath a platform and such
        MantleSystem.SetGlobalPosition(PlannedLocation);
        MantleSystem.SetRotation(new Vector3(
            MantleSystem.Rotation.X,
            _head.Rotation.Y,   
            MantleSystem.Rotation.Z));
        MantleSystem.ProcessMantle(false);
        ShouldMantle = MantleSystem.IsMantlePossible;
        
        // Setup dash target
        var targetColor = HasHit ? new Color(1f, 0.2f, 0.2f) : new Color(1f, 1f, 1f);
        targetColor = ShouldMantle ? new Color(0.2f, 0.2f, 1f) : targetColor;
        var targetMaterial = (StandardMaterial3D) _dashTarget.GetSurfaceOverrideMaterial(0);
        targetMaterial.SetAlbedo(targetColor);
        _dashTarget.SetVisible(true);
        var targetLocation = ShouldMantle ? MantleSystem.FirstMantleProfilePoint : PlannedLocation;
        _dashTarget.SetGlobalPosition(targetLocation);
        
        var shouldShowDropIndicator = !HasHit && !ShouldMantle;
        _dashDropIndicator.SetVisible(shouldShowDropIndicator);
        _dashDropLocationIndicator.SetVisible(shouldShowDropIndicator);
        if (shouldShowDropIndicator)
        {
            _dashCastDrop.GlobalPosition = targetLocation;  // Place drop indication cast at dash location
            var startDropLocation = targetLocation;  // Start of the drop is the dash target location 
            
            // End of the drop is either max cast distance or first collision
            var hasDropLocationHit = _dashCastDrop.IsColliding();
            var endDropLocation = hasDropLocationHit ? _dashCastDrop.GetCollisionPoint(0) : _dashCastDrop.ToGlobal(_dashCast3D.TargetPosition);
            
            // Only show drop location indicator if drop cast has hit
            _dashDropLocationIndicator.SetVisible(hasDropLocationHit);
            _dashDropLocationIndicator.SetGlobalPosition(endDropLocation);
            
            var dropLength = (endDropLocation - startDropLocation).Length();
            var dropDirection = (endDropLocation - startDropLocation).Normalized();
            _dashDropIndicator.SetScale(new Vector3(1, dropLength, 1));
            _dashDropIndicator.SetGlobalPosition(startDropLocation + dropDirection * dropLength * 0.5f);
        }
    }

    public void StopPreparingDash()
    {
        _dashTarget.SetVisible(false);
        _dashDropIndicator.SetVisible(false);
        _dashDropLocationIndicator.SetVisible(false);
    }

    public void StartPreparingDash()
    {
        _dashTarget.SetVisible(true);
    }
}