MVP of the plane throwing game (#77)

Co-authored-by: Michal Pikulski <michal@foolhardyhorizons.com>
Co-authored-by: Michal Pikulski <michal.a.pikulski@gmail.com>
Reviewed-on: #77

Assets/Scripts/Minigames/Airplane/Interactive/AirplaneGravityWell.cs

@@ -0,0 +1,148 @@
+using UnityEngine;
+
+namespace Minigames.Airplane.Interactive
+{
+    /// <summary>
+    /// Gravity well that pulls airplanes toward its center.
+    /// Creates challenging "danger zones" that players must avoid or escape from.
+    /// </summary>
+    [RequireComponent(typeof(Collider2D))]
+    public class AirplaneGravityWell : MonoBehaviour
+    {
+        [Header("Gravity Configuration")]
+        [SerializeField] private float pullStrength = 5f;
+        [SerializeField] private bool useInverseSquare = false;
+        [SerializeField] private float minPullDistance = 0.5f;
+        
+        [Header("Optional Modifiers")]
+        [SerializeField] private float maxPullForce = 15f;
+        [SerializeField] private AnimationCurve pullFalloff = AnimationCurve.Linear(0, 1, 1, 0);
+        
+        [Header("Visual Feedback (Optional)")]
+        [SerializeField] private ParticleSystem gravityParticles;
+        [SerializeField] private SpriteRenderer centerSprite;
+        [SerializeField] private float rotationSpeed = 90f;
+        
+        [Header("Debug")]
+        [SerializeField] private bool showDebugLogs;
+        [SerializeField] private bool drawDebugLines = true;
+        
+        private Vector2 centerPosition;
+        
+        private void Awake()
+        {
+            // Ensure collider is trigger
+            var collider = GetComponent<Collider2D>();
+            if (collider != null)
+            {
+                collider.isTrigger = true;
+            }
+            
+            centerPosition = transform.position;
+        }
+        
+        private void Update()
+        {
+            // Rotate center visual if present
+            if (centerSprite != null)
+            {
+                centerSprite.transform.Rotate(0, 0, rotationSpeed * Time.deltaTime);
+            }
+        }
+        
+        private void OnTriggerStay2D(Collider2D other)
+        {
+            // Check if it's an airplane
+            var airplane = other.GetComponent<Core.AirplaneController>();
+            if (airplane == null || !airplane.IsFlying) return;
+            
+            var rb = other.GetComponent<Rigidbody2D>();
+            if (rb == null) return;
+            
+            // Calculate direction and distance to center
+            Vector2 airplanePos = rb.position;
+            Vector2 toCenter = centerPosition - airplanePos;
+            float distance = toCenter.magnitude;
+            
+            // Prevent division by zero
+            if (distance < minPullDistance)
+            {
+                distance = minPullDistance;
+            }
+            
+            // Calculate pull force
+            float forceMagnitude;
+            
+            if (useInverseSquare)
+            {
+                // Realistic gravity-like force (inverse square law)
+                forceMagnitude = pullStrength / (distance * distance);
+            }
+            else
+            {
+                // Linear falloff based on distance
+                var collider = GetComponent<Collider2D>();
+                float maxDistance = collider != null ? collider.bounds.extents.magnitude : 5f;
+                float normalizedDistance = Mathf.Clamp01(distance / maxDistance);
+                float falloff = pullFalloff.Evaluate(1f - normalizedDistance);
+                forceMagnitude = pullStrength * falloff;
+            }
+            
+            // Clamp force
+            forceMagnitude = Mathf.Min(forceMagnitude, maxPullForce);
+            
+            // Apply force toward center
+            Vector2 pullForce = toCenter.normalized * forceMagnitude;
+            rb.AddForce(pullForce, ForceMode2D.Force);
+            
+            if (showDebugLogs && Time.frameCount % 30 == 0) // Log every 30 frames
+            {
+                Debug.Log($"[AirplaneGravityWell] Pulling {other.name}: force={forceMagnitude:F2}, distance={distance:F2}");
+            }
+        }
+        
+        private void OnDrawGizmos()
+        {
+            // Visualize gravity well in editor
+            Gizmos.color = new Color(1f, 0f, 1f, 0.3f); // Magenta transparent
+            
+            var collider = GetComponent<Collider2D>();
+            if (collider != null)
+            {
+                // Draw zone bounds
+                Gizmos.DrawWireSphere(collider.bounds.center, collider.bounds.extents.magnitude);
+                
+                // Draw center point
+                Gizmos.color = Color.magenta;
+                Gizmos.DrawWireSphere(transform.position, 0.5f);
+                
+                // Draw pull strength indicator
+                Gizmos.DrawRay(transform.position, Vector3.up * pullStrength * 0.2f);
+            }
+        }
+        
+        private void OnDrawGizmosSelected()
+        {
+            if (!drawDebugLines) return;
+            
+            // Draw pull force visualization at multiple points
+            var collider = GetComponent<Collider2D>();
+            if (collider == null) return;
+            
+            float radius = collider.bounds.extents.magnitude;
+            int samples = 8;
+            
+            for (int i = 0; i < samples; i++)
+            {
+                float angle = (i / (float)samples) * 360f * Mathf.Deg2Rad;
+                Vector2 offset = new Vector2(Mathf.Cos(angle), Mathf.Sin(angle)) * radius;
+                Vector3 samplePoint = transform.position + (Vector3)offset;
+                Vector3 direction = (transform.position - samplePoint).normalized;
+                
+                Gizmos.color = Color.yellow;
+                Gizmos.DrawLine(samplePoint, samplePoint + direction * 2f);
+            }
+        }
+    }
+}
+