Merge pull request #713 from uni-bremen-agst/694-avoid-player-leaving…

…-the-scene-through-wallsfloor

694 avoid player leaving the scene through wallsfloor

Closes #694

Assets/SEE/Controls/DesktopPlayerMovement.cs

@@ -1,4 +1,5 @@
-using UnityEngine;
+using SEE.GO;
+using UnityEngine;
 
 namespace SEE.Controls
 {
@@ -22,11 +23,29 @@ private struct CameraState
 
         private CameraState cameraState;
 
+        /// <summary>
+        /// Unity component that moves the player constrained by collisions.
+        /// It moves the player with its own <see cref="CharacterController.Move(Vector3)"/> method.
+        /// </summary>
+        private CharacterController controller;
+
         [Tooltip("The code city which the player is focusing on.")]
         public GO.Plane FocusedObject;
 
         private void Start()
         {
+            controller = gameObject.MustGetComponent<CharacterController>();
+
+            // The default layer should be ignored by the collider.
+            // LayerMasks are bit masks, so we need that 1 << shifting to get the right layer.
+            controller.excludeLayers = 1 << LayerMask.NameToLayer("Default");
+
+            // Defines the built-in collider of the CharacterController, by default the collider is a capsule.
+            // We chose the following values to minimize the collider to roughly fit around the player's head as a sphere.
+            controller.center = new Vector3(0.0f, 1.55f, 0.21f);
+            controller.radius = HeadRadius();
+            controller.height = 0.0f;
+
             if (FocusedObject != null)
             {
                 cameraState.Distance = 2.0f;
@@ -45,6 +64,21 @@ private void Start()
                 cameraState.FreeMode = true;
             }
             lastAxis = new Vector2(Input.mousePosition.x, Input.mousePosition.y);
+
+            // Returns the radius of the player's head.
+            float HeadRadius()
+            {
+                const string headName = "Root/Global/Position/Hips/LowerBack/Spine/Spine1/Neck/Head/HeadAdjust";
+                Transform head = transform.Find(headName);
+                if (head == null)
+                {
+                    Debug.LogError($"Player {gameObject.name} does not have a child {headName}.\n");
+                    return 1.0f;
+                }
+                // We want to fit the head completely into the CharacterController collider, so we use the maximum value
+                // to calculate the radius
+                return Mathf.Max(head.transform.localScale.x, head.transform.localScale.y, head.transform.localScale.z) / 2;
+            }
         }
 
         private void Update()
@@ -83,8 +117,7 @@ private void Update()
                 cameraState.Distance -= d;
 
                 HandleRotation();
-                transform.position = FocusedObject.CenterTop;
-                transform.rotation = Quaternion.Euler(cameraState.Pitch, cameraState.Yaw, 0.0f);
+                transform.SetPositionAndRotation(FocusedObject.CenterTop, Quaternion.Euler(cameraState.Pitch, cameraState.Yaw, 0.0f));
                 transform.position -= transform.forward * cameraState.Distance;
             }
             else // cameraState.freeMode == true
@@ -116,7 +149,9 @@ private void Update()
                 }
                 velocity.Normalize();
                 velocity *= speed;
-                transform.position += velocity;
+                // The following two lines may look strange, yet both are actually needed.
+                controller.Move(velocity); // this is the actual movement
+                controller.Move(Vector3.zero); // this prevents the player from sliding without input
 
                 HandleRotation();
                 // Players Yaw