10 files changed, 218 insertions, 30 deletions
diff --git a/Assets/Scripts/CustomGravity.cs b/Assets/Scripts/CustomGravity.cs
index 45f99bf..027cdd6 100644
--- a/Assets/Scripts/CustomGravity.cs
+++ b/Assets/Scripts/CustomGravity.cs
@@ -4,20 +4,45 @@ using UnityEngine;
 
 public class CustomGravity : MonoBehaviour
 {
+	static List<GravitySource> sources = new List<GravitySource>();
 
 	public static Vector3 GetGravity(Vector3 position, out Vector3 upAxis)
 	{
-		upAxis = GetUpAxis(position);
-		return position.normalized * Physics.gravity.y;
+		Vector3 g = Vector3.zero;
+		for(int i = 0; i < sources.Count; i++)
+			g += sources[i].GetGravity(position);
+		upAxis = -g.normalized;
+		return g;
 	}
 	public static Vector3 GetGravity(Vector3 position)
 	{
-		return position.normalized * Physics.gravity.y;
+		Vector3 g = Vector3.zero;
+		for(int i = 0; i < sources.Count; i++)
+			g += sources[i].GetGravity(position);
+		return g;
 	}
 
 	public static Vector3 GetUpAxis(Vector3 position)
 	{
-		Vector3 up = position.normalized;
-		return Physics.gravity.y < 0f ? up : -up;
+		return -GetGravity(position).normalized;
+	}
+
+	public static void Register(GravitySource source)
+	{
+		Debug.Assert(
+				!sources.Contains(source),
+				"WARNING: This source is already registered!",
+				source
+				);
+		sources.Add(source);
+	}
+	public static void Unregister(GravitySource source)
+	{
+		Debug.Assert(
+				sources.Contains(source),
+				"WARNING: Trying to unregister unknown gravity source!",
+				source
+				);
+		sources.Remove(source);
 	}
 }
diff --git a/Assets/Scripts/GravitySource.cs b/Assets/Scripts/GravitySource.cs
deleted file mode 100644
index e34a42e..0000000
--- a/Assets/Scripts/GravitySource.cs
+++ /dev/null
@@ -1,18 +0,0 @@
-using System.Collections;
-using System.Collections.Generic;
-using UnityEngine;
-
-public class GravitySource : MonoBehaviour
-{
-    // Start is called before the first frame update
-    void Start()
-    {
-        
-    }
-
-    // Update is called once per frame
-    void Update()
-    {
-        
-    }
-}
diff --git a/Assets/Scripts/GravityTypes.meta b/Assets/Scripts/GravityTypes.meta
new file mode 100644
index 0000000..e0cabd1
--- /dev/null
+++ b/Assets/Scripts/GravityTypes.meta
@@ -0,0 +1,8 @@
+fileFormatVersion: 2
+guid: 5767ee742d8a4c89690e8f1c18cf2564
+folderAsset: yes
+DefaultImporter:
+  externalObjects: {}
+  userData: 
+  assetBundleName: 
+  assetBundleVariant: 
diff --git a/Assets/Scripts/GravityTypes/GravityPlane.cs b/Assets/Scripts/GravityTypes/GravityPlane.cs
new file mode 100644
index 0000000..81a7005
--- /dev/null
+++ b/Assets/Scripts/GravityTypes/GravityPlane.cs
@@ -0,0 +1,45 @@
+using System.Collections;
+using System.Collections.Generic;
+using UnityEngine;
+
+public class GravityPlane : GravitySource
+{
+	[SerializeField]
+	float gravity = 9.81f;
+
+	[SerializeField]
+	float range = 1f;
+
+	public override Vector3 GetGravity(Vector3 position)
+	{
+		Vector3 up = transform.up;
+		float distance = Vector3.Dot(up, position - transform.position);
+		if(distance > range)
+			return Vector3.zero;
+
+		float g = -gravity;
+		if (distance > 0f)
+			g *= 1f - distance / range;
+		return -gravity * up;
+	}
+
+	void OnDrawGizmos()
+	{
+		Vector3 scale = transform.localScale;
+		scale.y = range;
+		Gizmos.matrix = Matrix4x4.TRS(
+				transform.position,
+				transform.rotation,
+				scale
+				);
+		//transform.localToWorldMatrix;
+		Vector3 size = new Vector3(1f, 0f, 1f);
+		Gizmos.color = Color.yellow;
+		Gizmos.DrawWireCube(Vector3.zero, size);
+		if (range > 0f)
+		{
+			Gizmos.color = Color.cyan;
+			Gizmos.DrawWireCube(Vector3.up, size);
+		}
+	}
+}
diff --git a/Assets/Scripts/GravityTypes/GravityPlane.cs.meta b/Assets/Scripts/GravityTypes/GravityPlane.cs.meta
new file mode 100644
index 0000000..e843793
--- /dev/null
+++ b/Assets/Scripts/GravityTypes/GravityPlane.cs.meta
@@ -0,0 +1,11 @@
+fileFormatVersion: 2
+guid: 76c633abed7adf812b42483ed0574852
+MonoImporter:
+  externalObjects: {}
+  serializedVersion: 2
+  defaultReferences: []
+  executionOrder: 0
+  icon: {instanceID: 0}
+  userData: 
+  assetBundleName: 
+  assetBundleVariant: 
diff --git a/Assets/Scripts/GravityTypes/GravitySource.cs b/Assets/Scripts/GravityTypes/GravitySource.cs
new file mode 100644
index 0000000..0e2cc94
--- /dev/null
+++ b/Assets/Scripts/GravityTypes/GravitySource.cs
@@ -0,0 +1,22 @@
+using System.Collections;
+using System.Collections.Generic;
+using UnityEngine;
+
+public class GravitySource : MonoBehaviour
+{
+
+	public virtual Vector3 GetGravity(Vector3 position)
+	{
+		return Physics.gravity;
+	}
+
+	void OnEnable()
+	{
+		CustomGravity.Register(this);
+	}
+
+	void OnDisable()
+	{
+		CustomGravity.Unregister(this);
+	}
+}
diff --git a/Assets/Scripts/GravitySource.cs.meta b/Assets/Scripts/GravityTypes/GravitySource.cs.meta
index 2f4fe9f..2f4fe9f 100644
--- a/Assets/Scripts/GravitySource.cs.meta
+++ b/Assets/Scripts/GravityTypes/GravitySource.cs.meta
diff --git a/Assets/Scripts/GravityTypes/GravitySphere.cs b/Assets/Scripts/GravityTypes/GravitySphere.cs
new file mode 100644
index 0000000..2eb67a8
--- /dev/null
+++ b/Assets/Scripts/GravityTypes/GravitySphere.cs
@@ -0,0 +1,49 @@
+using System.Collections;
+using System.Collections.Generic;
+using UnityEngine;
+
+public class GravitySphere : GravitySource
+{
+	[SerializeField]
+	float gravity = 0.981f;
+
+	[SerializeField, Min(0f)]
+	float outerRadius = 10f;
+	[SerializeField, Min(0f)]
+	float outerFalloffRadius = 15f;
+
+	public override Vector3 GetGravity(Vector3 position)
+	{
+		Vector3 vector = transform.position - position;
+		float distance = vector.magnitude;
+		if(distance > outerFalloffRadius)
+		{
+			return Vector3.zero;
+		}
+		float g = gravity / distance;
+		return g * vector;
+	}
+
+	void OnDrawGizmos()
+	{
+		Vector3 p = transform.position;
+		Gizmos.color = Color.yellow;
+		Gizmos.DrawWireSphere(p, outerRadius);
+		if(outerFalloffRadius > outerRadius)
+		{
+			Gizmos.color = Color.cyan;
+			Gizmos.DrawWireSphere(p, outerFalloffRadius);
+		}
+	}
+
+	void Awake()
+	{
+		OnValidate();
+	}
+
+	void OnValidate()
+	{
+		outerFalloffRadius = Mathf.Max(outerFalloffRadius, outerRadius);
+	}
+
+}
diff --git a/Assets/Scripts/GravityTypes/GravitySphere.cs.meta b/Assets/Scripts/GravityTypes/GravitySphere.cs.meta
new file mode 100644
index 0000000..e74fe93
--- /dev/null
+++ b/Assets/Scripts/GravityTypes/GravitySphere.cs.meta
@@ -0,0 +1,11 @@
+fileFormatVersion: 2
+guid: 777d997ba72cd51668cb6e0122d8a184
+MonoImporter:
+  externalObjects: {}
+  serializedVersion: 2
+  defaultReferences: []
+  executionOrder: 0
+  icon: {instanceID: 0}
+  userData: 
+  assetBundleName: 
+  assetBundleVariant: 
diff --git a/Assets/Scripts/OrbitCamera.cs b/Assets/Scripts/OrbitCamera.cs
index c0c84a7..57efdec 100644
--- a/Assets/Scripts/OrbitCamera.cs
+++ b/Assets/Scripts/OrbitCamera.cs
@@ -20,6 +20,9 @@ public class OrbitCamera : MonoBehaviour
 	[SerializeField, Range(0f, 1f)]
 	float focusCenteringSpeed = 0.5f;
 
+	[SerializeField, Range(0f, 1f)]
+	float rotationFlippingSpeed = 0.9f;
+
 	[SerializeField, Range(1f, 360f)]
 	float rotationSpeed = 90f;
 
@@ -57,10 +60,7 @@ public class OrbitCamera : MonoBehaviour
 
 	void LateUpdate()
 	{
-		gravityAlignment = Quaternion.FromToRotation(
-				gravityAlignment * Vector3.up,
-				CustomGravity.GetUpAxis(focusPoint)
-				) * gravityAlignment;
+		UpdateGravityAlignment();
 		UpdateFocusPoint();
 		if(ManualRotation() || AutomaticRotation())
 		{
@@ -96,6 +96,36 @@ public class OrbitCamera : MonoBehaviour
 		transform.SetPositionAndRotation(lookPosition, lookRotation);
 	}
 
+	void UpdateGravityAlignment() {
+		Vector3 fromUp = gravityAlignment * Vector3.up;
+		Vector3 toUp = CustomGravity.GetUpAxis(focusPoint);
+		float dot = Mathf.Clamp(
+				Vector3.Dot(fromUp, toUp),
+				-1f,
+				1f
+				);
+		float angle = Mathf.Acos(dot) * Mathf.Rad2Deg;
+
+
+		Quaternion newAlignment =
+			Quaternion.FromToRotation(fromUp, toUp) * gravityAlignment;
+
+		if(angle > 0.1f && rotationFlippingSpeed > 0f)
+		{
+			float t = Mathf.Pow(
+					1f - rotationFlippingSpeed,
+					Time.unscaledDeltaTime
+					);
+			gravityAlignment = Quaternion.SlerpUnclamped(
+					gravityAlignment,
+					newAlignment,
+					1-t
+					);
+		}
+		else
+			gravityAlignment = newAlignment;
+	}
+
 	void UpdateFocusPoint()
 	{
 		previousFocusPoint = focusPoint;
@@ -105,15 +135,20 @@ public class OrbitCamera : MonoBehaviour
 			float t = 1f;
 			float distance = Vector3.Distance(targetPoint, focusPoint);
 			if(distance > 0.01f && focusCenteringSpeed > 0f)
-				t = Mathf.Pow(1f - focusCenteringSpeed, Time.unscaledDeltaTime);
+			{
+				t = Mathf.Pow(
+						1f - focusCenteringSpeed,
+						Time.unscaledDeltaTime
+						);
+			}
 			if(distance > focusLimitRadius)
 			{
 				t = Mathf.Min(t, focusLimitRadius / distance);
 			}
 			focusPoint = Vector3.Lerp(
-					targetPoint,
 					focusPoint,
-					t
+					targetPoint,
+					1-t
 					);
 		}
 		else