Added support for local tangent points

Author: Railboy

Assets/MixedRealityToolkit/Inspectors/Utilities/Lines/DataProviders/BezierDataProviderInspector.cs

@@ -28,6 +28,7 @@ public class BezierDataProviderInspector : BaseLineDataProviderInspector
         private static readonly GUIContent PositionContent = new GUIContent("Position");
 
         private SerializedProperty controlPoints;
+        private SerializedProperty useLocalTangentPoints;
 
         private BezierDataProvider bezierData;
 
@@ -38,6 +39,7 @@ protected override void OnEnable()
             base.OnEnable();
 
             controlPoints = serializedObject.FindProperty("controlPoints");
+            useLocalTangentPoints = serializedObject.FindProperty("useLocalTangentPoints");
 
             bezierData = (BezierDataProvider)target;
         }
@@ -51,6 +53,7 @@ public override void OnInspectorGUI()
             DrawLinePoints = true;
 
             EditorGUILayout.PropertyField(controlPoints, true);
+            EditorGUILayout.PropertyField(useLocalTangentPoints);
 
             serializedObject.ApplyModifiedProperties();
         }

Assets/MixedRealityToolkit/Utilities/Lines/DataProviders/BezierDataProvider.cs

@@ -31,6 +31,10 @@ public BezierPointSet(float spread)
         [Header("Bezier Settings")]
         [SerializeField]
         private BezierPointSet controlPoints = new BezierPointSet(0.5f);
+        [Tooltip("If true, control points 2 and 3 will be transformed relative to points 1 and 4 respectively")]
+        [SerializeField]
+        private bool useLocalTangentPoints = false;
+        private Vector3 localOffset;
 
         protected override Vector3 GetPointInternal(int pointIndex)
         {
@@ -58,7 +62,13 @@ protected override void SetPointInternal(int pointIndex, Vector3 point)
             switch (pointIndex)
             {
                 case 0:
+                    localOffset = Vector3.zero;
+                    // If we're using local tangent points, apply this change to control point 2
+                    if (useLocalTangentPoints)
+                        localOffset = point - controlPoints.Point1;
+
                     controlPoints.Point1 = point;
+                    controlPoints.Point2 = controlPoints.Point2 + localOffset;
                     break;
 
                 case 1:
@@ -70,7 +80,12 @@ protected override void SetPointInternal(int pointIndex, Vector3 point)
                     break;
 
                 case 3:
+                    localOffset = Vector3.zero;
+                    if (useLocalTangentPoints)
+                        localOffset = point - controlPoints.Point4;
+
                     controlPoints.Point4 = point;
+                    controlPoints.Point3 = controlPoints.Point3 + localOffset;
                     break;
 
                 default: