From bf80827bfdad603fbee11db93910b00b7eb73c5a Mon Sep 17 00:00:00 2001
From: Wojtek Figat <wojtek@figat.pl>
Date: Mon, 1 Feb 2021 13:50:56 +0100
Subject: [PATCH] Add more Spline API for curve editing

---
 Source/Engine/Level/Actors/Spline.cpp | 24 ++++++++++++++++
 Source/Engine/Level/Actors/Spline.h   | 41 +++++++++++++++++++++------
 Source/Engine/Level/Spline.cs         | 22 ++++++++++++++
 3 files changed, 79 insertions(+), 8 deletions(-)

diff --git a/Source/Engine/Level/Actors/Spline.cpp b/Source/Engine/Level/Actors/Spline.cpp
index a3757253f..f522a8770 100644
--- a/Source/Engine/Level/Actors/Spline.cpp
+++ b/Source/Engine/Level/Actors/Spline.cpp
@@ -244,6 +244,14 @@ void Spline::ClearSpline()
     UpdateSpline();
 }
 
+void Spline::RemoveSplinePoint(int32 index, bool updateSpline)
+{
+    CHECK(index >= 0 && index < GetSplinePointsCount());
+    Curve.GetKeyframes().RemoveAtKeepOrder(index);
+    if (updateSpline)
+        UpdateSpline();
+}
+
 void Spline::SetSplinePoint(int32 index, const Vector3& point, bool updateSpline)
 {
     CHECK(index >= 0 && index < GetSplinePointsCount());
@@ -331,6 +339,22 @@ void Spline::AddSplineLocalPoint(const Transform& point, bool updateSpline)
         UpdateSpline();
 }
 
+void Spline::InsertSplinePoint(int32 index, float time, const Transform& point, bool updateSpline)
+{
+    const Keyframe k(time, _transform.WorldToLocal(point));
+    Curve.GetKeyframes().Insert(index, k);
+    if (updateSpline)
+        UpdateSpline();
+}
+
+void Spline::InsertSplineLocalPoint(int32 index, float time, const Transform& point, bool updateSpline)
+{
+    const Keyframe k(time, point);
+    Curve.GetKeyframes().Insert(index, k);
+    if (updateSpline)
+        UpdateSpline();
+}
+
 void Spline::SetTangentsLinear()
 {
     const int32 count = Curve.GetKeyframes().Count();
diff --git a/Source/Engine/Level/Actors/Spline.h b/Source/Engine/Level/Actors/Spline.h
index 772aac821..7f8076eac 100644
--- a/Source/Engine/Level/Actors/Spline.h
+++ b/Source/Engine/Level/Actors/Spline.h
@@ -216,12 +216,19 @@ public:
     /// </summary>
     API_FUNCTION() void ClearSpline();
 
+    /// <summary>
+    /// Removes the spline curve point at the given index.
+    /// </summary>
+    /// <param name="index">The curve keyframe index. Zero-based, smaller than GetSplinePointsCount().</param>
+    /// <param name="updateSpline">True if update spline after removing the point, otherwise false.</param>
+    API_FUNCTION() void RemoveSplinePoint(int32 index, bool updateSpline = true);
+
     /// <summary>
     /// Sets the spline curve at the given index (world-space).
     /// </summary>
     /// <param name="index">The curve keyframe index. Zero-based, smaller than GetSplinePointsCount().</param>
     /// <param name="point">The location of the point to set (world-space).</param>
-    /// <param name="updateSpline">True if update spline after adding the point, otherwise false.</param>
+    /// <param name="updateSpline">True if update spline after editing the point, otherwise false.</param>
     API_FUNCTION() void SetSplinePoint(int32 index, const Vector3& point, bool updateSpline = true);
 
     /// <summary>
@@ -229,7 +236,7 @@ public:
     /// </summary>
     /// <param name="index">The curve keyframe index. Zero-based, smaller than GetSplinePointsCount().</param>
     /// <param name="point">The location of the point to set (local-space).</param>
-    /// <param name="updateSpline">True if update spline after adding the point, otherwise false.</param>
+    /// <param name="updateSpline">True if update spline after editing the point, otherwise false.</param>
     API_FUNCTION() void SetSplineLocalPoint(int32 index, const Vector3& point, bool updateSpline = true);
 
     /// <summary>
@@ -237,7 +244,7 @@ public:
     /// </summary>
     /// <param name="index">The curve keyframe index. Zero-based, smaller than GetSplinePointsCount().</param>
     /// <param name="point">The transformation of the point to set (world-space).</param>
-    /// <param name="updateSpline">True if update spline after adding the point, otherwise false.</param>
+    /// <param name="updateSpline">True if update spline after editing the point, otherwise false.</param>
     API_FUNCTION() void SetSplineTransform(int32 index, const Transform& point, bool updateSpline = true);
 
     /// <summary>
@@ -245,7 +252,7 @@ public:
     /// </summary>
     /// <param name="index">The curve keyframe index. Zero-based, smaller than GetSplinePointsCount().</param>
     /// <param name="point">The transformation of the point to set (local-space).</param>
-    /// <param name="updateSpline">True if update spline after adding the point, otherwise false.</param>
+    /// <param name="updateSpline">True if update spline after editing the point, otherwise false.</param>
     API_FUNCTION() void SetSplineLocalTransform(int32 index, const Transform& point, bool updateSpline = true);
 
     /// <summary>
@@ -255,7 +262,7 @@ public:
     /// <param name="index">The curve keyframe index. Zero-based, smaller than GetSplinePointsCount().</param>
     /// <param name="point">The transformation of the tangent to set (world-space).</param>
     /// <param name="isIn">True if set arrive tangent, otherwise sets leave tangent (in or out).</param>
-    /// <param name="updateSpline">True if update spline after adding the point, otherwise false.</param>
+    /// <param name="updateSpline">True if update spline after editing the point, otherwise false.</param>
     API_FUNCTION() void SetSplineTangent(int32 index, const Transform& point, bool isIn, bool updateSpline = true);
 
     /// <summary>
@@ -265,7 +272,7 @@ public:
     /// <param name="index">The curve keyframe index. Zero-based, smaller than GetSplinePointsCount().</param>
     /// <param name="point">The transformation of the tangent to set (local-space).</param>
     /// <param name="isIn">True if set arrive tangent, otherwise sets leave tangent (in or out).</param>
-    /// <param name="updateSpline">True if update spline after adding the point, otherwise false.</param>
+    /// <param name="updateSpline">True if update spline after editing the point, otherwise false.</param>
     API_FUNCTION() void SetSplineLocalTangent(int32 index, const Transform& point, bool isIn, bool updateSpline = true);
 
     /// <summary>
@@ -273,14 +280,14 @@ public:
     /// </summary>
     /// <param name="index">The curve keyframe index. Zero-based, smaller than GetSplinePointsCount().</param>
     /// <param name="time">The time to set.</param>
-    /// <param name="updateSpline">True if update spline after adding the point, otherwise false.</param>
+    /// <param name="updateSpline">True if update spline after editing the point, otherwise false.</param>
     API_FUNCTION() void SetSplinePointTime(int32 index, float time, bool updateSpline = true);
 
     /// <summary>
     /// Adds the point to the spline curve (at the end).
     /// </summary>
     /// <param name="point">The location of the point to add to the curve (world-space).</param>
-    /// <param name="updateSpline">True if update spline after adding the point, otherwise false.</param>
+    /// <param name="updateSpline">True if update spline after editing the point, otherwise false.</param>
     API_FUNCTION() void AddSplinePoint(const Vector3& point, bool updateSpline = true);
 
     /// <summary>
@@ -304,6 +311,24 @@ public:
     /// <param name="updateSpline">True if update spline after adding the point, otherwise false.</param>
     API_FUNCTION() void AddSplineLocalPoint(const Transform& point, bool updateSpline = true);
 
+    /// <summary>
+    /// Inserts the spline curve point at the given index (world-space).
+    /// </summary>
+    /// <param name="index">The curve keyframe index. Zero-based, smaller than GetSplinePointsCount().</param>
+    /// <param name="time">The time value.</param>
+    /// <param name="point">The location of the point to add to the curve (world-space).</param>
+    /// <param name="updateSpline">True if update spline after removing the point, otherwise false.</param>
+    API_FUNCTION() void InsertSplinePoint(int32 index, float time, const Transform& point, bool updateSpline = true);
+
+    /// <summary>
+    /// Inserts the spline curve point at the given index (local-space).
+    /// </summary>
+    /// <param name="index">The curve keyframe index. Zero-based, smaller than GetSplinePointsCount().</param>
+    /// <param name="time">The time value.</param>
+    /// <param name="point">The location of the point to add to the curve (local-space).</param>
+    /// <param name="updateSpline">True if update spline after removing the point, otherwise false.</param>
+    API_FUNCTION() void InsertSplineLocalPoint(int32 index, float time, const Transform& point, bool updateSpline = true);
+
     /// <summary>
     /// Updates the curve tangent points to make curve linear.
     /// </summary>
diff --git a/Source/Engine/Level/Spline.cs b/Source/Engine/Level/Spline.cs
index 46a05cd5d..29c65763a 100644
--- a/Source/Engine/Level/Spline.cs
+++ b/Source/Engine/Level/Spline.cs
@@ -37,5 +37,27 @@ namespace FlaxEngine
                 Internal_SetKeyframes(__unmanagedPtr, value);
             }
         }
+
+        /// <summary>
+        /// Gets the spline keyframe.
+        /// </summary>
+        /// <param name="index">The spline point index.</param>
+        /// <returns>The keyframe.</returns>
+        public BezierCurve<Transform>.Keyframe GetSplineKeyframe(int index)
+        {
+            return SplineKeyframes[index];
+        }
+
+        /// <summary>
+        /// Sets the spline keyframe.
+        /// </summary>
+        /// <param name="index">The spline point index.</param>
+        /// <param name="keyframe">The keyframe.</param>
+        public void SetSplineKeyframe(int index, BezierCurve<Transform>.Keyframe keyframe)
+        {
+            SetSplineLocalTransform(index, keyframe.Value, false);
+            SetSplineLocalTangent(index, keyframe.Value + keyframe.TangentIn, true, false);
+            SetSplineLocalTangent(index, keyframe.Value + keyframe.TangentOut, false);
+        }
     }
 }