Lazy-init bezier drawing points

Author: TechPizzaDev

src/ImageSharp.Drawing/Shapes/ArcLineSegment.cs

@@ -44,8 +44,6 @@ public ArcLineSegment(PointF from, PointF to, SizeF radius, float rotation, bool
         {
             this.linePoints = EllipticArcFromEndParams(from, to, radius, rotation, largeArc, sweep);
         }
-
-        this.EndPoint = this.linePoints[^1];
     }
 
     /// <summary>
@@ -80,18 +78,15 @@ public ArcLineSegment(PointF center, SizeF radius, float rotation, float startAn
         {
             this.linePoints = EllipticArcFromEndParams(from, to, radius, rotation, largeArc, sweep);
         }
-
-        this.EndPoint = this.linePoints[^1];
     }
 
     private ArcLineSegment(PointF[] linePoints)
     {
         this.linePoints = linePoints;
-        this.EndPoint = this.linePoints[^1];
     }
 
     /// <inheritdoc/>
-    public PointF EndPoint { get; }
+    public PointF EndPoint => this.linePoints[^1];
 
     /// <inheritdoc/>
     public ReadOnlyMemory<PointF> Flatten() => this.linePoints;

src/ImageSharp.Drawing/Shapes/CubicBezierLineSegment.cs

@@ -18,7 +18,8 @@ public sealed class CubicBezierLineSegment : ILineSegment
     /// <summary>
     /// The line points.
     /// </summary>
-    private readonly PointF[] linePoints;
+    private PointF[]? linePoints;
+
     private readonly PointF[] controlPoints;
 
     /// <summary>
@@ -36,10 +37,6 @@ public CubicBezierLineSegment(PointF[] points)
         {
             throw new ArgumentOutOfRangeException(nameof(points), "points must be a multiple of 3 plus 1 long.");
         }
-
-        this.linePoints = GetDrawingPoints(this.controlPoints);
-
-        this.EndPoint = this.controlPoints[this.controlPoints.Length - 1];
     }
 
     /// <summary>
@@ -55,19 +52,31 @@ public CubicBezierLineSegment(PointF start, PointF controlPoint1, PointF control
     {
     }
 
+    /// <inheritdoc cref="CubicBezierLineSegment(PointF, PointF, PointF, PointF, PointF[])" />
+    public CubicBezierLineSegment(PointF start, PointF controlPoint1, PointF controlPoint2, PointF end)
+        : this(new[] { start, controlPoint1, controlPoint2, end })
+    {
+    }
+
     /// <summary>
     /// Gets the control points.
     /// </summary>
     public IReadOnlyList<PointF> ControlPoints => this.controlPoints;
 
     /// <inheritdoc/>
-    public PointF EndPoint { get; }
+    public PointF EndPoint => this.controlPoints[^1];
 
     /// <inheritdoc/>
-    public ReadOnlyMemory<PointF> Flatten() => this.linePoints;
+    public ReadOnlyMemory<PointF> Flatten() => this.linePoints ??= GetDrawingPoints(this.controlPoints);
+
+    /// <summary>
+    /// Gets the control points of this curve.
+    /// </summary>
+    /// <returns>The control points of this curve.</returns>
+    public ReadOnlyMemory<PointF> GetControlPoints() => this.controlPoints;
 
     /// <summary>
-    /// Transforms the current LineSegment using specified matrix.
+    /// Transforms this line segment using the specified matrix.
     /// </summary>
     /// <param name="matrix">The matrix.</param>
     /// <returns>A line segment with the matrix applied to it.</returns>

src/ImageSharp.Drawing/Shapes/Helpers/ArrayExtensions.cs

@@ -17,7 +17,7 @@ internal static class ArrayExtensions
     /// <returns>the Merged arrays</returns>
     public static T[] Merge<T>(this T[] source1, T[] source2)
     {
-        if (source2 is null)
+        if (source2 is null || source2.Length == 0)
         {
             return source1;
         }

src/ImageSharp.Drawing/Shapes/LinearLineSegment.cs

@@ -46,8 +46,6 @@ public LinearLineSegment(PointF[] points)
         this.points = points ?? throw new ArgumentNullException(nameof(points));
 
         Guard.MustBeGreaterThanOrEqualTo(this.points.Length, 2, nameof(points));
-
-        this.EndPoint = this.points[this.points.Length - 1];
     }
 
     /// <summary>
@@ -56,7 +54,7 @@ public LinearLineSegment(PointF[] points)
     /// <value>
     /// The end point.
     /// </value>
-    public PointF EndPoint { get; }
+    public PointF EndPoint => this.points[^1];
 
     /// <summary>
     /// Converts the <see cref="ILineSegment" /> into a simple linear path..