fix: use two-line V arrowheads with dark pen for cut direction

OpenNest/Controls/CutDirectionArrows.cs

@@ -1,7 +1,6 @@
 using OpenNest.CNC;
 using OpenNest.Geometry;
 using OpenNest.Math;
-using System;
 using System.Drawing;
 
 namespace OpenNest.Controls
@@ -128,19 +127,18 @@ namespace OpenNest.Controls
 
         private static void DrawArrowHead(Graphics g, Pen pen, PointF tip, double angle, float size)
         {
-            var sin = (float)System.Math.Sin(angle);
+            var leftAngle = angle + System.Math.PI + 0.5;
-            var cos = (float)System.Math.Cos(angle);
+            var rightAngle = angle + System.Math.PI - 0.5;
 
-            var backX = -size * cos;
+            var left = new PointF(
-            var backY = -size * sin;
+                tip.X + size * (float)System.Math.Cos(leftAngle),
-            var wingX = size * 0.5f * sin;
+                tip.Y + size * (float)System.Math.Sin(leftAngle));
-            var wingY = -size * 0.5f * cos;
+            var right = new PointF(
+                tip.X + size * (float)System.Math.Cos(rightAngle),
+                tip.Y + size * (float)System.Math.Sin(rightAngle));
 
-            var wing1 = new PointF(tip.X + backX + wingX, tip.Y + backY + wingY);
+            g.DrawLine(pen, left, tip);
-            var wing2 = new PointF(tip.X + backX - wingX, tip.Y + backY - wingY);
+            g.DrawLine(pen, right, tip);
-
-            g.DrawLine(pen, wing1, tip);
-            g.DrawLine(pen, wing2, tip);
         }
     }
 }

OpenNest/Controls/PlateRenderer.cs

@@ -515,7 +515,7 @@ namespace OpenNest.Controls
 
         private void DrawAllCutDirectionArrows(Graphics g)
         {
-            using var pen = new Pen(Color.FromArgb(220, Color.Black), 1.5f);
+            using var pen = new Pen(Color.FromArgb(60, 60, 60), 1.5f);
 
             var arrowSpacingWorld = view.LengthGuiToWorld(60f);
             var arrowSize = 6f;

OpenNest/Controls/ProgramEditorControl.cs

@@ -273,7 +273,7 @@ namespace OpenNest.Controls
                 var pgm = ConvertGeometry.ToProgram(contour.Shape);
                 if (pgm == null) continue;
 
-                using var pen = new Pen(Color.FromArgb(220, Color.Black), 1.5f);
+                using var pen = new Pen(Color.FromArgb(60, 60, 60), 1.5f);
                 var pos = new Vector();
                 CutDirectionArrows.DrawProgram(e.Graphics, preview, pgm, ref pos, pen, spacing, arrowSize);
             }