From 2c69ccbc2a2bd9a4bf590aa48e01e6d249323c21 Mon Sep 17 00:00:00 2001
From: Ryan Schmidt <rms@rms80.com>
Date: Tue, 24 Apr 2018 20:45:55 -0400
Subject: [PATCH] util functions

---
 curve/CurveUtils2.cs | 30 ++++++++++++++++++++++++++++++
 curve/Polygon2d.cs   | 11 +++++++++++
 2 files changed, 41 insertions(+)

diff --git a/curve/CurveUtils2.cs b/curve/CurveUtils2.cs
index a3abec8c..de6729c0 100644
--- a/curve/CurveUtils2.cs
+++ b/curve/CurveUtils2.cs
@@ -215,6 +215,36 @@ public static void LaplacianSmoothConstrained(GeneralPolygon2d solid, double alp
 
 
 
+		/// <summary>
+		/// return list of objects for which keepF(obj) returns true
+		/// </summary>
+		public static List<T> Filter<T>(List<T> objects, Func<T, bool> keepF)
+		{
+			List<T> result = new List<T>(objects.Count);
+			foreach (var obj in objects) {
+				if (keepF(obj))
+					result.Add(obj);
+			}
+			return result;
+		}
+
+
+		/// <summary>
+		/// Split the input list into two new lists, based on predicate (set1 == true)
+		/// </summary>
+		public static void Split<T>(List<T> objects, out List<T> set1, out List<T> set2, Func<T, bool> splitF)
+		{
+			set1 = new List<T>();
+			set2 = new List<T>();
+			foreach (var obj in objects) {
+				if (splitF(obj))
+					set1.Add(obj);
+				else
+					set2.Add(obj);
+			}
+		}
+
+
 
         /// <summary>
         /// Remove polygons and polygon-holes smaller than minArea
diff --git a/curve/Polygon2d.cs b/curve/Polygon2d.cs
index f938c31b..7bf37970 100644
--- a/curve/Polygon2d.cs
+++ b/curve/Polygon2d.cs
@@ -709,6 +709,17 @@ public void Chamfer(double chamfer_dist, double minConvexAngleDeg = 30, double m
 
 
 
+		/// <summary>
+		/// Return minimal bounding box of vertices, computed to epsilon tolerance
+		/// </summary>
+		public Box2d MinimalBoundingBox(double epsilon)
+		{
+			ContMinBox2 box2 = new ContMinBox2(vertices, epsilon, QueryNumberType.QT_DOUBLE, false);
+			return box2.MinBox;
+		}
+
+
+
         static public Polygon2d MakeRectangle(Vector2d center, double width, double height)
         {
             VectorArray2d vertices = new VectorArray2d(4);