From 578a48ebf7a8099c80a81b433ca0d14b4af6af6f Mon Sep 17 00:00:00 2001
From: Pawel Baran <pawel.baran@burohappold.com>
Date: Thu, 15 Feb 2024 14:58:40 +0100
Subject: [PATCH] #3285 fixed

---
 Geometry_Engine/Query/IsCollinear.cs | 20 ++++++++------------
 1 file changed, 8 insertions(+), 12 deletions(-)

diff --git a/Geometry_Engine/Query/IsCollinear.cs b/Geometry_Engine/Query/IsCollinear.cs
index e25a0bab52..888b781bf9 100644
--- a/Geometry_Engine/Query/IsCollinear.cs
+++ b/Geometry_Engine/Query/IsCollinear.cs
@@ -45,18 +45,14 @@ public static bool IsCollinear(this List<Point> pts, double tolerance = Toleranc
             if (pts.Count < 3)
                 return true;
 
-            double[,] vMatrix = new double[pts.Count - 1, 3];
-            for (int i = 0; i < pts.Count - 1; i++)
-            {
-                vMatrix[i, 0] = pts[i + 1].X - pts[0].X;
-                vMatrix[i, 1] = pts[i + 1].Y - pts[0].Y;
-                vMatrix[i, 2] = pts[i + 1].Z - pts[0].Z;
-            }
-
-            double REFTolerance = vMatrix.REFTolerance(tolerance);
-            double[,] rref = vMatrix.RowEchelonForm(true, REFTolerance);
-            int nonZeroRows = rref.CountNonZeroRows(REFTolerance);
-            return nonZeroRows < 2;
+            Line fitLine = pts.FitLine(tolerance);
+
+            // Coincident points can be considered collinear
+            if (fitLine == null)
+                return true;
+
+            double sqTol = tolerance * tolerance;
+            return pts.All(x => x.SquareDistance(fitLine, true) < sqTol);
         }