From e9bbe64115e2c5435300eb8cee4df4751e075c4c Mon Sep 17 00:00:00 2001
From: Alexander Gessler <alexander.gessler@gmx.net>
Date: Mon, 21 Jan 2013 22:46:11 +0100
Subject: [PATCH] - Ifc: fine-tune epsilons. Correct epsilon approximation for
 a squared value is max(e^2 +- 2e).

---
 code/IFCGeometry.cpp | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/code/IFCGeometry.cpp b/code/IFCGeometry.cpp
index ac335be77..563228556 100644
--- a/code/IFCGeometry.cpp
+++ b/code/IFCGeometry.cpp
@@ -1462,6 +1462,7 @@ bool IntersectingLineSegments(const IfcVector2& n0, const IfcVector2& n1,
 // ------------------------------------------------------------------------------------------------
 void FindAdjacentContours(ContourVector::iterator current, const ContourVector& contours)
 {
+	const IfcFloat sqlen_epsilon = static_cast<IfcFloat>(1e-8);
 	const BoundingBox& bb = (*current).bb;
 
 	// What is to be done here is to populate the skip lists for the contour
@@ -1507,7 +1508,7 @@ void FindAdjacentContours(ContourVector::iterator current, const ContourVector&
 					IfcVector2 isect0, isect1;
 					if (IntersectingLineSegments(n0,n1, m0, m1, isect0, isect1)) {
 
-						if ((isect0 - n0).SquareLength() > 1e-5) {
+						if ((isect0 - n0).SquareLength() > sqlen_epsilon) {
 							++n;
 
 							ncontour.insert(ncontour.begin() + n, isect0);	
@@ -1517,7 +1518,7 @@ void FindAdjacentContours(ContourVector::iterator current, const ContourVector&
 							skiplist[n] = true;
 						}
 
-						if ((isect1 - n1).SquareLength() > 1e-5) {
+						if ((isect1 - n1).SquareLength() > sqlen_epsilon) {
 							++n;
 
 							ncontour.insert(ncontour.begin() + n, isect1);