From: ifv <ifv@opencascade.com>
Date: Thu, 18 May 2017 13:10:45 +0000 (+0300)
Subject: 0028637: [regression] Extrema curve - curve can not find correct solution between... 
X-Git-Tag: V7_2_0_beta~136
X-Git-Url: http://git.dev.opencascade.org/gitweb/?a=commitdiff_plain;h=b493028765b080def002a7410e17710bf7db0404;p=occt-copy.git

0028637: [regression] Extrema curve - curve can not find correct solution between edge based on the line and BSpline edge

Adding condition for preventing decreasing Lipschitz constant if derivative are too small
Test case is created
---

diff --git a/src/Extrema/Extrema_GenExtCC.gxx b/src/Extrema/Extrema_GenExtCC.gxx
index 63294ae1bd..a03e33d116 100644
--- a/src/Extrema/Extrema_GenExtCC.gxx
+++ b/src/Extrema/Extrema_GenExtCC.gxx
@@ -220,6 +220,12 @@ void Extrema_GenExtCC::Perform()
 
   // Change constant value according to the concrete curve types.
   Standard_Boolean isConstLockedFlag = Standard_False;
+  //To prevent LipConst to became too small
+  const Standard_Real aCR = 0.001;
+  if (aMaxDer1 / aMaxDer < aCR || aMaxDer2 / aMaxDer < aCR)
+  {
+    isConstLockedFlag = Standard_True;
+  }
   if (C1.GetType() == GeomAbs_Line)
   {
     aMaxDer = 1.0 / C2.Resolution(1.0);
diff --git a/tests/bugs/modalg_6/bug28637 b/tests/bugs/modalg_6/bug28637
new file mode 100644
index 0000000000..5caeda323a
--- /dev/null
+++ b/tests/bugs/modalg_6/bug28637
@@ -0,0 +1,12 @@
+puts "========"
+puts "OCC28637"
+puts "========"
+puts ""
+####################################################################################
+## [regression] Extrema curve - curve can not find correct solution between edge based on the line and BSpline edge
+####################################################################################
+
+restore [locate_data_file bug28637_shapes.brep] b
+explode b
+distmini d b_1 b_2
+checkprops d -l 4.46857e-005 -deps 1.e-2