From bc9a61ec69fee1f9bd8f0443cefd6ddaa76195f1 Mon Sep 17 00:00:00 2001
From: anv <anv@opencascade.com>
Date: Wed, 2 Nov 2016 15:46:52 +0300
Subject: [PATCH] 0028012: Exception while intersecting two surfaces

Test case for issue CR28012
---
 src/IntPatch/IntPatch_PrmPrmIntersection.cxx | 100 +++++++++----------
 tests/bugs/modalg_6/bug28012                 |  17 ++++
 2 files changed, 66 insertions(+), 51 deletions(-)
 create mode 100644 tests/bugs/modalg_6/bug28012

diff --git a/src/IntPatch/IntPatch_PrmPrmIntersection.cxx b/src/IntPatch/IntPatch_PrmPrmIntersection.cxx
index 4e8f595c7b..bed58756f9 100644
--- a/src/IntPatch/IntPatch_PrmPrmIntersection.cxx
+++ b/src/IntPatch/IntPatch_PrmPrmIntersection.cxx
@@ -1894,60 +1894,58 @@ void IntPatch_PrmPrmIntersection::Perform(const Handle(Adaptor3d_HSurface)&    S
 
     PW.Perform(StartParams);
     if(PW.IsDone()) {
+      if(PW.NbPoints()>2) {
+        Point3dDebut = PW.Value(1).Value();
+        Point3dFin   = PW.Value(PW.NbPoints()).Value();
+
+        IntSurf_TypeTrans trans1,trans2;
+        Standard_Real locu,locv;
+        gp_Vec norm1,norm2,d1u,d1v;
+        gp_Pnt ptbid;
+        Standard_Integer indextg;
+        gp_Vec tgline(PW.TangentAtLine(indextg));
+        PW.Line()->Value(indextg).ParametersOnS1(locu,locv);
+        Surf1->D1(locu,locv,ptbid,d1u,d1v);
+        norm1 = d1u.Crossed(d1v);
+        PW.Line()->Value(indextg).ParametersOnS2(locu,locv);
+        Surf2->D1(locu,locv,ptbid,d1u,d1v);
+        norm2 = d1u.Crossed(d1v);
+        if (tgline.DotCross(norm2,norm1)>0.) {
+          trans1 = IntSurf_Out;
+          trans2 = IntSurf_In;
+        }
+        else {
+          trans1 = IntSurf_In;
+          trans2 = IntSurf_Out;
+        }
 
-      Point3dDebut = PW.Value(1).Value();
-      Point3dFin   = PW.Value(PW.NbPoints()).Value();
-
-      IntSurf_TypeTrans trans1,trans2;
-      Standard_Real locu,locv;
-      gp_Vec norm1,norm2,d1u,d1v;
-      gp_Pnt ptbid;
-      Standard_Integer indextg;
-      gp_Vec tgline(PW.TangentAtLine(indextg));
-      PW.Line()->Value(indextg).ParametersOnS1(locu,locv);
-      Surf1->D1(locu,locv,ptbid,d1u,d1v);
-      norm1 = d1u.Crossed(d1v);
-      PW.Line()->Value(indextg).ParametersOnS2(locu,locv);
-      Surf2->D1(locu,locv,ptbid,d1u,d1v);
-      norm2 = d1u.Crossed(d1v);
-      if (tgline.DotCross(norm2,norm1)>0.) {
-        trans1 = IntSurf_Out;
-        trans2 = IntSurf_In;
-      }
-      else {
-        trans1 = IntSurf_In;
-        trans2 = IntSurf_Out;
-      }
-
-
+        Standard_Real TolTang = TolTangency;
+        Handle(IntPatch_WLine) wline = new IntPatch_WLine(PW.Line(),Standard_False,trans1,trans2);
+        IntPatch_RstInt::PutVertexOnLine(wline,Surf1,D1,Surf2,Standard_True,TolTang);
+        IntPatch_RstInt::PutVertexOnLine(wline,Surf2,D2,Surf1,Standard_False,TolTang);
+
+        //---------------
+        if(wline->NbVertex() == 0) {
+          IntPatch_Point vtx;
+          IntSurf_PntOn2S POn2S = PW.Line()->Value(1);
+          POn2S.Parameters(pu1,pv1,pu2,pv2);
+          vtx.SetValue(Point3dDebut,TolTang,Standard_False);
+          vtx.SetParameters(pu1,pv1,pu2,pv2);
+          vtx.SetParameter(1);
+          wline->AddVertex(vtx);
+
+          POn2S = PW.Line()->Value(wline->NbPnts());
+          POn2S.Parameters(pu1,pv1,pu2,pv2);
+          vtx.SetValue(Point3dFin,TolTang,Standard_False);
+          vtx.SetParameters(pu1,pv1,pu2,pv2);
+          vtx.SetParameter(wline->NbPnts());
+          wline->AddVertex(vtx);
+        }
 
-      Standard_Real TolTang = TolTangency;
-      Handle(IntPatch_WLine) wline = new IntPatch_WLine(PW.Line(),Standard_False,trans1,trans2);
-      IntPatch_RstInt::PutVertexOnLine(wline,Surf1,D1,Surf2,Standard_True,TolTang);
-      IntPatch_RstInt::PutVertexOnLine(wline,Surf2,D2,Surf1,Standard_False,TolTang);
-
-      //---------------
-      if(wline->NbVertex() == 0) {
-        IntPatch_Point vtx;
-        IntSurf_PntOn2S POn2S = PW.Line()->Value(1);
-        POn2S.Parameters(pu1,pv1,pu2,pv2);
-        vtx.SetValue(Point3dDebut,TolTang,Standard_False);
-        vtx.SetParameters(pu1,pv1,pu2,pv2);
-        vtx.SetParameter(1);
-        wline->AddVertex(vtx);
-
-        POn2S = PW.Line()->Value(wline->NbPnts());
-        POn2S.Parameters(pu1,pv1,pu2,pv2);
-        vtx.SetValue(Point3dFin,TolTang,Standard_False);
-        vtx.SetParameters(pu1,pv1,pu2,pv2);
-        vtx.SetParameter(wline->NbPnts());
-        wline->AddVertex(vtx);
+        //---------------
+        SLin.Append(wline);
+        empt = Standard_False;
       }
-
-      //---------------
-      SLin.Append(wline);
-      empt = Standard_False;
-
     }
   }
 }
diff --git a/tests/bugs/modalg_6/bug28012 b/tests/bugs/modalg_6/bug28012
new file mode 100644
index 0000000000..6b92339a5a
--- /dev/null
+++ b/tests/bugs/modalg_6/bug28012
@@ -0,0 +1,17 @@
+puts "========"
+puts "OCC28012"
+puts "========"
+puts ""
+#################################################
+# Exception while intersecting two surfaces
+#################################################
+
+restore [locate_data_file bug28012_s1.draw] s1
+restore [locate_data_file bug28012_s2.draw] s2
+
+intersect result s1 s2 0.00012162815337817315 0.0010404164685680738 0.99999999999999989 0.22068942273845651
+
+smallview
+fit
+
+checkview -screenshot -2d -path ${imagedir}/${test_image}.png
-- 
2.39.5