From 59223e118db73b4b7dcaa45639f13287f8a48f59 Mon Sep 17 00:00:00 2001
From: oan <oan@opencascade.com>
Date: Wed, 31 Aug 2022 17:40:33 +0300
Subject: [PATCH] 0031926: Shape Healing - ShapeAnalysis::OuterWire() considers
 next iteration element always to be a wire causing skipping of primal one

ShapeAnalysis::OuterWire(): fixed missed logic when TopoDS_Iterator notifies about more objects to iterate, but there are only vertices and no additional wires at all.
---
 src/ShapeAnalysis/ShapeAnalysis.cxx | 35 +++++++++++---------------
 src/ShapeAnalysis/ShapeAnalysis.hxx |  9 +++----
 tests/bugs/mesh/bug31144            |  1 -
 tests/bugs/mesh/bug31926            | 39 +++++++++++++++++++++++++++++
 4 files changed, 57 insertions(+), 27 deletions(-)
 create mode 100644 tests/bugs/mesh/bug31926

diff --git a/src/ShapeAnalysis/ShapeAnalysis.cxx b/src/ShapeAnalysis/ShapeAnalysis.cxx
index 6e18ddd42c..5517a17b35 100644
--- a/src/ShapeAnalysis/ShapeAnalysis.cxx
+++ b/src/ShapeAnalysis/ShapeAnalysis.cxx
@@ -229,36 +229,31 @@ Standard_Boolean ShapeAnalysis::IsOuterBound(const TopoDS_Face& face)
 }
 
 //=======================================================================
-//function : OuterBound
-//purpose  : replacement of bad BRepTools::OuterBound(), to be merged
-// - skips internal vertices in face, if any, without exception
-// - returns positively oriented wire rather than greater one
+//function : OuterWire
+//purpose  : Returns positively oriented wire in the face.
+//           If there is no one - returns the last wire of the face.
 //=======================================================================
 
-TopoDS_Wire ShapeAnalysis::OuterWire(const TopoDS_Face& face) 
+TopoDS_Wire ShapeAnalysis::OuterWire(const TopoDS_Face& theFace) 
 {
-  TopoDS_Face F = face;
-  F.Orientation(TopAbs_FORWARD);
+  TopoDS_Face aF = theFace;
+  aF.Orientation (TopAbs_FORWARD);
 
-  BRep_Builder B;
-  TopoDS_Iterator anIt (F, Standard_False);
+  TopExp_Explorer anIt (aF, TopAbs_WIRE);
   while (anIt.More())
   {
-    TopoDS_Shape aWire = anIt.Value();
+    TopoDS_Wire aWire = TopoDS::Wire (anIt.Value());
     anIt.Next();
 
-    // skip possible internal vertices in face
-    if (aWire.ShapeType() != TopAbs_WIRE)
-      continue;
-
     // if current wire is the last one, return it without analysis
-    if (! anIt.More())
-      return TopoDS::Wire (aWire);
+    if (!anIt.More())
+      return aWire;
 
-    TopoDS_Shape aTestFace = F.EmptyCopied();
-    B.Add (aTestFace, aWire);
-    if (ShapeAnalysis::IsOuterBound (TopoDS::Face (aTestFace)))
-      return TopoDS::Wire (aWire);
+    // Check if the wire has positive area
+    Handle(ShapeExtend_WireData) aSEWD = new ShapeExtend_WireData (aWire);
+    Standard_Real anArea2d = ShapeAnalysis::TotCross2D (aSEWD, aF);
+    if (anArea2d >= 0.)
+      return aWire;
   }
   return TopoDS_Wire();
 }
diff --git a/src/ShapeAnalysis/ShapeAnalysis.hxx b/src/ShapeAnalysis/ShapeAnalysis.hxx
index be6f228ab5..fc6bdccdd4 100644
--- a/src/ShapeAnalysis/ShapeAnalysis.hxx
+++ b/src/ShapeAnalysis/ShapeAnalysis.hxx
@@ -51,12 +51,9 @@ public:
   DEFINE_STANDARD_ALLOC
 
   
-  //! Returns the outer wire on the face <Face>.
-  //! This is replacement of the method BRepTools::OuterWire
-  //! until it works badly.
-  //! Returns the first wire oriented as outer according to
-  //! FClass2d_Classifier. If none, last wire is returned.
-  Standard_EXPORT static TopoDS_Wire OuterWire (const TopoDS_Face& face);
+  //! Returns positively oriented wire in the face.
+  //! If there is no such wire - returns the last wire of the face.
+  Standard_EXPORT static TopoDS_Wire OuterWire (const TopoDS_Face& theFace);
   
   //! Returns a total area of 2d wire
   Standard_EXPORT static Standard_Real TotCross2D (const Handle(ShapeExtend_WireData)& sewd, const TopoDS_Face& aFace);
diff --git a/tests/bugs/mesh/bug31144 b/tests/bugs/mesh/bug31144
index 31f40afbe2..173e6403a7 100644
--- a/tests/bugs/mesh/bug31144
+++ b/tests/bugs/mesh/bug31144
@@ -2,7 +2,6 @@ puts "======="
 puts "0031144: Shape Healing - ShapeAnalysis::OuterWire() infinite loop on solid obtained from IFC"
 puts "======="
 puts ""
-puts "REQUIRED ALL: Meshing statuses: Failure"
 
 cpulimit 10
 
diff --git a/tests/bugs/mesh/bug31926 b/tests/bugs/mesh/bug31926
new file mode 100644
index 0000000000..edc55f2e0f
--- /dev/null
+++ b/tests/bugs/mesh/bug31926
@@ -0,0 +1,39 @@
+puts "========"
+puts "0031926: Shape Healing - ShapeAnalysis::OuterWire() considers next iteration element always to be a wire causing skipping of primal one"
+puts "========"
+puts ""
+
+vertex v11 0 1 0; vertex v12 1 0 0; vertex v13 0 0 0
+edge e11 v11 v12; edge e12 v12 v13; edge e13 v13 v11
+wire w1 e11 e12 e13
+mkplane f1 w1
+
+vertex v21 0 0 2; vertex v22 1 0 0; vertex v23 0 0 0
+edge e21 v21 v22; edge e22 v22 v23; edge e23 v23 v21
+wire w2 e21 e22 e23
+mkplane f2 w2
+
+vertex v31 0 0 2; vertex v32 0 1 0; vertex v33 1 0 0
+edge e31 v31 v32; edge e32 v32 v33; edge e33 v33 v31
+wire w3 e31 e32 e33
+mkplane f3 w3
+
+vertex v41 0 0 2; vertex v42 0 0 0; vertex v43 0 1 0
+edge e41 v41 v42; edge e42 v42 v43; edge e43 v43 v41
+wire w4 e41 e42 e43
+mkplane f4 w4
+
+psphere s1 1
+sewing sh2 f1 f2 f3 f4
+ssolid sh2 s2
+bcut result s1 s2
+incmesh result 1
+
+checkview -display result -3d -path ${imagedir}/${test_image}.png
+
+set log [tricheck result]
+if { [llength $log] != 0 } {
+  puts "Error : Invalid mesh"
+} else {
+  puts "Mesh is OK"
+}