From fd76595d64eb8b77a4a379622538ba32d6d8e1f8 Mon Sep 17 00:00:00 2001
From: vro <vladislav.romashko@opencascade.com>
Date: Mon, 15 Feb 2021 14:27:53 +0300
Subject: [PATCH] 0025936: Modeling Data - reusable data structure for 2D
 tesselation (3- and 4-nodal mesh)

// Fixed a twice-reverse of normals (revealed in bugs vis... tests).
---
 src/Poly/Poly.cxx                                |  9 ++++++---
 src/Poly/Poly_CoherentTriangulation.cxx          |  4 ++--
 src/Poly/Poly_Triangulation.hxx                  |  2 +-
 src/RWObj/RWObj_TriangulationReader.cxx          |  1 -
 src/Select3D/Select3D_SensitiveTriangulation.cxx |  5 ++---
 src/StdPrs/StdPrs_ShadedShape.cxx                | 10 +++-------
 6 files changed, 14 insertions(+), 17 deletions(-)

diff --git a/src/Poly/Poly.cxx b/src/Poly/Poly.cxx
index c163683aee..3b0b98db01 100644
--- a/src/Poly/Poly.cxx
+++ b/src/Poly/Poly.cxx
@@ -480,7 +480,6 @@ void Poly::ComputeNormals (const Handle(Poly_Triangulation)& theTri)
   }
 
   // Normalize all vectors
-  gp_Dir aNormal;
   gp_XYZ aNormXYZ;
   for (Standard_Integer aNodeIter = 0; aNodeIter < aNbNodes; ++aNodeIter)
   {
@@ -488,9 +487,13 @@ void Poly::ComputeNormals (const Handle(Poly_Triangulation)& theTri)
     aNormXYZ.SetCoord (aNormArr[anIndex + 0], aNormArr[anIndex + 1], aNormArr[anIndex + 2]);
     const Standard_Real aMod2 = aNormXYZ.SquareModulus();
     if (aMod2 > anEps2)
-      aNormal = aNormXYZ;
+    {
+      aNormXYZ /= Sqrt (aMod2);
+    }
     else
-      aNormal = gp::DZ();
+    {
+      aNormXYZ = gp::DZ().XYZ();
+    }
 
     // Set normal.
     theTri->SetNormal (aNodeIter + 1, aNormXYZ);
diff --git a/src/Poly/Poly_CoherentTriangulation.cxx b/src/Poly/Poly_CoherentTriangulation.cxx
index 82cf42f4b4..4123041c50 100644
--- a/src/Poly/Poly_CoherentTriangulation.cxx
+++ b/src/Poly/Poly_CoherentTriangulation.cxx
@@ -126,6 +126,8 @@ Handle(Poly_Triangulation) Poly_CoherentTriangulation::GetTriangulation() const
       if (aNode.IsFreeNode())
         vecNodeId.SetValue(i, 0);
       else {
+        vecNodeId.SetValue(i, ++aCount);
+
         const gp_XYZ aNormal = aNode.GetNormal();
         if (aNormal.SquareModulus() > Precision::Confusion()) {
           aResult->SetNormal (aCount, static_cast<Standard_ShortReal>(aNormal.X()),
@@ -133,9 +135,7 @@ Handle(Poly_Triangulation) Poly_CoherentTriangulation::GetTriangulation() const
                                       static_cast<Standard_ShortReal>(aNormal.Z()));
         }
 
-        vecNodeId.SetValue(i, ++aCount);
         aResult->ChangeNode (aCount) = aNode;
-
         aResult->ChangeUVNode (aCount) = gp_Pnt2d (aNode.GetU(), aNode.GetV());
         if (aNode.GetU()*aNode.GetU() + aNode.GetV()*aNode.GetV() >
             Precision::Confusion())
diff --git a/src/Poly/Poly_Triangulation.hxx b/src/Poly/Poly_Triangulation.hxx
index 7b0c8eb2d2..a5cc885b17 100644
--- a/src/Poly/Poly_Triangulation.hxx
+++ b/src/Poly/Poly_Triangulation.hxx
@@ -188,7 +188,7 @@ public:
                   const Vec3f&           theNormal)
   {
     // If an array for normals is not allocated yet, do it now.
-    if (myNormals.IsEmpty())
+    if (myNormals.IsEmpty() || myNormals.Size() != myNodes.Size())
       myNormals.Resize (1, myNodes.Size(), Standard_False);
 
     // Set a normal.
diff --git a/src/RWObj/RWObj_TriangulationReader.cxx b/src/RWObj/RWObj_TriangulationReader.cxx
index 912dce87fe..c4ef86170d 100644
--- a/src/RWObj/RWObj_TriangulationReader.cxx
+++ b/src/RWObj/RWObj_TriangulationReader.cxx
@@ -179,7 +179,6 @@ Handle(Poly_Triangulation) RWObj_TriangulationReader::GetTriangulation()
       {
         aPoly->SetNormal (aNodeIter + 1, 0.0f, 0.0f, 1.0f);
       }
-      aPoly->SetNormal (aNodeIter + 1, aNorm.x(), aNorm.y(), aNorm.z());
     }
   }
 
diff --git a/src/Select3D/Select3D_SensitiveTriangulation.cxx b/src/Select3D/Select3D_SensitiveTriangulation.cxx
index 3a7631404a..c611974c21 100644
--- a/src/Select3D/Select3D_SensitiveTriangulation.cxx
+++ b/src/Select3D/Select3D_SensitiveTriangulation.cxx
@@ -111,9 +111,8 @@ Select3D_SensitiveTriangulation::Select3D_SensitiveTriangulation (const Handle(S
   myBndBox.Clear();
   for (Standard_Integer aNodeIdx = 1; aNodeIdx <= myTriangul->NbNodes(); ++aNodeIdx)
   {
-    myBndBox.Add (SelectMgr_Vec3 (myTriangul->Node (aNodeIdx).X(),
-                                  myTriangul->Node (aNodeIdx).Y(),
-                                  myTriangul->Node (aNodeIdx).Z()));
+    const gp_Pnt& aNode = myTriangul->Node (aNodeIdx);
+    myBndBox.Add (SelectMgr_Vec3 (aNode.X(), aNode.Y(), aNode.Z()));
   }
 
   if (theIsInterior)
diff --git a/src/StdPrs/StdPrs_ShadedShape.cxx b/src/StdPrs/StdPrs_ShadedShape.cxx
index 2ba10dcc7c..a434c61daa 100644
--- a/src/StdPrs/StdPrs_ShadedShape.cxx
+++ b/src/StdPrs/StdPrs_ShadedShape.cxx
@@ -205,10 +205,6 @@ namespace
       {
         aPoint = aT->Node (aNodeIter);
         gp_Dir aNorm = aNormals (aNodeIter);
-        if ((aFace.Orientation() == TopAbs_REVERSED) ^ isMirrored)
-        {
-          aNorm.Reverse();
-        }
         if (!aLoc.IsIdentity())
         {
           aPoint.Transform (aTrsf);
@@ -242,9 +238,9 @@ namespace
           aT->Triangle (aTriIter).Get (anIndex[0], anIndex[1], anIndex[2]);
         }
 
-        gp_Pnt aP1 = aT->Node (anIndex[0]);
-        gp_Pnt aP2 = aT->Node (anIndex[1]);
-        gp_Pnt aP3 = aT->Node (anIndex[2]);
+        const gp_Pnt& aP1 = aT->Node (anIndex[0]);
+        const gp_Pnt& aP2 = aT->Node (anIndex[1]);
+        const gp_Pnt& aP3 = aT->Node (anIndex[2]);
 
         gp_Vec aV1 (aP1, aP2);
         if (aV1.SquareMagnitude() <= aPreci)
-- 
2.39.5