From 0cdaa8a4a5910bfae9bd3ed864790c88f24a7109 Mon Sep 17 00:00:00 2001
From: agv <agv@opencascade.com>
Date: Wed, 3 Jul 2019 20:04:16 +0300
Subject: [PATCH] 0030831: ShapeFix algorithm (creation of seam edge) takes too
 long time with thin faces

In class ShapeFix_ComposeShell the U- and V-closedness of input face is taken immediately avoiding the error when the face is small in any of these dimensions.
Test case for bug 0030831
---
 src/ShapeFix/ShapeFix_ComposeShell.cxx | 48 +++++++++++++++-----------
 tests/bugs/heal/bug30831               | 12 +++++++
 2 files changed, 39 insertions(+), 21 deletions(-)
 create mode 100644 tests/bugs/heal/bug30831

diff --git a/src/ShapeFix/ShapeFix_ComposeShell.cxx b/src/ShapeFix/ShapeFix_ComposeShell.cxx
index 9eb487d4f0..3d3709e344 100644
--- a/src/ShapeFix/ShapeFix_ComposeShell.cxx
+++ b/src/ShapeFix/ShapeFix_ComposeShell.cxx
@@ -30,7 +30,7 @@
 #include <Geom2dAdaptor_Curve.hxx>
 #include <Geom2dInt_GInter.hxx>
 #include <Geom_Curve.hxx>
-#include <Geom_Surface.hxx>
+#include <Geom_ElementarySurface.hxx>
 #include <GeomAdaptor_Surface.hxx>
 #include <gp_Dir2d.hxx>
 #include <gp_Lin2d.hxx>
@@ -118,26 +118,32 @@ void ShapeFix_ComposeShell::Init (const Handle(ShapeExtend_CompositeSurface) &Gr
 //  DTK-CKY 100531 : protection against very thin face
 //  Test "isclosed" should be filtered on the overall (non trimmed) surface, must be closed
   Handle(Geom_Surface) theSurface = BRep_Tool::Surface(Face,myLoc);
-  Standard_Real U0,U1,V0,V1,GU0 = 0.,GU1 = 0.,GV0 = 0.,GV1 = 0.;
-  theSurface->Bounds(U0,U1,V0,V1);
-  if (::Precision::IsInfinite (U0) || ::Precision::IsInfinite (U1) ||
-      ::Precision::IsInfinite (V0) || ::Precision::IsInfinite (V1))
-    BRepTools::UVBounds(Face, GU0, GU1, GV0, GV1);
-  if (myUClosed) {
-    if (::Precision::IsInfinite (V0)) V0 = GV0;
-    if (::Precision::IsInfinite (V1)) V1 = GV1;
-    gp_Pnt P0 = theSurface->Value(U0,(V0+V1)/2.);
-    gp_Pnt P1 = theSurface->Value(U1,(V0+V1)/2.);
-    if (P0.Distance(P1) > Precision::Confusion()*10)
-      myUClosed = Standard_False;
-  }
-  if (myVClosed) {
-    if (::Precision::IsInfinite (U0)) U0 = GU0;
-    if (::Precision::IsInfinite (U1)) U1 = GU1;
-    gp_Pnt P0 = theSurface->Value((U0+U1)/2.,V0);
-    gp_Pnt P1 = theSurface->Value((U0+U1)/2.,V1);
-    if (P0.Distance(P1) > Precision::Confusion()*10)
-      myVClosed = Standard_False;
+  // avoid false detection of 'Closed' on very thin faces
+  if (theSurface->IsKind(STANDARD_TYPE(Geom_ElementarySurface))) {
+    myUClosed = myUClosed && theSurface->IsUClosed();
+    myVClosed = myVClosed && theSurface->IsVClosed();
+  } else {
+    Standard_Real U0,U1,V0,V1,GU0 = 0.,GU1 = 0.,GV0 = 0.,GV1 = 0.;
+    theSurface->Bounds(U0,U1,V0,V1);
+    if (::Precision::IsInfinite (U0) || ::Precision::IsInfinite (U1) ||
+        ::Precision::IsInfinite (V0) || ::Precision::IsInfinite (V1))
+      BRepTools::UVBounds(Face, GU0, GU1, GV0, GV1);
+    if (myUClosed) {
+      if (::Precision::IsInfinite (V0)) V0 = GV0;
+      if (::Precision::IsInfinite (V1)) V1 = GV1;
+      gp_Pnt P0 = theSurface->Value(U0,(V0+V1)/2.);
+      gp_Pnt P1 = theSurface->Value(U1,(V0+V1)/2.);
+      if (P0.Distance(P1) > Precision::Confusion()*10)
+        myUClosed = Standard_False;
+    }
+    if (myVClosed) {
+      if (::Precision::IsInfinite (U0)) U0 = GU0;
+      if (::Precision::IsInfinite (U1)) U1 = GU1;
+      gp_Pnt P0 = theSurface->Value((U0+U1)/2.,V0);
+      gp_Pnt P1 = theSurface->Value((U0+U1)/2.,V1);
+      if (P0.Distance(P1) > Precision::Confusion()*10)
+        myVClosed = Standard_False;
+    }
   }
 //  DTK-CKY 100531 end
 
diff --git a/tests/bugs/heal/bug30831 b/tests/bugs/heal/bug30831
new file mode 100644
index 0000000000..cd21c66d3b
--- /dev/null
+++ b/tests/bugs/heal/bug30831
@@ -0,0 +1,12 @@
+puts "========================"                                                                                      
+puts "0030831: Shape Healing - ShapeFix algorithm (creation of seam edge) takes too long time with thin faces"
+puts "========================"                                                                                      
+
+cpulimit 10
+binrestore [locate_data_file bug30831.bin] a
+
+fixshape r a 1.e-7 1.
+checkshape r a
+tolerance r
+
+checkview -display r -2d -path ${imagedir}/${test_image}.png