0024521: Visualization - automatic back face culling is not turned on for Solids packed into compound

StdPrs_ToolShadedShape::IsClosed():
- return true if shape is closed Solid (NOT just free closed Shell)
- accept compound of closed Solids as well
- ignore Solids with incomplete triangulation

TKOpenGl, automatically disable back face culling when:
- clipping/capping planes are in effect
- for translucent objects

Update bug23227 test case (now back faces are clipped).

OpenGl_Workspace::AspectFace() - disable culling in case of hatched style

src/InterfaceGraphic/InterfaceGraphic_telem.hxx

@@ -46,7 +46,8 @@ typedef TEL_COLOUR* tel_colour;
 
 typedef enum
 {
-  TelCullNone, 
+  TelCullUndefined = -1,
+  TelCullNone = 0,
   TelCullFront,
   TelCullBack
 } TelCullMode;

src/OpenGl/OpenGl_Clipping.cxx

@@ -27,9 +27,9 @@ namespace
 // purpose  :
 // =======================================================================
 OpenGl_Clipping::OpenGl_Clipping ()
-: myPlanes(),
-  myPlaneStates(),
-  myEmptyPlaneIds (new Aspect_GenId (GL_CLIP_PLANE0, GL_CLIP_PLANE5))
+: myEmptyPlaneIds (new Aspect_GenId (GL_CLIP_PLANE0, GL_CLIP_PLANE5)),
+  myNbClipping (0),
+  myNbCapping  (0)
 {}
 
 // =======================================================================
@@ -40,6 +40,8 @@ void OpenGl_Clipping::Init (const Standard_Integer theMaxPlanes)
 {
   myPlanes.Clear();
   myPlaneStates.Clear();
+  myNbClipping = 0;
+  myNbCapping  = 0;
   Standard_Integer aLowerId = GL_CLIP_PLANE0;
   Standard_Integer aUpperId = GL_CLIP_PLANE0 + theMaxPlanes - 1;
   myEmptyPlaneIds = new Aspect_GenId (aLowerId, aUpperId);
@@ -104,6 +106,15 @@ void OpenGl_Clipping::Add (Graphic3d_SequenceOfHClipPlane& thePlanes, const Equa
 
     glEnable ((GLenum)anID);
     glClipPlane ((GLenum)anID, aPlane->GetEquation());
+    if (aPlane->IsCapping())
+    {
+      ++myNbCapping;
+    }
+    else
+    {
+      ++myNbClipping;
+    }
+
     aPlaneIt.Next();
   }
 
@@ -129,10 +140,22 @@ void OpenGl_Clipping::Remove (const Graphic3d_SequenceOfHClipPlane& thePlanes)
     }
 
     Standard_Integer anID = myPlaneStates.Find (aPlane).ContextID;
+    PlaneProps& aProps = myPlaneStates.ChangeFind (aPlane);
+    if (aProps.IsEnabled)
+    {
+      glDisable ((GLenum)anID);
+      if (aPlane->IsCapping())
+      {
+        --myNbCapping;
+      }
+      else
+      {
+        --myNbClipping;
+      }
+    }
+
     myEmptyPlaneIds->Free (anID);
     myPlaneStates.UnBind (aPlane);
-
-    glDisable ((GLenum)anID);
   }
 
   // renew collection of planes
@@ -173,10 +196,26 @@ void OpenGl_Clipping::SetEnabled (const Handle(Graphic3d_ClipPlane)& thePlane,
   if (theIsEnabled)
   {
     glEnable (anID);
+    if (thePlane->IsCapping())
+    {
+      ++myNbCapping;
+    }
+    else
+    {
+      ++myNbClipping;
+    }
   }
   else
   {
     glDisable (anID);
+    if (thePlane->IsCapping())
+    {
+      --myNbCapping;
+    }
+    else
+    {
+      --myNbClipping;
+    }
   }
 
   aProps.IsEnabled = theIsEnabled;

src/OpenGl/OpenGl_Clipping.hxx

@@ -81,6 +81,24 @@ public: //! @name non-modifying getters
     return myPlaneStates.Find (thePlane).IsEnabled;
   }
 
+  //! @return true if there are enabled clipping planes (NOT capping)
+  inline Standard_Boolean IsClippingOn() const
+  {
+    return myNbClipping > 0;
+  }
+
+  //! @return true if there are enabled capping planes
+  inline Standard_Boolean IsCappingOn() const
+  {
+    return myNbCapping > 0;
+  }
+
+  //! @return true if there are enabled clipping or capping planes
+  inline Standard_Boolean IsClippingOrCappingOn() const
+  {
+    return (myNbClipping + myNbCapping) > 0;
+  }
+
 public: //! @name clipping state modification commands
 
   //! Add planes to the context clipping at the specified system of coordinates.
@@ -198,9 +216,11 @@ private:
   typedef NCollection_DataMap<Handle(Graphic3d_ClipPlane), PlaneProps> OpenGl_MapOfPlaneStates;
   typedef NCollection_Handle<Aspect_GenId> OpenGl_EmptyPlaneIds;
 
-  Graphic3d_SequenceOfHClipPlane myPlanes;        //!< defined clipping planes.
-  OpenGl_MapOfPlaneStates        myPlaneStates;   //!< map of clip planes bound for the props.
-  OpenGl_EmptyPlaneIds           myEmptyPlaneIds; //!< generator of empty ids.
+  Graphic3d_SequenceOfHClipPlane myPlanes;        //!< defined clipping planes
+  OpenGl_MapOfPlaneStates        myPlaneStates;   //!< map of clip planes bound for the props
+  OpenGl_EmptyPlaneIds           myEmptyPlaneIds; //!< generator of empty ids
+  Standard_Boolean               myNbClipping;    //!< number of enabled clipping-only planes (NOT capping)
+  Standard_Boolean               myNbCapping;     //!< number of enabled capping  planes
 
 private:
 

src/OpenGl/OpenGl_Workspace.cxx

@@ -166,6 +166,7 @@ OpenGl_Workspace::OpenGl_Workspace (const Handle(OpenGl_Display)& theDisplay,
   TextParam_applied (NULL),
   ViewMatrix_applied (&myDefaultMatrix),
   StructureMatrix_applied (&myDefaultMatrix),
+  myCullingMode (TelCullUndefined),
   myModelViewMatrix (myDefaultMatrix),
   PolygonOffset_applied (NULL)
 {
@@ -269,6 +270,7 @@ void OpenGl_Workspace::ResetAppliedAspect()
   TextParam_set         = &myDefaultTextParam;
   TextParam_applied     = NULL;
   PolygonOffset_applied = NULL;
+  myCullingMode         = TelCullUndefined;
 
   AspectLine(Standard_True);
   AspectFace(Standard_True);

src/OpenGl/OpenGl_Workspace.hxx

@@ -442,6 +442,7 @@ protected: //! @name fields related to status
   OpenGl_Material myMatFront;    //!< current front material state (cached to reduce GL context updates)
   OpenGl_Material myMatBack;     //!< current back  material state
   OpenGl_Material myMatTmp;      //!< temporary variable
+  TelCullMode     myCullingMode; //!< back face culling mode, applied from face aspect
 
   //! Model matrix with applied structure transformations
   OpenGl_Matrix myModelViewMatrix;

src/OpenGl/OpenGl_Workspace_5.cxx

@@ -319,7 +319,55 @@ const OpenGl_AspectLine * OpenGl_Workspace::AspectLine(const Standard_Boolean Wi
 
 const OpenGl_AspectFace* OpenGl_Workspace::AspectFace (const Standard_Boolean theToApply)
 {
-  if (!theToApply || (AspectFace_set == AspectFace_applied))
+  if (!theToApply)
+  {
+    return AspectFace_set;
+  }
+
+  if (!ActiveView()->Backfacing())
+  {
+    // manage back face culling mode, disable culling when clipping is enabled
+    TelCullMode aCullingMode = (myGlContext->Clipping().IsClippingOrCappingOn()
+                             || AspectFace_set->InteriorStyle() == Aspect_IS_HATCH)
+                             ? TelCullNone
+                             : (TelCullMode )AspectFace_set->CullingMode();
+    if (aCullingMode != TelCullNone
+     && myUseTransparency && !(NamedStatus & OPENGL_NS_2NDPASSDO))
+    {
+      // disable culling in case of translucent shading aspect
+      if (AspectFace_set->IntFront().trans != 1.0f)
+      {
+        aCullingMode = TelCullNone;
+      }
+    }
+    if (myCullingMode != aCullingMode)
+    {
+      myCullingMode = aCullingMode;
+      switch (myCullingMode)
+      {
+        case TelCullNone:
+        case TelCullUndefined:
+        {
+          glDisable (GL_CULL_FACE);
+          break;
+        }
+        case TelCullFront:
+        {
+          glCullFace (GL_FRONT);
+          glEnable (GL_CULL_FACE);
+          break;
+        }
+        case TelCullBack:
+        {
+          glCullFace (GL_BACK);
+          glEnable (GL_CULL_FACE);
+          break;
+        }
+      }
+    }
+  }
+
+  if (AspectFace_set == AspectFace_applied)
   {
     return AspectFace_set;
   }
@@ -365,34 +413,6 @@ const OpenGl_AspectFace* OpenGl_Workspace::AspectFace (const Standard_Boolean th
     }
   }
 
-  if (!ActiveView()->Backfacing())
-  {
-    const Tint aCullingMode = AspectFace_set->CullingMode();
-    if (AspectFace_applied == NULL || AspectFace_applied->CullingMode() != aCullingMode)
-    {
-      switch ((TelCullMode )aCullingMode)
-      {
-        case TelCullNone:
-        {
-          glDisable (GL_CULL_FACE);
-          break;
-        }
-        case TelCullFront:
-        {
-          glCullFace (GL_FRONT);
-          glEnable (GL_CULL_FACE);
-          break;
-        }
-        case TelCullBack:
-        {
-          glCullFace (GL_BACK);
-          glEnable (GL_CULL_FACE);
-          break;
-        }
-      }
-    }
-  }
-
   // Aspect_POM_None means: do not change current settings
   if ((AspectFace_set->PolygonOffset().mode & Aspect_POM_None) != Aspect_POM_None)
   {

src/StdPrs/StdPrs_ShadedShape.cxx

@@ -100,7 +100,7 @@ namespace
     Standard_Real    aUmin (0.0), aUmax (0.0), aVmin (0.0), aVmax (0.0), dUmax (0.0), dVmax (0.0);
 
     // precision for compare square distances
-    const double aPreci = Precision::SquareConfusion();
+    const Standard_Real aPreci = Precision::SquareConfusion();
 
     if (!theDrawer->ShadingAspectGlobal())
     {
@@ -126,9 +126,12 @@ namespace
         nbVertices  += T->NbNodes();
       }
     }
-
-    if (nbVertices > 2 && nbTriangles > 0)
+    if (nbVertices  <  3
+     || nbTriangles <= 0)
     {
+      return Standard_False;
+    }
+
     Handle(Graphic3d_ArrayOfTriangles) aPArray
       = new Graphic3d_ArrayOfTriangles (nbVertices, 3 * nbTriangles,
                                         Standard_True, Standard_False, theHasTexels, Standard_True);
@@ -177,7 +180,7 @@ namespace
         }
       }
 
-        // Fill parray with vertex and edge visibillity info
+      // Fill array with vertex and edge visibility info
       const Poly_Array1OfTriangle& aTriangles = T->Triangles();
       for (Standard_Integer aTriIter = 1; aTriIter <= T->NbTriangles(); ++aTriIter)
       {
@@ -218,7 +221,7 @@ namespace
       }
     }
     Prs3d_Root::CurrentGroup (thePresentation)->AddPrimitiveArray (aPArray);
-    }
+
     return Standard_True;
   }
 

src/StdPrs/StdPrs_ToolShadedShape.cdl

@@ -25,7 +25,9 @@ uses
     Location      from TopLoc
 is
 
-    IsClosed(myclass; aShape: Shape from TopoDS) returns Boolean from Standard; 
+    IsClosed (myclass; theShape : Shape from TopoDS) returns Boolean from Standard;
+    ---Purpose: Checks back faces visibility for specified shape (to activate back-face culling).
+    --          @return true if shape is closed Solid or compound of closed Solids.
 
     Triangulation(myclass; aFace: Face from TopoDS;
     	    	    	   loc  : out Location from TopLoc) 

src/StdPrs/StdPrs_ToolShadedShape.cxx

@@ -32,13 +32,99 @@
 #include <TShort_HArray1OfShortReal.hxx>
 #include <TShort_Array1OfShortReal.hxx>
 
+namespace
+{
+  //=======================================================================
+  //function : isTriangulated
+  //purpose  : Returns true if all faces within shape are triangulated.
+  //           Same as BRepTools::Triangulation() but without extra checks.
+  //=======================================================================
+  static Standard_Boolean isTriangulated (const TopoDS_Shape& theShape)
+  {
+    TopLoc_Location aLocDummy;
+    for (TopExp_Explorer aFaceIter (theShape, TopAbs_FACE); aFaceIter.More(); aFaceIter.Next())
+    {
+      const TopoDS_Face&                aFace = TopoDS::Face (aFaceIter.Current());
+      const Handle(Poly_Triangulation)& aTri  = BRep_Tool::Triangulation (aFace, aLocDummy);
+      if (aTri.IsNull())
+      {
+        return Standard_False;
+      }
+    }
+    return Standard_True;
+  }
+}
+
 //=======================================================================
 //function : IsClosed
 //purpose  :
 //=======================================================================
 Standard_Boolean StdPrs_ToolShadedShape::IsClosed (const TopoDS_Shape& theShape)
 {
-  return theShape.Closed();
+  if (theShape.IsNull())
+  {
+    return Standard_True;
+  }
+
+  switch (theShape.ShapeType())
+  {
+    case TopAbs_COMPOUND:
+    case TopAbs_COMPSOLID:
+    default:
+    {
+      // check that compound consists of closed solids
+      for (TopoDS_Iterator anIter (theShape); anIter.More(); anIter.Next())
+      {
+        const TopoDS_Shape& aShape = anIter.Value();
+        if (!IsClosed (aShape))
+        {
+          return Standard_False;
+        }
+      }
+      return Standard_True;
+    }
+    case TopAbs_SOLID:
+    {
+      for (TopoDS_Iterator anIter (theShape); anIter.More(); anIter.Next())
+      {
+        const TopoDS_Shape& aShape = anIter.Value();
+        if (aShape.IsNull())
+        {
+          continue;
+        }
+
+        if (aShape.ShapeType() == TopAbs_SHELL
+        && !aShape.Closed())
+        {
+          return Standard_False;
+        }
+        else if (aShape.ShapeType() == TopAbs_FACE)
+        {
+          // invalid solid
+          return Standard_False;
+        }
+        else if (!isTriangulated (aShape))
+        {
+          // mesh contains holes
+          return Standard_False;
+        }
+      }
+      return Standard_True;
+    }
+    case TopAbs_SHELL:
+    case TopAbs_FACE:
+    {
+      // free faces / shell are not allowed
+      return Standard_False;
+    }
+    case TopAbs_WIRE:
+    case TopAbs_EDGE:
+    case TopAbs_VERTEX:
+    {
+      // ignore
+      return Standard_True;
+    }
+  }
 }
 
 //=======================================================================

tests/bugs/vis/bug23227

@@ -1,19 +1,19 @@
 puts "============"
 puts "OCC23227"
+puts "New Draw Harness command to estimate current geometry complexity of OpenGL scene"
 puts "============"
 puts ""
-#######################################################################
-# New Draw Harness command to estimate current geometry complexity of OpenGL scene
-#######################################################################
 
 set BugNumber OCC23227
 
 box b 1 2 3
-vinit
+vinit View1
+vclear
 vdisplay b
 vsetdispmode 1
 vfit
 set vfeedback1 [vfeedback]
+vdump $imagedir/${casename}_box.png
 
 vclear
 set vfeedback2 [vfeedback]
@@ -29,7 +29,7 @@ if { ${llength_vfeedback1} < 36 || ${llength_vfeedback2} < 36 || ${IndexTriangle
 } else {
   set Triangles1 [lindex ${vfeedback1} ${IndexTriangles1}+1]
   set Triangles2 [lindex ${vfeedback2} ${IndexTriangles1}+1]
-   if { ${Triangles1} == 12 && ${Triangles2} == 0 } {
+  if { ${Triangles1} == 6 && ${Triangles2} == 0 } {
     puts "OK ${BugNumber}"
   } else {
     puts "Faulty ${BugNumber}"
@@ -37,4 +37,3 @@ if { ${llength_vfeedback1} < 36 || ${llength_vfeedback2} < 36 || ${IndexTriangle
 }
 
 set only_screen 1
-