0024785: Visualization - Modifying z-layers concept to gain more control over OpenGl depth buffer.

Cosmetic fixes.
glDepthFunc fix.

src/OpenGl/OpenGl_Layer.hxx

@@ -0,0 +1,60 @@
+// Created on: 2014-03-31
+// Created by: Danila ULYANOV
+// Copyright (c) 2014 OPEN CASCADE SAS
+//
+// This file is part of Open CASCADE Technology software library.
+//
+// This library is free software; you can redistribute it and / or modify it
+// under the terms of the GNU Lesser General Public version 2.1 as published
+// by the Free Software Foundation, with special exception defined in the file
+// OCCT_LGPL_EXCEPTION.txt. Consult the file LICENSE_LGPL_21.txt included in OCCT
+// distribution for complete text of the license and disclaimer of any warranty.
+//
+// Alternatively, this file may be used under the terms of Open CASCADE
+// commercial license or contractual agreement.
+
+#ifndef _OpenGl_Layer_Header
+#define _OpenGl_Layer_Header
+
+#include <OpenGl_PriorityList.hxx>
+#include <Graphic3d_ZLayerSettings.hxx>
+
+class Handle(OpenGl_Workspace);
+
+class OpenGl_Layer
+{
+public:
+
+  //! Initializes associated priority list and layer properties
+  OpenGl_Layer (const Standard_Integer theNbPriorities = 11);
+
+  //! Returns settings of the layer object.
+  const Graphic3d_ZLayerSettings LayerSettings() const { return myLayerSettings; };
+
+  //! Sets settings of the layer object.
+  void SetLayerSettings (Graphic3d_ZLayerSettings theSettings)
+  {
+    myLayerSettings = theSettings;
+  }
+
+  //! Returns true if theSetting is enabled for the layer.
+  const Standard_Boolean IsSettingEnabled (const Graphic3d_ZLayerSetting theSetting) const
+  {
+    return myLayerSettings.IsSettingEnabled (theSetting);
+  }
+
+  //! Returns reference to associated priority list.
+  OpenGl_PriorityList& PriorityList() { return myPriorityList; }
+
+  //! Returns const reference to associated priority list.
+  const OpenGl_PriorityList& PriorityList() const { return myPriorityList; }
+
+  void Render (const Handle(OpenGl_Workspace) &AWorkspace, int theDefaultDepthFunc) const;
+
+private:
+
+  OpenGl_PriorityList myPriorityList;       //!< Associated priority list object.
+
+  Graphic3d_ZLayerSettings myLayerSettings; //!< Layer setting flags.
+};
+#endif //_OpenGl_Layer_Header