0027751: Visualization, Graphic3d_ClipPlane - add option to inherit material from object

Graphic3d_ClipPlane - Graphic3d_AspectFillArea3d is now stored as class field.
OpenGl_CappingAlgo::RenderCapping() now handles special mode
preserving material from rendered object.

MeshVS_ElementalColorPrsBuilder::Build() now creates single primitives group
for triangles, thus Closed flag is correctly applied.

Redundant methods OpenGl_Structure::DrawGroups() and ::renderClosedGeometry()
have been removed.

Draw Harness, ViewerTest - vaspects now preserves display mode
and location when assigning sub-shape aspects.
The syntax of command vclipplane has been revised
(preserving compatibility with old syntax):
- Use "-param" style syntax for all arguments.
- Eliminate redundant arguments "change", "view", "object".
- Allow passing multiple parameters withing single call.
- Do not require "create" command - create new plane implicitly.
- "maxplanes" argument does not require view name anymore.
- "delete" does not throws TCL exception for non-existing plane.
- "view" argument without list now applies to active view.
- Handle * and ALL withing "delete" to remove all defined planes.

update test case bugs/vis/bug26028

src/OpenGl/OpenGl_StructureShadow.cxx

@@ -16,6 +16,7 @@
 #include <OpenGl_StructureShadow.hxx>
 
 #include <Graphic3d_GraphicDriver.hxx>
+#include <Standard_ProgramError.hxx>
 
 IMPLEMENT_STANDARD_RTTIEXT(OpenGl_StructureShadow,OpenGl_Structure)
 
@@ -38,4 +39,25 @@ OpenGl_StructureShadow::OpenGl_StructureShadow (const Handle(Graphic3d_Structure
   UpdateTransformation();
   myInstancedStructure = const_cast<OpenGl_Structure*> (myParent->InstancedStructure());
   TransformPersistence = myParent->TransformPersistence;
+
+  // reuse instanced structure API
+  myInstancedStructure = myParent.operator->();
+}
+
+// =======================================================================
+// function : Connect
+// purpose  :
+// =======================================================================
+void OpenGl_StructureShadow::Connect (Graphic3d_CStructure& )
+{
+  Standard_ProgramError::Raise ("Error! OpenGl_StructureShadow::Connect() should not be called!");
+}
+
+// =======================================================================
+// function : Disconnect
+// purpose  :
+// =======================================================================
+void OpenGl_StructureShadow::Disconnect (Graphic3d_CStructure& )
+{
+  Standard_ProgramError::Raise ("Error! OpenGl_StructureShadow::Disconnect() should not be called!");
 }