0031570: Samples - add Qt samples similar to standard MFC samples

Added Qt sample OCCTOverview providing examples of use of OCCT API with relevant code and demonstration of results in the viewer.

Off-topic: some unused images are removed from dox/introduction/images/

samples/OCCTOverview/code/Sample2D_Markers.h

@@ -0,0 +1,88 @@
+// Copyright (c) 2020 OPEN CASCADE SAS
+//
+// This file is part of the examples of the Open CASCADE Technology software library.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in all
+// copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE
+
+#ifndef _Sample2D_Markers_HeaderFile
+#define _Sample2D_Markers_HeaderFile
+
+#include <AIS_InteractiveObject.hxx>
+#include <Graphic3d_ArrayOfPoints.hxx>
+
+//! AIS AIS interactive object for sample 2D marker
+class Sample2D_Markers : public AIS_InteractiveObject
+{
+  DEFINE_STANDARD_RTTI_INLINE(Sample2D_Markers, AIS_InteractiveObject)
+private:
+  enum Sample2D_CurrentTypeOfMarker
+  {
+    Sample2D_CTOM_Generic,
+    Sample2D_CTOM_Polyline,
+    Sample2D_CTOM_Circle,
+    Sample2D_CTOM_Ellips
+  };
+
+public:
+
+ //! Generic marker
+ Standard_EXPORT Sample2D_Markers (const Standard_Real theXPosition,
+                   const Standard_Real theYPosition,
+                   const Aspect_TypeOfMarker theMarkerType,
+                   const Quantity_Color theColor,
+                   const Standard_Real theScaleOrId=5.0);
+
+  //! Polyline marker
+  Standard_EXPORT Sample2D_Markers (const Standard_Real theXPosition,
+                   const Standard_Real theYPosition,
+                   const Handle(Graphic3d_ArrayOfPoints)& theArrayOfPoints,
+                   const Aspect_TypeOfMarker theMarkerType,
+                   const Quantity_Color theColor,
+                   const Standard_Real theScaleOrId=2.0);
+
+private:
+
+  //! Return TRUE for supported display modes (only mode 0 is supported).
+  virtual Standard_Boolean AcceptDisplayMode (const Standard_Integer theMode) const Standard_OVERRIDE { return theMode == 0; }
+
+  //! Compute presentation.
+  virtual void Compute (const Handle(PrsMgr_PresentationManager3d)& /*aPresentationManager*/,
+                        const Handle(Prs3d_Presentation)& /*aPresentation*/,
+                        const Standard_Integer theMode) Standard_OVERRIDE;
+
+  //! Compute selection (not implemented).
+  virtual void ComputeSelection (const Handle(SelectMgr_Selection)& ,
+                                 const Standard_Integer ) Standard_OVERRIDE {}
+
+  virtual void SetContext(const Handle(AIS_InteractiveContext)& ) Standard_OVERRIDE {}
+
+private:
+
+  Sample2D_CurrentTypeOfMarker myCurrentTypeOfMarker;
+  Standard_Real  myXPosition;
+  Standard_Real  myYPosition;
+  Aspect_TypeOfMarker myMarkerType;
+  Quantity_Color myColor;
+  Standard_Real  myWidth;
+  Standard_Real  myHeight;
+  Standard_Real  myIndex;
+  //! specific polyline marker
+  Handle(Graphic3d_ArrayOfPoints) myArrayOfPoints;
+};
+
+#endif