doc/tutorials/viz/creating_widgets/creating_widgets.markdown

   1 Creating Widgets {#tutorial_creating_widgets}
   2 ================
   3
   4 @prev_tutorial{tutorial_transformations}
   5 @next_tutorial{tutorial_histo3D}
   6
   7 Goal
   8 ----
   9
  10 In this tutorial you will learn how to
  11
  12 -   Create your own widgets using WidgetAccessor and VTK.
  13 -   Show your widget in the visualization window.
  14
  15 Code
  16 ----
  17
  18 You can download the code from [here ](https://github.com/opencv/opencv/tree/3.4/samples/cpp/tutorial_code/viz/creating_widgets.cpp).
  19 @include samples/cpp/tutorial_code/viz/creating_widgets.cpp
  20
  21 Explanation
  22 -----------
  23
  24 Here is the general structure of the program:
  25
  26 -   Extend Widget3D class to create a new 3D widget.
  27     @code{.cpp}
  28     class WTriangle : public viz::Widget3D
  29     {
  30         public:
  31             WTriangle(const Point3f &pt1, const Point3f &pt2, const Point3f &pt3, const viz::Color & color = viz::Color::white());
  32     };
  33     @endcode
  34 -   Assign a VTK actor to the widget.
  35     @code{.cpp}
  36     // Store this actor in the widget in order that visualizer can access it
  37     viz::WidgetAccessor::setProp(*this, actor);
  38     @endcode
  39 -   Set color of the widget.
  40     @code{.cpp}
  41     // Set the color of the widget. This has to be called after WidgetAccessor.
  42     setColor(color);
  43     @endcode
  44 -   Construct a triangle widget and display it in the window.
  45     @code{.cpp}
  46     /// Create a triangle widget
  47     WTriangle tw(Point3f(0.0,0.0,0.0), Point3f(1.0,1.0,1.0), Point3f(0.0,1.0,0.0), viz::Color::red());
  48
  49     /// Show widget in the visualizer window
  50     myWindow.showWidget("TRIANGLE", tw);
  51     @endcode
  52
  53 Results
  54 -------
  55
  56 Here is the result of the program.
  57
  58 ![](images/red_triangle.png)