# Polygon

VTKExamples/CSharp/GeometricObjects/Polygon

### Description

A tutorial on how to setup a Windows Forms Application utilizing ActiViz.NET can be found here: Setup a Windows Forms Application to use ActiViz.NET

### Code

Polygon.cs

    using System;
    using System.Collections.Generic;
    using System.ComponentModel;
    using System.Windows.Forms;
    using System.Diagnostics;

    using Kitware.VTK;

    namespace ActiViz.Examples {
       public partial class Form1 : Form {
          public Form1() {
             InitializeComponent();
          }

          private void renderWindowControl1_Load(object sender, EventArgs e) {
             try {
                Polygon();
             }
             catch(Exception ex) {
                MessageBox.Show(ex.Message, "Exception", MessageBoxButtons.OK);
             }
          }

          private void Polygon() {
             // Setup four points
             vtkPoints points = vtkPoints.New();
             double c = Math.Cos(Math.PI / 6); // helper variable

             points.InsertNextPoint(0.0, -1.0, 0.0);
             points.InsertNextPoint(c, -0.5, 0.0);
             points.InsertNextPoint(c, 0.5, 0.0);
             points.InsertNextPoint(0.0, 1.0, 0.0);
             points.InsertNextPoint(-c, 0.5, 0.0);
             points.InsertNextPoint(-c, -0.5, 0.0);

             // Create the polygon
             vtkPolygon polygon = vtkPolygon.New();
             polygon.GetPointIds().SetNumberOfIds(6); //make a six-sided figure
             polygon.GetPointIds().SetId(0, 0);
             polygon.GetPointIds().SetId(1, 1);
             polygon.GetPointIds().SetId(2, 2);
             polygon.GetPointIds().SetId(3, 3);
             polygon.GetPointIds().SetId(4, 4);
             polygon.GetPointIds().SetId(5, 5);

             // Add the polygon to a list of polygons
             vtkCellArray polygons = vtkCellArray.New();
             polygons.InsertNextCell(polygon);

             // Create a PolyData
             vtkPolyData polygonPolyData = vtkPolyData.New();
             polygonPolyData.SetPoints(points);
             polygonPolyData.SetPolys(polygons);

             // Create a mapper and actor
             vtkPolyDataMapper mapper = vtkPolyDataMapper.New();
             mapper.SetInput(polygonPolyData);
             vtkActor actor = vtkActor.New();
             actor.SetMapper(mapper);
             vtkRenderWindow renderWindow = renderWindowControl1.RenderWindow;
             vtkRenderer renderer = renderWindow.GetRenderers().GetFirstRenderer();
             renderer.SetBackground(0.2, 0.3, 0.4);
             renderer.AddActor(actor);
             renderer.ResetCamera();
          }
       }
    }