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| − | This example creates a polydata object with 3 points and attaches a distance value to each point. To retrieve the array from the polydata, we have to use a SafeDownCast to the type that we want. This is necessary because to keep things as general as possible the polydata will return an abstract array class.
| + | = '''See [https://lorensen.github.io/VTKExamples/site/Cxx/PolyData/Casting Casting] on the new [https://lorensen.github.io/VTKExamples/site/ VTKExamples website].''' = |
| − | | |
| − | ==Casting.cxx== | |
| − | <source lang="cpp">
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| − | #include <vtkSmartPointer.h>
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| − | #include <vtkDoubleArray.h>
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| − | #include <vtkIntArray.h>
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| − | #include <vtkPoints.h>
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| − | #include <vtkPolyData.h>
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| − | #include <vtkPointData.h>
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| − | | |
| − | int main(int, char *[])
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| − | {
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| − | // Create points
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| − | vtkSmartPointer<vtkPoints> points =
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| − | vtkSmartPointer<vtkPoints>::New();
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| − | | |
| − | unsigned int numberOfPoints = 3;
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| − | points->InsertNextPoint ( 0.0, 0.0, 0.0 );
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| − | points->InsertNextPoint ( 1.0, 0.0, 0.0 );
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| − | points->InsertNextPoint ( 0.0, 1.0, 0.0 );
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| − | | |
| − | // Add the points to a polydata
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| − | vtkSmartPointer<vtkPolyData> polydata =
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| − | vtkSmartPointer<vtkPolyData>::New();
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| − | polydata->SetPoints ( points );
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| − | | |
| − | // Add distances to each point
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| − | vtkSmartPointer<vtkDoubleArray> distances =
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| − | vtkSmartPointer<vtkDoubleArray>::New();
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| − | distances->SetNumberOfComponents(1);
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| − | distances->SetName("Distances");
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| − | | |
| − | distances->InsertNextValue(1.1);
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| − | distances->InsertNextValue(2.2);
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| − | distances->InsertNextValue(3.3);
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| − | | |
| − | polydata->GetPointData()->AddArray ( distances );
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| − | | |
| − | // Get the distances from the polydata
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| − | vtkDoubleArray* array = vtkDoubleArray::SafeDownCast ( polydata->GetPointData()->GetArray ( "Distances" ) );
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| − | | |
| − | if ( array )
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| − | {
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| − | for ( unsigned int i = 0; i < numberOfPoints; i++ )
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| − | {
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| − | double dist;
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| − | dist = array->GetValue ( i );
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| − | std::cout << "Distance: " << dist << std::endl;
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| − | }
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| − | }
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| − | | |
| − | // Cast the double distances to ints
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| − | vtkDoubleArray* doubleDistances = vtkDoubleArray::SafeDownCast(
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| − | polydata->GetPointData()->GetArray("Distances"));
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| − | vtkIntArray* intDistances = vtkIntArray::SafeDownCast(doubleDistances);
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| − | | |
| − | if(intDistances)
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| − | {
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| − | for(unsigned int i = 0; i < numberOfPoints; i++)
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| − | {
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| − | int dist;
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| − | dist = intDistances->GetValue ( i );
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| − | std::cout << "Distance: " << dist << std::endl;
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| − | }
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| − | }
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| − | else
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| − | {
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| − | std::cout << "invalid cast." << std::endl;
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| − | }
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| − | | |
| − | return EXIT_SUCCESS;
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| − | }
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| − | | |
| − | </source>
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| − | | |
| − | {{VTKCMakeLists|{{SUBPAGENAME}}}}
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| − | | |
| − | [[Category:VTKNoVizRequired]]
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