VTK/Examples/Cxx/Visualization/BackgroundTexture

#include <vtkVersion.h>
#include <vtkActor.h>
#include <vtkCamera.h>
#include <vtkImageActor.h>
#include <vtkImageData.h>
#include <vtkJPEGReader.h>
#include <vtkPolyData.h>
#include <vtkPolyDataMapper.h>
#include <vtkRenderer.h>
#include <vtkRenderWindow.h>
#include <vtkRenderWindowInteractor.h>
#include <vtkSmartPointer.h>
#include <vtkTexture.h>
 
static void CreateColorImage(vtkImageData*);
 
int main(int argc, char *argv[])
{
 
  vtkSmartPointer<vtkImageData> image = vtkSmartPointer<vtkImageData>::New();
  CreateColorImage(image);
 
  // Create a mapper and actor
  vtkSmartPointer<vtkTexture> texture = vtkSmartPointer<vtkTexture>::New();
#if VTK_MAJOR_VERSION <= 5
  texture->SetInputConnection(image->GetProducerPort());
#else
  texture->SetInputData(image);
#endif
  //texture->Update(); // Do not call this. It seems to work anyway, but it produces an error as well: vtkOpenGLTexture (0x8ffbe28): Definition of Execute() method should be in subclass and you should really use the ExecuteData(vtkInformation *request,...) signature instead
 
  vtkSmartPointer<vtkRenderer> renderer = vtkSmartPointer<vtkRenderer>::New();
  renderer->SetBackgroundTexture(texture);
  renderer->TexturedBackgroundOn();
 
  vtkSmartPointer<vtkRenderWindow> renderWindow = vtkSmartPointer<vtkRenderWindow>::New();
 
  renderWindow->AddRenderer(renderer);
 
  vtkSmartPointer<vtkRenderWindowInteractor> renderWindowInteractor = vtkSmartPointer<vtkRenderWindowInteractor>::New();
  renderWindowInteractor->SetRenderWindow(renderWindow);
 
  renderWindow->Render();
  renderWindowInteractor->Start();
 
  return EXIT_SUCCESS;
}
 
 
void CreateColorImage(vtkImageData* image)
{
  unsigned int dim = 20;
 
  image->SetDimensions(dim, dim, 1);
 
#if VTK_MAJOR_VERSION <= 5
  image->SetNumberOfScalarComponents(3);
  image->SetScalarTypeToUnsignedChar();
  image->AllocateScalars();
#else
  image->AllocateScalars(VTK_UNSIGNED_CHAR,3);
#endif
  for(unsigned int x = 0; x < dim; x++)
    {
    for(unsigned int y = 0; y < dim; y++)
      {
      unsigned char* pixel = static_cast<unsigned char*>(image->GetScalarPointer(x,y,0));
      if(x < dim/2)
	{
	pixel[0] = 255;
	}
      else
	{
	pixel[0] = 0;
	}
      pixel[1] = 0;
      pixel[2] = 255;
      }
    }
 
  image->Modified();
}