[vtkusers] VTK Examples and C++

[Amy Henderson]

Hi Nick,

The problem with your C++ code is that you're missing a couple of include 
files, specifically vtkPolyData.h and vtkImageData.h.  Otherwise your 
program doesn't know that vtkPolyData (the output of vtkWarpScalar) is a 
subclass of vtkPointSet and that vtkImageData (the output of vtkBMPReader) 
is a subclass of vtkDataSet.

- Amy

At 09:41 AM 6/15/2004, Nick Arini wrote:

>Dear VTK Users,
>
>I am learning VTK by example. I am however not at all experienced in Tcl 
>or Python. There are not a great many C++ examples in VTK/Examples.
>
>My assumption therefore was that I could read the Tcl code and convert it 
>directly to C++. I have for example done that for the Tcl example 
>mentioned on pp391 of the VTK book:
>
>Examples/VisualizationAlgorithms/Tcl/imageWarp.tcl
>
>I converted this line for line into what I thought was equivalent C++ code 
>(see below), however the objects don't seem to be compatible as C++. The 
>compiler errors describing mismatched prototypes is also pasted in below.
>
>What is the difference if any between VTK code written in Tcl (or python) 
>and pure C++? (Or what have I done bad?)
>
>Why are there so few C++ examples in VTK/Examples?
>
>Is there any interest in more C++ examples?
>
>
>Best regards and thanks,
>
>Nick
>
>
><begin Tcl>
>
>vtkBMPReader reader
>   reader SetFileName $VTK_DATA_ROOT/Data/masonry.bmp
>
>vtkImageLuminance luminance
>   luminance SetInput [reader GetOutput]
>
>vtkImageDataGeometryFilter geometry
>   geometry SetInput [luminance GetOutput]
>
>vtkWarpScalar warp
>   warp SetInput [geometry GetOutput]
>   warp SetScaleFactor -0.1
>
>vtkMergeFilter merge
>   merge SetGeometry [warp GetOutput]
>   merge SetScalars  [reader GetOutput]
>
>vtkDataSetMapper mapper
>   mapper SetInput [merge GetOutput]
>   mapper SetScalarRange 0 255
>   mapper ImmediateModeRenderingOff
>
><end Tcl>
>
>
><begin C++>
>
>#include <vtkTIFFReader.h>
>#include <vtkImageLuminance.h>
>#include <vtkImageDataGeometryFilter.h>
>#include <vtkWarpScalar.h>
>#include <vtkMergeFilter.h>
>#include <vtkDataSetMapper.h>
>
>int main( int argc, char * argv[] )
>{
>
>   vtkTIFFReader *reader = vtkTIFFReader::New();
>   reader->SetFilePrefix("test.tif");
>   reader->SetFilePattern("%s");
>
>   vtkImageLuminance *luminance = vtkImageLuminance::New();
>   luminance->SetInput( reader->GetOutput() );
>
>   vtkImageDataGeometryFilter *geometry = vtkImageDataGeometryFilter::New();
>   geometry->SetInput( luminance->GetOutput() );
>
>   vtkWarpScalar *warp = vtkWarpScalar::New();
>   warp->SetInput( geometry->GetOutput() );
>   warp->SetScaleFactor( -0.1 );
>
>   vtkMergeFilter *merge = vtkMergeFilter::New();
>   merge->SetGeometry( warp->GetOutput() );
>   merge->SetScalars( reader->GetOutput() );
>
>   vtkDataSetMapper *mapper = vtkDataSetMapper::New();
>   mapper->SetInput( merge->GetOutput() );
>   mapper->SetScalarRange( 0, 255 );
>   mapper->ImmediateModeRenderingOff();
>
>   return 0;
>}
>
><end C++>
>
>
><begin compiler>
>
>[nicha at localhost Linux_x86]$ make
>Building dependencies cmake.check_depends...
>-- Loading VTK CMake commands
>-- Loading VTK CMake commands - done
>Building object file vtkimage.o...
>/home/nicha/vtkimage/vtkimage.cpp: In function `int main(int, char**)':
>/home/nicha/vtkimage/vtkimage.cpp:38: error: no matching function for call 
>to `
>    vtkWarpScalar::SetInput(vtkPolyData*)'
>/usr/local/include/vtk/vtkPointSetToPointSetFilter.h:57: error: candidates 
>are:
>    void vtkPointSetToPointSetFilter::SetInput(vtkPointSet*)
>/home/nicha/vtkimage/vtkimage.cpp:42: error: no matching function for call 
>to `
>    vtkMergeFilter::SetGeometry(vtkPointSet*)'
>/usr/local/include/vtk/vtkMergeFilter.h:41: error: candidates are: void
>    vtkMergeFilter::SetGeometry(vtkDataSet*)
>/home/nicha/vtkimage/vtkimage.cpp:43: error: no matching function for call 
>to `
>    vtkMergeFilter::SetScalars(vtkImageData*)'
>/usr/local/include/vtk/vtkMergeFilter.h:46: error: candidates are: void
>    vtkMergeFilter::SetScalars(vtkDataSet*)
>make[1]: *** [vtkimage.o] Error 1
>make: *** [default_target] Error 2
>
><end compiler>
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