Merge topic 'keep-gdal-nodatavalue'

bf1cd7e2 Change iterator from postincrement to preincrement
5c97e44a Move variable declaration inside loop to limit its scope
5e1fc1bf Fix indentation and restore empty line
761a643e Add field data to vtkUniformGrid to save GDALDataset NoDataValue

Acked-by: Kitware Robot <kwrobot@kitware.com>
Merge-request: !344

IO/GDAL/vtkGDALRasterReader.cxx

@@ -24,6 +24,7 @@
 #include <vtkInformationVector.h>
 #include <vtkInformation.h>
 #include <vtkIntArray.h>
+#include <vtkMath.h>
 #include <vtkObjectFactory.h>
 #include <vtkPointData.h>
 #include <vtkPoints.h>
@@ -746,6 +747,28 @@ int vtkGDALRasterReader::RequestData(vtkInformation* vtkNotUsed(request),
   this->Implementation->UniformGridData->GetFieldData()->AddArray(
     projectionData);
 
+  // Add NoDataValue as field data
+  // GDALDatset can have 1 value for each raster band
+  // Use NaN for undefined values
+  vtkSmartPointer<vtkDoubleArray> noDataArray =
+    vtkSmartPointer<vtkDoubleArray>::New();
+  noDataArray->SetName("NO_DATA_VALUE");
+  noDataArray->SetNumberOfComponents(1);
+  noDataArray->SetNumberOfTuples(this->Implementation->NumberOfBands);
+  for (int i=0; i<this->Implementation->NumberOfBands; ++i)
+    {
+    int success = 0;
+    double noDataValue = this->Implementation->GDALData->GetRasterBand(
+      i+1)->GetNoDataValue(&success);
+    if (!success)
+      {
+      noDataValue = vtkMath::Nan();
+      }
+     noDataArray->SetValue(i, noDataValue);
+    }
+  this->Implementation->UniformGridData->GetFieldData()->AddArray(
+    noDataArray);
+
   // Check if file has been changed here.
   // If changed then throw the vtxId time and load a new one.
   vtkInformation* outInfo = outputVector->GetInformationObject(0);