message: BUG: Fixed missing #ifdef RTK_USE_CUDA
diff: @@ -157,7 +157,11 @@ MechlemOneStepSpectralReconstructionFilter< TOutputImage, TPhotonCounts, TSpectr
  fw = rtk::JosephForwardProjectionImageFilter<TSingleComponent, TSingleComponent>::New();
  break;
  case(MechlemOneStepSpectralReconstructionFilter::FP_CUDARAYCAST):
  +#ifdef RTK_USE_CUDA
  fw = rtk::CudaForwardProjectionImageFilter<TSingleComponent, TSingleComponent>::New();
  +#else
  + itkGenericExceptionMacro(<< "The program has not been compiled with cuda option");
  +#endif
  break;
  default:
  @@ -187,10 +191,14 @@ MechlemOneStepSpectralReconstructionFilter< TOutputImage, TPhotonCounts, TSpectr
  bp = rtk::JosephBackProjectionImageFilter<THessians, THessians>::New();
  break;
  case(MechlemOneStepSpectralReconstructionFilter::BP_CUDAVOXELBASED):
  +#ifdef RTK_USE_CUDA
  bp = rtk::CudaBackProjectionImageFilter<THessians>::New();
  +#else
  + itkGenericExceptionMacro(<< "The program has not been compiled with cuda option");
  +#endif
  break;
  case(MechlemOneStepSpectralReconstructionFilter::BP_CUDARAYCAST):
  - itkGenericExceptionMacro(<< "MechlemOneStep can currently not use CUDA projectors");
  + itkGenericExceptionMacro(<< "The CUDA ray cast back projector can currently not handle vector images");
  break;
  default:
  itkGenericExceptionMacro(<< "Unhandled --bp value.");
  