exec/CellLocatorUniformGrid.h

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//============================================================================
//  The contents of this file are covered by the Viskores license. See
//  LICENSE.txt for details.
//
//  By contributing to this file, all contributors agree to the Developer
//  Certificate of Origin Version 1.1 (DCO 1.1) as stated in DCO.txt.
//============================================================================
 
//============================================================================
//  Copyright (c) Kitware, Inc.
//  All rights reserved.
//  See LICENSE.txt for details.
//
//  This software is distributed WITHOUT ANY WARRANTY; without even
//  the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
//  PURPOSE.  See the above copyright notice for more information.
//============================================================================
#ifndef viskores_exec_celllocatoruniformgrid_h
#define viskores_exec_celllocatoruniformgrid_h
 
#include <viskores/Bounds.h>
#include <viskores/Math.h>
#include <viskores/TopologyElementTag.h>
#include <viskores/Types.h>
#include <viskores/VecFromPortalPermute.h>
 
#include <viskores/cont/CellSetStructured.h>
 
#include <viskores/exec/CellInside.h>
#include <viskores/exec/ParametricCoordinates.h>
 
namespace viskores
{
 
namespace exec
{
 
class VISKORES_ALWAYS_EXPORT CellLocatorUniformGrid
{
public:
  VISKORES_CONT
  CellLocatorUniformGrid(const viskores::Id3 cellDims,
                         const viskores::Vec3f origin,
                         const viskores::Vec3f invSpacing,
                         const viskores::Vec3f maxPoint)
    : CellDims(cellDims)
    , MaxCellIds(viskores::Max(cellDims - viskores::Id3(1), viskores::Id3(0)))
    , Origin(origin)
    , InvSpacing(invSpacing)
    , MaxPoint(maxPoint)
  {
  }
 
  VISKORES_EXEC inline bool IsInside(const viskores::Vec3f& point) const
  {
    bool inside = true;
    if (point[0] < this->Origin[0] || point[0] > this->MaxPoint[0])
      inside = false;
    if (point[1] < this->Origin[1] || point[1] > this->MaxPoint[1])
      inside = false;
    if (point[2] < this->Origin[2] || point[2] > this->MaxPoint[2])
      inside = false;
    return inside;
  }
 
  struct LastCell
  {
  };
 
  VISKORES_EXEC viskores::ErrorCode FindCell(const viskores::Vec3f& point,
                                             viskores::Id& cellId,
                                             viskores::Vec3f& parametric,
                                             LastCell& lastCell) const
  {
    (void)lastCell;
    return this->FindCell(point, cellId, parametric);
  }
 
  VISKORES_EXEC viskores::ErrorCode FindCell(const viskores::Vec3f& point,
                                             viskores::Id& cellId,
                                             viskores::Vec3f& parametric) const
  {
    if (!this->IsInside(point))
    {
      cellId = -1;
      return viskores::ErrorCode::CellNotFound;
    }
    // Get the Cell Id from the point.
    viskores::Id3 logicalCell(0, 0, 0);
 
    viskores::Vec3f temp;
    temp = point - this->Origin;
    temp = temp * this->InvSpacing;
 
    //make sure that if we border the upper edge, we sample the correct cell
    logicalCell = viskores::Min(viskores::Id3(temp), this->MaxCellIds);
 
    cellId =
      (logicalCell[2] * this->CellDims[1] + logicalCell[1]) * this->CellDims[0] + logicalCell[0];
    parametric = temp - logicalCell;
 
    return viskores::ErrorCode::Success;
  }
 
private:
  viskores::Id3 CellDims;
  viskores::Id3 MaxCellIds;
  viskores::Vec3f Origin;
  viskores::Vec3f InvSpacing;
  viskores::Vec3f MaxPoint;
};
}
}
 
#endif //viskores_exec_celllocatoruniformgrid_h