vtk-m/vtkm/exec/Jacobian.h
Kenneth Moreland 43da67f747 Fix Jacobian cases for wedge and pyramid
When the implementation for the cell derivative functions was made, the
special cases for creating the Jacobian for wedge and pyramid cell
shapes was not working. Instead, it just used the hexahedra case for a
degenerate cell. This fixes the issues with the special cases.

There were multiple issues to be fixed. There were some complaints
by the compiler about types. There was a mistake in the pyramid table.
But the biggest issue was a problem with macro expansions. It was
the classic tale of forgetting that you have to encase parameters
in parenthesis to make sure that operator precedence comes out as
expected.
2018-01-31 15:45:12 -07:00

250 lines
11 KiB
C++

//============================================================================
// 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.
//
// Copyright 2015 National Technology & Engineering Solutions of Sandia, LLC (NTESS).
// Copyright 2015 UT-Battelle, LLC.
// Copyright 2015 Los Alamos National Security.
//
// Under the terms of Contract DE-NA0003525 with NTESS,
// the U.S. Government retains certain rights in this software.
//
// Under the terms of Contract DE-AC52-06NA25396 with Los Alamos National
// Laboratory (LANL), the U.S. Government retains certain rights in
// this software.
//============================================================================
#ifndef vtk_m_exec_Jacobian_h
#define vtk_m_exec_Jacobian_h
#include <vtkm/Assert.h>
#include <vtkm/CellShape.h>
#include <vtkm/Math.h>
#include <vtkm/Matrix.h>
#include <vtkm/VectorAnalysis.h>
namespace vtkm
{
namespace exec
{
namespace internal
{
template <typename T>
struct Space2D
{
using Vec3 = vtkm::Vec<T, 3>;
using Vec2 = vtkm::Vec<T, 2>;
Vec3 Origin;
Vec3 Basis0;
Vec3 Basis1;
VTKM_EXEC
Space2D(const Vec3& origin, const Vec3& pointFirst, const Vec3& pointLast)
{
this->Origin = origin;
this->Basis0 = vtkm::Normal(pointFirst - this->Origin);
Vec3 n = vtkm::Cross(this->Basis0, pointLast - this->Origin);
this->Basis1 = vtkm::Normal(vtkm::Cross(this->Basis0, n));
}
VTKM_EXEC
Vec2 ConvertCoordToSpace(const Vec3 coord) const
{
Vec3 vec = coord - this->Origin;
return Vec2(vtkm::dot(vec, this->Basis0), vtkm::dot(vec, this->Basis1));
}
template <typename U>
VTKM_EXEC vtkm::Vec<U, 3> ConvertVecFromSpace(const vtkm::Vec<U, 2> vec) const
{
return vec[0] * this->Basis0 + vec[1] * this->Basis1;
}
};
} //namespace internal
#define VTKM_DERIVATIVE_WEIGHTS_HEXAHEDRON(pc, rc, call) \
call(0, (-rc[1] * rc[2]), (-rc[0] * rc[2]), (-rc[0] * rc[1])); \
call(1, (rc[1] * rc[2]), (-pc[0] * rc[2]), (-pc[0] * rc[1])); \
call(2, (pc[1] * rc[2]), (pc[0] * rc[2]), (-pc[0] * pc[1])); \
call(3, (-pc[1] * rc[2]), (rc[0] * rc[2]), (-rc[0] * pc[1])); \
call(4, (-rc[1] * pc[2]), (-rc[0] * pc[2]), (rc[0] * rc[1])); \
call(5, (rc[1] * pc[2]), (-pc[0] * pc[2]), (pc[0] * rc[1])); \
call(6, (pc[1] * pc[2]), (pc[0] * pc[2]), (pc[0] * pc[1])); \
call(7, (-pc[1] * pc[2]), (rc[0] * pc[2]), (rc[0] * pc[1]))
#define VTKM_DERIVATIVE_WEIGHTS_WEDGE(pc, rc, call) \
call(0, (-rc[2]), (-rc[2]), (pc[0] - rc[1])); \
call(1, (0.0f), (rc[2]), (-pc[1])); \
call(2, (rc[2]), (0.0f), (-pc[0])); \
call(3, (-pc[2]), (-pc[2]), (rc[0] - pc[1])); \
call(4, (0.0f), (pc[2]), (pc[1])); \
call(5, (pc[2]), (0.0f), (pc[0]))
#define VTKM_DERIVATIVE_WEIGHTS_PYRAMID(pc, rc, call) \
call(0, (-rc[1] * rc[2]), (-rc[0] * rc[2]), (-rc[0] * rc[1])); \
call(1, (rc[1] * rc[2]), (-pc[0] * rc[2]), (-pc[0] * rc[1])); \
call(2, (pc[1] * rc[2]), (pc[0] * rc[2]), (-pc[0] * pc[1])); \
call(3, (-pc[1] * rc[2]), (rc[0] * rc[2]), (-rc[0] * pc[1])); \
call(4, (0.0f), (0.0f), (1.0f))
#define VTKM_DERIVATIVE_WEIGHTS_QUAD(pc, rc, call) \
call(0, (-rc[1]), (-rc[0])); \
call(1, (rc[1]), (-pc[0])); \
call(2, (pc[1]), (pc[0])); \
call(3, (-pc[1]), (rc[0]))
//-----------------------------------------------------------------------------
// This returns the Jacobian of a hexahedron's (or other 3D cell's) coordinates
// with respect to parametric coordinates. Explicitly, this is (d is partial
// derivative):
//
// | |
// | dx/du dx/dv dx/dw |
// | |
// | dy/du dy/dv dy/dw |
// | |
// | dz/du dz/dv dz/dw |
// | |
//
#define VTKM_ACCUM_JACOBIAN_3D(pointIndex, weight0, weight1, weight2) \
jacobian(0, 0) += static_cast<JacobianType>(wCoords[pointIndex][0] * (weight0)); \
jacobian(1, 0) += static_cast<JacobianType>(wCoords[pointIndex][1] * (weight0)); \
jacobian(2, 0) += static_cast<JacobianType>(wCoords[pointIndex][2] * (weight0)); \
jacobian(0, 1) += static_cast<JacobianType>(wCoords[pointIndex][0] * (weight1)); \
jacobian(1, 1) += static_cast<JacobianType>(wCoords[pointIndex][1] * (weight1)); \
jacobian(2, 1) += static_cast<JacobianType>(wCoords[pointIndex][2] * (weight1)); \
jacobian(0, 2) += static_cast<JacobianType>(wCoords[pointIndex][0] * (weight2)); \
jacobian(1, 2) += static_cast<JacobianType>(wCoords[pointIndex][1] * (weight2)); \
jacobian(2, 2) += static_cast<JacobianType>(wCoords[pointIndex][2] * (weight2))
template <typename WorldCoordType, typename ParametricCoordType, typename JacobianType>
VTKM_EXEC void JacobianFor3DCell(const WorldCoordType& wCoords,
const vtkm::Vec<ParametricCoordType, 3>& pcoords,
vtkm::Matrix<JacobianType, 3, 3>& jacobian,
vtkm::CellShapeTagHexahedron)
{
vtkm::Vec<JacobianType, 3> pc(pcoords);
vtkm::Vec<JacobianType, 3> rc = vtkm::Vec<JacobianType, 3>(JacobianType(1)) - pc;
jacobian = vtkm::Matrix<JacobianType, 3, 3>(JacobianType(0));
VTKM_DERIVATIVE_WEIGHTS_HEXAHEDRON(pc, rc, VTKM_ACCUM_JACOBIAN_3D);
}
template <typename WorldCoordType, typename ParametricCoordType, typename JacobianType>
VTKM_EXEC void JacobianFor3DCell(const WorldCoordType& wCoords,
const vtkm::Vec<ParametricCoordType, 3>& pcoords,
vtkm::Matrix<JacobianType, 3, 3>& jacobian,
vtkm::CellShapeTagWedge)
{
vtkm::Vec<JacobianType, 3> pc(pcoords);
vtkm::Vec<JacobianType, 3> rc = vtkm::Vec<JacobianType, 3>(JacobianType(1)) - pc;
jacobian = vtkm::Matrix<JacobianType, 3, 3>(JacobianType(0));
VTKM_DERIVATIVE_WEIGHTS_WEDGE(pc, rc, VTKM_ACCUM_JACOBIAN_3D);
}
template <typename WorldCoordType, typename ParametricCoordType, typename JacobianType>
VTKM_EXEC void JacobianFor3DCell(const WorldCoordType& wCoords,
const vtkm::Vec<ParametricCoordType, 3>& pcoords,
vtkm::Matrix<JacobianType, 3, 3>& jacobian,
vtkm::CellShapeTagPyramid)
{
vtkm::Vec<JacobianType, 3> pc(pcoords);
vtkm::Vec<JacobianType, 3> rc = vtkm::Vec<JacobianType, 3>(JacobianType(1)) - pc;
jacobian = vtkm::Matrix<JacobianType, 3, 3>(JacobianType(0));
VTKM_DERIVATIVE_WEIGHTS_PYRAMID(pc, rc, VTKM_ACCUM_JACOBIAN_3D);
}
// Derivatives in quadrilaterals are computed in much the same way as
// hexahedra. Review the documentation for hexahedra derivatives for details
// on the math. The major difference is that the equations are performed in
// a 2D space built with make_SpaceForQuadrilateral.
#define VTKM_ACCUM_JACOBIAN_2D(pointIndex, weight0, weight1) \
wcoords2d = space.ConvertCoordToSpace(wCoords[pointIndex]); \
jacobian(0, 0) += wcoords2d[0] * (weight0); \
jacobian(1, 0) += wcoords2d[1] * (weight0); \
jacobian(0, 1) += wcoords2d[0] * (weight1); \
jacobian(1, 1) += wcoords2d[1] * (weight1)
template <typename WorldCoordType,
typename ParametricCoordType,
typename SpaceType,
typename JacobianType>
VTKM_EXEC void JacobianFor2DCell(const WorldCoordType& wCoords,
const vtkm::Vec<ParametricCoordType, 3>& pcoords,
const vtkm::exec::internal::Space2D<SpaceType>& space,
vtkm::Matrix<JacobianType, 2, 2>& jacobian,
vtkm::CellShapeTagQuad)
{
vtkm::Vec<JacobianType, 2> pc(static_cast<JacobianType>(pcoords[0]),
static_cast<JacobianType>(pcoords[1]));
vtkm::Vec<JacobianType, 2> rc = vtkm::Vec<JacobianType, 2>(JacobianType(1)) - pc;
vtkm::Vec<SpaceType, 2> wcoords2d;
jacobian = vtkm::Matrix<JacobianType, 2, 2>(JacobianType(0));
VTKM_DERIVATIVE_WEIGHTS_QUAD(pc, rc, VTKM_ACCUM_JACOBIAN_2D);
}
#if 0
// This code doesn't work, so I'm bailing on it. Instead, I'm just grabbing a
// triangle and finding the derivative of that. If you can do better, please
// implement it.
template<typename WorldCoordType,
typename ParametricCoordType,
typename JacobianType>
VTKM_EXEC
void JacobianFor2DCell(const WorldCoordType &wCoords,
const vtkm::Vec<ParametricCoordType,3> &pcoords,
const vtkm::exec::internal::Space2D<JacobianType> &space,
vtkm::Matrix<JacobianType,2,2> &jacobian,
vtkm::CellShapeTagPolygon)
{
const vtkm::IdComponent numPoints = wCoords.GetNumberOfComponents();
vtkm::Vec<JacobianType,2> pc(pcoords[0], pcoords[1]);
JacobianType deltaAngle = static_cast<JacobianType>(2*vtkm::Pi()/numPoints);
jacobian = vtkm::Matrix<JacobianType,2,2>(0);
for (vtkm::IdComponent pointIndex = 0; pointIndex < numPoints; pointIndex++)
{
JacobianType angle = pointIndex*deltaAngle;
vtkm::Vec<JacobianType,2> nodePCoords(0.5f*(vtkm::Cos(angle)+1),
0.5f*(vtkm::Sin(angle)+1));
// This is the vector pointing from the user provided parametric coordinate
// to the node at pointIndex in parametric space.
vtkm::Vec<JacobianType,2> pvec = nodePCoords - pc;
// The weight (the derivative of the interpolation factor) happens to be
// pvec scaled by the cube root of pvec's magnitude.
JacobianType magSqr = vtkm::MagnitudeSquared(pvec);
JacobianType invMag = vtkm::RSqrt(magSqr);
JacobianType scale = invMag*invMag*invMag;
vtkm::Vec<JacobianType,2> weight = scale*pvec;
vtkm::Vec<JacobianType,2> wcoords2d =
space.ConvertCoordToSpace(wCoords[pointIndex]);
jacobian(0,0) += wcoords2d[0] * weight[0];
jacobian(1,0) += wcoords2d[1] * weight[0];
jacobian(0,1) += wcoords2d[0] * weight[1];
jacobian(1,1) += wcoords2d[1] * weight[1];
}
}
#endif
#undef VTKM_ACCUM_JACOBIAN_3D
#undef VTKM_ACCUM_JACOBIAN_2D
}
} // namespace vtkm::exec
#endif //vtk_m_exec_Jacobian_h