vtk-m/vtkm/exec/Jacobian.h
2017-05-25 07:51:37 -04:00

326 lines
15 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 Sandia Corporation.
// Copyright 2015 UT-Battelle, LLC.
// Copyright 2015 Los Alamos National Security.
//
// Under the terms of Contract DE-AC04-94AL85000 with Sandia Corporation,
// 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
{
typedef vtkm::Vec<T, 3> Vec3;
typedef vtkm::Vec<T, 2> Vec2;
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;
}
};
// Given a series of point values for a wedge, return a new series of point
// for a hexahedron that has the same interpolation within the wedge.
template <typename FieldVecType>
VTKM_EXEC vtkm::Vec<typename FieldVecType::ComponentType, 8> PermuteWedgeToHex(
const FieldVecType& field)
{
vtkm::Vec<typename FieldVecType::ComponentType, 8> hexField;
hexField[0] = field[0];
hexField[1] = field[2];
hexField[2] = field[2] + field[1] - field[0];
hexField[3] = field[1];
hexField[4] = field[3];
hexField[5] = field[5];
hexField[6] = field[5] + field[4] - field[3];
hexField[7] = field[4];
return hexField;
}
// Given a series of point values for a pyramid, return a new series of point
// for a hexahedron that has the same interpolation within the pyramid.
template <typename FieldVecType>
VTKM_EXEC vtkm::Vec<typename FieldVecType::ComponentType, 8> PermutePyramidToHex(
const FieldVecType& field)
{
typedef typename FieldVecType::ComponentType T;
vtkm::Vec<T, 8> hexField;
T baseCenter = T(0.25f) * (field[0] + field[1] + field[2] + field[3]);
hexField[0] = field[0];
hexField[1] = field[1];
hexField[2] = field[2];
hexField[3] = field[3];
hexField[4] = field[4] + (field[0] - baseCenter);
hexField[5] = field[4] + (field[1] - baseCenter);
hexField[6] = field[4] + (field[2] - baseCenter);
hexField[7] = field[4] + (field[3] - baseCenter);
return hexField;
}
} //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_VOXEL(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], rc[0] * rc[2], -rc[0] * pc[1]); \
call(3, pc[1] * rc[2], pc[0] * rc[2], -pc[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], rc[0] * pc[2], rc[0] * pc[1]); \
call(7, pc[1] * pc[2], pc[0] * pc[2], pc[0] * pc[1])
#define VTKM_DERIVATIVE_WEIGHTS_WEDGE(pc, rc, call) \
call(0, -rc[2], -rc[2], -1.0f + pc[0] + pc[1]); \
call(1, 0.0f, rc[2], -pc[1]); \
call(2, rc[2], 0.0f, -pc[0]); \
call(3, -pc[2], -pc[2], 1.0f - pc[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(3, 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])
#define VTKM_DERIVATIVE_WEIGHTS_PIXEL(pc, rc, call) \
call(0, -rc[1], -rc[0]); \
call(1, rc[1], -pc[0]); \
call(2, -pc[1], rc[0]); \
call(3, pc[1], pc[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)
{
#if 0
// This is not working. Just leverage the hexahedron code that is working.
vtkm::Vec<JacobianType,3> pc(pcoords);
vtkm::Vec<JacobianType,3> rc = vtkm::Vec<JacobianType,3>(1) - pc;
jacobian = vtkm::Matrix<JacobianType,3,3>(0);
VTKM_DERIVATIVE_WEIGHTS_WEDGE(pc, rc, VTKM_ACCUM_JACOBIAN_3D);
#else
JacobianFor3DCell(internal::PermuteWedgeToHex(wCoords), pcoords, jacobian,
vtkm::CellShapeTagHexahedron());
#endif
}
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)
{
#if 0
// This is not working. Just leverage the hexahedron code that is working.
vtkm::Vec<JacobianType,3> pc(pcoords);
vtkm::Vec<JacobianType,3> rc = vtkm::Vec<JacobianType,3>(1) - pc;
jacobian = vtkm::Matrix<JacobianType,3,3>(0);
VTKM_DERIVATIVE_WEIGHTS_PYRAMID(pc, rc, VTKM_ACCUM_JACOBIAN_3D);
#else
JacobianFor3DCell(internal::PermutePyramidToHex(wCoords), pcoords, jacobian,
vtkm::CellShapeTagHexahedron());
#endif
}
// 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
#undef VTKM_DERIVATIVE_WEIGHTS_HEXAHEDRON
#undef VTKM_DERIVATIVE_WEIGHTS_VOXEL
#undef VTKM_DERIVATIVE_WEIGHTS_WEDGE
#undef VTKM_DERIVATIVE_WEIGHTS_PYRAMID
#undef VTKM_DERIVATIVE_WEIGHTS_QUAD
#undef VTKM_DERIVATIVE_WEIGHTS_PIXEL
}
} // namespace vtkm::exec
#endif //vtk_m_exec_Jacobian_h