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Doc improvements

This commit is contained in:
Mael Rouxel-Labbé 2024-02-24 23:11:58 +01:00
parent 4ca692378b
commit 225fe9f89d
20 changed files with 67 additions and 67 deletions
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2
Isosurfacing_3/benchmark/Isosurfacing_3/contouring_seq_vs_parallel_image.cpp
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@ -57,7 +57,7 @@ int main(int argc, char** argv)
for (std::size_t k=0; k<grid.zdim(); ++k)
values(i, j, k) = - values(i, j, k); // inside out
std::cout << "Bbox: " << grid.bbox() << std::endl;
std::cout << "Span: " << grid.span() << std::endl;
std::cout << "Cell dimensions: " << grid.spacing()[0] << " " << grid.spacing()[1] << " " << grid.spacing()[2] << std::endl;
std::cout << "Cell #: " << grid.xdim() << ", " << grid.ydim() << ", " << grid.zdim() << std::endl;

2
Isosurfacing_3/benchmark/Isosurfacing_3/contouring_seq_vs_parallel_implicit.cpp
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@ -48,7 +48,7 @@ int main(int argc, char** argv)
const CGAL::Bbox_3 bbox = {-2., -2., -2., 2., 2., 2.};
Grid grid { bbox, CGAL::make_array<std::size_t>(150, 150, 150) };
std::cout << "Bbox: " << grid.bbox() << std::endl;
std::cout << "Span: " << grid.span() << std::endl;
std::cout << "Cell dimensions: " << grid.spacing()[0] << " " << grid.spacing()[1] << " " << grid.spacing()[2] << std::endl;
std::cout << "Cell #: " << grid.xdim() << ", " << grid.ydim() << ", " << grid.zdim() << std::endl;

4
Isosurfacing_3/doc/Isosurfacing_3/Concepts/GradientField_3.h
View File

@ -6,8 +6,8 @@
The concept `GradientField_3` describes the set of requirements to be fulfilled
by the gradient field template parameter of the domain class `CGAL::Isosurfacing::Dual_contouring_domain_3`.
Gradient fields must be continuous and defined over the bounding box of whatever
space partitioning data structure (also known as "partition") is being used.
Gradient fields must be continuous and defined over the geometric span of the
space partitioning data structure (also known as "partition") being used.
\cgalHasModelsBegin
\cgalHasModels{CGAL::Isosurfacing::Gradient_function_3}

4
Isosurfacing_3/doc/Isosurfacing_3/Concepts/ValueField_3.h
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@ -6,8 +6,8 @@
The concept `ValueField_3` describes the set of requirements to be fulfilled
by the value field template parameter of the domain classes `CGAL::Isosurfacing::Marching_cubes_domain_3` and `CGAL::Isosurfacing::Dual_contouring_domain_3`.
Value fields must be continuous and defined over the bounding box of whatever
space partitioning data structure (also known as "partition") is being used.
Value fields must be continuous and defined over the geometric span of the
space partitioning data structure (also known as "partition") being used.
\cgalHasModelsBegin
\cgalHasModels{CGAL::Isosurfacing::Value_function_3}

2
Isosurfacing_3/examples/Isosurfacing_3/contouring_discrete_data.cpp
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@ -110,7 +110,7 @@ int main(int argc, char** argv)
const CGAL::Bbox_3 bbox { -1., -1., -1., 1., 1., 1. };
Grid grid { bbox, CGAL::make_array<std::size_t>(30, 30, 30) };
std::cout << "Bbox: " << grid.bbox() << std::endl;
std::cout << "Span: " << grid.span() << std::endl;
std::cout << "Cell dimensions: " << grid.spacing()[0] << " " << grid.spacing()[1] << " " << grid.spacing()[2] << std::endl;
std::cout << "Cell #: " << grid.xdim() << ", " << grid.ydim() << ", " << grid.zdim() << std::endl;

2
Isosurfacing_3/examples/Isosurfacing_3/contouring_image.cpp
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@ -103,7 +103,7 @@ int main(int argc, char* argv[])
return EXIT_FAILURE;
}
std::cout << "Bbox: " << grid.bbox() << std::endl;
std::cout << "Span: " << grid.span() << std::endl;
std::cout << "Cell dimensions: " << grid.spacing()[0] << " " << grid.spacing()[1] << " " << grid.spacing()[2] << std::endl;
std::cout << "Cell #: " << grid.xdim() << ", " << grid.ydim() << ", " << grid.zdim() << std::endl;

2
Isosurfacing_3/examples/Isosurfacing_3/contouring_implicit_data.cpp
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@ -106,7 +106,7 @@ int main(int argc, char** argv)
const std::array<FT, 3> spacing { step, step, step };
const Grid grid { bbox, spacing };
std::cout << "Bbox: " << grid.bbox() << std::endl;
std::cout << "Span: " << grid.span() << std::endl;
std::cout << "Cell dimensions: " << grid.spacing()[0] << " " << grid.spacing()[1] << " " << grid.spacing()[2] << std::endl;
std::cout << "Cell #: " << grid.xdim() << ", " << grid.ydim() << ", " << grid.zdim() << std::endl;

2
Isosurfacing_3/examples/Isosurfacing_3/contouring_mesh_offset.cpp
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@ -161,7 +161,7 @@ int main(int argc, char** argv)
bbox = CGAL::Bbox_3{ -5, -5, -5, 15, 15, 15 };
Grid grid { bbox, CGAL::make_array<std::size_t>(nv, nv, nv) };
std::cout << "Bbox: " << grid.bbox() << std::endl;
std::cout << "Span: " << grid.span() << std::endl;
std::cout << "Cell dimensions: " << grid.spacing()[0] << " " << grid.spacing()[1] << " " << grid.spacing()[2] << std::endl;
std::cout << "Cell #: " << grid.xdim() << ", " << grid.ydim() << ", " << grid.zdim() << std::endl;

2
Isosurfacing_3/examples/Isosurfacing_3/dual_contouring.cpp
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@ -31,7 +31,7 @@ int main(int argc, char** argv)
const CGAL::Bbox_3 bbox { -1., -1., -1., 1., 1., 1. };
Grid grid { bbox, CGAL::make_array<std::size_t>(30, 30, 30) };
std::cout << "Bbox: " << grid.bbox() << std::endl;
std::cout << "Span: " << grid.span() << std::endl;
std::cout << "Cell dimensions: " << grid.spacing()[0] << " " << grid.spacing()[1] << " " << grid.spacing()[2] << std::endl;
std::cout << "Cell #: " << grid.xdim() << ", " << grid.ydim() << ", " << grid.zdim() << std::endl;

2
Isosurfacing_3/examples/Isosurfacing_3/dual_contouring_intersection_oracles.cpp
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@ -49,7 +49,7 @@ int main(int argc, char** argv)
const CGAL::Bbox_3 bbox = {-2., -2., -2., 2., 2., 2.};
Grid grid { bbox, CGAL::make_array<std::size_t>(50, 50, 50) };
std::cout << "Bbox: " << grid.bbox() << std::endl;
std::cout << "Span: " << grid.span() << std::endl;
std::cout << "Cell dimensions: " << grid.spacing()[0] << " " << grid.spacing()[1] << " " << grid.spacing()[2] << std::endl;
std::cout << "Cell #: " << grid.xdim() << ", " << grid.ydim() << ", " << grid.zdim() << std::endl;

2
Isosurfacing_3/examples/Isosurfacing_3/dual_contouring_strategies.cpp
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@ -47,7 +47,7 @@ int main(int argc, char** argv)
const CGAL::Bbox_3 bbox = {-2., -2., -2., 2., 2., 2.};
Grid grid { bbox, CGAL::make_array<std::size_t>(50, 50, 50) };
std::cout << "Bbox: " << grid.bbox() << std::endl;
std::cout << "Span: " << grid.span() << std::endl;
std::cout << "Cell dimensions: " << grid.spacing()[0] << " " << grid.spacing()[1] << " " << grid.spacing()[2] << std::endl;
std::cout << "Cell #: " << grid.xdim() << ", " << grid.ydim() << ", " << grid.zdim() << std::endl;

2
Isosurfacing_3/examples/Isosurfacing_3/marching_cubes.cpp
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@ -29,7 +29,7 @@ int main(int argc, char** argv)
const CGAL::Bbox_3 bbox { -1., -1., -1., 1., 1., 1. };
Grid grid { bbox, CGAL::make_array<std::size_t>(30, 30, 30) };
std::cout << "Bbox: " << grid.bbox() << std::endl;
std::cout << "Span: " << grid.span() << std::endl;
std::cout << "Cell dimensions: " << grid.spacing()[0] << " " << grid.spacing()[1] << " " << grid.spacing()[2] << std::endl;
std::cout << "Cell #: " << grid.xdim() << ", " << grid.ydim() << ", " << grid.zdim() << std::endl;

2
Isosurfacing_3/examples/Isosurfacing_3/marching_cubes_strategies.cpp
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@ -30,7 +30,7 @@ int main(int argc, char** argv)
const CGAL::Bbox_3 bbox { -1., -1., -1., 1., 1., 1. };
Grid grid { bbox, CGAL::make_array<std::size_t>(30, 30, 30) };
std::cout << "Bbox: " << grid.bbox() << std::endl;
std::cout << "Span: " << grid.span() << std::endl;
std::cout << "Cell dimensions: " << grid.spacing()[0] << " " << grid.spacing()[1] << " " << grid.spacing()[2] << std::endl;
std::cout << "Cell #: " << grid.xdim() << ", " << grid.ydim() << ", " << grid.zdim() << std::endl;

66
Isosurfacing_3/include/CGAL/Isosurfacing_3/Cartesian_grid_3.h
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@ -19,7 +19,6 @@
#include <CGAL/Isosurfacing_3/IO/OBJ.h>
#include <CGAL/assertions.h>
#include <CGAL/Bbox_3.h>
#include <CGAL/boost/graph/named_params_helper.h>
#include <CGAL/Named_function_parameters.h>
@ -83,7 +82,7 @@ public:
using Iso_cuboid_3 = typename Geom_traits::Iso_cuboid_3;
private:
Iso_cuboid_3 m_bbox;
Iso_cuboid_3 m_span;
std::array<std::size_t, 3> m_sizes;
Vector_3 m_spacing;
@ -99,8 +98,8 @@ private:
auto vertex = m_gt.construct_vertex_3_object();
// calculate grid spacing
const Point_3& min_p = vertex(m_bbox, 0);
const Point_3& max_p = vertex(m_bbox, 7);
const Point_3& min_p = vertex(m_span, 0);
const Point_3& max_p = vertex(m_span, 7);
const FT x_span = x_coord(max_p) - x_coord(min_p);
const FT y_span = y_coord(max_p) - y_coord(min_p);
const FT z_span = z_coord(max_p) - z_coord(min_p);
@ -117,7 +116,7 @@ public:
* \brief Default constructor
*/
Cartesian_grid_3()
: m_bbox{Point_3{0, 0, 0}, Point_3{0, 0, 0}},
: m_span{Point_3{0, 0, 0}, Point_3{0, 0, 0}},
m_sizes{2, 2, 2},
m_spacing{0, 0, 0},
m_gt{Geom_traits()}
@ -126,18 +125,18 @@ public:
/**
* \brief creates a %Cartesian grid with `xdim * ydim * zdim` grid vertices.
*
* The grid covers the space described by a bounding box.
* The grid covers the space described by an iso-cuboid.
*
* \param bbox the bounding box of the grid
* \param span the geometric span of the grid
* \param dimensions the number of grid vertices in the `x`, `y`, and `z` directions
* \param gt the geometric traits
*
* \pre all dimensions are (strictly) positive.
*/
Cartesian_grid_3(const Iso_cuboid_3& bbox,
Cartesian_grid_3(const Iso_cuboid_3& span,
const std::array<std::size_t, 3>& dimensions,
const Geom_traits& gt = Geom_traits())
: m_bbox{bbox},
: m_span{span},
m_sizes{dimensions},
m_gt{gt}
{
@ -147,10 +146,11 @@ public:
/**
* \brief creates a %Cartesian grid with `xdim * ydim * zdim` grid vertices.
*
* The grid covers the space described by a bounding box, itself described through two diagonal corners.
* The grid covers the space described by an iso-cuboid,
* itself described through two diagonal corners.
*
* \param p the lowest corner of the bounding box of the grid
* \param q the upper corner of the bounding box of the grid
* \param p the lexicographically smallest corner of the iso-cuboid
* \param q the lexicographically largest corner of the iso-cuboid
* \param dimensions the number of grid vertices in the `x`, `y`, and `z` directions
* \param gt the geometric traits
*
@ -166,18 +166,18 @@ public:
/**
* \brief creates a %Cartesian grid using a prescribed grid step.
*
* The grid covers the space described by a bounding box.
* The grid covers the space described by an iso-cuboid.
*
* \param bbox the bounding box of the grid
* \param spacing the dimension of the paving cell, in the `x`, `y`, and `z` directions, respectively.
* \param span the geometric span of the grid
* \param spacing the dimension of the paving cell, in the `x`, `y`, and `z` directions
* \param gt the geometric traits
*
* \pre the diagonal of `bbox` has length a multiple of `spacing`
* \pre the diagonal of `span` has length a multiple of `spacing`
*/
Cartesian_grid_3(const Iso_cuboid_3& bbox,
Cartesian_grid_3(const Iso_cuboid_3& span,
const Vector_3& spacing,
const Geom_traits& gt = Geom_traits())
: m_bbox{bbox},
: m_span{span},
m_spacing{spacing},
m_gt{gt}
{
@ -186,8 +186,8 @@ public:
auto z_coord = gt.compute_z_3_object();
auto vertex = gt.construct_vertex_3_object();
const Point_3& min_p = vertex(bbox, 0);
const Point_3& max_p = vertex(bbox, 7);
const Point_3& min_p = vertex(span, 0);
const Point_3& max_p = vertex(span, 7);
const FT x_span = x_coord(max_p) - x_coord(min_p);
const FT y_span = y_coord(max_p) - y_coord(min_p);
const FT z_span = z_coord(max_p) - z_coord(min_p);
@ -200,15 +200,15 @@ public:
/**
* \brief creates a %Cartesian grid using a prescribed grid step.
*
* The grid covers the space described by a bounding box, itself described through two diagonal corners.
* The grid covers the space described by an iso-cuboid, itself described through two diagonal corners.
*
* \param p the lowest corner of the bounding box of the grid
* \param q the upper corner of the bounding box of the grid
* \param p the lexicographically smallest corner of the iso-cuboid
* \param q the lexicographically largest corner of the iso-cuboid
* \param spacing the dimension of the paving cell, in the `x`, `y`, and `z` directions, respectively.
* \param gt the geometric traits
*
* \pre `p` is lexicographically (strictly) smaller than `q`
* \pre the diagonal of the bounding box has length a multiple of `spacing`
* \pre the diagonal of the iso-cuboid has length a multiple of `spacing`
*/
Cartesian_grid_3(const Point_3& p, const Point_3& q,
const Vector_3& spacing,
@ -226,16 +226,16 @@ public:
}
/**
* returns the bounding box of the %Cartesian grid
* returns an iso-cuboid representing the geometric span of the %Cartesian grid
*/
const Iso_cuboid_3& bbox() const { return m_bbox; }
const Iso_cuboid_3& span() const { return m_span; }
/**
* sets the bounding box of the %Cartesian grid and recomputes the spacing.
* sets the geometric span of the %Cartesian grid and recomputes the spacing.
*/
void set_bbox(const Iso_cuboid_3& bbox)
void set_span(const Iso_cuboid_3& span)
{
m_bbox = bbox;
m_span = span;
compute_spacing();
}
@ -288,7 +288,7 @@ public:
*
* \param p the point to be located
*
* \pre `p` is inside the bounding box of the grid.
* \pre `p` is inside the grid.
*/
std::array<std::size_t, 3> index(const Point_3& p) const
{
@ -297,7 +297,7 @@ public:
auto z_coord = m_gt.compute_z_3_object();
auto vertex = m_gt.construct_vertex_3_object();
const Point_3& min_p = vertex(m_bbox, 0);
const Point_3& min_p = vertex(m_span, 0);
std::size_t i = (x_coord(p) - x_coord(min_p)) / m_spacing[0];
std::size_t j = (y_coord(p) - y_coord(min_p)) / m_spacing[1];
std::size_t k = (z_coord(p) - z_coord(min_p)) / m_spacing[2];
@ -318,7 +318,7 @@ public:
* \brief returns the geometric position of the grid vertex described by a set of indices.
*
* Depending on the value of the template parameter `cache_points`, positions might not be stored
* but calculated using the lowest corner of the bounding box and grid spacing.
* but calculated on-the-fly.
*
* \param i the index in the `x` direction
* \param j the index in the `y` direction
@ -336,7 +336,7 @@ public:
typename Geom_traits::Construct_point_3 point = m_gt.construct_point_3_object();
typename Geom_traits::Construct_vertex_3 vertex = m_gt.construct_vertex_3_object();
const Point_3& min_p = vertex(m_bbox, 0);
const Point_3& min_p = vertex(m_span, 0);
return point(x_coord(min_p) + i * m_spacing[0],
y_coord(min_p) + j * m_spacing[1],
z_coord(min_p) + k * m_spacing[2]);

8
Isosurfacing_3/include/CGAL/Isosurfacing_3/Dual_contouring_domain_3.h
View File

@ -58,8 +58,8 @@ public:
* \brief constructs a domain that can be used with the %Dual Contouring algorithm.
*
* \param partition the space partitioning data structure
* \param values a continuous field of scalar values, defined over the bounding box of `partition`
* \param gradients a continuous field of normalized vectors, defined over the bounding box of `partition`
* \param values a continuous field of scalar values, defined over the geometric span of `partition`
* \param gradients a continuous field of normalized vectors, defined over the geometric span of `partition`
* \param intersection_oracle the oracle for edge-isosurface intersection computation
*
* \warning the domain class keeps a reference to the `partition`, `values` and `gradients` objects.
@ -84,8 +84,8 @@ public:
* \tparam EdgeIntersectionOracle must be a model of `EdgeIntersectionOracle_3`
*
* \param partition the space partitioning data structure
* \param values a continuous field of scalar values, defined over the bounding box of `partition`
* \param gradients a continuous field of normalized vectors, defined over the bounding box of `partition`
* \param values a continuous field of scalar values, defined over the geometric span of `partition`
* \param gradients a continuous field of normalized vectors, defined over the geometric span of `partition`
* \param intersection_oracle the oracle for edge-isosurface intersection computation
*
* \warning the domain class keeps a reference to the `partition`, `values` and `gradients` objects.

10
Isosurfacing_3/include/CGAL/Isosurfacing_3/IO/Image_3.h
View File

@ -29,7 +29,7 @@ namespace IO {
*
* \brief creates a grid from a `CGAL::Image_3`.
*
* The dimensions and bounding box are read from the image. The values stored
* The dimensions and geometric span are read from the image. The values stored
* in the image must be of type `Geom_traits::FT` or implicitly convertible to it.
*
* \tparam Grid must be `CGAL::Cartesian_grid_3<GeomTraits>` whose `GeomTraits` is a model of `IsosurfacingTraits_3`
@ -52,18 +52,18 @@ bool read_Image_3(const CGAL::Image_3& image,
auto point = grid.geom_traits().construct_point_3_object();
auto iso_cuboid = grid.geom_traits().construct_iso_cuboid_3_object();
// compute bounding box
// compute span
const FT max_x = image.tx() + (image.xdim() - 1) * image.vx();
const FT max_y = image.ty() + (image.ydim() - 1) * image.vy();
const FT max_z = image.tz() + (image.zdim() - 1) * image.vz();
Iso_cuboid_3 bbox = iso_cuboid(point(image.tx(), image.ty(), image.tz()),
Iso_cuboid_3 span = iso_cuboid(point(image.tx(), image.ty(), image.tz()),
point(max_x, max_y, max_z));
// get spacing
// std::array<FT, 3> spacing = make_array(image.vx(), image.vy(), image.vz());
// get sizes
grid.set_bbox(bbox);
grid.set_span(span);
grid.set_sizes(image.xdim(), image.ydim(), image.zdim());
// copy values
@ -133,7 +133,7 @@ CGAL::Image_3 write_Image_3(const Grid& grid,
throw std::bad_alloc(); // @todo idk?
// set min coordinates
const Point_3& min_p = vertex(grid.bbox(), 0);
const Point_3& min_p = vertex(grid.span(), 0);
im->tx = float(CGAL::to_double(x_coord(min_p)));
im->ty = float(CGAL::to_double(y_coord(min_p)));
im->tz = float(CGAL::to_double(z_coord(min_p)));

2
Isosurfacing_3/include/CGAL/Isosurfacing_3/IO/OBJ.h
View File

@ -55,7 +55,7 @@ bool write_OBJ(std::ostream& out,
for(std::size_t y=0; y<grid.ydim(); ++y) {
for(std::size_t z=0; z<grid.zdim(); ++z)
{
const Point_3& p = vertex(grid.bbox(), 0);
const Point_3& p = vertex(grid.span(), 0);
const double x_coord_d = CGAL::to_double(x_coord(p) + x * grid.spacing()[0]);
const double y_coord_d = CGAL::to_double(y_coord(p) + y * grid.spacing()[1]);
const double z_coord_d = CGAL::to_double(z_coord(p) + z * grid.spacing()[2]);

4
Isosurfacing_3/include/CGAL/Isosurfacing_3/Marching_cubes_domain_3.h
View File

@ -56,7 +56,7 @@ public:
* \brief constructs a domain that can be used with the Marching Cubes algorithm.
*
* \param partition the space partitioning data structure
* \param values a continuous field of scalar values, defined over the bounding box of `partition`
* \param values a continuous field of scalar values, defined over the geometric span of `partition`
* \param intersection_oracle the oracle for edge-isosurface intersection computation
*
* \warning the domain class keeps a reference to the `partition`, `values` and `gradients` objects.
@ -79,7 +79,7 @@ public:
* \tparam EdgeIntersectionOracle must be a model of `EdgeIntersectionOracle_3`
*
* \param partition the space partitioning data structure
* \param values a continuous field of scalar values, defined over the bounding box of `partition`
* \param values a continuous field of scalar values, defined over the geometric span of `partition`
* \param intersection_oracle the oracle for edge-isosurface intersection computation
*
* \warning the domain class keeps a reference to the `partition`, `values` and `gradients` objects.

2
Isosurfacing_3/include/CGAL/Isosurfacing_3/internal/dual_contouring_functors.h
View File

@ -102,7 +102,7 @@ bool cell_position_QEM(const typename Domain::Cell_descriptor& c,
#endif
FT x_min, y_min, z_min, x_max, y_max, z_max;
x_min = y_min = z_min = std::numeric_limits<FT>::max(); // @todo domain.bbox()
x_min = y_min = z_min = std::numeric_limits<FT>::max(); // @todo domain.span()
x_max = y_max = z_max = std::numeric_limits<FT>::lowest();
FT x(0), y(0), z(0);

12
Isosurfacing_3/include/CGAL/Isosurfacing_3/interpolation_schemes_3.h
View File

@ -49,7 +49,7 @@ public:
*
* \param p the point at which to interpolate the values
* \param g the grid
* \param values the continuous field of scalar values, defined over the bounding box of `g`
* \param values the continuous field of scalar values, defined over the geometric span of `g`
*/
FT interpolate_values(const Point_3& p,
const Grid& g,
@ -61,11 +61,11 @@ public:
typename Geom_traits::Construct_vertex_3 vertex = g.geom_traits().construct_vertex_3_object();
// trilinear interpolation of stored values
const Iso_cuboid_3& bbox = g.bbox();
const Iso_cuboid_3& span = g.span();
const Vector_3& spacing = g.spacing();
// calculate min index including border case
const Point_3& min_p = vertex(bbox, 0);
const Point_3& min_p = vertex(span, 0);
std::size_t i = (x_coord(p) - x_coord(min_p)) / x_coord(spacing);
std::size_t j = (y_coord(p) - y_coord(min_p)) / y_coord(spacing);
std::size_t k = (z_coord(p) - z_coord(min_p)) / z_coord(spacing);
@ -119,7 +119,7 @@ public:
*
* \param p the point at which to interpolate the gradients
* \param g the grid
* \param gradients the continuous field of vector values, defined over the bounding box of `g`
* \param gradients the continuous field of vector values, defined over the geometric span of `g`
*/
Vector_3 interpolate_gradients(const Point_3& p,
const Grid& g,
@ -132,11 +132,11 @@ public:
typename Geom_traits::Construct_vertex_3 vertex = g.geom_traits().construct_vertex_3_object();
// trilinear interpolation of stored gradients
const Iso_cuboid_3& bbox = g.bbox();
const Iso_cuboid_3& span = g.span();
const Vector_3& spacing = g.spacing();
// calculate min index including border case
const Point_3& min_p = vertex(bbox, 0);
const Point_3& min_p = vertex(span, 0);
std::size_t i = static_cast<std::size_t>((x_coord(p) - x_coord(min_p)) / x_coord(spacing));
std::size_t j = static_cast<std::size_t>((y_coord(p) - y_coord(min_p)) / y_coord(spacing));
std::size_t k = static_cast<std::size_t>((z_coord(p) - z_coord(min_p)) / z_coord(spacing));