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Add prisms and pyramids creation

This commit is contained in:
Guillaume Damiand 2025-09-03 12:46:19 +02:00
parent cc19bd4a80
commit f41b5b60f7
2 changed files with 310 additions and 7 deletions
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176
Combinatorial_map/include/CGAL/Combinatorial_map.h
View File

@ -4019,6 +4019,182 @@ namespace CGAL {
return make_combinatorial_hexahedron(d1, d2, d3, d4, d5, d6);
}
/** Test if a volume is a combinatorial prism.
* @param adart an intial dart
* @return true iff the volume containing adart is a combinatorial prism.
*/
bool is_volume_combinatorial_prism(Dart_const_descriptor d1) const
{
Dart_const_descriptor d2=beta(d1, 2);
Dart_const_descriptor d3=beta(d1, 1, 2);
Dart_const_descriptor d4=beta(d1, 0, 2);
Dart_const_descriptor d5=beta(d2, 1, 1, 2);
if ( d1==null_dart_descriptor || d2==null_dart_descriptor ||
d3==null_dart_descriptor || d4==null_dart_descriptor ||
d5==null_dart_descriptor ) { return false; }
if (!is_face_combinatorial_polygon(d1, 3) ||
!is_face_combinatorial_polygon(d2, 4) ||
!is_face_combinatorial_polygon(d3, 4) ||
!is_face_combinatorial_polygon(d4, 4) ||
!is_face_combinatorial_polygon(d5, 3)) { return false; }
// TODO do better with marks.
if (belong_to_same_cell<2,1>(d1, d2) ||
belong_to_same_cell<2,1>(d1, d3) ||
belong_to_same_cell<2,1>(d1, d4) ||
belong_to_same_cell<2,1>(d1, d5) ||
belong_to_same_cell<2,1>(d2, d3) ||
belong_to_same_cell<2,1>(d2, d4) ||
belong_to_same_cell<2,1>(d2, d5) ||
belong_to_same_cell<2,1>(d3, d4) ||
belong_to_same_cell<2,1>(d3, d5) ||
belong_to_same_cell<2,1>(d4, d5))
{ return false; }
if (beta(d2,0,2) !=beta(d3,1) ||
beta(d2,1,2) !=beta(d4,0) ||
beta(d3,0,2) !=beta(d4,1) ||
beta(d3,1,1,2)!=beta(d5,0) ||
beta(d4,1,1,2)!=beta(d5,1)) { return false; }
return true;
}
/** Create a combinatorial prism from 2 triangles and 3 squares.
* @param d1 a dart onto a first triangle.
* @param d2 a dart onto a first square.
* @param d3 a dart onto a second square.
* @param d4 a dart onto a thirth square.
* @param d5 a dart onto a second triangle.
* @return a new dart.
*/
Dart_descriptor make_combinatorial_prism(Dart_descriptor d1,
Dart_descriptor d2,
Dart_descriptor d3,
Dart_descriptor d4,
Dart_descriptor d5)
{
// 2-link for first triangle
basic_link_beta_for_involution(d1, d2, 2);
basic_link_beta_for_involution(beta(d1, 1), d3, 2);
basic_link_beta_for_involution(beta(d1, 0), d4, 2);
// 2-link for quandrangles between them
basic_link_beta_for_involution(beta(d2, 0), beta(d3, 1), 2);
basic_link_beta_for_involution(beta(d2, 1), beta(d4, 0), 2);
basic_link_beta_for_involution(beta(d3, 0), beta(d4, 1), 2);
// 2-link for second triangle
basic_link_beta_for_involution(beta(d2, 1, 1), d5, 2);
basic_link_beta_for_involution(beta(d3, 1, 1), beta(d5, 0), 2);
basic_link_beta_for_involution(beta(d4, 1, 1), beta(d5, 1), 2);
return d1;
}
/** Create a new combinatorial prism.
* @return a new dart.
*/
Dart_descriptor make_combinatorial_prism()
{
Dart_descriptor d1 = make_combinatorial_polygon(3);
Dart_descriptor d2 = make_combinatorial_polygon(4);
Dart_descriptor d3 = make_combinatorial_polygon(4);
Dart_descriptor d4 = make_combinatorial_polygon(4);
Dart_descriptor d5 = make_combinatorial_polygon(3);
return make_combinatorial_prism( d1, d2, d3, d4, d5);
}
/** Test if a volume is a combinatorial pyramid.
* @param adart an intial dart
* @return true iff the volume containing adart is a combinatorial pyramid.
*/
bool is_volume_combinatorial_pyramid(Dart_const_descriptor d1) const
{
Dart_const_descriptor d2=beta(d1, 2);
Dart_const_descriptor d3=beta(d1, 0, 2);
Dart_const_descriptor d4=beta(d1, 1, 1, 2);
Dart_const_descriptor d5=beta(d1, 1, 2);
if (d1==null_dart_descriptor || d2==null_dart_descriptor ||
d3==null_dart_descriptor || d4==null_dart_descriptor ||
d5==null_dart_descriptor) { return false; }
if (!is_face_combinatorial_polygon(d1, 4) ||
!is_face_combinatorial_polygon(d2, 3) ||
!is_face_combinatorial_polygon(d3, 3) ||
!is_face_combinatorial_polygon(d4, 3) ||
!is_face_combinatorial_polygon(d5, 3)) { return false; }
// TODO do better with marks.
if (belong_to_same_cell<2,1>(d1, d2) ||
belong_to_same_cell<2,1>(d1, d3) ||
belong_to_same_cell<2,1>(d1, d4) ||
belong_to_same_cell<2,1>(d1, d5) ||
belong_to_same_cell<2,1>(d2, d3) ||
belong_to_same_cell<2,1>(d2, d4) ||
belong_to_same_cell<2,1>(d2, d5) ||
belong_to_same_cell<2,1>(d3, d4) ||
belong_to_same_cell<2,1>(d3, d5) ||
belong_to_same_cell<2,1>(d4, d5))
{ return false; }
if (beta(d2,1,2)!=beta(d3,0) ||
beta(d2,0,2)!=beta(d5,1) ||
beta(d5,0,2)!=beta(d4,1) ||
beta(d4,0,2)!=beta(d3,1)) { return false; }
return true;
}
/** Create a combinatorial pyramid from 1 square and 4 triangles.
* @param d1 a dart onto the square.
* @param d2 a dart onto a first triangle.
* @param d3 a dart onto a second triangle.
* @param d4 a dart onto a thirth triangle.
* @param d5 a dart onto a fourth triangle.
* @return a new dart.
*/
Dart_descriptor make_combinatorial_pyramid(Dart_descriptor d1,
Dart_descriptor d2,
Dart_descriptor d3,
Dart_descriptor d4,
Dart_descriptor d5)
{
// 2-link for the square
basic_link_beta_for_involution(d1, d2, 2);
basic_link_beta_for_involution(beta(d1, 1), d5, 2);
basic_link_beta_for_involution(beta(d1, 1, 1), d4, 2);
basic_link_beta_for_involution(beta(d1, 0), d3, 2);
// 2-link for first triangle
basic_link_beta_for_involution(beta(d2, 1), beta(d3, 0), 2);
basic_link_beta_for_involution(beta(d2, 0), beta(d5, 1), 2);
// 2-link for triangles between them
basic_link_beta_for_involution(beta(d5, 0), beta(d4, 1), 2);
basic_link_beta_for_involution(beta(d4, 0), beta(d3, 1), 2);
return d1;
}
/** Create a new combinatorial pyramid.
* @return a new dart.
*/
Dart_descriptor make_combinatorial_pyramid()
{
Dart_descriptor d1=make_combinatorial_polygon(4);
Dart_descriptor d2=make_combinatorial_polygon(3);
Dart_descriptor d3=make_combinatorial_polygon(3);
Dart_descriptor d4=make_combinatorial_polygon(3);
Dart_descriptor d5=make_combinatorial_polygon(3);
return make_combinatorial_pyramid(d1, d2, d3, d4, d5);
}
/** Test if an i-cell can be removed.
* An i-cell can be removed if i==dimension or i==dimension-1,
* or if there are at most two (i+1)-cell incident to it.

141
Linear_cell_complex/include/CGAL/Linear_cell_complex_base.h
View File

@ -660,13 +660,13 @@ namespace CGAL {
* h0,h5 and to the facet (h0,h5,h6,h1).
*/
Dart_descriptor make_hexahedron(Vertex_attribute_descriptor h0,
Vertex_attribute_descriptor h1,
Vertex_attribute_descriptor h2,
Vertex_attribute_descriptor h3,
Vertex_attribute_descriptor h4,
Vertex_attribute_descriptor h5,
Vertex_attribute_descriptor h6,
Vertex_attribute_descriptor h7)
Vertex_attribute_descriptor h1,
Vertex_attribute_descriptor h2,
Vertex_attribute_descriptor h3,
Vertex_attribute_descriptor h4,
Vertex_attribute_descriptor h5,
Vertex_attribute_descriptor h6,
Vertex_attribute_descriptor h7)
{
Dart_descriptor d1 = make_quadrangle(h0, h5, h6, h1);
Dart_descriptor d2 = make_quadrangle(h1, h6, h7, h2);
@ -717,6 +717,133 @@ namespace CGAL {
create_vertex_attribute(p7));
}
/** Create an prism given 6 Vertex_attribute_descriptor.
* (6 vertices, 9 edges and 5 facets)
* \verbatim
* 3---4
* |\ /|
* 0-5-1
* \|/
* 2
* \endverbatim
* @param h0 the first vertex handle.
* @param h1 the second vertex handle.
* @param h2 the third vertex handle.
* @param h3 the fourth vertex handle.
* @param h4 the fifth vertex handle.
* @param h5 the sixth vertex handle.
* @return the dart of the new prism incident to h0 and to
* the facet (h0,h1,h2).
*/
Dart_descriptor make_prism(Vertex_attribute_descriptor h0,
Vertex_attribute_descriptor h1,
Vertex_attribute_descriptor h2,
Vertex_attribute_descriptor h3,
Vertex_attribute_descriptor h4,
Vertex_attribute_descriptor h5)
{
Dart_descriptor d1=make_triangle(h0, h1, h2);
Dart_descriptor d2=make_quadrangle(h1, h0, h3, h4);
Dart_descriptor d3=make_quadrangle(h2, h1, h4, h5);
Dart_descriptor d4=make_quadrangle(h0, h2, h5, h3);
Dart_descriptor d5=make_triangle(h4, h3, h5);
return make_combinatorial_prism(d1, d2, d3, d4, d5);
}
/** Create an prism given 6 points.
* \verbatim
* 3---4
* |\ /|
* 0-5-1
* \|/
* 2
* \endverbatim
* @param p0 the first point.
* @param p1 the second point.
* @param p2 the third point.
* @param p3 the fourth point.
* @param p4 the fifth point.
* @param p5 the sixth point.
* @return the dart of the new prism incident to p0 and to
* the facet (p0,p1,p2).
*/
Dart_descriptor make_prism(const Point& p0,
const Point& p1,
const Point& p2,
const Point& p3,
const Point& p4,
const Point& p5)
{
return make_prism(create_vertex_attribute(p0),
create_vertex_attribute(p1),
create_vertex_attribute(p2),
create_vertex_attribute(p3),
create_vertex_attribute(p4),
create_vertex_attribute(p5));
}
/** Create an pyramid given 5 Vertex_attribute_descriptor.
* (5 vertices, 8 edges and 5 facets)
* \verbatim
* 4
* /|\
* 0-|-1
* | | |
* 3---2
* \endverbatim
* @param h0 the first vertex handle.
* @param h1 the second vertex handle.
* @param h2 the third vertex handle.
* @param h3 the fourth vertex handle.
* @param h4 the fifth vertex handle.
* @return the dart of the new pyramid incident to h0 and to
* the facet (h0,h1,h2,h3).
*/
Dart_descriptor make_pyramid(Vertex_attribute_descriptor h0,
Vertex_attribute_descriptor h1,
Vertex_attribute_descriptor h2,
Vertex_attribute_descriptor h3,
Vertex_attribute_descriptor h4)
{
Dart_descriptor d1=make_quadrangle(h0, h1, h2, h3);
Dart_descriptor d2=make_triangle(h1, h0, h4);
Dart_descriptor d3=make_triangle(h0, h3, h4);
Dart_descriptor d4=make_triangle(h3, h2, h4);
Dart_descriptor d5=make_triangle(h2, h1, h4);
return make_combinatorial_pyramid(d1, d2, d3, d4, d5);
}
/** Create an pyramid given 5 points.
* \verbatim
* 4
* /|\
* 0-|-1
* | | |
* 3---2
* \endverbatim
* @param p0 the first point.
* @param p1 the second point.
* @param p2 the third point.
* @param p3 the fourth point.
* @param p4 the fifth point.
* @return the dart of the new pyramid incident to p0 and to
* the facet (p0,p1,p2,p3).
*/
Dart_descriptor make_pyramid(const Point& p0,
const Point& p1,
const Point& p2,
const Point& p3,
const Point& p4)
{
return make_pyramid(create_vertex_attribute(p0),
create_vertex_attribute(p1),
create_vertex_attribute(p2),
create_vertex_attribute(p3),
create_vertex_attribute(p4));
}
/** Compute the barycenter of a given cell.
* @param adart a dart incident to the cell.
* @param adim the dimension of the cell.