CGAL::compare_x

Depending on which Cgal kernel is used, different versions of this global function are available. This is described below.

With the basic 2D and 3D Kernel (see Chapter 11)

Comparison_result compare_x ( Point_2<Kernel> p, Point_2<Kernel> q)
compares the x-coordinates of p and q.

Comparison_result compare_x ( Point_3<Kernel> p, Point_3<Kernel> q)
compares the x-coordinates of p and q.

Comparison_result compare_x ( Point_2<Kernel> p, Line_2<Kernel> l1, Line_2<Kernel> l2)
compares the x-coordinates of p and the intersection of lines l1 and l2, see (a) in the figure below.

Comparison_result compare_x ( Line_2<Kernel> l, Line_2<Kernel> h1, Line_2<Kernel> h2)
compares the x-coordinates of the intersection of line l with line h1 and with line h2, see (b) in the figure below.

Comparison_result compare_x ( Line_2<Kernel> l1, Line_2<Kernel> l2, Line_2<Kernel> h1, Line_2<Kernel> h2)
compares the x-coordinates of the intersection of lines l1 and l2 and the intersection of lines h1 and h2, see (c) in the figure below.

Comparison of the x 
or y coordinates of the (implicitly given) points in the boxes

With the 2D Circular Kernel (see Chapter 13)

#include <CGAL/global_functions_circular_kernel_2.h>

If this kernel is used, in addition to the function and the combination of 2D types described above, another version of the function is provided.

Comparison_result compare_x ( Circular_arc_point_2<CircularKernel> p, Circular_arc_point_2<CircularKernel> q)
compares the x-coordinates of p and q.

Comparison_result compare_x ( Circular_arc_point_2<CircularKernel> p, Point_2<CircularKernel> q)
compares the x-coordinates of p and q.

With the 3D Spherical Kernel (see Chapter 14)

#include <CGAL/global_functions_spherical_kernel_3.h>

If this kernel is used, in addition to the function and the combination of 2D types described above, another version of the function is provided.

Comparison_result compare_x ( Circular_arc_point_3<SphericalKernel> p, Circular_arc_point_3<SphericalKernel> q)
compares the x-coordinates of p and q.

Comparison_result compare_x ( Circular_arc_point_3<SphericalKernel> p, Point_3<SphericalKernel> q)
compares the x-coordinates of p and q.

See Also

CGAL::compare_xy
CGAL::compare_xyz
CGAL::compare_x_at_y
CGAL::compare_y
CGAL::compare_yx
CGAL::compare_y_at_x
CGAL::compare_z