CGAL::angle() applications

[petrasvestartas]

Hi,

What do you usually use CGAL:angle method for?

I tried to search in CGAL repo but I cannot find explanation about:
CGAL::OBTUSE, CGAL::RIGHT or CGAL::ACUT
I guess that CGAL::Right is 90 degrees and CGAL::OBTUSE is x>90 degrees and CGAL::ACUT x<90.

Is it correct? And what do you usually use this for? Detection of concave or convex corners?

[lrineau]

Usage in CGAL

CGAL::angle is not directly used, in CGAL. In the CGAL algorithm, we use the kernel API: CGAL::Angle_2 and CGAL::Angle_3.

• Angle_2 is used in:
  • Mesh_2/include/CGAL/Mesh_2/Refine_edges.h, and
  • Mesh_2/include/CGAL/Mesh_2/Clusters.h.
• Angle_3 is used in:
  • Mesh_3/include/CGAL/Mesh_domain_with_polyline_features_3.h, and
  • Surface_mesh_segmentation/include/CGAL/Surface_mesh_segmentation/internal/SDF_calculation.h.

Meaning

I tried to search in CGAL repo but I cannot find explanation about:
CGAL::OBTUSE, CGAL::RIGHT or CGAL::ACUTE
I guess that CGAL::RIGHT is 90 degrees and CGAL::OBTUSE is x>90 degrees and CGAL::ACUTE x<90.

Yes, that is right. That has the same meaning as the mathematical meaning:

• a right angle is 90°,
• an acute angle is <90°,
• and an obtuse angle is >90°.