CGLAB computational geometry toolbox for Scilab 2025.0.0

Tools Atoms packages
1

Hello,

The CGLAB toolbox has been updated and rebuilt for Scilab 2025.0.0. This toolbox makes available in Scilab a small (yet interesting) subset of the features of CGAL (Computational Geometry Algorithms Library, https://cgal.org), namely

  • Delaunay 2D and 3D triangulation/tesselation
  • Delaunay 2D meshing with refinement
  • Surface mesh from 3D volumic data
  • …

To install the toolbox, as usual, just update the package list before calling atomsInstall:

atomsSystemUpdate
atomsInstall cglab
atomsLoad cglab // or restart Scilab

Here is a small example of Delaunay 2D mesh with refinement:

N = 50;
t1 = linspace(0,2*%pi,2*N)';
C1 = [cos(t1(1:$-1)) sin(t1(1:$-1)) cos(t1(2:$)) sin(t1(2:$))];
C1($) = 0;
C2 = 0.5*[-1 -1 1 -1
        1 -1 1 1
        1  1 -1 1
        -1 1 -1 -1]
[coord,tri,ptr] = mesh_2([C1;C2]);
mesh2_set_seeds(ptr,0,0);
mesh2_refine(ptr,0.1,t1(2)-t1(1));
tri = mesh2_get_connectivity(ptr);
coord = mesh2_get_coord(ptr);
clf();
xx = matrix(coord(tri,1),-1,3)';
yy = matrix(coord(tri,2),-1,3)';
gca().data_bounds=[-1 1 -1 1];
gca().axes_visible="on"
isoview
xfpolys(xx,yy);
mesh2_delete(ptr,"ptr");

mesh

Enjoy !

S.

3 Likes
2

How do you handle CGAL external dependency? I am interesting in writing an extension for DuckDB. I would like to know how linked libraries are handled. Static or Dynamic.

3

Hello,

We provide builds of CGAL for each platform in the toolbox bundle.

You can start by reading the following (legacy but still valid) wiki : howto/Create a toolbox

You can also consider building yourself some toolboxes which include compiled gateways interfacing thirdparty libraries (sci_ipopt, cgal, IPCV, …).

S.