barycentric.C

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#include "barycentric.H"
#include "Random.H"

// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

Foam::barycentric Foam::barycentric01(Random& rndGen)
{
    scalar s = rndGen.scalar01();
    scalar t = rndGen.scalar01();
    scalar u = rndGen.scalar01();

    // Transform the random point in the unit cube to a random point in the
    // unit tet by means of a series of reflections. See
    // <http://vcg.isti.cnr.it/jgt/tetra.htm> for details.

    if (s + t > 1)
    {
        s = 1 - s;
        t = 1 - t;
    }

    if (s + t + u > 1)
    {
        Foam::scalar temp = u;

        if (t + u > 1)
        {
            u = 1 - s - t;
            t = 1 - temp;
        }
        else
        {
            u = s + t + u - 1;
            s = 1 - t - temp;
        }
    }

    return Foam::barycentric(1 - s - t - u, s, t, u);
}


// ************************************************************************* //