Function is_in_triangle

utils/algorithms.cpp:9–18

// helper functions

static bool is_in_triangle(const Vec3 &pt, const Vec3 &v1, const Vec3 &v2, const Vec3 &v3, const Vec3 &normal)
{
    const float s1 = Vec3::dot(Vec3::cross(v2 - v1, pt - v1), normal);
    const float s2 = Vec3::dot(Vec3::cross(v3 - v2, pt - v2), normal);
    const float s3 = Vec3::dot(Vec3::cross(v1 - v3, pt - v3), normal);

    const bool same_sign = (s1 >= 0 && s2 >= 0 && s3 >= 0) || (s1 <= 0 && s2 <= 0 && s3 <= 0);

    return same_sign;
}

static bool is_ear(const size_t i, const std::vector<Vec3> &points, const std::vector<size_t> &indices, const Vec3 &normal)
{