geometry.h

/*
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 *  modification, are permitted provided that the following conditions are met:
 *
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 *  this list of conditions and the following disclaimer.
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 *  and/or other materials provided with the distribution.
 *  * Neither the name of the ALICE Project-Team nor the names of its
 *  contributors may be used to endorse or promote products derived from this
 *  software without specific prior written permission.
 *
 *  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 *  AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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 *  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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 *  ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 *  POSSIBILITY OF SUCH DAMAGE.
 *
 *  Contact: Bruno Levy
 *
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 *
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#ifndef H_HEXDOM_ALGO_GEOMETRY_H
#define H_HEXDOM_ALGO_GEOMETRY_H
 
#include <exploragram/basic/common.h>
#include <exploragram/hexdom/basic.h>
#include <geogram/basic/geometry.h>
 
namespace GEO {
 
    struct EXPLORAGRAM_API CoTan3D{
        double w[6];
        double tetvol;
 
        CoTan3D(vec3 P[4], double* anisotropy_as_xx_yy_zz_xy_yz_xz = nullptr);
 
        index_t org(index_t e);
        index_t dest(index_t e);
        double coeff(index_t e);
 
        void check_for_grad(vec3 P[4], vec3 grad);
    };
 
    /*******************************************************************************/
 
    class EXPLORAGRAM_API TrglGradient {
    public:
    TrglGradient(const vec3& p0, const vec3& p1, const vec3& p2);
 
    TrglGradient();
 
    void initialize(const vec3& p0, const vec3& p1, const vec3& p2);
 
    const vec3& vertex(index_t i) const;
 
    void basis(vec3& origin, vec3& X, vec3& Y, vec3& Z) const;
 
    double TX(index_t i) const;
 
    double TY(index_t i) const;
    bool is_flat() const { return is_flat_; }
 
    vec3 gradient_3d(double value0, double value1, double value2) const;
 
    private:
    double TX_[3];
    double TY_[3];
    vec3 vertex_[3];
    bool is_flat_;
    };
 
    /*******************************************************************************/
 
    struct Basis3d {
        Basis3d(vec3 z) { // TODO DOCUMENT THIS!
            v[2] = normalize(z);
            if (std::fabs(v[2].z) < .8)
                v[0] = cross(v[2], vec3(0, 0, 1));
            else v[0] = cross(v[2], vec3(1, 0, 0));
            v[0] = normalize(v[0]);
            v[1] = cross(v[2], v[0]);
            geo_assert(std::abs(v[1].length2() - 1) < .001);
        }
        vec2 project_xy(vec3 in){
            return vec2(dot(in, v[0]), dot(in, v[1]));
        }
        vec3 un_project_xy(vec2 in){
            return in[0] * v[0] + in[1] * v[1];
        }
        vec3 v[3];
    };
 
    /*******************************************************************************/
 
    /*     _____   _____            ____  _____                                _                    _                    _
     *    |  __ \ / ____|   /\     |___ \|  __ \                              | |                  | |                  | |
     *    | |__) | |       /  \      __) | |  | |  ______ ______   _ __   ___ | |_    ___ ___ _ __ | |_ ___ _ __ ___  __| |
     *    |  ___/| |      / /\ \    |__ <| |  | | |______|______| | '_ \ / _ \| __|  / __/ _ \ '_ \| __/ _ \ '__/ _ \/ _` |
     *    | |    | |____ / ____ \   ___) | |__| |                 | | | | (_) | |_  | (_|  __/ | | | ||  __/ | |  __/ (_| |
     *    |_|     \_____/_/    \_\ |____/|_____/                  |_| |_|\___/ \__|  \___\___|_| |_|\__\___|_|  \___|\__,_|
     *
     */
 
    struct EXPLORAGRAM_API UncenteredPCA3D {
    public:
    void begin_points();
    void end_points();
    void point(const vec3& p, double weight = 1.0);
    vec3 axis[3];
    double eigen_value[3];
    private:
    double M_[6];
    int nb_points_;
    double sum_weights_;
    };
 
 
    /*******************************************************************************/
 
 
    /* Triangle/triangle intersection test routine,
     * by Tomas Moller, 1997.
     * See article "A Fast Triangle-Triangle Intersection Test",
     * Journal of Graphics Tools, 2(2), 1997
     *
     * Updated June 1999: removed the divisions -- a little faster now!
     * Updated October 1999: added {} to CROSS and SUB macros
     *
     * int NoDivTriTriIsect(double V0[3],double V1[3],double V2[3],
     *                      double U0[3],double U1[3],double U2[3])
     *
     * parameters: vertices of triangle 1: V0,V1,V2
     *             vertices of triangle 2: U0,U1,U2
     * result    : returns 1 if the triangles intersect, otherwise 0
     *
     */
    int EXPLORAGRAM_API NoDivTriTriIsect(
        double V0[3], double V1[3], double V2[3],
        double U0[3], double U1[3], double U2[3]
    );
 
    /********************************************************/
    /* AABB-triangle overlap test code                      */
    /* by Tomas Akenine-Möller                              */
    /* Function: int triBoxOverlap(float boxcenter[3],      */
    /*          float boxhalfsize[3],float triverts[3][3]); */
    /* History:                                             */
    /*   2001-03-05: released the code in its first version */
    /*   2001-06-18: changed the order of the tests, faster */
    /*                                                      */
    /* Acknowledgement: Many thanks to Pierre Terdiman for  */
    /* suggestions and discussions on how to optimize code. */
    /* Thanks to David Hunt for finding a ">="-bug!         */
    /********************************************************/
    int EXPLORAGRAM_API triBoxOverlap(
        float boxcenter[3], float boxhalfsize[3], float triverts[3][3]
    );
 
    /*******************************************************************************/
 
}
 
#endif