geometry.H

/*
 * This file is part of the "Archon" framework.
 * (http://files3d.sourceforge.net)
 *
 * Copyright © 2002 by Kristian Spangsege and Brian Kristiansen.
 *
 * Permission to use, copy, modify, and distribute this software and
 * its documentation under the terms of the GNU General Public License is
 * hereby granted. No representations are made about the suitability of
 * this software for any purpose. It is provided "as is" without express
 * or implied warranty. See the GNU General Public License
 * (http://www.gnu.org/copyleft/gpl.html) for more details.
 *
 * The characters in this file are ISO8859-1 encoded.
 *
 * The documentation in this file is in "Doxygen" style
 * (http://www.doxygen.org).
 */

#ifndef ARCHON_MATH_GEOMETRY_H
#define ARCHON_MATH_GEOMETRY_H

#include <archon/math/vector.H>
#include <archon/math/matrix.H>

namespace Archon
{
  namespace Math
  {
    struct Line3
    {
      Vector3 point;
      Vector3 direction; // Must be a unit vector

      Line3() {}
      Line3(Vector3 point, Vector3 direction): point(point), direction(direction) {}
    };

    struct Plane3
    {
      Vector3 normal;

      double dist;

      Plane3() {}
      Plane3(Vector3 normal, double dist): normal(normal), dist(dist) {}
      Plane3(Vector3 normal, Vector3 point): normal(normal), dist(-dot(normal, point)) {}
    };

    Vector3 intersect(const Plane3 &, const Plane3 &, const Plane3 &);

    struct Ray3
    {
      Vector3 origin;
      Vector3 direction; // Must be a unit vector

      Ray3() {}
      Ray3(const Vector3 &origin, const Vector3 &direction):
        origin(origin), direction(direction) {}
      Ray3(const Line3 &l): origin(l.point), direction(l.direction) {}
    };

    struct Box3
    {
      Vector3 lowerCorner; // Lower-left-back corner in 3D
      Vector3 upperCorner; // Upper-right-front corner in 3D

      Box3() {}
      Box3(const Vector3 &lowerCorner, const Vector3 &upperCorner):
        lowerCorner(lowerCorner), upperCorner(upperCorner) {}
      Box3(const Vector3 &size):
        lowerCorner(-size/2), upperCorner(size/2) {}

      Vector3 getCenter() const { return (lowerCorner + upperCorner)/2; }
      Vector3 getSize() const
      {
        Vector3 v = lowerCorner;
        v -= upperCorner;
        if(v[0] < 0) v[0] = -v[0];
        if(v[1] < 0) v[1] = -v[1];
        if(v[2] < 0) v[2] = -v[2];
        return v;
      }
    };

    struct Sphere3
    {
      Vector3 center;
      double radius;

      Sphere3() {}
      Sphere3(Vector3 center, double radius):
        center(center), radius(radius) {}
      Sphere3(double radius):
        center(Vector3::zero()), radius(radius) {}
    };

    bool intersect(const Ray3 &, const Plane3 &, bool frontToBackOnly, double &dist);

    int intersect(const Ray3 &, const Box3 &, double &dist);

    bool intersect(const Ray3 &, const Sphere3 &, double &dist);

    int intersectCylinder(const Ray3 &, double height, double radius,
                          double &dist, bool side=true, bool top=true,
                          bool bottom=true, bool enterOnly = true);

    int intersectCone(const Ray3 &, double height, double bottomRadius,
                      double &dist, bool side=true, bool bottom=true,
                      bool enterOnly = true);

    bool intersectTorus(const Ray3 &, double majorTorusRadius,
                        double minorTorusRadius, double &dist,
                        bool surfaceOrigin = false, bool extToIntOnly = true);
  }
}

#endif // ARCHON_MATH_GEOMETRY_H

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