Dogcows Code - chaz/yoink/blob - src/Moof/Frustum.cc

   1
   2 /*]  Copyright (c) 2009-2010, Charles McGarvey  [**************************
   3 **]  All rights reserved.
   4 *
   5 * vi:ts=4 sw=4 tw=75
   6 *
   7 * Distributable under the terms and conditions of the 2-clause BSD license;
   8 * see the file COPYING for a complete text of the license.
   9 *
  10 **************************************************************************/
  11
  12 #include <Moof/Aabb.hh>
  13 #include <Moof/Frustum.hh>
  14 #include <Moof/Sphere.hh>
  15
  16
  17 namespace Mf {
  18
  19
  20 void Frustum::init(const Matrix4& modelview, const Matrix4& projection)
  21 {
  22         Scalar planes[6][4];
  23
  24         cml::extract_frustum_planes(modelview, projection, planes,
  25                                                                 cml::z_clip_neg_one);
  26
  27         mPlanes[0] = Plane(planes[0][0], planes[0][1],
  28                                            planes[0][2], planes[0][3]);
  29         mPlanes[1] = Plane(planes[1][0], planes[1][1],
  30                                            planes[1][2], planes[1][3]);
  31         mPlanes[2] = Plane(planes[2][0], planes[2][1],
  32                                            planes[2][2], planes[2][3]);
  33         mPlanes[3] = Plane(planes[3][0], planes[3][1],
  34                                            planes[3][2], planes[3][3]);
  35         mPlanes[4] = Plane(planes[4][0], planes[4][1],
  36                                            planes[4][2], planes[4][3]);
  37         mPlanes[5] = Plane(planes[5][0], planes[5][1],
  38                                            planes[5][2], planes[5][3]);
  39 }
  40
  41 void Frustum::init(const Matrix4& modelview, Scalar fovy, Scalar aspect,
  42                                    Scalar abutting, Scalar distant)
  43 {
  44         Matrix4 projection;
  45
  46         cml::matrix_perspective_yfov_RH(projection, fovy, aspect, abutting,
  47                                                                         distant, cml::z_clip_neg_one);
  48
  49         init(modelview, projection);
  50 }
  51
  52 Frustum::Collision Frustum::contains(const Aabb<3>& aabb) const
  53 {
  54         Vector3 corners[8];
  55         int nTotalInside = 0;
  56
  57         aabb.getCorners(corners);
  58
  59         for (int i = 0; i < 6; ++i)
  60         {
  61                 int nInside = 8;
  62
  63                 for (int j = 0; j < 8; ++j)
  64                 {
  65                         if (mPlanes[i].intersects(corners[j]) == Plane::NEGATIVE)
  66                         {
  67                                 --nInside;
  68                         }
  69                 }
  70
  71                 if (nInside == 0)      return OUTSIDE;
  72                 else if (nInside == 8) ++nTotalInside;
  73         }
  74
  75         if (nTotalInside == 6) return INSIDE;
  76         else                   return INTERSECT;
  77 }
  78
  79
  80 Frustum::Collision Frustum::contains(const Sphere<3>& sphere) const
  81 {
  82         for (int i = 0; i < 6; ++i)
  83         {
  84                 Plane::Halfspace halfspace = mPlanes[i].intersects(sphere);
  85
  86                 if (halfspace == Plane::NEGATIVE)       return OUTSIDE;
  87                 else if (halfspace == Plane::INTERSECT) return INTERSECT;
  88         }
  89
  90         return INSIDE;
  91 }
  92
  93
  94 } // namespace Mf
  95