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 "aabb.hh"
  13 #include "frustum.hh"
  14 #include "sphere.hh"
  15
  16
  17 namespace moof {
  18
  19
  20 void frustum::init(const matrix4& modelview, const matrix4& projection)
  21 {
  22         scalar planes[6][4];
  23
  24         extract_frustum_planes(modelview, projection, planes, z_clip_neg_one);
  25
  26         planes_[0] = plane(planes[0][0], planes[0][1],
  27                                            planes[0][2], planes[0][3]);
  28         planes_[1] = plane(planes[1][0], planes[1][1],
  29                                            planes[1][2], planes[1][3]);
  30         planes_[2] = plane(planes[2][0], planes[2][1],
  31                                            planes[2][2], planes[2][3]);
  32         planes_[3] = plane(planes[3][0], planes[3][1],
  33                                            planes[3][2], planes[3][3]);
  34         planes_[4] = plane(planes[4][0], planes[4][1],
  35                                            planes[4][2], planes[4][3]);
  36         planes_[5] = plane(planes[5][0], planes[5][1],
  37                                            planes[5][2], planes[5][3]);
  38 }
  39
  40 void frustum::init(const matrix4& modelview, scalar fovy, scalar aspect,
  41                                    scalar abutting, scalar distant)
  42 {
  43         matrix4 projection;
  44
  45         matrix_perspective_yfov_RH(projection, fovy, aspect, abutting,
  46                                                                         distant, z_clip_neg_one);
  47
  48         init(modelview, projection);
  49 }
  50
  51 frustum::collision frustum::contains(const aabb<3>& aabb) const
  52 {
  53         vector3 corners[8];
  54         int nTotalInside = 0;
  55
  56         aabb.get_corners(corners);
  57
  58         for (int i = 0; i < 6; ++i)
  59         {
  60                 int nInside = 8;
  61
  62                 for (int j = 0; j < 8; ++j)
  63                 {
  64                         if (planes_[i].intersects(corners[j]) == plane::negative)
  65                         {
  66                                 --nInside;
  67                         }
  68                 }
  69
  70                 if (nInside == 0)      return outside;
  71                 else if (nInside == 8) ++nTotalInside;
  72         }
  73
  74         if (nTotalInside == 6) return inside;
  75         else                   return intersecting;
  76 }
  77
  78
  79 frustum::collision frustum::contains(const sphere<3>& sphere) const
  80 {
  81         for (int i = 0; i < 6; ++i)
  82         {
  83                 plane::halfspace halfspace = planes_[i].intersects(sphere);
  84
  85                 if (halfspace == plane::negative)       return outside;
  86                 else if (halfspace == plane::intersecting) return intersecting;
  87         }
  88
  89         return inside;
  90 }
  91
  92
  93 } // namespace moof
  94