src/raycast.cpp

   1 /*
   2 Minetest
   3 Copyright (C) 2016 juhdanad, Daniel Juhasz <juhdanad@gmail.com>
   4
   5 This program is free software; you can redistribute it and/or modify
   6 it under the terms of the GNU Lesser General Public License as published by
   7 the Free Software Foundation; either version 2.1 of the License, or
   8 (at your option) any later version.
   9
  10 This program is distributed in the hope that it will be useful,
  11 but WITHOUT ANY WARRANTY; without even the implied warranty of
  12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13 GNU Lesser General Public License for more details.
  14
  15 You should have received a copy of the GNU Lesser General Public License along
  16 with this program; if not, write to the Free Software Foundation, Inc.,
  17 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  18 */
  19
  20 #include "irr_v3d.h"
  21 #include "irr_aabb3d.h"
  22
  23 bool boxLineCollision(const aabb3f &box, const v3f &start,
  24                 const v3f &dir, v3f *collision_point, v3s16 *collision_normal) {
  25         if (box.isPointInside(start)) {
  26                 *collision_point = start;
  27                 collision_normal->set(0, 0, 0);
  28                 return true;
  29         }
  30         float m = 0;
  31
  32         // Test X collision
  33         if (dir.X != 0) {
  34                 if (dir.X > 0)
  35                         m = (box.MinEdge.X - start.X) / dir.X;
  36                 else
  37                         m = (box.MaxEdge.X - start.X) / dir.X;
  38
  39                 if (m >= 0 && m <= 1) {
  40                         *collision_point = start + dir * m;
  41                         if ((collision_point->Y >= box.MinEdge.Y)
  42                                         && (collision_point->Y <= box.MaxEdge.Y)
  43                                         && (collision_point->Z >= box.MinEdge.Z)
  44                                         && (collision_point->Z <= box.MaxEdge.Z)) {
  45                                 collision_normal->set((dir.X > 0) ? -1 : 1, 0, 0);
  46                                 return true;
  47                         }
  48                 }
  49         }
  50
  51         // Test Y collision
  52         if (dir.Y != 0) {
  53                 if (dir.Y > 0)
  54                         m = (box.MinEdge.Y - start.Y) / dir.Y;
  55                 else
  56                         m = (box.MaxEdge.Y - start.Y) / dir.Y;
  57
  58                 if (m >= 0 && m <= 1) {
  59                         *collision_point = start + dir * m;
  60                         if ((collision_point->X >= box.MinEdge.X)
  61                                         && (collision_point->X <= box.MaxEdge.X)
  62                                         && (collision_point->Z >= box.MinEdge.Z)
  63                                         && (collision_point->Z <= box.MaxEdge.Z)) {
  64                                 collision_normal->set(0, (dir.Y > 0) ? -1 : 1, 0);
  65                                 return true;
  66                         }
  67                 }
  68         }
  69
  70         // Test Z collision
  71         if (dir.Z != 0) {
  72                 if (dir.Z > 0)
  73                         m = (box.MinEdge.Z - start.Z) / dir.Z;
  74                 else
  75                         m = (box.MaxEdge.Z - start.Z) / dir.Z;
  76
  77                 if (m >= 0 && m <= 1) {
  78                         *collision_point = start + dir * m;
  79                         if ((collision_point->X >= box.MinEdge.X)
  80                                         && (collision_point->X <= box.MaxEdge.X)
  81                                         && (collision_point->Y >= box.MinEdge.Y)
  82                                         && (collision_point->Y <= box.MaxEdge.Y)) {
  83                                 collision_normal->set(0, 0, (dir.Z > 0) ? -1 : 1);
  84                                 return true;
  85                         }
  86                 }
  87         }
  88         return false;
  89 }