src/voxelalgorithms.h

   1 /*
   2 Minetest
   3 Copyright (C) 2010-2013 celeron55, Perttu Ahola <celeron55@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 #pragma once
  21
  22 #include "voxel.h"
  23 #include "mapnode.h"
  24 #include "util/container.h"
  25
  26 class Map;
  27 class ServerMap;
  28 class MapBlock;
  29 class MMVManip;
  30
  31 namespace voxalgo
  32 {
  33
  34 /*!
  35  * Updates the lighting on the map.
  36  * The result will be correct only if
  37  * no nodes were changed except the given ones.
  38  * Before calling this procedure make sure that all new nodes on
  39  * the map have zero light level!
  40  *
  41  * \param oldnodes contains the MapNodes that were replaced by the new
  42  * MapNodes and their positions
  43  * \param modified_blocks output, contains all map blocks that
  44  * the function modified
  45  */
  46 void update_lighting_nodes(
  47         Map *map,
  48         std::vector<std::pair<v3s16, MapNode> > &oldnodes,
  49         std::map<v3s16, MapBlock*> &modified_blocks);
  50
  51 /*!
  52  * Updates borders of the given mapblock.
  53  * Only updates if the block was marked with incomplete
  54  * lighting and the neighbor is also loaded.
  55  *
  56  * \param block the block to update
  57  * \param modified_blocks output, contains all map blocks that
  58  * the function modified
  59  */
  60 void update_block_border_lighting(Map *map, MapBlock *block,
  61         std::map<v3s16, MapBlock*> &modified_blocks);
  62
  63 /*!
  64  * Copies back nodes from a voxel manipulator
  65  * to the map and updates lighting.
  66  * For server use only.
  67  *
  68  * \param modified_blocks output, contains all map blocks that
  69  * the function modified
  70  */
  71 void blit_back_with_light(ServerMap *map, MMVManip *vm,
  72         std::map<v3s16, MapBlock*> *modified_blocks);
  73
  74 /*!
  75  * Corrects the light in a map block.
  76  * For server use only.
  77  *
  78  * \param block the block to update
  79  */
  80 void repair_block_light(ServerMap *map, MapBlock *block,
  81         std::map<v3s16, MapBlock*> *modified_blocks);
  82
  83 /*!
  84  * This class iterates trough voxels that intersect with
  85  * a line. The collision detection does not see nodeboxes,
  86  * every voxel is a cube and is returned.
  87  * This iterator steps to all nodes exactly once.
  88  */
  89 struct VoxelLineIterator
  90 {
  91 public:
  92         //! Starting position of the line in world coordinates.
  93         v3f m_start_position;
  94         //! Direction and length of the line in world coordinates.
  95         v3f m_line_vector;
  96         /*!
  97          * Each component stores the next smallest positive number, by
  98          * which multiplying the line's vector gives a vector that ends
  99          * on the intersection of two nodes.
 100          */
 101         v3f m_next_intersection_multi { 10000.0f, 10000.0f, 10000.0f };
 102         /*!
 103          * Each component stores the smallest positive number, by which
 104          * m_next_intersection_multi's components can be increased.
 105          */
 106         v3f m_intersection_multi_inc { 10000.0f, 10000.0f, 10000.0f };
 107         /*!
 108          * Direction of the line. Each component can be -1 or 1 (if a
 109          * component of the line's vector is 0, then there will be 1).
 110          */
 111         v3s16 m_step_directions { 1, 1, 1 };
 112         //! Position of the current node.
 113         v3s16 m_current_node_pos;
 114         //! Index of the current node
 115         s16 m_current_index = 0;
 116         //! Position of the start node.
 117         v3s16 m_start_node_pos;
 118         //! Index of the last node
 119         s16 m_last_index;
 120
 121         /*!
 122          * Creates a voxel line iterator with the given line.
 123          * @param start_position starting point of the line
 124          * in voxel coordinates
 125          * @param line_vector    length and direction of the
 126          * line in voxel coordinates. start_position+line_vector
 127          * is the end of the line
 128          */
 129         VoxelLineIterator(const v3f &start_position,const v3f &line_vector);
 130
 131         /*!
 132          * Steps to the next voxel.
 133          * Updates m_current_node_pos and
 134          * m_previous_node_pos.
 135          * Note that it works even if hasNext() is false,
 136          * continuing the line as a ray.
 137          */
 138         void next();
 139
 140         /*!
 141          * Returns true if the next voxel intersects the given line.
 142          */
 143         inline bool hasNext() const
 144         {
 145                 return m_current_index < m_last_index;
 146         }
 147
 148         /*!
 149          * Returns how many times next() must be called until
 150          * voxel==m_current_node_pos.
 151          * If voxel does not intersect with the line,
 152          * the result is undefined.
 153          */
 154         s16 getIndex(v3s16 voxel);
 155 };
 156
 157 } // namespace voxalgo