src/animated_tile.cpp

   1 /* $Id$ */
   2
   3 /*
   4  * This file is part of OpenTTD.
   5  * OpenTTD is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, version 2.
   6  * OpenTTD is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
   7  * See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with OpenTTD. If not, see <http://www.gnu.org/licenses/>.
   8  */
   9
  10 /** @file animated_tile.cpp Everything related to animated tiles. */
  11
  12 #include "stdafx.h"
  13 #include "core/alloc_func.hpp"
  14 #include "tile_cmd.h"
  15 #include "viewport_func.h"
  16
  17 /** The table/list with animated tiles. */
  18 TileIndex *_animated_tile_list = NULL;
  19 /** The number of animated tiles in the current state. */
  20 uint _animated_tile_count = 0;
  21 /** The number of slots for animated tiles allocated currently. */
  22 uint _animated_tile_allocated = 0;
  23
  24 /**
  25  * Removes the given tile from the animated tile table.
  26  * @param tile the tile to remove
  27  */
  28 void DeleteAnimatedTile(TileIndex tile)
  29 {
  30         for (TileIndex *ti = _animated_tile_list; ti < _animated_tile_list + _animated_tile_count; ti++) {
  31                 if (tile == *ti) {
  32                         /* Remove the hole
  33                          * The order of the remaining elements must stay the same, otherwise the animation loop
  34                          * may miss a tile; that's why we must use memmove instead of just moving the last element.
  35                          */
  36                         memmove(ti, ti + 1, (_animated_tile_list + _animated_tile_count - (ti + 1)) * sizeof(*ti));
  37                         _animated_tile_count--;
  38                         MarkTileDirtyByTile(tile);
  39                         return;
  40                 }
  41         }
  42 }
  43
  44 /**
  45  * Add the given tile to the animated tile table (if it does not exist
  46  * on that table yet). Also increases the size of the table if necessary.
  47  * @param tile the tile to make animated
  48  */
  49 void AddAnimatedTile(TileIndex tile)
  50 {
  51         MarkTileDirtyByTile(tile);
  52
  53         for (const TileIndex *ti = _animated_tile_list; ti < _animated_tile_list + _animated_tile_count; ti++) {
  54                 if (tile == *ti) return;
  55         }
  56
  57         /* Table not large enough, so make it larger */
  58         if (_animated_tile_count == _animated_tile_allocated) {
  59                 _animated_tile_allocated *= 2;
  60                 _animated_tile_list = ReallocT<TileIndex>(_animated_tile_list, _animated_tile_allocated);
  61         }
  62
  63         _animated_tile_list[_animated_tile_count] = tile;
  64         _animated_tile_count++;
  65 }
  66
  67 /**
  68  * Animate all tiles in the animated tile list, i.e.\ call AnimateTile on them.
  69  */
  70 void AnimateAnimatedTiles()
  71 {
  72         const TileIndex *ti = _animated_tile_list;
  73         while (ti < _animated_tile_list + _animated_tile_count) {
  74                 const TileIndex curr = *ti;
  75                 AnimateTile(curr);
  76                 /* During the AnimateTile call, DeleteAnimatedTile could have been called,
  77                  * deleting an element we've already processed and pushing the rest one
  78                  * slot to the left. We can detect this by checking whether the index
  79                  * in the current slot has changed - if it has, an element has been deleted,
  80                  * and we should process the current slot again instead of going forward.
  81                  * NOTE: this will still break if more than one animated tile is being
  82                  *       deleted during the same AnimateTile call, but no code seems to
  83                  *       be doing this anyway.
  84                  */
  85                 if (*ti == curr) ++ti;
  86         }
  87 }
  88
  89 /**
  90  * Initialize all animated tile variables to some known begin point
  91  */
  92 void InitializeAnimatedTiles()
  93 {
  94         _animated_tile_list = ReallocT<TileIndex>(_animated_tile_list, 256);
  95         _animated_tile_count = 0;
  96         _animated_tile_allocated = 256;
  97 }