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 #include "safeguards.h"
  18
  19 /** The table/list with animated tiles. */
  20 TileIndex *_animated_tile_list = nullptr;
  21 /** The number of animated tiles in the current state. */
  22 uint _animated_tile_count = 0;
  23 /** The number of slots for animated tiles allocated currently. */
  24 uint _animated_tile_allocated = 0;
  25
  26 /**
  27  * Removes the given tile from the animated tile table.
  28  * @param tile the tile to remove
  29  */
  30 void DeleteAnimatedTile(TileIndex tile)
  31 {
  32         for (TileIndex *ti = _animated_tile_list; ti < _animated_tile_list + _animated_tile_count; ti++) {
  33                 if (tile == *ti) {
  34                         /* Remove the hole
  35                          * The order of the remaining elements must stay the same, otherwise the animation loop
  36                          * may miss a tile; that's why we must use memmove instead of just moving the last element.
  37                          */
  38                         memmove(ti, ti + 1, (_animated_tile_list + _animated_tile_count - (ti + 1)) * sizeof(*ti));
  39                         _animated_tile_count--;
  40                         MarkTileDirtyByTile(tile, ZOOM_LVL_DRAW_MAP);
  41                         return;
  42                 }
  43         }
  44 }
  45
  46 /**
  47  * Add the given tile to the animated tile table (if it does not exist
  48  * on that table yet). Also increases the size of the table if necessary.
  49  * @param tile the tile to make animated
  50  */
  51 void AddAnimatedTile(TileIndex tile)
  52 {
  53         MarkTileDirtyByTile(tile, ZOOM_LVL_DRAW_MAP);
  54
  55         for (const TileIndex *ti = _animated_tile_list; ti < _animated_tile_list + _animated_tile_count; ti++) {
  56                 if (tile == *ti) return;
  57         }
  58
  59         /* Table not large enough, so make it larger */
  60         if (_animated_tile_count == _animated_tile_allocated) {
  61                 _animated_tile_allocated *= 2;
  62                 _animated_tile_list = ReallocT<TileIndex>(_animated_tile_list, _animated_tile_allocated);
  63         }
  64
  65         _animated_tile_list[_animated_tile_count] = tile;
  66         _animated_tile_count++;
  67 }
  68
  69 /**
  70  * Animate all tiles in the animated tile list, i.e.\ call AnimateTile on them.
  71  */
  72 void AnimateAnimatedTiles()
  73 {
  74         const TileIndex *ti = _animated_tile_list;
  75         while (ti < _animated_tile_list + _animated_tile_count) {
  76                 const TileIndex curr = *ti;
  77                 AnimateTile(curr);
  78                 /* During the AnimateTile call, DeleteAnimatedTile could have been called,
  79                  * deleting an element we've already processed and pushing the rest one
  80                  * slot to the left. We can detect this by checking whether the index
  81                  * in the current slot has changed - if it has, an element has been deleted,
  82                  * and we should process the current slot again instead of going forward.
  83                  * NOTE: this will still break if more than one animated tile is being
  84                  *       deleted during the same AnimateTile call, but no code seems to
  85                  *       be doing this anyway.
  86                  */
  87                 if (*ti == curr) ++ti;
  88         }
  89 }
  90
  91 /**
  92  * Initialize all animated tile variables to some known begin point
  93  */
  94 void InitializeAnimatedTiles()
  95 {
  96         _animated_tile_list = ReallocT<TileIndex>(_animated_tile_list, 256);
  97         _animated_tile_count = 0;
  98         _animated_tile_allocated = 256;
  99 }