1 /* $Id$ */

     2 

     3 /** @file animated_tile.cpp Everything related to animated tiles. */

     4 

     5 #include "stdafx.h"

     6 #include "openttd.h"

     7 #include "saveload.h"

     8 #include "landscape.h"

     9 #include "core/alloc_func.hpp"

    10 #include "functions.h"

    11 

    12 /** The table/list with animated tiles. */

    13 TileIndex *_animated_tile_list = NULL;

    14 /** The number of animated tiles in the current state. */

    15 uint _animated_tile_count = 0;

    16 /** The number of slots for animated tiles allocated currently. */

    17 static uint _animated_tile_allocated = 0;

    18 

    19 /**

    20  * Removes the given tile from the animated tile table.

    21  * @param tile the tile to remove

    22  */

    23 void DeleteAnimatedTile(TileIndex tile)

    24 {

    25 	for (TileIndex *ti = _animated_tile_list; ti < _animated_tile_list + _animated_tile_count; ti++) {

    26 		if (tile == *ti) {

    27 			/* Remove the hole

    28 			 * The order of the remaining elements must stay the same, otherwise the animation loop

    29 			 * may miss a tile; that's why we must use memmove instead of just moving the last element.

    30 			 */

    31 			memmove(ti, ti + 1, (_animated_tile_list + _animated_tile_count - (ti + 1)) * sizeof(*ti));

    32 			_animated_tile_count--;

    33 			MarkTileDirtyByTile(tile);

    34 			return;

    35 		}

    36 	}

    37 }

    38 

    39 /**

    40  * Add the given tile to the animated tile table (if it does not exist

    41  * on that table yet). Also increases the size of the table if necessary.

    42  * @param tile the tile to make animated

    43  */

    44 void AddAnimatedTile(TileIndex tile)

    45 {

    46 	MarkTileDirtyByTile(tile);

    47 

    48 	for (const TileIndex *ti = _animated_tile_list; ti < _animated_tile_list + _animated_tile_count; ti++) {

    49 		if (tile == *ti) return;

    50 	}

    51 

    52 	/* Table not large enough, so make it larger */

    53 	if (_animated_tile_count == _animated_tile_allocated) {

    54 		_animated_tile_allocated *= 2;

    55 		_animated_tile_list = ReallocT<TileIndex>(_animated_tile_list, _animated_tile_allocated);

    56 	}

    57 

    58 	_animated_tile_list[_animated_tile_count] = tile;

    59 	_animated_tile_count++;

    60 }

    61 

    62 /**

    63  * Animate all tiles in the animated tile list, i.e.\ call AnimateTile on them.

    64  */

    65 void AnimateAnimatedTiles()

    66 {

    67 	const TileIndex *ti = _animated_tile_list;

    68 	while (ti < _animated_tile_list + _animated_tile_count) {

    69 		const TileIndex curr = *ti;

    70 		AnimateTile(curr);

    71 		/* During the AnimateTile call, DeleteAnimatedTile could have been called,

    72 		 * deleting an element we've already processed and pushing the rest one

    73 		 * slot to the left. We can detect this by checking whether the index

    74 		 * in the current slot has changed - if it has, an element has been deleted,

    75 		 * and we should process the current slot again instead of going forward.

    76 		 * NOTE: this will still break if more than one animated tile is being

    77 		 *       deleted during the same AnimateTile call, but no code seems to

    78 		 *       be doing this anyway.

    79 		 */

    80 		if (*ti == curr) ++ti;

    81 	}

    82 }

    83 

    84 /**

    85  * Initialize all animated tile variables to some known begin point

    86  */

    87 void InitializeAnimatedTiles()

    88 {

    89 	_animated_tile_list = ReallocT<TileIndex>(_animated_tile_list, 256);

    90 	_animated_tile_count = 0;

    91 	_animated_tile_allocated = 256;

    92 }

    93 

    94 /**

    95  * Save the ANIT chunk.

    96  */

    97 static void Save_ANIT()

    98 {

    99 	SlSetLength(_animated_tile_count * sizeof(*_animated_tile_list));

   100 	SlArray(_animated_tile_list, _animated_tile_count, SLE_UINT32);

   101 }

   102 

   103 /**

   104  * Load the ANIT chunk; the chunk containing the animated tiles.

   105  */

   106 static void Load_ANIT()

   107 {

   108 	/* Before version 80 we did NOT have a variable length animated tile table */

   109 	if (CheckSavegameVersion(80)) {

   110 		/* In pre version 6, we has 16bit per tile, now we have 32bit per tile, convert it ;) */

   111 		SlArray(_animated_tile_list, 256, CheckSavegameVersion(6) ? (SLE_FILE_U16 | SLE_VAR_U32) : SLE_UINT32);

   112 

   113 		for (_animated_tile_count = 0; _animated_tile_count < 256; _animated_tile_count++) {

   114 			if (_animated_tile_list[_animated_tile_count] == 0) break;

   115 		}

   116 		return;

   117 	}

   118 

   119 	_animated_tile_count = SlGetFieldLength() / sizeof(*_animated_tile_list);

   120 

   121 	/* Determine a nice rounded size for the amount of allocated tiles */

   122 	_animated_tile_allocated = 256;

   123 	while (_animated_tile_allocated < _animated_tile_count) _animated_tile_allocated *= 2;

   124 

   125 	_animated_tile_list = ReallocT<TileIndex>(_animated_tile_list, _animated_tile_allocated);

   126 	SlArray(_animated_tile_list, _animated_tile_count, SLE_UINT32);

   127 }

   128 

   129 /**

   130  * "Definition" imported by the saveload code to be able to load and save

   131  * the animated tile table.

   132  */

   133 extern const ChunkHandler _animated_tile_chunk_handlers[] = {

   134 	{ 'ANIT', Save_ANIT, Load_ANIT, CH_RIFF | CH_LAST},

   135 };