/**
* Function performing a search around a center tile and going outward, thus in circle.
* Although it really is a square search...
* Every tile will be tested by means of the callback function proc,
* which will determine if yes or no the given tile meets criteria of search.
* @param tile to start the search from. Upon completion, it will return the tile matching the search
* @param size: number of tiles per side of the desired search area
* @param proc: callback testing function pointer.
* @param user_data to be passed to the callback function. Depends on the implementation
* @return result of the search
* @pre proc != NULL
* @pre size > 0
*/
bool CircularTileSearch(TileIndex *tile, uint size, TestTileOnSearchProc proc, void *user_data)
{
assert(proc != NULL);
assert(size > 0);
if (size % 2 == 1) {
/* If the length of the side is uneven, the center has to be checked
* separately, as the pattern of uneven sides requires to go around the center */
if (proc(*tile, user_data)) return true;
/* If tile test is not successful, get one tile up,
* ready for a test in first circle around center tile */
*tile = TILE_ADD(*tile, TileOffsByDir(DIR_N));
return CircularTileSearch(tile, size / 2, 1, 1, proc, user_data);
} else {
return CircularTileSearch(tile, size / 2, 0, 0, proc, user_data);
}
}
static uint32 GetRailContinuationInfo(TileIndex tile)
{
/* Tile offsets and exit dirs for X axis */
static const Direction x_dir[8] = { DIR_SW, DIR_NE, DIR_SE, DIR_NW, DIR_S, DIR_E, DIR_W, DIR_N };
static const DiagDirection x_exits[8] = { DIAGDIR_SW, DIAGDIR_NE, DIAGDIR_SE, DIAGDIR_NW, DIAGDIR_SW, DIAGDIR_NE, DIAGDIR_SW, DIAGDIR_NE };
/* Tile offsets and exit dirs for Y axis */
static const Direction y_dir[8] = { DIR_SE, DIR_NW, DIR_SW, DIR_NE, DIR_S, DIR_W, DIR_E, DIR_N };
static const DiagDirection y_exits[8] = { DIAGDIR_SE, DIAGDIR_NW, DIAGDIR_SW, DIAGDIR_NE, DIAGDIR_SE, DIAGDIR_NW, DIAGDIR_SE, DIAGDIR_NW };
Axis axis = GetRailStationAxis(tile);
/* Choose appropriate lookup table to use */
const Direction *dir = axis == AXIS_X ? x_dir : y_dir;
const DiagDirection *diagdir = axis == AXIS_X ? x_exits : y_exits;
uint32 res = 0;
uint i;
for (i = 0; i < lengthof(x_dir); i++, dir++, diagdir++) {
TileIndex neighbour_tile = tile + TileOffsByDir(*dir);
TrackBits trackbits = TrackStatusToTrackBits(GetTileTrackStatus(neighbour_tile, TRANSPORT_RAIL, 0));
if (trackbits != TRACK_BIT_NONE) {
/* If there is any track on the tile, set the bit in the second byte */
SetBit(res, i + 8);
/* With tunnels and bridges the tile has tracks, but they are not necessarily connected
* with the next tile because the ramp is not going in the right direction. */
if (IsTileType(neighbour_tile, MP_TUNNELBRIDGE) && GetTunnelBridgeDirection(neighbour_tile) != *diagdir) {
continue;
}
/* If any track reaches our exit direction, set the bit in the lower byte */
if (trackbits & DiagdirReachesTracks(*diagdir)) SetBit(res, i);
}
}
return res;
}
/**
* Marks the tiles around a tile as dirty, if they are canals or rivers.
*
* @param tile The center of the tile where all other tiles are marked as dirty
* @ingroup dirty
*/
static void MarkCanalsAndRiversAroundDirty(TileIndex tile)
{
for (Direction dir = DIR_BEGIN; dir < DIR_END; dir++) {
MarkTileDirtyIfCanalOrRiver(tile + TileOffsByDir(dir));
}
}
static void TileLoop_Trees(TileIndex tile)
{
if (GetTreeGround(tile) == TREE_GROUND_SHORE) {
TileLoop_Water(tile);
} else {
switch (_settings_game.game_creation.landscape) {
case LT_TROPIC: TileLoopTreesDesert(tile); break;
case LT_ARCTIC: TileLoopTreesAlps(tile); break;
}
}
TileLoopClearHelper(tile);
uint treeCounter = GetTreeCounter(tile);
/* Handle growth of grass (under trees/on MP_TREES tiles) at every 8th processings, like it's done for grass on MP_CLEAR tiles. */
if ((treeCounter & 7) == 7 && GetTreeGround(tile) == TREE_GROUND_GRASS) {
uint density = GetTreeDensity(tile);
if (density < 3) {
SetTreeGroundDensity(tile, TREE_GROUND_GRASS, density + 1);
MarkTileDirtyByTile(tile);
}
}
if (GetTreeCounter(tile) < 15) {
AddTreeCounter(tile, 1);
return;
}
SetTreeCounter(tile, 0);
switch (GetTreeGrowth(tile)) {
case 3: // regular sized tree
if (_settings_game.game_creation.landscape == LT_TROPIC &&
GetTreeType(tile) != TREE_CACTUS &&
GetTropicZone(tile) == TROPICZONE_DESERT) {
AddTreeGrowth(tile, 1);
} else {
switch (GB(Random(), 0, 3)) {
case 0: // start destructing
AddTreeGrowth(tile, 1);
break;
case 1: // add a tree
if (GetTreeCount(tile) < 4) {
AddTreeCount(tile, 1);
SetTreeGrowth(tile, 0);
break;
}
/* FALL THROUGH */
case 2: { // add a neighbouring tree
/* Don't plant extra trees if that's not allowed. */
if ((_settings_game.game_creation.landscape == LT_TROPIC && GetTropicZone(tile) == TROPICZONE_RAINFOREST) ?
_settings_game.construction.extra_tree_placement == ETP_NONE :
_settings_game.construction.extra_tree_placement != ETP_ALL) {
break;
}
TreeType treetype = GetTreeType(tile);
tile += TileOffsByDir((Direction)(Random() & 7));
/* Cacti don't spread */
if (!CanPlantTreesOnTile(tile, false)) return;
/* Don't plant trees, if ground was freshly cleared */
if (IsTileType(tile, MP_CLEAR) && GetClearGround(tile) == CLEAR_GRASS && GetClearDensity(tile) != 3) return;
PlantTreesOnTile(tile, treetype, 0, 0);
break;
}
default:
return;
}
}
break;
case 6: // final stage of tree destruction
if (GetTreeCount(tile) > 1) {
/* more than one tree, delete it */
AddTreeCount(tile, -1);
SetTreeGrowth(tile, 3);
} else {
/* just one tree, change type into MP_CLEAR */
switch (GetTreeGround(tile)) {
case TREE_GROUND_SHORE: MakeShore(tile); break;
case TREE_GROUND_GRASS: MakeClear(tile, CLEAR_GRASS, GetTreeDensity(tile)); break;
case TREE_GROUND_ROUGH: MakeClear(tile, CLEAR_ROUGH, 3); break;
case TREE_GROUND_ROUGH_SNOW: {
uint density = GetTreeDensity(tile);
MakeClear(tile, CLEAR_ROUGH, 3);
MakeSnow(tile, density);
break;
}
default: // snow or desert
if (_settings_game.game_creation.landscape == LT_TROPIC) {
MakeClear(tile, CLEAR_DESERT, GetTreeDensity(tile));
} else {
uint density = GetTreeDensity(tile);
MakeClear(tile, CLEAR_GRASS, 3);
MakeSnow(tile, density);
}
break;
}
}
break;
default:
AddTreeGrowth(tile, 1);
break;
}
MarkTileDirtyByTile(tile);
}
