Function TileLoop_Water

src/water_cmd.cpp:1269–1322

* Let a water tile floods its diagonal adjoining tiles * called from tunnelbridge_cmd, and by TileLoop_Industry() and TileLoop_Track() * * @param tile the water/shore tile that floods */

 * @param tile the water/shore tile that floods
 */
void TileLoop_Water(TileIndex tile)
{
	if (IsTileType(tile, MP_WATER)) {
		AmbientSoundEffect(tile);
		if (IsNonFloodingWaterTile(tile)) return;
	}

	switch (GetFloodingBehaviour(tile)) {
		case FLOOD_ACTIVE: {
			bool continue_flooding = false;
			for (Direction dir = DIR_BEGIN; dir < DIR_END; dir++) {
				TileIndex dest = AddTileIndexDiffCWrap(tile, TileIndexDiffCByDir(dir));
				/* Contrary to drying up, flooding does not consider MP_VOID tiles. */
				if (!IsValidTile(dest)) continue;
				/* do not try to flood water tiles - increases performance a lot */
				if (IsTileType(dest, MP_WATER)) continue;

				/* Buoys and docks cannot be flooded, and when removed turn into flooding water. */
				if (IsTileType(dest, MP_STATION) && (IsBuoy(dest) || IsDock(dest))) continue;

				/* This neighbour tile might be floodable later if the tile is cleared, so allow flooding to continue. */
				continue_flooding = true;

				/* TREE_GROUND_SHORE is the sign of a previous flood. */
				if (IsTileType(dest, MP_TREES) && GetTreeGround(dest) == TREE_GROUND_SHORE) continue;

				auto [slope_dest, z_dest] = GetFoundationSlope(dest);
				if (z_dest > 0) continue;

				if (!_flood_from_dirs[slope_dest & ~SLOPE_HALFTILE_MASK & ~SLOPE_STEEP].Test(ReverseDir(dir))) continue;

				DoFloodTile(dest);
			}
			if (!continue_flooding && IsTileType(tile, MP_WATER)) SetNonFloodingWaterTile(tile, true);
			break;
		}

		case FLOOD_DRYUP: {
			Slope slope_here = std::get<0>(GetFoundationSlope(tile)) & ~SLOPE_HALFTILE_MASK & ~SLOPE_STEEP;
			for (Direction dir : _flood_from_dirs[slope_here]) {
				TileIndex dest = AddTileIndexDiffCWrap(tile, TileIndexDiffCByDir(dir));
				/* Contrary to flooding, drying up does consider MP_VOID tiles. */
				if (dest == INVALID_TILE) continue;

				FloodingBehaviour dest_behaviour = GetFloodingBehaviour(dest);
				if ((dest_behaviour == FLOOD_ACTIVE) || (dest_behaviour == FLOOD_PASSIVE)) return;
			}
			DoDryUp(tile);
			break;
		}

		default: return;
	}
}

void ConvertGroundTilesIntoWaterTiles()
{