src/clear_cmd.cpp
author maedhros
Tue, 20 Mar 2007 13:47:00 +0000
changeset 6343 76d17f784c13
parent 6248 e4a2ed7e5613
child 6357 f0f5e7d1713c
permissions -rw-r--r--
(svn r9371) -Feature: Add support for variable snow lines in the arctic climate, supplied
by newgrf files. When this is enabled forests cannot be built below the highest
snow line, and farms can't be built above it. Houses still use the
_opt.snow_line so they are all consistent, so to make them respect the snowline
you may want to use some newhouses features as well.
/* $Id$ */

/** @file clear_cmd.cpp */

#include "stdafx.h"
#include "openttd.h"
#include "clear_map.h"
#include "rail_map.h"
#include "table/strings.h"
#include "functions.h"
#include "map.h"
#include "player.h"
#include "tile.h"
#include "viewport.h"
#include "command.h"
#include "tunnel_map.h"
#include "bridge_map.h"
#include "bridge.h"
#include "landscape.h"
#include "variables.h"
#include "table/sprites.h"
#include "unmovable_map.h"
#include "genworld.h"
#include "industry.h"

struct TerraformerHeightMod {
	TileIndex tile;
	byte height;
};

struct TerraformerState {
	int height[4];
	uint32 flags;

	int direction;
	int modheight_count;
	int tile_table_count;

	int32 cost;

	TileIndex *tile_table;
	TerraformerHeightMod *modheight;

};

static int TerraformAllowTileProcess(TerraformerState *ts, TileIndex tile)
{
	TileIndex *t;
	int count;

	if (TileX(tile) == MapMaxX() || TileY(tile) == MapMaxY()) return -1;

	t = ts->tile_table;
	for (count = ts->tile_table_count; count != 0; count--, t++) {
		if (*t == tile) return 0;
	}

	return 1;
}

static int TerraformGetHeightOfTile(TerraformerState *ts, TileIndex tile)
{
	TerraformerHeightMod *mod = ts->modheight;
	int count;

	for (count = ts->modheight_count; count != 0; count--, mod++) {
		if (mod->tile == tile) return mod->height;
	}

	return TileHeight(tile);
}

static void TerraformAddDirtyTile(TerraformerState *ts, TileIndex tile)
{
	int count;
	TileIndex *t;

	count = ts->tile_table_count;

	if (count >= 625) return;

	for (t = ts->tile_table; count != 0; count--,t++) {
		if (*t == tile) return;
	}

	ts->tile_table[ts->tile_table_count++] = tile;
}

static void TerraformAddDirtyTileAround(TerraformerState *ts, TileIndex tile)
{
	TerraformAddDirtyTile(ts, tile + TileDiffXY( 0, -1));
	TerraformAddDirtyTile(ts, tile + TileDiffXY(-1, -1));
	TerraformAddDirtyTile(ts, tile + TileDiffXY(-1,  0));
	TerraformAddDirtyTile(ts, tile);
}

static int TerraformProc(TerraformerState *ts, TileIndex tile, int mode)
{
	int r;
	int32 ret;

	assert(tile < MapSize());

	r = TerraformAllowTileProcess(ts, tile);
	if (r <= 0) return r;

	if (IsTileType(tile, MP_RAILWAY)) {
		static const TrackBits safe_track[] = { TRACK_BIT_LOWER, TRACK_BIT_LEFT, TRACK_BIT_UPPER, TRACK_BIT_RIGHT };
		static const Slope unsafe_slope[] = { SLOPE_S, SLOPE_W, SLOPE_N, SLOPE_E };

		Slope tileh;
		uint z;

		/* Nothing could be built at the steep slope - this avoids a bug
		 * when you have a single diagonal track in one corner on a
		 * basement and then you raise/lower the other corner. */
		tileh = GetTileSlope(tile, &z);
		if (tileh == unsafe_slope[mode] ||
				tileh == ComplementSlope(unsafe_slope[mode])) {
			_terraform_err_tile = tile;
			_error_message = STR_1008_MUST_REMOVE_RAILROAD_TRACK;
			return -1;
		}

		/* If we have a single diagonal track there, the other side of
		 * tile can be terraformed. */
		if (IsPlainRailTile(tile) && GetTrackBits(tile) == safe_track[mode]) {
			/* If terraforming downwards prevent damaging a potential tunnel below.
			 * This check is only necessary for flat tiles, because if the tile is
			 * non-flat, then the corner opposing the rail is raised. Only this corner
			 * can be lowered and this is a safe action
			 */
			if (tileh == SLOPE_FLAT &&
					ts->direction == -1 &&
					IsTunnelInWay(tile, z - TILE_HEIGHT)) {
				_terraform_err_tile = tile;
				_error_message = STR_1002_EXCAVATION_WOULD_DAMAGE;
				return -1;
			}
			return 0;
		}
	}

	ret = DoCommand(tile, 0,0, ts->flags & ~DC_EXEC, CMD_LANDSCAPE_CLEAR);

	if (CmdFailed(ret)) {
		_terraform_err_tile = tile;
		return -1;
	}

	ts->cost += ret;

	if (ts->tile_table_count >= 625) return -1;
	ts->tile_table[ts->tile_table_count++] = tile;

	return 0;
}

static bool TerraformTileHeight(TerraformerState *ts, TileIndex tile, int height)
{
	int nh;
	TerraformerHeightMod *mod;
	int count;

	assert(tile < MapSize());

	if (height < 0) {
		_error_message = STR_1003_ALREADY_AT_SEA_LEVEL;
		return false;
	}

	_error_message = STR_1004_TOO_HIGH;

	if (height > 15) return false;

	nh = TerraformGetHeightOfTile(ts, tile);
	if (nh < 0 || height == nh) return false;

	if (TerraformProc(ts, tile, 0) < 0) return false;
	if (TerraformProc(ts, tile + TileDiffXY( 0, -1), 1) < 0) return false;
	if (TerraformProc(ts, tile + TileDiffXY(-1, -1), 2) < 0) return false;
	if (TerraformProc(ts, tile + TileDiffXY(-1,  0), 3) < 0) return false;

	mod = ts->modheight;
	count = ts->modheight_count;

	for (;;) {
		if (count == 0) {
			if (ts->modheight_count >= 576) return false;
			ts->modheight_count++;
			break;
		}
		if (mod->tile == tile) break;
		mod++;
		count--;
	}

	mod->tile = tile;
	mod->height = (byte)height;

	ts->cost += _price.terraform;

	{
		int direction = ts->direction, r;
		const TileIndexDiffC *ttm;

		static const TileIndexDiffC _terraform_tilepos[] = {
			{ 1,  0},
			{-2,  0},
			{ 1,  1},
			{ 0, -2}
		};

		for (ttm = _terraform_tilepos; ttm != endof(_terraform_tilepos); ttm++) {
			tile += ToTileIndexDiff(*ttm);

			r = TerraformGetHeightOfTile(ts, tile);
			if (r != height && r-direction != height && r+direction != height) {
				if (!TerraformTileHeight(ts, tile, r+direction))
					return false;
			}
		}
	}

	return true;
}

/** Terraform land
 * @param tile tile to terraform
 * @param flags for this command type
 * @param p1 corners to terraform.
 * @param p2 direction; eg up or down
 * @return error or cost of terraforming
 */
int32 CmdTerraformLand(TileIndex tile, uint32 flags, uint32 p1, uint32 p2)
{
	TerraformerState ts;
	TileIndex t;
	int direction;

	TerraformerHeightMod modheight_data[576];
	TileIndex tile_table_data[625];

	SET_EXPENSES_TYPE(EXPENSES_CONSTRUCTION);

	_terraform_err_tile = 0;

	ts.direction = direction = p2 ? 1 : -1;
	ts.flags = flags;
	ts.modheight_count = ts.tile_table_count = 0;
	ts.cost = 0;
	ts.modheight = modheight_data;
	ts.tile_table = tile_table_data;

	/* Make an extra check for map-bounds cause we add tiles to the originating tile */
	if (tile + TileDiffXY(1, 1) >= MapSize()) return CMD_ERROR;

	if (p1 & 1) {
		t = tile + TileDiffXY(1, 0);
		if (!TerraformTileHeight(&ts, t, TileHeight(t) + direction)) {
			return CMD_ERROR;
		}
	}

	if (p1 & 2) {
		t = tile + TileDiffXY(1, 1);
		if (!TerraformTileHeight(&ts, t, TileHeight(t) + direction)) {
			return CMD_ERROR;
		}
	}

	if (p1 & 4) {
		t = tile + TileDiffXY(0, 1);
		if (!TerraformTileHeight(&ts, t, TileHeight(t) + direction)) {
			return CMD_ERROR;
		}
	}

	if (p1 & 8) {
		t = tile + TileDiffXY(0, 0);
		if (!TerraformTileHeight(&ts, t, TileHeight(t) + direction)) {
			return CMD_ERROR;
		}
	}

	{
		/* Check if tunnel would take damage */
		int count;
		TileIndex *ti = ts.tile_table;

		for (count = ts.tile_table_count; count != 0; count--, ti++) {
			TileIndex tile = *ti;

			if (MayHaveBridgeAbove(tile) && IsBridgeAbove(tile)) {
				return_cmd_error(STR_5007_MUST_DEMOLISH_BRIDGE_FIRST);
			}

			if (direction == -1) {
				uint z, t;

				z = TerraformGetHeightOfTile(&ts, tile + TileDiffXY(0, 0));
				t = TerraformGetHeightOfTile(&ts, tile + TileDiffXY(1, 0));
				if (t <= z) z = t;
				t = TerraformGetHeightOfTile(&ts, tile + TileDiffXY(1, 1));
				if (t <= z) z = t;
				t = TerraformGetHeightOfTile(&ts, tile + TileDiffXY(0, 1));
				if (t <= z) z = t;

				if (IsTunnelInWay(tile, z * TILE_HEIGHT)) {
					return_cmd_error(STR_1002_EXCAVATION_WOULD_DAMAGE);
				}
			}
		}
	}

	if (flags & DC_EXEC) {
		/* Clear the landscape at the tiles */
		{
			int count;
			TileIndex *ti = ts.tile_table;
			for (count = ts.tile_table_count; count != 0; count--, ti++) {
				DoCommand(*ti, 0, 0, flags, CMD_LANDSCAPE_CLEAR);
			}
		}

		/* change the height */
		{
			int count;
			TerraformerHeightMod *mod;

			mod = ts.modheight;
			for (count = ts.modheight_count; count != 0; count--, mod++) {
				TileIndex til = mod->tile;

				SetTileHeight(til, mod->height);
				TerraformAddDirtyTileAround(&ts, til);
			}
		}

		/* finally mark the dirty tiles dirty */
		{
			int count;
			TileIndex *ti = ts.tile_table;
			for (count = ts.tile_table_count; count != 0; count--, ti++) {
				MarkTileDirtyByTile(*ti);
			}
		}
	}
	return ts.cost;
}


/** Levels a selected (rectangle) area of land
 * @param tile end tile of area-drag
 * @param flags for this command type
 * @param p1 start tile of area drag
 * @param p2 unused
 * @return  error or cost of terraforming
 */
int32 CmdLevelLand(TileIndex tile, uint32 flags, uint32 p1, uint32 p2)
{
	int size_x, size_y;
	int ex;
	int ey;
	int sx, sy;
	uint h, curh;
	int32 ret, cost, money;

	if (p1 >= MapSize()) return CMD_ERROR;

	SET_EXPENSES_TYPE(EXPENSES_CONSTRUCTION);

	/* remember level height */
	h = TileHeight(p1);

	/* make sure sx,sy are smaller than ex,ey */
	ex = TileX(tile);
	ey = TileY(tile);
	sx = TileX(p1);
	sy = TileY(p1);
	if (ex < sx) Swap(ex, sx);
	if (ey < sy) Swap(ey, sy);
	tile = TileXY(sx, sy);

	size_x = ex-sx+1;
	size_y = ey-sy+1;

	money = GetAvailableMoneyForCommand();
	cost = 0;

	BEGIN_TILE_LOOP(tile2, size_x, size_y, tile) {
		curh = TileHeight(tile2);
		while (curh != h) {
			ret = DoCommand(tile2, 8, (curh > h) ? 0 : 1, flags & ~DC_EXEC, CMD_TERRAFORM_LAND);
			if (CmdFailed(ret)) break;
			cost += ret;

			if (flags & DC_EXEC) {
				if ((money -= ret) < 0) {
					_additional_cash_required = ret;
					return cost - ret;
				}
				DoCommand(tile2, 8, (curh > h) ? 0 : 1, flags, CMD_TERRAFORM_LAND);
			}

			curh += (curh > h) ? -1 : 1;
		}
	} END_TILE_LOOP(tile2, size_x, size_y, tile)

	return (cost == 0) ? CMD_ERROR : cost;
}

/** Purchase a land area. Actually you only purchase one tile, so
 * the name is a bit confusing ;p
 * @param tile the tile the player is purchasing
 * @param flags for this command type
 * @param p1 unused
 * @param p2 unused
 * @return error of cost of operation
 */
int32 CmdPurchaseLandArea(TileIndex tile, uint32 flags, uint32 p1, uint32 p2)
{
	int32 cost;

	SET_EXPENSES_TYPE(EXPENSES_CONSTRUCTION);

	if (!EnsureNoVehicle(tile)) return CMD_ERROR;

	if (IsOwnedLandTile(tile) && IsTileOwner(tile, _current_player)) {
		return_cmd_error(STR_5807_YOU_ALREADY_OWN_IT);
	}

	cost = DoCommand(tile, 0, 0, flags, CMD_LANDSCAPE_CLEAR);
	if (CmdFailed(cost)) return CMD_ERROR;

	if (flags & DC_EXEC) {
		MakeOwnedLand(tile, _current_player);
		MarkTileDirtyByTile(tile);
	}

	return cost + _price.purchase_land * 10;
}


static int32 ClearTile_Clear(TileIndex tile, byte flags)
{
	static const int32* clear_price_table[] = {
		&_price.clear_1,
		&_price.purchase_land,
		&_price.clear_2,
		&_price.clear_3,
		&_price.purchase_land,
		&_price.purchase_land,
		&_price.clear_2, // XXX unused?
	};
	int32 price;

	if (IsClearGround(tile, CLEAR_GRASS) && GetClearDensity(tile) == 0) {
		price = 0;
	} else {
		price = *clear_price_table[GetClearGround(tile)];
	}

	if (flags & DC_EXEC) DoClearSquare(tile);

	return price;
}

/** Sell a land area. Actually you only sell one tile, so
 * the name is a bit confusing ;p
 * @param tile the tile the player is selling
 * @param flags for this command type
 * @param p1 unused
 * @param p2 unused
 * @return error or cost of operation
 */
int32 CmdSellLandArea(TileIndex tile, uint32 flags, uint32 p1, uint32 p2)
{
	SET_EXPENSES_TYPE(EXPENSES_CONSTRUCTION);

	if (!IsOwnedLandTile(tile)) return CMD_ERROR;
	if (!CheckTileOwnership(tile) && _current_player != OWNER_WATER) return CMD_ERROR;


	if (!EnsureNoVehicle(tile)) return CMD_ERROR;

	if (flags & DC_EXEC) DoClearSquare(tile);

	return - _price.purchase_land * 2;
}


#include "table/clear_land.h"


void DrawClearLandTile(const TileInfo *ti, byte set)
{
	DrawGroundSprite(SPR_FLAT_BARE_LAND + _tileh_to_sprite[ti->tileh] + set * 19, PAL_NONE);
}

void DrawHillyLandTile(const TileInfo *ti)
{
	if (ti->tileh != SLOPE_FLAT) {
		DrawGroundSprite(SPR_FLAT_ROUGH_LAND + _tileh_to_sprite[ti->tileh], PAL_NONE);
	} else {
		DrawGroundSprite(_landscape_clear_sprites[GB(ti->x ^ ti->y, 4, 3)], PAL_NONE);
	}
}

void DrawClearLandFence(const TileInfo *ti)
{
	byte z = ti->z;

	if (ti->tileh & SLOPE_S) {
		z += TILE_HEIGHT;
		if (ti->tileh == SLOPE_STEEP_S) z += TILE_HEIGHT;
	}

	if (GetFenceSW(ti->tile) != 0) {
		DrawGroundSpriteAt(_clear_land_fence_sprites_1[GetFenceSW(ti->tile) - 1] + _fence_mod_by_tileh[ti->tileh], PAL_NONE, ti->x, ti->y, z);
	}

	if (GetFenceSE(ti->tile) != 0) {
		DrawGroundSpriteAt(_clear_land_fence_sprites_1[GetFenceSE(ti->tile) - 1] + _fence_mod_by_tileh_2[ti->tileh], PAL_NONE, ti->x, ti->y, z);
	}
}

static void DrawTile_Clear(TileInfo *ti)
{
	switch (GetClearGround(ti->tile)) {
		case CLEAR_GRASS:
			DrawClearLandTile(ti, GetClearDensity(ti->tile));
			break;

		case CLEAR_ROUGH:
			DrawHillyLandTile(ti);
			break;

		case CLEAR_ROCKS:
			DrawGroundSprite(SPR_FLAT_ROCKY_LAND_1 + _tileh_to_sprite[ti->tileh], PAL_NONE);
			break;

		case CLEAR_FIELDS:
			DrawGroundSprite(_clear_land_sprites_1[GetFieldType(ti->tile)] + _tileh_to_sprite[ti->tileh], PAL_NONE);
			break;

		case CLEAR_SNOW:
			DrawGroundSprite(_clear_land_sprites_2[GetClearDensity(ti->tile)] + _tileh_to_sprite[ti->tileh], PAL_NONE);
			break;

		case CLEAR_DESERT:
			DrawGroundSprite(_clear_land_sprites_3[GetClearDensity(ti->tile)] + _tileh_to_sprite[ti->tileh], PAL_NONE);
			break;
	}

	DrawClearLandFence(ti);
	DrawBridgeMiddle(ti);
}

static uint GetSlopeZ_Clear(TileIndex tile, uint x, uint y)
{
	uint z;
	Slope tileh = GetTileSlope(tile, &z);

	return z + GetPartialZ(x & 0xF, y & 0xF, tileh);
}

static Slope GetSlopeTileh_Clear(TileIndex tile, Slope tileh)
{
	return tileh;
}

static void GetAcceptedCargo_Clear(TileIndex tile, AcceptedCargo ac)
{
	/* unused */
}

static void AnimateTile_Clear(TileIndex tile)
{
	/* unused */
}

void TileLoopClearHelper(TileIndex tile)
{
	byte self;
	byte neighbour;
	TileIndex dirty = INVALID_TILE;

	self = (IsTileType(tile, MP_CLEAR) && IsClearGround(tile, CLEAR_FIELDS));

	neighbour = (IsTileType(TILE_ADDXY(tile, 1, 0), MP_CLEAR) && IsClearGround(TILE_ADDXY(tile, 1, 0), CLEAR_FIELDS));
	if (GetFenceSW(tile) == 0) {
		if (self != neighbour) {
			SetFenceSW(tile, 3);
			dirty = tile;
		}
	} else {
		if (self == 0 && neighbour == 0) {
			SetFenceSW(tile, 0);
			dirty = tile;
		}
	}

	neighbour = (IsTileType(TILE_ADDXY(tile, 0, 1), MP_CLEAR) && IsClearGround(TILE_ADDXY(tile, 0, 1), CLEAR_FIELDS));
	if (GetFenceSE(tile) == 0) {
		if (self != neighbour) {
			SetFenceSE(tile, 3);
			dirty = tile;
		}
	} else {
		if (self == 0 && neighbour == 0) {
			SetFenceSE(tile, 0);
			dirty = tile;
		}
	}

	if (dirty != INVALID_TILE) MarkTileDirtyByTile(dirty);
}


/* convert into snowy tiles */
static void TileLoopClearAlps(TileIndex tile)
{
	int k = GetTileZ(tile) - GetSnowLine() + TILE_HEIGHT;

	if (k < 0) { // well below the snow line
		if (!IsClearGround(tile, CLEAR_SNOW)) return;
		if (GetClearDensity(tile) == 0) SetClearGroundDensity(tile, CLEAR_GRASS, 3);
	} else {
		if (!IsClearGround(tile, CLEAR_SNOW)) {
			SetClearGroundDensity(tile, CLEAR_SNOW, 0);
		} else {
			uint density = min((uint)k / TILE_HEIGHT, 3);

			if (GetClearDensity(tile) < density) {
				AddClearDensity(tile, 1);
			} else if (GetClearDensity(tile) > density) {
				AddClearDensity(tile, -1);
			} else {
				return;
			}
		}
	}

	MarkTileDirtyByTile(tile);
}

static void TileLoopClearDesert(TileIndex tile)
{
	if (IsClearGround(tile, CLEAR_DESERT)) return;

	if (GetTropicZone(tile) == TROPICZONE_DESERT) {
		SetClearGroundDensity(tile, CLEAR_DESERT, 3);
	} else {
		if (GetTropicZone(tile + TileDiffXY( 1,  0)) != TROPICZONE_DESERT &&
				GetTropicZone(tile + TileDiffXY(-1,  0)) != TROPICZONE_DESERT &&
				GetTropicZone(tile + TileDiffXY( 0,  1)) != TROPICZONE_DESERT &&
				GetTropicZone(tile + TileDiffXY( 0, -1)) != TROPICZONE_DESERT)
			return;
		SetClearGroundDensity(tile, CLEAR_DESERT, 1);
	}

	MarkTileDirtyByTile(tile);
}

static void TileLoop_Clear(TileIndex tile)
{
	TileLoopClearHelper(tile);

	switch (_opt.landscape) {
		case LT_DESERT: TileLoopClearDesert(tile); break;
		case LT_HILLY:  TileLoopClearAlps(tile);   break;
	}

	switch (GetClearGround(tile)) {
		case CLEAR_GRASS:
			if (GetClearDensity(tile) == 3) return;

			if (_game_mode != GM_EDITOR) {
				if (GetClearCounter(tile) < 7) {
					AddClearCounter(tile, 1);
					return;
				} else {
					SetClearCounter(tile, 0);
					AddClearDensity(tile, 1);
				}
			} else {
				SetClearGroundDensity(tile, GB(Random(), 0, 8) > 21 ? CLEAR_GRASS : CLEAR_ROUGH, 3);
			}
			break;

		case CLEAR_FIELDS: {
			uint field_type;

			if (_game_mode == GM_EDITOR) return;

			if (GetClearCounter(tile) < 7) {
				AddClearCounter(tile, 1);
				return;
			} else {
				SetClearCounter(tile, 0);
			}

			if (GetIndustryIndexOfField(tile) == INVALID_INDUSTRY && GetFieldType(tile) >= 7) {
				/* This farmfield is no longer farmfield, so make it grass again */
				MakeClear(tile, CLEAR_GRASS, 2);
			} else {
				field_type = GetFieldType(tile);
				field_type = (field_type < 8) ? field_type + 1 : 0;
				SetFieldType(tile, field_type);
			}
			break;
		}

		default:
			return;
	}

	MarkTileDirtyByTile(tile);
}

void GenerateClearTile()
{
	uint i, gi;
	TileIndex tile;

	/* add rough tiles */
	i = ScaleByMapSize(GB(Random(), 0, 10) + 0x400);
	gi = ScaleByMapSize(GB(Random(), 0, 7) + 0x80);

	SetGeneratingWorldProgress(GWP_ROUGH_ROCKY, gi + i);
	do {
		IncreaseGeneratingWorldProgress(GWP_ROUGH_ROCKY);
		tile = RandomTile();
		if (IsTileType(tile, MP_CLEAR) && !IsClearGround(tile, CLEAR_DESERT)) SetClearGroundDensity(tile, CLEAR_ROUGH, 3);
	} while (--i);

	/* add rocky tiles */
	i = gi;
	do {
		uint32 r = Random();
		tile = RandomTileSeed(r);

		IncreaseGeneratingWorldProgress(GWP_ROUGH_ROCKY);
		if (IsTileType(tile, MP_CLEAR) && !IsClearGround(tile, CLEAR_DESERT)) {
			uint j = GB(r, 16, 4) + 5;
			for (;;) {
				TileIndex tile_new;

				SetClearGroundDensity(tile, CLEAR_ROCKS, 3);
				do {
					if (--j == 0) goto get_out;
					tile_new = tile + TileOffsByDiagDir(GB(Random(), 0, 2));
				} while (!IsTileType(tile_new, MP_CLEAR) || IsClearGround(tile_new, CLEAR_DESERT));
				tile = tile_new;
			}
get_out:;
		}
	} while (--i);
}

static void ClickTile_Clear(TileIndex tile)
{
	/* not used */
}

static uint32 GetTileTrackStatus_Clear(TileIndex tile, TransportType mode)
{
	return 0;
}

static const StringID _clear_land_str[] = {
	STR_080D_GRASS,
	STR_080B_ROUGH_LAND,
	STR_080A_ROCKS,
	STR_080E_FIELDS,
	STR_080F_SNOW_COVERED_LAND,
	STR_0810_DESERT
};

static void GetTileDesc_Clear(TileIndex tile, TileDesc *td)
{
	if (IsClearGround(tile, CLEAR_GRASS) && GetClearDensity(tile) == 0) {
		td->str = STR_080C_BARE_LAND;
	} else {
		td->str = _clear_land_str[GetClearGround(tile)];
	}
	td->owner = GetTileOwner(tile);
}

static void ChangeTileOwner_Clear(TileIndex tile, PlayerID old_player, PlayerID new_player)
{
	return;
}

void InitializeClearLand()
{
	_opt.snow_line = _patches.snow_line_height * TILE_HEIGHT;
}

extern const TileTypeProcs _tile_type_clear_procs = {
	DrawTile_Clear,           ///< draw_tile_proc
	GetSlopeZ_Clear,          ///< get_slope_z_proc
	ClearTile_Clear,          ///< clear_tile_proc
	GetAcceptedCargo_Clear,   ///< get_accepted_cargo_proc
	GetTileDesc_Clear,        ///< get_tile_desc_proc
	GetTileTrackStatus_Clear, ///< get_tile_track_status_proc
	ClickTile_Clear,          ///< click_tile_proc
	AnimateTile_Clear,        ///< animate_tile_proc
	TileLoop_Clear,           ///< tile_loop_clear
	ChangeTileOwner_Clear,    ///< change_tile_owner_clear
	NULL,                     ///< get_produced_cargo_proc
	NULL,                     ///< vehicle_enter_tile_proc
	GetSlopeTileh_Clear,      ///< get_slope_tileh_proc
};