path: root/src/smallmap_gui.cpp

/* $Id$ */

/*
 * This file is part of OpenTTD.
 * 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.
 * 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.
 * 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/>.
 */

/** @file smallmap_gui.cpp GUI that shows a small map of the world with metadata like owner or height. */

#include "stdafx.h"
#include "clear_map.h"
#include "industry.h"
#include "station_map.h"
#include "landscape.h"
#include "window_gui.h"
#include "tree_map.h"
#include "viewport_func.h"
#include "town.h"
#include "blitter/factory.hpp"
#include "tunnelbridge_map.h"
#include "strings_func.h"
#include "core/endian_func.hpp"
#include "vehicle_base.h"
#include "sound_func.h"
#include "window_func.h"
#include "company_base.h"

#include "table/strings.h"
#include "table/sprites.h"

/** Widget numbers of the small map window. */
enum SmallMapWindowWidgets {
	SM_WIDGET_CAPTION,           ///< Caption widget.
	SM_WIDGET_MAP_BORDER,        ///< Border around the smallmap.
	SM_WIDGET_MAP,               ///< Panel containing the smallmap.
	SM_WIDGET_LEGEND,            ///< Bottom panel to display smallmap legends.
	SM_WIDGET_ZOOM_IN,           ///< Button to zoom in one step.
	SM_WIDGET_ZOOM_OUT,          ///< Button to zoom out one step.
	SM_WIDGET_CONTOUR,           ///< Button to select the contour view (height map).
	SM_WIDGET_VEHICLES,          ///< Button to select the vehicles view.
	SM_WIDGET_INDUSTRIES,        ///< Button to select the industries view.
	SM_WIDGET_ROUTES,            ///< Button to select the routes view.
	SM_WIDGET_VEGETATION,        ///< Button to select the vegetation view.
	SM_WIDGET_OWNERS,            ///< Button to select the owners view.
	SM_WIDGET_CENTERMAP,         ///< Button to move smallmap center to main window center.
	SM_WIDGET_TOGGLETOWNNAME,    ///< Toggle button to display town names.
	SM_WIDGET_SELECTINDUSTRIES,  ///< Selection widget for the buttons at the industry mode.
	SM_WIDGET_ENABLEINDUSTRIES,  ///< Button to enable display of all industries.
	SM_WIDGET_DISABLEINDUSTRIES, ///< Button to disable display of all industries.
	SM_WIDGET_SHOW_HEIGHT,       ///< Show heightmap toggle button.
};

static int _smallmap_industry_count; ///< Number of used industries

/** Macro for ordinary entry of LegendAndColour */
#define MK(a, b) {a, b, INVALID_INDUSTRYTYPE, true, false, false}
/** Macro for end of list marker in arrays of LegendAndColour */
#define MKEND() {0, STR_NULL, INVALID_INDUSTRYTYPE, true, true, false}
/** Macro for break marker in arrays of LegendAndColour.
 * It will have valid data, though */
#define MS(a, b) {a, b, INVALID_INDUSTRYTYPE, true, false, true}

/** Structure for holding relevant data for legends in small map */
struct LegendAndColour {
	uint8 colour;      ///< colour of the item on the map
	StringID legend;   ///< string corresponding to the coloured item
	IndustryType type; ///< type of industry
	bool show_on_map;  ///< for filtering industries, if true is shown on map in colour
	bool end;          ///< this is the end of the list
	bool col_break;    ///< perform a break and go one column further
};

/** Legend text giving the colours to look for on the minimap */
static const LegendAndColour _legend_land_contours[] = {
	MK(0x5A, STR_SMALLMAP_LEGENDA_100M),
	MK(0x5C, STR_SMALLMAP_LEGENDA_200M),
	MK(0x5E, STR_SMALLMAP_LEGENDA_300M),
	MK(0x1F, STR_SMALLMAP_LEGENDA_400M),
	MK(0x27, STR_SMALLMAP_LEGENDA_500M),

	MS(0xD7, STR_SMALLMAP_LEGENDA_ROADS),
	MK(0x0A, STR_SMALLMAP_LEGENDA_RAILROADS),
	MK(0x98, STR_SMALLMAP_LEGENDA_STATIONS_AIRPORTS_DOCKS),
	MK(0xB5, STR_SMALLMAP_LEGENDA_BUILDINGS_INDUSTRIES),
	MK(0x0F, STR_SMALLMAP_LEGENDA_VEHICLES),
	MKEND()
};

static const LegendAndColour _legend_vehicles[] = {
	MK(0xB8, STR_SMALLMAP_LEGENDA_TRAINS),
	MK(0xBF, STR_SMALLMAP_LEGENDA_ROAD_VEHICLES),
	MK(0x98, STR_SMALLMAP_LEGENDA_SHIPS),
	MK(0x0F, STR_SMALLMAP_LEGENDA_AIRCRAFT),

	MS(0xD7, STR_SMALLMAP_LEGENDA_TRANSPORT_ROUTES),
	MK(0xB5, STR_SMALLMAP_LEGENDA_BUILDINGS_INDUSTRIES),
	MKEND()
};

static const LegendAndColour _legend_routes[] = {
	MK(0xD7, STR_SMALLMAP_LEGENDA_ROADS),
	MK(0x0A, STR_SMALLMAP_LEGENDA_RAILROADS),
	MK(0xB5, STR_SMALLMAP_LEGENDA_BUILDINGS_INDUSTRIES),

	MS(0x56, STR_SMALLMAP_LEGENDA_RAILROAD_STATION),
	MK(0xC2, STR_SMALLMAP_LEGENDA_TRUCK_LOADING_BAY),
	MK(0xBF, STR_SMALLMAP_LEGENDA_BUS_STATION),
	MK(0xB8, STR_SMALLMAP_LEGENDA_AIRPORT_HELIPORT),
	MK(0x98, STR_SMALLMAP_LEGENDA_DOCK),
	MKEND()
};

static const LegendAndColour _legend_vegetation[] = {
	MK(0x52, STR_SMALLMAP_LEGENDA_ROUGH_LAND),
	MK(0x54, STR_SMALLMAP_LEGENDA_GRASS_LAND),
	MK(0x37, STR_SMALLMAP_LEGENDA_BARE_LAND),
	MK(0x25, STR_SMALLMAP_LEGENDA_FIELDS),
	MK(0x57, STR_SMALLMAP_LEGENDA_TREES),
	MK(0xD0, STR_SMALLMAP_LEGENDA_FOREST),

	MS(0x0A, STR_SMALLMAP_LEGENDA_ROCKS),
	MK(0xC2, STR_SMALLMAP_LEGENDA_DESERT),
	MK(0x98, STR_SMALLMAP_LEGENDA_SNOW),
	MK(0xD7, STR_SMALLMAP_LEGENDA_TRANSPORT_ROUTES),
	MK(0xB5, STR_SMALLMAP_LEGENDA_BUILDINGS_INDUSTRIES),
	MKEND()
};

static const LegendAndColour _legend_land_owners[] = {
	MK(0xCA, STR_SMALLMAP_LEGENDA_WATER),
	MK(0x54, STR_SMALLMAP_LEGENDA_NO_OWNER),
	MK(0xB4, STR_SMALLMAP_LEGENDA_TOWNS),
	MK(0x20, STR_SMALLMAP_LEGENDA_INDUSTRIES),
	MKEND()
};
#undef MK
#undef MS
#undef MKEND

/** Allow room for all industries, plus a terminator entry
 * This is required in order to have the indutry slots all filled up */
static LegendAndColour _legend_from_industries[NUM_INDUSTRYTYPES + 1];
/* For connecting industry type to position in industries list(small map legend) */
static uint _industry_to_list_pos[NUM_INDUSTRYTYPES];
/** Show heightmap in industry mode of smallmap window. */
static bool _smallmap_industry_show_heightmap;

/**
 * Fills an array for the industries legends.
 */
void BuildIndustriesLegend()
{
	uint j = 0;

	/* Add each name */
	for (IndustryType i = 0; i < NUM_INDUSTRYTYPES; i++) {
		const IndustrySpec *indsp = GetIndustrySpec(i);
		if (indsp->enabled) {
			_legend_from_industries[j].legend = indsp->name;
			_legend_from_industries[j].colour = indsp->map_colour;
			_legend_from_industries[j].type = i;
			_legend_from_industries[j].show_on_map = true;
			_legend_from_industries[j].col_break = false;
			_legend_from_industries[j].end = false;

			/* Store widget number for this industry type */
			_industry_to_list_pos[i] = j;
			j++;
		}
	}
	/* Terminate the list */
	_legend_from_industries[j].end = true;

	/* Store number of enabled industries */
	_smallmap_industry_count = j;
}

static const LegendAndColour * const _legend_table[] = {
	_legend_land_contours,
	_legend_vehicles,
	_legend_from_industries,
	_legend_routes,
	_legend_vegetation,
	_legend_land_owners,
};

#define MKCOLOUR(x) TO_LE32X(x)

/**
 * Height encodings; MAX_TILE_HEIGHT + 1 levels, from 0 to MAX_TILE_HEIGHT
 */
static const uint32 _map_height_bits[] = {
	MKCOLOUR(0x5A5A5A5A),
	MKCOLOUR(0x5A5B5A5B),
	MKCOLOUR(0x5B5B5B5B),
	MKCOLOUR(0x5B5C5B5C),
	MKCOLOUR(0x5C5C5C5C),
	MKCOLOUR(0x5C5D5C5D),
	MKCOLOUR(0x5D5D5D5D),
	MKCOLOUR(0x5D5E5D5E),
	MKCOLOUR(0x5E5E5E5E),
	MKCOLOUR(0x5E5F5E5F),
	MKCOLOUR(0x5F5F5F5F),
	MKCOLOUR(0x5F1F5F1F),
	MKCOLOUR(0x1F1F1F1F),
	MKCOLOUR(0x1F271F27),
	MKCOLOUR(0x27272727),
	MKCOLOUR(0x27272727),
};
assert_compile(lengthof(_map_height_bits) == MAX_TILE_HEIGHT + 1);

struct AndOr {
	uint32 mor;
	uint32 mand;
};

static inline uint32 ApplyMask(uint32 colour, const AndOr *mask)
{
	return (colour & mask->mand) | mask->mor;
}


/** Colour masks for "Contour" and "Routes" modes. */
static const AndOr _smallmap_contours_andor[] = {
	{MKCOLOUR(0x00000000), MKCOLOUR(0xFFFFFFFF)}, // MP_CLEAR
	{MKCOLOUR(0x000A0A00), MKCOLOUR(0xFF0000FF)}, // MP_RAILWAY
	{MKCOLOUR(0x00D7D700), MKCOLOUR(0xFF0000FF)}, // MP_ROAD
	{MKCOLOUR(0x00B5B500), MKCOLOUR(0xFF0000FF)}, // MP_HOUSE
	{MKCOLOUR(0x00000000), MKCOLOUR(0xFFFFFFFF)}, // MP_TREES
	{MKCOLOUR(0x98989898), MKCOLOUR(0x00000000)}, // MP_STATION
	{MKCOLOUR(0xCACACACA), MKCOLOUR(0x00000000)}, // MP_WATER
	{MKCOLOUR(0x00000000), MKCOLOUR(0xFFFFFFFF)}, // MP_VOID
	{MKCOLOUR(0xB5B5B5B5), MKCOLOUR(0x00000000)}, // MP_INDUSTRY
	{MKCOLOUR(0x00000000), MKCOLOUR(0xFFFFFFFF)}, // MP_TUNNELBRIDGE
	{MKCOLOUR(0x00B5B500), MKCOLOUR(0xFF0000FF)}, // MP_UNMOVABLE
	{MKCOLOUR(0x000A0A00), MKCOLOUR(0xFF0000FF)},
};

/** Colour masks for "Vehicles", "Industry", and "Vegetation" modes. */
static const AndOr _smallmap_vehicles_andor[] = {
	{MKCOLOUR(0x00000000), MKCOLOUR(0xFFFFFFFF)}, // MP_CLEAR
	{MKCOLOUR(0x00D7D700), MKCOLOUR(0xFF0000FF)}, // MP_RAILWAY
	{MKCOLOUR(0x00D7D700), MKCOLOUR(0xFF0000FF)}, // MP_ROAD
	{MKCOLOUR(0x00B5B500), MKCOLOUR(0xFF0000FF)}, // MP_HOUSE
	{MKCOLOUR(0x00000000), MKCOLOUR(0xFFFFFFFF)}, // MP_TREES
	{MKCOLOUR(0x00D7D700), MKCOLOUR(0xFF0000FF)}, // MP_STATION
	{MKCOLOUR(0xCACACACA), MKCOLOUR(0x00000000)}, // MP_WATER
	{MKCOLOUR(0x00000000), MKCOLOUR(0xFFFFFFFF)}, // MP_VOID
	{MKCOLOUR(0xB5B5B5B5), MKCOLOUR(0x00000000)}, // MP_INDUSTRY
	{MKCOLOUR(0x00000000), MKCOLOUR(0xFFFFFFFF)}, // MP_TUNNELBRIDGE
	{MKCOLOUR(0x00B5B500), MKCOLOUR(0xFF0000FF)}, // MP_UNMOVABLE
	{MKCOLOUR(0x00D7D700), MKCOLOUR(0xFF0000FF)},
};

typedef uint32 GetSmallMapPixels(TileIndex tile); ///< Typedef callthrough function


static inline TileType GetEffectiveTileType(TileIndex tile)
{
	TileType t = GetTileType(tile);

	if (t == MP_TUNNELBRIDGE) {
		TransportType tt = GetTunnelBridgeTransportType(tile);

		switch (tt) {
			case TRANSPORT_RAIL: t = MP_RAILWAY; break;
			case TRANSPORT_ROAD: t = MP_ROAD;    break;
			default:             t = MP_WATER;   break;
		}
	}
	return t;
}

/**
 * Return the colour a tile would be displayed with in the small map in mode "Contour".
 * @param tile The tile of which we would like to get the colour.
 * @return The colour of tile in the small map in mode "Contour"
 */
static inline uint32 GetSmallMapContoursPixels(TileIndex tile)
{
	TileType t = GetEffectiveTileType(tile);

	return ApplyMask(_map_height_bits[TileHeight(tile)], &_smallmap_contours_andor[t]);
}

/**
 * Return the colour a tile would be displayed with in the small map in mode "Vehicles".
 *
 * @param tile The tile of which we would like to get the colour.
 * @return The colour of tile in the small map in mode "Vehicles"
 */
static inline uint32 GetSmallMapVehiclesPixels(TileIndex tile)
{
	TileType t = GetEffectiveTileType(tile);

	return ApplyMask(MKCOLOUR(0x54545454), &_smallmap_vehicles_andor[t]);
}

/**
 * Return the colour a tile would be displayed with in the small map in mode "Industries".
 *
 * @param tile The tile of which we would like to get the colour.
 * @return The colour of tile in the small map in mode "Industries"
 */
static inline uint32 GetSmallMapIndustriesPixels(TileIndex tile)
{
	TileType t = GetEffectiveTileType(tile);

	if (t == MP_INDUSTRY) {
		/* If industry is allowed to be seen, use its colour on the map */
		if (_legend_from_industries[_industry_to_list_pos[Industry::GetByTile(tile)->type]].show_on_map) {
			return GetIndustrySpec(Industry::GetByTile(tile)->type)->map_colour * 0x01010101;
		} else {
			/* Otherwise, return the colour of the clear tiles, which will make it disappear */
			t = MP_CLEAR;
		}
	}

	return ApplyMask(_smallmap_industry_show_heightmap ? _map_height_bits[TileHeight(tile)] : MKCOLOUR(0x54545454), &_smallmap_vehicles_andor[t]);
}

/**
 * Return the colour a tile would be displayed with in the small map in mode "Routes".
 *
 * @param tile The tile of which we would like to get the colour.
 * @return The colour of tile  in the small map in mode "Routes"
 */
static inline uint32 GetSmallMapRoutesPixels(TileIndex tile)
{
	TileType t = GetEffectiveTileType(tile);

	if (t == MP_STATION) {
		switch (GetStationType(tile)) {
			case STATION_RAIL:    return MKCOLOUR(0x56565656);
			case STATION_AIRPORT: return MKCOLOUR(0xB8B8B8B8);
			case STATION_TRUCK:   return MKCOLOUR(0xC2C2C2C2);
			case STATION_BUS:     return MKCOLOUR(0xBFBFBFBF);
			case STATION_DOCK:    return MKCOLOUR(0x98989898);
			default:              return MKCOLOUR(0xFFFFFFFF);
		}
	}

	/* Ground colour */
	return ApplyMask(MKCOLOUR(0x54545454), &_smallmap_contours_andor[t]);
}


static const uint32 _vegetation_clear_bits[] = {
	MKCOLOUR(0x54545454), ///< full grass
	MKCOLOUR(0x52525252), ///< rough land
	MKCOLOUR(0x0A0A0A0A), ///< rocks
	MKCOLOUR(0x25252525), ///< fields
	MKCOLOUR(0x98989898), ///< snow
	MKCOLOUR(0xC2C2C2C2), ///< desert
	MKCOLOUR(0x54545454), ///< unused
	MKCOLOUR(0x54545454), ///< unused
};

/**
 * Return the colour a tile would be displayed with in the smallmap in mode "Vegetation".
 *
 * @param tile The tile of which we would like to get the colour.
 * @return The colour of tile  in the smallmap in mode "Vegetation"
 */
static inline uint32 GetSmallMapVegetationPixels(TileIndex tile)
{
	TileType t = GetEffectiveTileType(tile);

	switch (t) {
		case MP_CLEAR:
			return (IsClearGround(tile, CLEAR_GRASS) && GetClearDensity(tile) < 3) ? MKCOLOUR(0x37373737) : _vegetation_clear_bits[GetClearGround(tile)];

		case MP_INDUSTRY:
			return GetIndustrySpec(Industry::GetByTile(tile)->type)->check_proc == CHECK_FOREST ? MKCOLOUR(0xD0D0D0D0) : MKCOLOUR(0xB5B5B5B5);

		case MP_TREES:
			if (GetTreeGround(tile) == TREE_GROUND_SNOW_DESERT || GetTreeGround(tile) == TREE_GROUND_ROUGH_SNOW) {
				return (_settings_game.game_creation.landscape == LT_ARCTIC) ? MKCOLOUR(0x98575798) : MKCOLOUR(0xC25757C2);
			}
			return MKCOLOUR(0x54575754);

		default:
			return ApplyMask(MKCOLOUR(0x54545454), &_smallmap_vehicles_andor[t]);
	}
}


static uint32 _owner_colours[OWNER_END + 1];

/**
 * Return the colour a tile would be displayed with in the small map in mode "Owner".
 *
 * @param tile The tile of which we would like to get the colour.
 * @return The colour of tile in the small map in mode "Owner"
 */
static inline uint32 GetSmallMapOwnerPixels(TileIndex tile)
{
	Owner o;

	switch (GetTileType(tile)) {
		case MP_INDUSTRY: o = OWNER_END;          break;
		case MP_HOUSE:    o = OWNER_TOWN;         break;
		default:          o = GetTileOwner(tile); break;
		/* FIXME: For MP_ROAD there are multiple owners.
		 * GetTileOwner returns the rail owner (level crossing) resp. the owner of ROADTYPE_ROAD (normal road),
		 * even if there are no ROADTYPE_ROAD bits on the tile.
		 */
	}

	return _owner_colours[o];
}

/* Each tile has 4 x pixels and 1 y pixel */

/** Holds function pointers to determine tile colour in the smallmap for each smallmap mode. */
static GetSmallMapPixels * const _smallmap_draw_procs[] = {
	GetSmallMapContoursPixels,
	GetSmallMapVehiclesPixels,
	GetSmallMapIndustriesPixels,
	GetSmallMapRoutesPixels,
	GetSmallMapVegetationPixels,
	GetSmallMapOwnerPixels,
};

/** Vehicle colours in #SMT_VEHICLES mode. Indexed by #VehicleTypeByte. */
static const byte _vehicle_type_colours[6] = {
	184, 191, 152, 15, 215, 184
};


/** Class managing the smallmap window. */
class SmallMapWindow : public Window {
	/** Types of legends in the #SM_WIDGET_LEGEND widget. */
	enum SmallMapType {
		SMT_CONTOUR,
		SMT_VEHICLES,
		SMT_INDUSTRY,
		SMT_ROUTES,
		SMT_VEGETATION,
		SMT_OWNER,
	};

	/** Available kinds of zoomlevel changes. */
	enum ZoomLevelChange {
		ZLC_INITIALIZE, ///< Initialize zoom level.
		ZLC_ZOOM_OUT,   ///< Zoom out.
		ZLC_ZOOM_IN,    ///< Zoom in.
	};

	static SmallMapType map_type; ///< Currently displayed legends.
	static bool show_towns;       ///< Display town names in the smallmap.

	static const uint LEGEND_BLOB_WIDTH = 8;              ///< Width of the coloured blob in front of a line text in the #SM_WIDGET_LEGEND widget.
	static const uint INDUSTRY_MIN_NUMBER_OF_COLUMNS = 2; ///< Minimal number of columns in the #SM_WIDGET_LEGEND widget for the #SMT_INDUSTRY legend.
	uint min_number_of_columns;    ///< Minimal number of columns in  legends.
	uint min_number_of_fixed_rows; ///< Minimal number of rows in the legends for the fixed layouts only (all except #SMT_INDUSTRY).
	uint column_width;             ///< Width of a column in the #SM_WIDGET_LEGEND widget.

	int32 scroll_x;  ///< Horizontal world coordinate of the base tile left of the top-left corner of the smallmap display.
	int32 scroll_y;  ///< Vertical world coordinate of the base tile left of the top-left corner of the smallmap display.
	int32 subscroll; ///< Number of pixels (0..3) between the right end of the base tile and the pixel at the top-left corner of the smallmap display.
	int zoom;        ///< Zoom level. Bigger number means more zoom-out (further away).

	static const uint8 FORCE_REFRESH_PERIOD = 0x1F; ///< map is redrawn after that many ticks
	uint8 refresh; ///< refresh counter, zeroed every FORCE_REFRESH_PERIOD ticks

	/**
	 * Remap tile to location on this smallmap.
	 * @param tile_x X coordinate of the tile.
	 * @param tile_y Y coordinate of the tile.
	 * @return Position to draw on.
	 */
	FORCEINLINE Point RemapTile(int tile_x, int tile_y) const
	{
		int x_offset = tile_x - this->scroll_x / TILE_SIZE;
		int y_offset = tile_y - this->scroll_y / TILE_SIZE;

		if (this->zoom == 1) return RemapCoords(x_offset, y_offset, 0);

		/* For negative offsets, round towards -inf. */
		if (x_offset < 0) x_offset -= this->zoom - 1;
		if (y_offset < 0) y_offset -= this->zoom - 1;

		return RemapCoords(x_offset / this->zoom, y_offset / this->zoom, 0);
	}

	/**
	 * Determine the tile relative to the base tile of the smallmap, and the pixel position at
	 * that tile for a point in the smallmap.
	 * @param px Horizontal coordinate of the pixel.
	 * @param py Vertical coordinate of the pixel.
	 * @param sub[out] Pixel position at the tile (0..3).
	 * @return Tile being displayed at the given position relative to #scroll_x and #scroll_y.
	 * @note The #subscroll offset is already accounted for.
	 */
	FORCEINLINE Point PixelToTile(int dx, int dy, int *sub) const
	{
		dx += this->subscroll;  // Total horizontal offset.

		/* For each two rows down, add a x and a y tile, and
		 * For each four pixels to the right, move a tile to the right. */
		Point pt = {((dy >> 1) - (dx >> 2)) * this->zoom, ((dy >> 1) + (dx >> 2)) * this->zoom};
		dx &= 3;

		if (dy & 1) { // Odd number of rows, handle the 2 pixel shift.
			if (dx < 2) {
				pt.x += this->zoom;
				dx += 2;
			} else {
				pt.y += this->zoom;
				dx -= 2;
			}
		}

		*sub = dx;
		return pt;
	}

	/** Initialize or change the zoom level.
	 * @param change Way to change the zoom level.
	 */
	void SetZoomLevel(ZoomLevelChange change)
	{
		static const int zoomlevels[] = {1, 2, 4, 6, 8}; // Available zoom levels. Bigger number means more zoom-out (further away).
		static const int MIN_ZOOM_INDEX = 0;
		static const int MAX_ZOOM_INDEX = lengthof(zoomlevels) - 1;

		int new_index, cur_index, sub;
		Point tile;
		const NWidgetBase *wid = this->GetWidget<NWidgetBase>(SM_WIDGET_MAP);
		switch (change) {
			case ZLC_INITIALIZE:
				cur_index = - 1; // Definitely different from new_index.
				new_index = MIN_ZOOM_INDEX;
				break;

			case ZLC_ZOOM_IN:
			case ZLC_ZOOM_OUT:
				for (cur_index = MIN_ZOOM_INDEX; cur_index <= MAX_ZOOM_INDEX; cur_index++) {
					if (this->zoom == zoomlevels[cur_index]) break;
				}
				assert(cur_index <= MAX_ZOOM_INDEX);

				tile = this->PixelToTile(wid->current_x / 2, wid->current_y / 2, &sub);
				new_index = Clamp(cur_index + ((change == ZLC_ZOOM_IN) ? -1 : 1), MIN_ZOOM_INDEX, MAX_ZOOM_INDEX);
				break;

			default: NOT_REACHED();
		}

		if (new_index != cur_index) {
			this->zoom = zoomlevels[new_index];
			if (cur_index >= 0) {
				Point new_tile = this->PixelToTile(wid->current_x / 2, wid->current_y / 2, &sub);
				this->SetNewScroll(this->scroll_x + (tile.x - new_tile.x) * TILE_SIZE,
						this->scroll_y + (tile.y - new_tile.y) * TILE_SIZE, sub);
			}
			this->SetWidgetDisabledState(SM_WIDGET_ZOOM_IN,  this->zoom == zoomlevels[MIN_ZOOM_INDEX]);
			this->SetWidgetDisabledState(SM_WIDGET_ZOOM_OUT, this->zoom == zoomlevels[MAX_ZOOM_INDEX]);
			this->SetDirty();
		}
	}

	/**
	 * Draws one column of tiles of the small map in a certain mode onto the screen buffer, skipping the shifted rows in between.
	 *
	 * @param dst Pointer to a part of the screen buffer to write to.
	 * @param xc The X coordinate of the first tile in the column.
	 * @param yc The Y coordinate of the first tile in the column
	 * @param pitch Number of pixels to advance in the screen buffer each time a pixel is written.
	 * @param reps Number of lines to draw
	 * @param start_pos Position of first pixel to draw.
	 * @param end_pos Position of last pixel to draw (exclusive).
	 * @param blitter current blitter
	 * @param proc Pointer to the colour function
	 * @note If pixel position is below \c 0, skip drawing.
	 * @see GetSmallMapPixels(TileIndex)
	 */
	void DrawSmallMapColumn(void *dst, uint xc, uint yc, int pitch, int reps, int start_pos, int end_pos, Blitter *blitter, GetSmallMapPixels *proc) const
	{
		void *dst_ptr_abs_end = blitter->MoveTo(_screen.dst_ptr, 0, _screen.height);
		uint min_xy = _settings_game.construction.freeform_edges ? 1 : 0;

		do {
			/* Check if the tile (xc,yc) is within the map range */
			if (IsInsideMM(xc, min_xy, MapMaxX()) && IsInsideMM(yc, min_xy, MapMaxY())) {
				/* Check if the dst pointer points to a pixel inside the screen buffer */
				if (dst < _screen.dst_ptr) continue;
				if (dst >= dst_ptr_abs_end) continue;

				uint32 val = proc(TileXY(xc, yc));
				uint8 *val8 = (uint8 *)&val;
				int idx = max(0, -start_pos);
				for (int pos = max(0, start_pos); pos < end_pos; pos++) {
					blitter->SetPixel(dst, idx, 0, val8[idx]);
					idx++;
				}
			}
		/* Switch to next tile in the column */
		} while (xc += this->zoom, yc += this->zoom, dst = blitter->MoveTo(dst, pitch, 0), --reps != 0);
	}

	/**
	 * Adds vehicles to the smallmap.
	 * @param dpi the part of the smallmap to be drawn into
	 * @param blitter current blitter
	 */
	void DrawVehicles(const DrawPixelInfo *dpi, Blitter *blitter) const
	{
		const Vehicle *v;
		FOR_ALL_VEHICLES(v) {
			if (v->type == VEH_EFFECT) continue;
			if (v->vehstatus & (VS_HIDDEN | VS_UNCLICKABLE)) continue;

			/* Remap into flat coordinates. */
			Point pt = this->RemapTile(v->x_pos / TILE_SIZE, v->y_pos / TILE_SIZE);

			int y = pt.y - dpi->top;
			if (!IsInsideMM(y, 0, dpi->height)) continue; // y is out of bounds.

			bool skip = false; // Default is to draw both pixels.
			int x = pt.x - this->subscroll - 3 - dpi->left; // Offset X coordinate.
			if (x < 0) {
				/* if x+1 is 0, that means we're on the very left edge,
				 * and should thus only draw a single pixel */
				if (++x != 0) continue;
				skip = true;
			} else if (x >= dpi->width - 1) {
				/* Check if we're at the very right edge, and if so draw only a single pixel */
				if (x != dpi->width - 1) continue;
				skip = true;
			}

			/* Calculate pointer to pixel and the colour */
			byte colour = (this->map_type == SMT_VEHICLES) ? _vehicle_type_colours[v->type] : 0xF;

			/* And draw either one or two pixels depending on clipping */
			blitter->SetPixel(dpi->dst_ptr, x, y, colour);
			if (!skip) blitter->SetPixel(dpi->dst_ptr, x + 1, y, colour);
		}
	}

	/**
	 * Adds town names to the smallmap.
	 * @param dpi the part of the smallmap to be drawn into
	 */
	void DrawTowns(const DrawPixelInfo *dpi) const
	{
		const Town *t;
		FOR_ALL_TOWNS(t) {
			/* Remap the town coordinate */
			Point pt = this->RemapTile(TileX(t->xy), TileY(t->xy));
			int x = pt.x - this->subscroll - (t->sign.width_small >> 1);
			int y = pt.y;

			/* Check if the town sign is within bounds */
			if (x + t->sign.width_small > dpi->left &&
					x < dpi->left + dpi->width &&
					y + FONT_HEIGHT_SMALL > dpi->top &&
					y < dpi->top + dpi->height) {
				/* And draw it. */
				SetDParam(0, t->index);
				DrawString(x, x + t->sign.width_small, y, STR_SMALLMAP_TOWN);
			}
		}
	}

	/**
	 * Draws vertical part of map indicator
	 * @param x X coord of left/right border of main viewport
	 * @param y Y coord of top border of main viewport
	 * @param y2 Y coord of bottom border of main viewport
	 */
	static inline void DrawVertMapIndicator(int x, int y, int y2)
	{
		GfxFillRect(x, y,      x, y + 3, 69);
		GfxFillRect(x, y2 - 3, x, y2,    69);
	}

	/**
	 * Draws horizontal part of map indicator
	 * @param x X coord of left border of main viewport
	 * @param x2 X coord of right border of main viewport
	 * @param y Y coord of top/bottom border of main viewport
	 */
	static inline void DrawHorizMapIndicator(int x, int x2, int y)
	{
		GfxFillRect(x,      y, x + 3, y, 69);
		GfxFillRect(x2 - 3, y, x2,    y, 69);
	}

	/**
	 * Adds map indicators to the smallmap.
	 */
	void DrawMapIndicators() const
	{
		/* Find main viewport. */
		const ViewPort *vp = FindWindowById(WC_MAIN_WINDOW, 0)->viewport;

		Point tile = InverseRemapCoords(vp->virtual_left, vp->virtual_top);
		Point tl = this->RemapTile(tile.x >> 4, tile.y >> 4);
		tl.x -= this->subscroll;

		tile = InverseRemapCoords(vp->virtual_left + vp->virtual_width, vp->virtual_top + vp->virtual_height);
		Point br = this->RemapTile(tile.x >> 4, tile.y >> 4);
		br.x -= this->subscroll;

		SmallMapWindow::DrawVertMapIndicator(tl.x, tl.y, br.y);
		SmallMapWindow::DrawVertMapIndicator(br.x, tl.y, br.y);

		SmallMapWindow::DrawHorizMapIndicator(tl.x, br.x, tl.y);
		SmallMapWindow::DrawHorizMapIndicator(tl.x, br.x, br.y);
	}

	/**
	 * Draws the small map.
	 *
	 * Basically, the small map is draw column of pixels by column of pixels. The pixels
	 * are drawn directly into the screen buffer. The final map is drawn in multiple passes.
	 * The passes are:
	 * <ol><li>The colours of tiles in the different modes.</li>
	 * <li>Town names (optional)</li></ol>
	 *
	 * @param dpi pointer to pixel to write onto
	 */
	void DrawSmallMap(DrawPixelInfo *dpi) const
	{
		Blitter *blitter = BlitterFactoryBase::GetCurrentBlitter();
		DrawPixelInfo *old_dpi;

		old_dpi = _cur_dpi;
		_cur_dpi = dpi;

		/* Clear it */
		GfxFillRect(dpi->left, dpi->top, dpi->left + dpi->width - 1, dpi->top + dpi->height - 1, 0);

		/* Setup owner table */
		if (this->map_type == SMT_OWNER) {
			const Company *c;

			/* Fill with some special colours */
			_owner_colours[OWNER_TOWN]  = MKCOLOUR(0xB4B4B4B4);
			_owner_colours[OWNER_NONE]  = MKCOLOUR(0x54545454);
			_owner_colours[OWNER_WATER] = MKCOLOUR(0xCACACACA);
			_owner_colours[OWNER_END]   = MKCOLOUR(0x20202020); // Industry

			/* Now fill with the company colours */
			FOR_ALL_COMPANIES(c) {
				_owner_colours[c->index] = _colour_gradient[c->colour][5] * 0x01010101;
			}
		}

		/* Which tile is displayed at (dpi->left, dpi->top)? */
		int dx;
		Point tile = this->PixelToTile(dpi->left, dpi->top, &dx);
		int tile_x = this->scroll_x / TILE_SIZE + tile.x;
		int tile_y = this->scroll_y / TILE_SIZE + tile.y;

		void *ptr = blitter->MoveTo(dpi->dst_ptr, -dx - 4, 0);
		int x = - dx - 4;
		int y = 0;

		for (;;) {
			/* Distance from left edge */
			if (x >= -3) {
				if (x >= dpi->width) break; // Exit the loop.

				int end_pos = min(dpi->width, x + 4);
				int reps = (dpi->height - y + 1) / 2; // Number of lines.
				if (reps > 0) {
					this->DrawSmallMapColumn(ptr, tile_x, tile_y, dpi->pitch * 2, reps, x, end_pos, blitter, _smallmap_draw_procs[this->map_type]);
				}
			}

			if (y == 0) {
				tile_y += this->zoom;
				y++;
				ptr = blitter->MoveTo(ptr, 0, 1);
			} else {
				tile_x -= this->zoom;
				y--;
				ptr = blitter->MoveTo(ptr, 0, -1);
			}
			ptr = blitter->MoveTo(ptr, 2, 0);
			x += 2;
		}

		/* Draw vehicles */
		if (this->map_type == SMT_CONTOUR || this->map_type == SMT_VEHICLES) this->DrawVehicles(dpi, blitter);

		/* Draw town names */
		if (this->show_towns) this->DrawTowns(dpi);

		/* Draw map indicators */
		this->DrawMapIndicators();

		_cur_dpi = old_dpi;
	}

public:
	SmallMapWindow(const WindowDesc *desc, int window_number) : Window(), refresh(FORCE_REFRESH_PERIOD)
	{
		this->InitNested(desc, window_number);
		this->LowerWidget(this->map_type + SM_WIDGET_CONTOUR);

		_smallmap_industry_show_heightmap = false;
		this->SetWidgetLoweredState(SM_WIDGET_SHOW_HEIGHT, _smallmap_industry_show_heightmap);

		this->SetWidgetLoweredState(SM_WIDGET_TOGGLETOWNNAME, this->show_towns);
		this->GetWidget<NWidgetStacked>(SM_WIDGET_SELECTINDUSTRIES)->SetDisplayedPlane(this->map_type != SMT_INDUSTRY);

		this->SetZoomLevel(ZLC_INITIALIZE);
		this->SmallMapCenterOnCurrentPos();
	}

	/** Compute maximal required height of the legends.
	 * @return Maximally needed height for displaying the smallmap legends in pixels.
	 */
	inline uint GetMaxLegendHeight() const
	{
		uint num_rows = max(this->min_number_of_fixed_rows, (_smallmap_industry_count + this->min_number_of_columns - 1) / this->min_number_of_columns);
		return WD_FRAMERECT_TOP + WD_FRAMERECT_BOTTOM + num_rows * FONT_HEIGHT_SMALL;
	}

	/** Compute minimal required width of the legends.
	 * @return Minimally needed width for displaying the smallmap legends in pixels.
	 */
	inline uint GetMinLegendWidth() const
	{
		return WD_FRAMERECT_LEFT + this->min_number_of_columns * this->column_width;
	}

	/** Return number of columns that can be displayed in \a width pixels.
	 * @return Number of columns to display.
	 */
	inline uint GetNumberColumnsLegend(uint width) const
	{
		return width / this->column_width;
	}

	/** Compute height given a width.
	 * @return Needed height for displaying the smallmap legends in pixels.
	 */
	uint GetLegendHeight(uint width) const
	{
		uint num_columns = this->GetNumberColumnsLegend(width);
		uint num_rows = max(this->min_number_of_fixed_rows, (_smallmap_industry_count + num_columns - 1) / num_columns);
		return WD_FRAMERECT_TOP + WD_FRAMERECT_BOTTOM + num_rows * FONT_HEIGHT_SMALL;
	}

	virtual void SetStringParameters(int widget) const
	{
		switch (widget) {
			case SM_WIDGET_CAPTION:
				SetDParam(0, STR_SMALLMAP_TYPE_CONTOURS + this->map_type);
				break;
		}
	}

	virtual void OnInit()
	{
		uint min_width = 0;
		this->min_number_of_columns = INDUSTRY_MIN_NUMBER_OF_COLUMNS;
		this->min_number_of_fixed_rows = 0;
		for (uint i = 0; i < lengthof(_legend_table); i++) {
			uint height = 0;
			uint num_columns = 1;
			for (const LegendAndColour *tbl = _legend_table[i]; !tbl->end; ++tbl) {
				StringID str;
				if (i == SMT_INDUSTRY) {
					SetDParam(0, tbl->legend);
					SetDParam(1, IndustryPool::MAX_SIZE);
					str = STR_SMALLMAP_INDUSTRY;
				} else {
					if (tbl->col_break) {
						this->min_number_of_fixed_rows = max(this->min_number_of_fixed_rows, height);
						height = 0;
						num_columns++;
					}
					height++;
					str = tbl->legend;
				}
				min_width = max(GetStringBoundingBox(str).width, min_width);
			}
			this->min_number_of_fixed_rows = max(this->min_number_of_fixed_rows, height);
			this->min_number_of_columns = max(this->min_number_of_columns, num_columns);
		}

		/* The width of a column is the minimum width of all texts + the size of the blob + some spacing */
		this->column_width = min_width + LEGEND_BLOB_WIDTH + WD_FRAMERECT_LEFT + WD_FRAMERECT_RIGHT;
	}

	virtual void DrawWidget(const Rect &r, int widget) const
	{
		switch (widget) {
			case SM_WIDGET_MAP: {
				DrawPixelInfo new_dpi;
				if (!FillDrawPixelInfo(&new_dpi, r.left + 1, r.top + 1, r.right - r.left - 1, r.bottom - r.top - 1)) return;
				this->DrawSmallMap(&new_dpi);
			} break;

			case SM_WIDGET_LEGEND: {
				uint columns = this->GetNumberColumnsLegend(r.right - r.left + 1);
				uint number_of_rows = max(this->map_type == SMT_INDUSTRY ? (_smallmap_industry_count + columns - 1) / columns : 0, this->min_number_of_fixed_rows);
				bool rtl = _dynlang.text_dir == TD_RTL;
				uint y_org = r.top + WD_FRAMERECT_TOP;
				uint x = rtl ? r.right - this->column_width - WD_FRAMERECT_RIGHT : r.left + WD_FRAMERECT_LEFT;
				uint y = y_org;
				uint i = 0; // Row counter for industry legend.
				uint row_height = FONT_HEIGHT_SMALL;

				uint text_left  = rtl ? 0 : LEGEND_BLOB_WIDTH + WD_FRAMERECT_LEFT;
				uint text_right = this->column_width - 1 - (rtl ? LEGEND_BLOB_WIDTH + WD_FRAMERECT_RIGHT : 0);
				uint blob_left  = rtl ? this->column_width - 1 - LEGEND_BLOB_WIDTH : 0;
				uint blob_right = rtl ? this->column_width - 1 : LEGEND_BLOB_WIDTH;

				for (const LegendAndColour *tbl = _legend_table[this->map_type]; !tbl->end; ++tbl) {
					if (tbl->col_break || (this->map_type == SMT_INDUSTRY && i++ >= number_of_rows)) {
						/* Column break needed, continue at top, COLUMN_WIDTH pixels
						 * (one "row") to the right. */
						x += rtl ? -(int)this->column_width : this->column_width;
						y = y_org;
						i = 1;
					}

					if (this->map_type == SMT_INDUSTRY) {
						/* Industry name must be formatted, since it's not in tiny font in the specs.
						 * So, draw with a parameter and use the STR_SMALLMAP_INDUSTRY string, which is tiny font */
						SetDParam(0, tbl->legend);
						assert(tbl->type < NUM_INDUSTRYTYPES);
						SetDParam(1, _industry_counts[tbl->type]);
						if (!tbl->show_on_map) {
							/* Simply draw the string, not the black border of the legend colour.
							 * This will enforce the idea of the disabled item */
							DrawString(x + text_left, x + text_right, y, STR_SMALLMAP_INDUSTRY, TC_GREY);
						} else {
							DrawString(x + text_left, x + text_right, y, STR_SMALLMAP_INDUSTRY, TC_BLACK);
							GfxFillRect(x + blob_left, y + 1, x + blob_right, y + row_height - 1, 0); // Outer border of the legend colour
						}
					} else {
						/* Anything that is not an industry is using normal process */
						GfxFillRect(x + blob_left, y + 1, x + blob_right, y + row_height - 1, 0);
						DrawString(x + text_left, x + text_right, y, tbl->legend);
					}
					GfxFillRect(x + blob_left + 1, y + 2, x + blob_right - 1, y + row_height - 2, tbl->colour); // Legend colour

					y += row_height;
				}
			}
		}
	}

	virtual void OnPaint()
	{
		this->DrawWidgets();
	}

	virtual void OnClick(Point pt, int widget, int click_count)
	{
		switch (widget) {
			case SM_WIDGET_MAP: { // Map window
				/*
				 * XXX: scrolling with the left mouse button is done by subsequently
				 * clicking with the left mouse button; clicking once centers the
				 * large map at the selected point. So by unclicking the left mouse
				 * button here, it gets reclicked during the next inputloop, which
				 * would make it look like the mouse is being dragged, while it is
				 * actually being (virtually) clicked every inputloop.
				 */
				_left_button_clicked = false;

				const NWidgetBase *wid = this->GetWidget<NWidgetBase>(SM_WIDGET_MAP);
				Window *w = FindWindowById(WC_MAIN_WINDOW, 0);
				int sub;
				pt = this->PixelToTile(pt.x - wid->pos_x, pt.y - wid->pos_y, &sub);
				pt = RemapCoords(this->scroll_x + pt.x * TILE_SIZE + this->zoom * (TILE_SIZE - sub * TILE_SIZE / 4),
						this->scroll_y + pt.y * TILE_SIZE + sub * this->zoom * TILE_SIZE / 4, 0);

				w->viewport->follow_vehicle = INVALID_VEHICLE;
				w->viewport->dest_scrollpos_x = pt.x - (w->viewport->virtual_width  >> 1);
				w->viewport->dest_scrollpos_y = pt.y - (w->viewport->virtual_height >> 1);

				this->SetDirty();
			} break;

			case SM_WIDGET_ZOOM_IN:
				this->SetZoomLevel(ZLC_ZOOM_IN);
				break;

			case SM_WIDGET_ZOOM_OUT:
				this->SetZoomLevel(ZLC_ZOOM_OUT);
				break;

			case SM_WIDGET_CONTOUR:    // Show land contours
			case SM_WIDGET_VEHICLES:   // Show vehicles
			case SM_WIDGET_INDUSTRIES: // Show industries
			case SM_WIDGET_ROUTES:     // Show transport routes
			case SM_WIDGET_VEGETATION: // Show vegetation
			case SM_WIDGET_OWNERS:     // Show land owners
				this->RaiseWidget(this->map_type + SM_WIDGET_CONTOUR);
				this->map_type = (SmallMapType)(widget - SM_WIDGET_CONTOUR);
				this->LowerWidget(this->map_type + SM_WIDGET_CONTOUR);

				/* Hide Enable all/Disable all buttons if is not industry type small map */
				this->GetWidget<NWidgetStacked>(SM_WIDGET_SELECTINDUSTRIES)->SetDisplayedPlane(this->map_type != SMT_INDUSTRY);

				this->SetDirty();
				SndPlayFx(SND_15_BEEP);
				break;

			case SM_WIDGET_CENTERMAP: // Center the smallmap again
				this->SmallMapCenterOnCurrentPos();
				this->HandleButtonClick(SM_WIDGET_CENTERMAP);
				SndPlayFx(SND_15_BEEP);
				break;

			case SM_WIDGET_TOGGLETOWNNAME: // Toggle town names
				this->show_towns = !this->show_towns;
				this->SetWidgetLoweredState(SM_WIDGET_TOGGLETOWNNAME, this->show_towns);

				this->SetDirty();
				SndPlayFx(SND_15_BEEP);
				break;

			case SM_WIDGET_LEGEND: // Legend
				/* If industry type small map*/
				if (this->map_type == SMT_INDUSTRY) {
					/* If click on industries label, find right industry type and enable/disable it */
					const NWidgetBase *wi = this->GetWidget<NWidgetBase>(SM_WIDGET_LEGEND); // Label panel
					uint line = (pt.y - wi->pos_y - WD_FRAMERECT_TOP) / FONT_HEIGHT_SMALL;
					uint columns = this->GetNumberColumnsLegend(wi->current_x);
					uint number_of_rows = max((_smallmap_industry_count + columns - 1) / columns, this->min_number_of_fixed_rows);
					if (line >= number_of_rows) break;

					bool rtl = _dynlang.text_dir == TD_RTL;
					int x = pt.x - wi->pos_x;
					if (rtl) x = wi->current_x - x;
					uint column = (x - WD_FRAMERECT_LEFT) / this->column_width;

					/* Check if click is on industry label*/
					int industry_pos = (column * number_of_rows) + line;
					if (industry_pos < _smallmap_industry_count) {
						_legend_from_industries[industry_pos].show_on_map = !_legend_from_industries[industry_pos].show_on_map;
					}

					/* Raise the two buttons "all", as we have done a specific choice */
					this->RaiseWidget(SM_WIDGET_ENABLEINDUSTRIES);
					this->RaiseWidget(SM_WIDGET_DISABLEINDUSTRIES);
					this->SetDirty();
				}
				break;

			case SM_WIDGET_ENABLEINDUSTRIES: // Enable all industries
				for (int i = 0; i != _smallmap_industry_count; i++) {
					_legend_from_industries[i].show_on_map = true;
				}
				/* Toggle appeareance indicating the choice */
				this->LowerWidget(SM_WIDGET_ENABLEINDUSTRIES);
				this->RaiseWidget(SM_WIDGET_DISABLEINDUSTRIES);
				this->SetDirty();
				break;

			case SM_WIDGET_DISABLEINDUSTRIES: // Disable all industries
				for (int i = 0; i != _smallmap_industry_count; i++) {
					_legend_from_industries[i].show_on_map = false;
				}
				/* Toggle appeareance indicating the choice */
				this->RaiseWidget(SM_WIDGET_ENABLEINDUSTRIES);
				this->LowerWidget(SM_WIDGET_DISABLEINDUSTRIES);
				this->SetDirty();
				break;

			case SM_WIDGET_SHOW_HEIGHT: // Enable/disable showing of heightmap.
				_smallmap_industry_show_heightmap = !_smallmap_industry_show_heightmap;
				this->SetWidgetLoweredState(SM_WIDGET_SHOW_HEIGHT, _smallmap_industry_show_heightmap);
				this->SetDirty();
				break;
		}
	}

	virtual void OnRightClick(Point pt, int widget)
	{
		if (widget == SM_WIDGET_MAP) {
			if (_scrolling_viewport) return;
			_scrolling_viewport = true;
		}
	}

	virtual void OnTick()
	{
		/* Update the window every now and then */
		if (--this->refresh != 0) return;

		this->refresh = FORCE_REFRESH_PERIOD;
		this->SetDirty();
	}

	/**
	 * Set new #scroll_x, #scroll_y, and #subscroll values after limiting them such that the center
	 * of the smallmap always contains a part of the map.
	 * @param sx  Proposed new #scroll_x
	 * @param sy  Proposed new #scroll_y
	 * @param sub Proposed new #subscroll
	 */
	void SetNewScroll(int sx, int sy, int sub)
	{
		const NWidgetBase *wi = this->GetWidget<NWidgetBase>(SM_WIDGET_MAP);
		Point hv = InverseRemapCoords(wi->current_x * TILE_SIZE / 2, wi->current_y * TILE_SIZE / 2);
		hv.x *= this->zoom;
		hv.y *= this->zoom;

		if (sx < -hv.x) {
			sx = -hv.x;
			sub = 0;
		}
		if (sx > (int)MapMaxX() * TILE_SIZE - hv.x) {
			sx = MapMaxX() * TILE_SIZE - hv.x;
			sub = 0;
		}
		if (sy < -hv.y) {
			sy = -hv.y;
			sub = 0;
		}
		if (sy > (int)MapMaxY() * TILE_SIZE - hv.y) {
			sy = MapMaxY() * TILE_SIZE - hv.y;
			sub = 0;
		}

		this->scroll_x = sx;
		this->scroll_y = sy;
		this->subscroll = sub;
	}

	virtual void OnScroll(Point delta)
	{
		_cursor.fix_at = true;

		/* While tile is at (delta.x, delta.y)? */
		int sub;
		Point pt = this->PixelToTile(delta.x, delta.y, &sub);
		this->SetNewScroll(this->scroll_x + pt.x * TILE_SIZE, this->scroll_y + pt.y * TILE_SIZE, sub);

		this->SetDirty();
	}

	void SmallMapCenterOnCurrentPos()
	{
		const ViewPort *vp = FindWindowById(WC_MAIN_WINDOW, 0)->viewport;
		Point pt = InverseRemapCoords(vp->virtual_left + vp->virtual_width  / 2, vp->virtual_top  + vp->virtual_height / 2);

		int sub;
		const NWidgetBase *wid = this->GetWidget<NWidgetBase>(SM_WIDGET_MAP);
		Point tile = this->PixelToTile(wid->current_x / 2, wid->current_y / 2, &sub);

		this->SetNewScroll(pt.x - tile.x * TILE_SIZE, pt.y - tile.y * TILE_SIZE, sub);
		this->SetDirty();
	}
};

SmallMapWindow::SmallMapType SmallMapWindow::map_type = SMT_CONTOUR;
bool SmallMapWindow::show_towns = true;

/**
 * Custom container class for displaying smallmap with a vertically resizing legend panel.
 * The legend panel has a smallest height that depends on its width. Standard containers cannot handle this case.
 *
 * @note The container assumes it has two childs, the first is the display, the second is the bar with legends and selection image buttons.
 *       Both childs should be both horizontally and vertically resizable and horizontally fillable.
 *       The bar should have a minimal size with a zero-size legends display. Child padding is not supported.
 */
class NWidgetSmallmapDisplay : public NWidgetContainer {
	const SmallMapWindow *smallmap_window; ///< Window manager instance.
public:
	NWidgetSmallmapDisplay() : NWidgetContainer(NWID_VERTICAL)
	{
		this->smallmap_window = NULL;
	}

	virtual void SetupSmallestSize(Window *w, bool init_array)
	{
		NWidgetBase *display = this->head;
		NWidgetBase *bar = display->next;

		display->SetupSmallestSize(w, init_array);
		bar->SetupSmallestSize(w, init_array);

		this->smallmap_window = dynamic_cast<SmallMapWindow *>(w);
		this->smallest_x = max(display->smallest_x, bar->smallest_x + smallmap_window->GetMinLegendWidth());
		this->smallest_y = display->smallest_y + max(bar->smallest_y, smallmap_window->GetMaxLegendHeight());
		this->fill_x = max(display->fill_x, bar->fill_x);
		this->fill_y = (display->fill_y == 0 && bar->fill_y == 0) ? 0 : min(display->fill_y, bar->fill_y);
		this->resize_x = max(display->resize_x, bar->resize_x);
		this->resize_y = min(display->resize_y, bar->resize_y);
	}

	virtual void AssignSizePosition(SizingType sizing, uint x, uint y, uint given_width, uint given_height, bool rtl)
	{
		this->pos_x = x;
		this->pos_y = y;
		this->current_x = given_width;
		this->current_y = given_height;

		NWidgetBase *display = this->head;
		NWidgetBase *bar = display->next;

		if (sizing == ST_SMALLEST) {
			this->smallest_x = given_width;
			this->smallest_y = given_height;
			/* Make display and bar exactly equal to their minimal size. */
			display->AssignSizePosition(ST_SMALLEST, x, y, display->smallest_x, display->smallest_y, rtl);
			bar->AssignSizePosition(ST_SMALLEST, x, y + display->smallest_y, bar->smallest_x, bar->smallest_y, rtl);
		}

		uint bar_height = max(bar->smallest_y, this->smallmap_window->GetLegendHeight(given_width - bar->smallest_x));
		uint display_height = given_height - bar_height;
		display->AssignSizePosition(ST_RESIZE, x, y, given_width, display_height, rtl);
		bar->AssignSizePosition(ST_RESIZE, x, y + display_height, given_width, bar_height, rtl);
	}

	virtual NWidgetCore *GetWidgetFromPos(int x, int y)
	{
		if (!IsInsideBS(x, this->pos_x, this->current_x) || !IsInsideBS(y, this->pos_y, this->current_y)) return NULL;
		for (NWidgetBase *child_wid = this->head; child_wid != NULL; child_wid = child_wid->next) {
			NWidgetCore *widget = child_wid->GetWidgetFromPos(x, y);
			if (widget != NULL) return widget;
		}
		return NULL;
	}

	virtual void Draw(const Window *w)
	{
		for (NWidgetBase *child_wid = this->head; child_wid != NULL; child_wid = child_wid->next) child_wid->Draw(w);
	}
};

/** Widget parts of the smallmap display. */
static const NWidgetPart _nested_smallmap_display[] = {
	NWidget(WWT_PANEL, COLOUR_BROWN, SM_WIDGET_MAP_BORDER),
		NWidget(WWT_INSET, COLOUR_BROWN, SM_WIDGET_MAP), SetMinimalSize(346, 140), SetResize(1, 1), SetPadding(2, 2, 2, 2), EndContainer(),
	EndContainer(),
};

/** Widget parts of the smallmap legend bar + image buttons. */
static const NWidgetPart _nested_smallmap_bar[] = {
	NWidget(WWT_PANEL, COLOUR_BROWN),
		NWidget(NWID_HORIZONTAL),
			NWidget(WWT_EMPTY, INVALID_COLOUR, SM_WIDGET_LEGEND), SetResize(1, 1),
			NWidget(NWID_VERTICAL),
				/* Top button row. */
				NWidget(NWID_HORIZONTAL, NC_EQUALSIZE),
					NWidget(WWT_PUSHIMGBTN, COLOUR_BROWN, SM_WIDGET_ZOOM_IN), SetDataTip(SPR_IMG_ZOOMIN, STR_TOOLBAR_TOOLTIP_ZOOM_THE_VIEW_IN),
					NWidget(WWT_PUSHIMGBTN, COLOUR_BROWN, SM_WIDGET_CENTERMAP), SetDataTip(SPR_IMG_SMALLMAP, STR_SMALLMAP_CENTER),
					NWidget(WWT_IMGBTN, COLOUR_BROWN, SM_WIDGET_CONTOUR), SetDataTip(SPR_IMG_SHOW_COUNTOURS, STR_SMALLMAP_TOOLTIP_SHOW_LAND_CONTOURS_ON_MAP),
					NWidget(WWT_IMGBTN, COLOUR_BROWN, SM_WIDGET_VEHICLES), SetDataTip(SPR_IMG_SHOW_VEHICLES, STR_SMALLMAP_TOOLTIP_SHOW_VEHICLES_ON_MAP),
					NWidget(WWT_IMGBTN, COLOUR_BROWN, SM_WIDGET_INDUSTRIES), SetDataTip(SPR_IMG_INDUSTRY, STR_SMALLMAP_TOOLTIP_SHOW_INDUSTRIES_ON_MAP),
				EndContainer(),
				/* Bottom button row. */
				NWidget(NWID_HORIZONTAL, NC_EQUALSIZE),
					NWidget(WWT_PUSHIMGBTN, COLOUR_BROWN, SM_WIDGET_ZOOM_OUT), SetDataTip(SPR_IMG_ZOOMOUT, STR_TOOLBAR_TOOLTIP_ZOOM_THE_VIEW_OUT),
					NWidget(WWT_IMGBTN, COLOUR_BROWN, SM_WIDGET_TOGGLETOWNNAME), SetDataTip(SPR_IMG_TOWN, STR_SMALLMAP_TOOLTIP_TOGGLE_TOWN_NAMES_ON_OFF),
					NWidget(WWT_IMGBTN, COLOUR_BROWN, SM_WIDGET_ROUTES), SetDataTip(SPR_IMG_SHOW_ROUTES, STR_SMALLMAP_TOOLTIP_SHOW_TRANSPORT_ROUTES_ON),
					NWidget(WWT_IMGBTN, COLOUR_BROWN, SM_WIDGET_VEGETATION), SetDataTip(SPR_IMG_PLANTTREES, STR_SMALLMAP_TOOLTIP_SHOW_VEGETATION_ON_MAP),
					NWidget(WWT_IMGBTN, COLOUR_BROWN, SM_WIDGET_OWNERS), SetDataTip(SPR_IMG_COMPANY_GENERAL, STR_SMALLMAP_TOOLTIP_SHOW_LAND_OWNERS_ON_MAP),
				EndContainer(),
				NWidget(NWID_SPACER), SetResize(0, 1),
			EndContainer(),
		EndContainer(),
	EndContainer(),
};

static NWidgetBase *SmallMapDisplay(int *biggest_index)
{
	NWidgetContainer *map_display = new NWidgetSmallmapDisplay;

	MakeNWidgets(_nested_smallmap_display, lengthof(_nested_smallmap_display), biggest_index, map_display);
	MakeNWidgets(_nested_smallmap_bar, lengthof(_nested_smallmap_bar), biggest_index, map_display);
	return map_display;
}


static const NWidgetPart _nested_smallmap_widgets[] = {
	NWidget(NWID_HORIZONTAL),
		NWidget(WWT_CLOSEBOX, COLOUR_BROWN),
		NWidget(WWT_CAPTION, COLOUR_BROWN, SM_WIDGET_CAPTION), SetDataTip(STR_SMALLMAP_CAPTION, STR_TOOLTIP_WINDOW_TITLE_DRAG_THIS),
		NWidget(WWT_SHADEBOX, COLOUR_BROWN),
		NWidget(WWT_STICKYBOX, COLOUR_BROWN),
	EndContainer(),
	NWidgetFunction(SmallMapDisplay), // Smallmap display and legend bar + image buttons.
	/* Bottom button row and resize box. */
	NWidget(NWID_HORIZONTAL),
		NWidget(WWT_PANEL, COLOUR_BROWN),
			NWidget(NWID_HORIZONTAL),
				NWidget(NWID_SELECTION, INVALID_COLOUR, SM_WIDGET_SELECTINDUSTRIES),
					NWidget(NWID_HORIZONTAL, NC_EQUALSIZE),
						NWidget(WWT_TEXTBTN, COLOUR_BROWN, SM_WIDGET_ENABLEINDUSTRIES), SetDataTip(STR_SMALLMAP_ENABLE_ALL, STR_SMALLMAP_TOOLTIP_ENABLE_ALL),
						NWidget(WWT_TEXTBTN, COLOUR_BROWN, SM_WIDGET_DISABLEINDUSTRIES), SetDataTip(STR_SMALLMAP_DISABLE_ALL, STR_SMALLMAP_TOOLTIP_DISABLE_ALL),
						NWidget(WWT_TEXTBTN, COLOUR_BROWN, SM_WIDGET_SHOW_HEIGHT), SetDataTip(STR_SMALLMAP_SHOW_HEIGHT, STR_SMALLMAP_TOOLTIP_SHOW_HEIGHT),
					EndContainer(),
					NWidget(NWID_SPACER), SetFill(1, 1),
				EndContainer(),
				NWidget(NWID_SPACER), SetFill(1, 0), SetResize(1, 0),
			EndContainer(),
		EndContainer(),
		NWidget(WWT_RESIZEBOX, COLOUR_BROWN),
	EndContainer(),
};

static const WindowDesc _smallmap_desc(
	WDP_AUTO, 446, 314,
	WC_SMALLMAP, WC_NONE,
	WDF_UNCLICK_BUTTONS,
	_nested_smallmap_widgets, lengthof(_nested_smallmap_widgets)
);

void ShowSmallMap()
{
	AllocateWindowDescFront<SmallMapWindow>(&_smallmap_desc, 0);
}

/**
 * Scrolls the main window to given coordinates.
 * @param x x coordinate
 * @param y y coordinate
 * @param z z coordinate; -1 to scroll to terrain height
 * @param instant scroll instantly (meaningful only when smooth_scrolling is active)
 * @return did the viewport position change?
 */
bool ScrollMainWindowTo(int x, int y, int z, bool instant)
{
	bool res = ScrollWindowTo(x, y, z, FindWindowById(WC_MAIN_WINDOW, 0), instant);

	/* If a user scrolls to a tile (via what way what so ever) and already is on
	 * that tile (e.g.: pressed twice), move the smallmap to that location,
	 * so you directly see where you are on the smallmap. */

	if (res) return res;

	SmallMapWindow *w = dynamic_cast<SmallMapWindow*>(FindWindowById(WC_SMALLMAP, 0));
	if (w != NULL) w->SmallMapCenterOnCurrentPos();

	return res;
}