Point new_tile = this->PixelToTile(zoom_pt->x, zoom_pt->y, &sub);

			this->SetNewScroll(this->scroll_x + (tile.x - new_tile.x) * TILE_SIZE,

					this->scroll_y + (tile.y - new_tile.y) * TILE_SIZE, sub);

		} else if (this->map_type == SMT_LINKSTATS) {

			this->overlay->RebuildCache();

		}

		this->SetWidgetDisabledState(WID_SM_ZOOM_IN,  this->zoom == zoomlevels[MIN_ZOOM_INDEX]);

		this->SetWidgetDisabledState(WID_SM_ZOOM_OUT, this->zoom == zoomlevels[MAX_ZOOM_INDEX]);

		this->SetDirty();

	}

}

/**

 * Decide which colours to show to the user for a group of tiles.

 * @param ta Tile area to investigate.

 * @return Colours to display.

 */

inline uint32 SmallMapWindow::GetTileColours(const TileArea &ta) const

{

	int importance = 0;

	TileIndex tile = INVALID_TILE; // Position of the most important tile.

	TileType et = MP_VOID;         // Effective tile type at that position.

	TILE_AREA_LOOP(ti, ta) {

		switch (ttype) {

			case MP_TUNNELBRIDGE: {

				switch (tt) {

					case TRANSPORT_RAIL: ttype = MP_RAILWAY; break;

					case TRANSPORT_ROAD: ttype = MP_ROAD;    break;

					default:             ttype = MP_WATER;   break;

				}

				break;

			}

			default:

				break;

		}

		if (_tiletype_importance[ttype] > importance) {

			importance = _tiletype_importance[ttype];

			tile = ti;

			et = ttype;

		}

	}

	switch (this->map_type) {

		case SMT_CONTOUR:

			return GetSmallMapContoursPixels(tile, et);