Function SetRedErrorSquare

src/viewport.cpp:2601–2612

* Set a tile to display a red error square. * @param tile Tile that should show the red error square. */

 * @param tile Tile that should show the red error square.
 */
void SetRedErrorSquare(TileIndex tile)
{
	TileIndex old;

	old = _thd.redsq;
	_thd.redsq = tile;

	if (tile != old) {
		if (tile != INVALID_TILE) MarkTileDirtyByTile(tile);
		if (old  != INVALID_TILE) MarkTileDirtyByTile(old);
	}
}

/**
 * Highlight \a w by \a h tiles at the cursor.