replace(source, dest, x, y, width, height, layer)
Scans the given area for tiles with an index matching source and updates their index to match dest.
Parameters
Name Type Argument Description source number The tile index value to scan for. dest number The tile index value to replace found tiles with. x number X position of the top left of the area to operate one, given in tiles, not pixels. y number Y position of the top left of the area to operate one, given in tiles, not pi