1. A non-transitory computer readable medium having instructions stored thereon that, when executed by a processor, causes the processor to determine coverage of a metal layer mosaic, the determining coverage comprising: applying a tile pattern to a design including at least one layer; identifying at least one tile of the tile pattern that violates at least one first design rule; applying a sub-tile pattern to an area identified in the identifying the at least one tile of the tile pattern that violates the at least one first design rule; identifying at least one sub-tile of the sub-tile pattern that violates at least one second design rule; and applying a deep-sub-tile pattern to an area identified in the identifying the at least one sub-tile of the sub-tile pattern that violates the second design rule.