I'm setting up a tile system where every tile has x and y coordinates. Right now I assume that the top left corner of the tile is positioned on it's coordinate on the screen, x = tileX * tileWidth and y = tileY x tileWidth. However, it seems strange that the tile with coordinate (0, 0) is completely drawn in the 'positive' side of the coordinate system as opposed to in the center of the origin. Is it common practice to assume that a coordinate lays in the center of a tile or at the top left corner of a tile? So basically x = tileX x tileWidth or x = tileX x tilewidth - ( tileWidth / 2 )?