From Emanuele Feronato: "We are getting closer to the final algorithm to calculate dynamic light and shadow in tile based roguelike games, and we are going to cover another important feature: drawing circles in a tile based environment.
While in previous step I showed you the Bresenhams line algorithm although you probably still do not know why, this time it’s quite easy to understand how we are going to use circles in a tile based environment: to simulate the radius of a point light, which could be a torch on the wall or the light halo around your character."