Method for converting two-dimensional objects to distance fields

摘要

A method converts a two-dimensional object to a two-dimensional distance field. The object is represented as a set of boundary descriptors and a fill rule. The set of boundary descriptors is preprocessed and a spatial hierarchy is constructed from the preprocessed set of boundary descriptors. A cache of intersections is initialized. The spatial hierarchy is queried at a set of locations to determine a set of distances at the locations. The query invokes a distance function at each location to determine an unsigned distance. A sign of the unsigned distance is determined from the cache of intersections, the location, and the fill rule. The set of distances is used to construct the two-dimensional distance field.