1. A polygon rendering system for receiving geometric data defining a polygon in an image being generated and rendering said geometric data as pixel data, said pixel data defining pixels used to display said image, said system comprising: a first memory buffer for storing said pixel data; a second memory buffer for storing additional pixel data used to render edge pixels at a higher resolution than pixels that are not said edge pixels, said edge pixels located on an edge of said polygon in said image; and a display controller for outputting said pixel data in said first memory buffer to output circuitry; wherein said polygon rendering system identifies which of said pixels are said edge pixels and said display controller updates contents of said first buffer with data based on contents of said second buffer.