1. A method comprising: selecting a rasterization mode for a graphics primitive from a set of at least two candidate rasterization modes based on a metric indicative of an area of the graphics primitive, the set of at least two candidate rasterization modes including a first candidate rasterization mode and a second candidate rasterization mode; performing, with fixed function scan conversion hardware, scan conversion for the graphics primitive when the first candidate rasterization mode is selected as the rasterization mode for the graphics primitive; and performing, with a programmable shader unit, scan conversion for the graphics primitive when the second candidate rasterization mode is selected as the rasterization mode for the graphics primitive.