You specify an engine's antialiasing mode by assigning a value to its kQATag_Antialias state variable. The default value of this variable for a drawing engine that supports antialiasing is kQAAntiAlias_Fast .
#define kQAAntiAlias_Off 0
#define kQAAntiAlias_Fast 1
#define kQAAntiAlias_Mid 2
#define kQAAntiAlias_Best 3