- rectOn = pygame.Rect((rect.left - rect.width/2, 0),
- (rect.width * ON_COLUMN_OVERSIZING, rect.height))
+ onWidth = rect.width * ON_COLUMN_OVERSIZING
+ onLeft = rect.centerx - onWidth / 2
+ rectOn = pygame.Rect((onLeft, 0),
+ (onWidth, rect.height))