In this chapter there are some small things that a bit confusing:
1) in QuartsFun project, some properties are used in "_property_name" notation (_firstTouch), while others are uses in "self.property_name" notation (self.redrawRect).
2) in QuartsFun we define fistTouch as
while in GLFun we define fistTouch as
((nonatomic) is missing)
3) in GLFun project, for one of the touched method, we use
UITouch* touch = [[event touchesForView:self] anyObject];
while on two others, we continue to use
UITouch *touch = [touches anyObject];
For all those 3 cases, if that was made on purpose, it would be nice to give an explanation why. If there is no any special reason to do that, it would be less confusing to stick with the same pattern all the times.