Difference between quartz2d on iphone and mac
1 answer
As far as the low-level drawing is concerned, both platforms are almost identical. One problem you'll run into is that many of these tutorials were written before Leopard was released, so they don't account for support for the Core Animation layer for views, which is everywhere on iPhones.
You don't have access to some of the iPhone text drawing systems you do on Mac.
Another key difference between the two platforms is the coordinate space for drawing quartz. Standard quartz on a Mac has a bottom left corner of be (0,0), where the support levels for UIViews have an inverted geometry, the top left corner of which is (0,0). I provide a little more detail in this answer .
+2
source to share