Looking at the QuickDraw source, it's exactly what he did[1]. Ovals and roundrects, both solid and hollow, are all handled by a single DrawArc function. Essenti

Looking at the QuickDraw source, it's exactly what he did[1]. Ovals and roundrects, both solid and hollow, are all handled by a single DrawArc function. Essentially an oval _is_ a round rect whose border radiuses are the entirety of the oval's radiuses. Arcs are also handled by DrawArc, but of course there's a fast path for when start=0 and end=360. [1] https://d1yx3ys82bpsa0.cloudfront.net/102658076_quickdraw_acc.zip https://d1yx3ys82bpsa0.cloudfront.net/102658076_quickdraw_ac...