can't draw fast enough to keep up with touchesMoved?

Question

I am trying to implement simple paint functionality in my iPhone app. I tried updating a bitmap with a bitmap brush, and I also tried this tutorial.

Both methods have

Answer 1

You can't directly call drawRect:. To refresh your screen on demand, try calling [self setNeedsDisplay] from your touchesMoved method, which will setup the proper contexts for a call to drawRect:.