Offscreen Rendering

Occasionally you will want to do some custom drawing, but not have that presented directly on the screen. Sometimes this is to "bake" the drawing into an image for faster scrolling performance (a single flattened image can be sent to the GPU easily without having to composite a bunch of views together). This is also often used to resize images that are too large for the intended view. This episode covers drawing to a custom context offscreen and obtaining an image out of it.

This is a companion discussion topic for the original entry at https://nsscreencast.com/episodes/289-core-graphics-offscreen-rendering