A method to pack rectangles together.
Packs rects into a rectangular region with size width by height, using method. Accounts for padding grid-spaces of padding on all sides of the rects. The data in rects will be re-ordered.
Same as pack, but requires rects to be sorted by their height (tallest first) for the following methods: - rows
A rectangular region with an optional userData field of type U to associate it with an external resource (e.g. an image).