[venning]

Correct me if I'm wrong, but some of this sounds like blitting, except optimized for the in-memory structure and not the on-disk structure.

In 2008, Joel Spolsky wrote about 1990s-era Excel file formats and how they used this technique to deal with how slow computers were then [1]. Same technique, new problem set.

[1] http://www.joelonsoftware.com/items/2008/02/19.html