This is a dithered/patterned drawing routine, where you can supply your custom patterns. Plus added in a couple of (somewhat ugly) shape drawing/rasterizer routines too (rect, circle, triangle).
There are a couple of demos in that cart, each benchamrked, and it is possible to switch between simply using "pix" to draw or using "memcpy". Memcpy generally seems to be faster, but there can be cases when not - the memcpy version needs to do a lot more checks and whatnot, and when you need to draw lots of short lines (see the "flag" demo), it adds up.
Ohh, and since the benchmarks are not guaranteed to run exactly the same between different drawing routines, and the speed directly proportional to the number of pixels drawn, the times shown are more of a "general idea" about the speeds, not necessary directly comparable.