First I greatly appreciate the nice doc about SLP files drs-files.md in your repository, because that doc may be the most comprehensive one explaining SLPs that I can find on the whole Internet. :)

I'm recently trying to analyze one of my SLP files, and I'm using the doc as some basic resources. But I found some problems in that doc and it took me quite a long time to figure out the right way.
In drs-files.md you listed a couple of 'byte values' under the 'SLP drawing commands' section. After studying your slp.pyx file I finally found out that the name 'byte values' is not accurate. For 0x00 and 0x01, they mean 'the most insignificant (rightmost/lowest) two bits of cmd_byte being 0x00 and 0x01, and count is equal to cmd_byte >> 2; For 0x02, 0x03 and all the way to 0x0F, they all mean 'the most insignificant (rightmost/lowest) 4 bits of cmd_byte being 0x02, 0x03, ..., 0x0F.

I would suggest you to modify the text at the top of the chart 'byte value' to something like 'value of the most insignificant n bits' and note something like this in addition:

if cmd_byte == 0x00 or cmd_byte == 0x01: n = 2; else: n = 4.

Thx!