[cairo] clarification on some misc pattern documents?

[jimmy frasche]

> Yes.

I just realized why that was confusing to me. I was parsing the sentence as:

Values of index are (0 to 1) (less than the number)...

instead of

Values of index are (0) to (1 less than the number...)

If that notation is clear.

I think the "0 to n-1 where n is" makes it clearer. I'll prepare a
patch for that and the three similar sentences on various mesh patch
getters, in case I'm not the only one confused by that.

> I looked for the word "overlap". Do you mean the following text?
>
>  *snip*

Yes.

> I think this tries to define the coordinates when it talks to "range from 0 to 1
> when moving from side 3 to side 1".
>
> I feel like I do understand this description. However, feel free to submit
> enhancements which you think are necessary.

Apparently I understood it too, but it's so awkward that I could only
confirm I understood after scrolling back and forth between that
description and the ASCII image, reading the ISO spec, and asking the
internet for help!

I think it could be much clearer. I think the easiest way would be to
augment the ASCII image with labeled axes that can be referred to.
I'll make a patch.