Draft document-rendering tiling API to be called from viewer apps

[Tor Lillqvist]

>        IMHO the decision to render just squares prolly complicates the
> situation un-necessarily.

Sure, but on the other hand it makes it simpler in that we don't need
to figure out the aspect ratio of each page (they can be different)
beforehand.

BTW, I didn't mention in the IDL, but I did think that the not only
would it be a square, but also the side of the square would be a
power-of-two. Presumably you also want power-of-two for each side?

> Consider an A4 document - 2 x sqrt(2) in
> dimensions - almost certainly we end up with some 21x17 type ratio and
> then have to work hard to try to pack squares into it.

Hmm, but isn't this then an argument *in favour* of keeping the
rendered area square (and with a power-of-two side)? (Note that this
would mean that when zoomed in at some level and beyond, some tiles
will be completely outside of the page area.)

--tml