Bit-level descriptions for section 2.3 "More complex 2-D texel addressing"

[pwnall]

I think that section 2.3 would benefit from bit-level illustrations and descriptions for computing offsets from coordinates. I think this would be a good complement to the C implementations which are great.

In the first approach (linear tiles?), the bits are combined as follows (modulo lineStride), from lsb to msb.

• least significant "twb" bits of x
• least significant "twh" bits of y
• remaining bits of x
• remaining bits of y

The Morton order effectively merges (similarly to MergeSort) the bits from the x and y coordinates.

• least significant bit of x
• least significant bit of y
• next-to-least significant bit of x
• next-to-least significant bit of y
• ...

[fluppeteer]

That's reasonable - this is often implemented in hardware, after all. KDFS updates have stalled for a while for logistical reasons, but I'm really hoping to see a number of updates incorporated soon, and I'll try to get this in there.