First, the input string to is hashed with sdbm to get an integer.
For example, sdbm("Hello world.") -> 860116106. The binary representation (e.g. 110011010001000101010010001010) is used for the algorithm moving forward.
The two colors are chosen by using 5-bit chunks (32 choices) for each R, G, and B value. Thus, two RGB colors require 30 (5 * 3, twice) bits. From the example bits, one color would come from: 10101,00100,01010. Finally, the 17th bit (why not?) is used to determine if the image should be flipped vertically -- basically "the other" orientation (upside-down cube).
If the hexagon is imagined to be an isometric cube (below, left), one "square" side is used to draw the shape. This side is mapped as a unit square, with the origin (0,0) at the center of the hexagon (blue dot below).
This unit square is mapped evenly into 16 points, incrementing by 1/3 unit, as shown in the lower right. The red line shows the ordering the points are traversed. Based on the bits from the input hash, a polygon is created, using points where the bit is set. From the example value, the lowest sixteen bits 0101010010001010 means the polygon would include points 1, 3, 7, 10, 12, and 14.
This polygon (once transformed to fit the skewed isometric side) is added to the svg. The same polygon is rotated to cover the remaining two "sides" of the isometric cube as well.
