[ft] Scaled Outline Coordinates at Scanline Intersections

[Infinality]

I am asking this from the point of view of the Freetype code, as opposed
to a client program using the code.  I am interested in being able to
calculate the value, in 26.6 coordinates, where the scanlines (at a
given ppem) intersect each point in a given outline.

For instance, as a crude example just using pixels:  If I'm dealing with
an outline of the letter "T", at 8x5 px, I'm looking for a result of
something like:

line 0 (top): 1.0 and 7.0
line 1      : 3.0 and 5.0
line 2      : 3.0 and 5.0
line 3      : 3.0 and 5.0
line 4      : 3.0 and 5.0

Which visually corresponds to:

|_|1|2|3|4|5|6|_|
|_|_|_|3|4|_|_|_|
|_|_|_|3|4|_|_|_|
|_|_|_|3|4|_|_|_|
|_|_|_|3|4|_|_|_|

What is the easiest way to obtain these values, given an outline and a
ppem?  I've looked in ftgrays.c, where I imagine I could obtain this
information, however I'm having a hard time comprehending what is
happening in there.

Thank you for any assistance!