As you may or may not know, I've been attempting to write an editor. My
next ****tion of coding now requires an algorithm for a node builder, and
obviously produces a few questions.
For this posting, we will be using a generic sample map: a circular ring.
The ring is composed of two concentric circles, with an outer circle
defining the boundires of the map, and an inner circle that defines the
central pillar. The outer radius of the ring is 768 units, with the inner
radius being 512 units. However, this ring is asymettrical, as it has 9
sides (or some other odd number).
My diagram for this map simple has the outer circle being a scaled up
version of the inner circle, with lines going from the outer points to the
inner counterparts (or vice versa - can't count on the map designer being
consistant.)
Now, the questions:
1. I've been thinking about building the SSECTORS and SEGS first before
the
nodes - however, the an initial BSP cut would obviously go right through
one of the segs in such a ring if it were radial. What is the procedure
for the SEGS in the remote sectors that get divided by this - is there
some
magic number (such as -1) that needs to be set, or is there some other
procedure?
I do know that that partition lines seem to be spanning across multiple
sectors, as in E2M8 (sometimes going through the entire map but sometimes
stopping halfway through, where I assume another partition line is
located.)
2. The DOOM Specification is not exactly clear on the NODES and similar
lumps work - is there a better resource that describs the data structure
more clearly or is that the best thing our there aside from the Doom
source
code?
3. For the BLOCKMAP, I've been attempting to write an algorithm that
minimize its size (since it is a significant bottleneck.) It basically
does a frequency count of the lines that are on a specific coordinate
(after X Modulus 128) from all points after the start line, and takes the
starting blockmap location to be the position that has the lowest
frequency
count. Is this a correct algorithm, or is there a better alternative? (If
you've done something like this before, you either know what I'm talking
about or have something completely different.
That seems to be all of them. Normally, I'd check with another program to
see how it does the magic, but that would almost feel like plagerism
regardless of whether copying algorithms is permitted or not.
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