Re: [Rails-devel] Automatic route calculation

[Erik V. <eri...@xs...>]

OK, I see you have already though about route determination. 

-----Original Message-----
From: alexti [mailto:al...@sh...] 
Let's say we have a hex  
oriented so that one side is facing north, another south and the other 4  
NW, SW, NE and SE. For each hex there will be 13 vertices. One in the  
center (#0), 6 vertices each in the middle of the hex edge (#1-#6, #1 is  
North, counting clockwise) and 6 more in the middle of the line connecting  
each of vertices #1-#6 to the center. Vertices #1-#6 will be shared with  
other adjacent hexes. Let's say we have green Y tile (two gently curving  
tracks from S to NW and from S to NE). Connectivity graph for such tile  
will be (2-8,8-10,10-4,6-12,12-10). 10-4 edge represents the bottom of "Y"  
and this ensures that only one of the track segments on this tile can be  
used. 

[EV] How do you prevent backtracking in this case? Going 2-8-10-12-6?

-----Original Message-----
From: Stefan Frey [mailto:ste...@we...] 
- I prefer your definition of the graph to the one in tiles.xml (inherited 
from the tiledesigner) as you only have to count edges and you do not have
to 
consider that you are not allowed to visit the same side (a node/vertex in 
Rails) twice. Rails defines tile 25 (the green Y) with two edges that both 
start from the same side  (see tiles.xml), but only one of each edge can be 
used per revenue turn.

[EV] I would rather think that the current Rails Tile definition would be
easier to use, as the only two requirements to make it work are:
- each edge (and station) may be visited only once,
- return from an edge is never allowed.
See my question above: it seems harder to do with the extra vertexes, as it
doen't seem to be clear what would prevent going 8-12-10. Or is that somehow
built into the vertex #7-12 properties?

Erik.