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[mkgmap-dev] [PATCH v1] increase Table B size

From Mark Burton markb at ordern.com on Mon Nov 23 15:13:01 GMT 2009


    Support larger Table B sizes.
    
    Until now, we have limited Table B to less than 0x40 entries but by using
    an extra byte to hold the Table B index in RouteArc objects, the number of
    entries can be increased up to a new limit of 0x100.

Just discovered that Table B can actually be larger than we have been
using. Table B overflow is one of the criteria for dividing a route
centre so by allowing them to be larger, it should reduce the number of
route centre splits. Having said that, on the GB map data, only a few
Table B's grew larger than the previous limit so I think the benefit is
probably marginal. Still, for complex city regions it could make a
difference.  I have verified that for the GB map, those roads that
cause a Table B to be larger than the previous limit are routable as
normal. Anyway, please test if you can and as long as it doesn't
introduce any problems it's worth incorporating this.

Mark
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