[Xastir] A snapshot of the missing island

[Curt Mills, WE7U]

On Thu, 24 Apr 2003, Jack Twilley wrote:

> Currently, I think it was either lost or that we're not handling it
> well.  It's also possible that my layering may not be island-friendly.
> 
> Here's what I've got for layers:
> 
>   100  County area shapefiles
>   200  Place area shapefiles
>   300  Water area shapefiles
>  1100  Physical line shapefiles
>  1200  Non-visible? line shapefiles
>  1300  Hydro line shapefiles
>  1400  Misc transportation line shapefiles
>  1500  Railroad line shapefiles
>  1600  Road line shapefiles
>  1700  Landmark line shapefiles
> 
> I disabled automap for the water area shapefiles from the mix, and
> here's what I see:
> 
> http://www.twilley.org/~jmt/xastir-no-water.png
> 
> The same thing is displayed when I set the water area shapefile layer
> to 50.
> 
> Maybe it's our algorithm on filling in the water space?

It could be.  There's one minor little itty bitty piece of the
Shapefile spec that we didn't implement.  It has to do with the
direction of the polygon, whether it is clockwise or
counterclockwise.  One direction means do a fill.  The other means
it's a hole in the polygon.  We didn't implement the hole.  Our
donuts look more like biscuits.

I'm curious whether you have fill set for the land areas.  If you
don't, then you'd just get the outline, and they wouldn't fill in.

Can you run "shpdump filename | sort" on the land area file (County
shapefile), then look for lat/longs that contain the outline of that
island?  That should tell you whether the shape is even in the
Shapefile.

Curt, WE7U.				archer at eskimo.com
http://www.eskimo.com/~archer
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