[mapserver-users] R

[David Nugent]

Greetings all,

On Thu, 11 Jun 2009 16:37:11 +1000, I wrote:
> One last problem I'm scratching my head on.
>
> I want to highlight bridges by using a thick border on each side of the  
> road (and if possible an angular section at each end of the border as  
> often seen in traditional road maps). Using an outline won't work for  
> this as outlines close the end points of the line segment with a border  
> and I would prefer them to blend directly with the road to which they  
> belong. I'm thinking a symbol would be needed but not sure how to  
> approach it.
>
> Like (view this with a fixed width font):
>
> ____\____________________________/__
> ____ ____________________________ __
>     /                             \
>
> (imagine lines joining \/ being thick)
>
> How to achieve such a border?


Following up on my own post again...

SYMBOL does not appear to be well suited (unless I'm missing something)  
but I've come close with GEOMTRANSFORM, however only at the start and end  
of a line segment using what are essentially reversed arrowheads.

I read the RFC in the mapserver 5.4 documentation and it talks about plans  
to extend functionality of GEOMTRANSFORM (which it incorrectly refers to  
as GEOTRANSFORM and GEOMETRYTRANSFORM, incidentally), and I *think* either  
the "distance" or "buffer" might achieve most of what I need with ANGLE  
AUTO - to draw a parallel line segment. However neither appears to be  
implemented yet.


Regards,
David