Dave

The colour_water_bg colour can be defined in a separate layout that is toggled on or off using a simple statement in your main layout file.

If you look further down the wiki metapost page in the Code to make full colour symbols block of code you will see

          layout LayoutColourSymbols
…
           #define colours for redefined water point & area
          code metapost  
          %these colours affect fills, not the linework
                    !color colour_water_bg; %! forces interpretation as metapost
                    colour_water_bg := (0.86,1,1);      %light blue
                    !color colour_sump_bg;  %! forces interpretation as metapost
                    colour_sump_bg := (.22,.22,.95);    %dark blue
…
          endlayout LayoutColourSymbols
 

and the toggle switch that  activates any changes in symbol definitions due to colour symbol activation is;

copy LayoutColourSymbols #excludes labels

also further down the page.  The key points are spread quite far apart however.

I was in the passage shown in the wiki water example this morning, we surveyed through the sump, that turned out to be a wade. It pays to get in and make sure whether there is airspace when you find these things!

Bruce

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From: therion-bounces@speleo.sk [mailto:therion-bounces@speleo.sk] On Behalf Of Dave Clucas

I took a look at Bruce's code, in particular Code to redefine area and point water symbols

.

This looks like something I'd like to use but how and where do I define the colour eg. 

    if known colour_water_bg: thfill Path withcolor colour_water_bg; else: thfill Path withcolor white; fi;