[Mapserver-dev] Changing Colors in Map !!

[Frank Warmerdam]

Stephen Woodbridge wrote:
> Sorry, I did not mean to imply explicit loading of the color raster 
> entries, only that they would get loaded last by default process that 
> happens when rasters get loaded. While this would work for many of us, I 
> think there may be some raster guys the would like more control that 
> this, but I'll let them speak up if they care.
> 
> I have had the colors on my bitmap symbols change which for me are 
> things like the Interstate highway badge where the Blue field turn gray.
> 
> Since I suspect that we can never make all the people happy all the time 
> and we are talking about a compromise, another idea would be to have a 
> color table object that would allow you to define the color table 
> entries and a tool that scans the mapfile and prints out a table that 
> you can edit and include in the mapfile. While this would be a pain, it 
> would give you full control of the colors if you needed it. Or maybe 
> support the automate color table generation unless there is a table 
> defined, then load the table first and scan the mapfile to pick up 
> additional entries not already defined in the pre loaded table.

Steve,

The more I think about it, the harder I think it would be to make
the pre-scanning work ideally.  In a complex mapfile you might have alot
of layers that are technically on but don't intersect the map area, or
that have alot of classes that don't appear in a given render.  Prescanning
could result in alot of colors being allocated but not used.

I think the ability to declare some colors that you absolute want to be
allocated is a minimum we could do to at least make it practical for
folks to see certain colors they want to see.

Best regards,

-- 
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