ALPHACOLOR_ENABLED code in mapfile.c

[Paul Spencer]

Would there be any benefit for the AGG work?  I can't think of any  
reason, just asking :)

Paul

On 23-Mar-07, at 4:05 PM, Daniel Morissette wrote:

> We've been reminded in bug 2052 (http://mapserver.gis.umn.edu/bugs/ 
> show_bug.cgi?id=2052) that there is some unused code in mapfile.c  
> and a few other files dating from 2003 to add ALPHA to the  
> ColorObj. This code is all inside #ifdef ALPHACOLOR_ENABLED but  
> there is no documentation for this or any way to use this code  
> without manually adding the flag to the makefiles (i.e. no  
> configure options, etc.).
>
> Steve's suggestion in the bug, which I agree with is:
>
>> I haven't had any plans (or heard a good reason) to use alpha  
>> channel values in colors. Rather I would support a style-level or  
>> label-level opacity value that would serve that function and  
>> impact all colors associated with an object. Doing so would  
>> mitigate configuration confusion, would not require a change to  
>> the colorObj (and all supporting code), and would keep  
>> configuration in the mapfile straight forward.
>> Unless other complelling reasons exist (and they might) I would  
>> just as soon remove all references to ALPHACOLOR_ENABLED...
>
>
> I'm sending this email to find out if anyone sees a need to  
> maintain, complete and document this code to handle ALPHA in the  
> ColorObj. If not then we'll remove the code and add style-level or  
> label-level opacity to the TODO list as suggested by Steve.
>
> Daniel
>
> P.S. Please reply to mapserver-dev and not via the bug report. This  
> question is off-topic for the bug which was just about a compile  
> error and turned into a longer debate about the usefulness of this  
> code.
> -- 
> Daniel Morissette
> http://www.mapgears.com/

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|Paul Spencer                          pspencer at dmsolutions.ca    |
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|Chief Technology Officer                                         |
|DM Solutions Group Inc                http://www.dmsolutions.ca/ |
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