[mapserver-dev] GD, filled ellipse, rendering: fill is bleedingoutside the outline

[Havard Tveite]

Steve Lime wrote:
> A different algorithm is probably used to fill an ellipse as opposed
> stroking the outline and you get the
> off by 1 errors you've seen. I'm not sure how we'd work around it short
> of making the outline circle 
> larger?

I like the current behaviour of not letting the outline
extend beyond the area it is outlining, so I would not
like to see a larger circle outline.

Håvard

> Steve
> 
>>>> On 9/21/2009 at 9:51 AM, in message <4AB792F6.60805 at umb.no>, Havard
> Tveite
> <havard.tveite at umb.no> wrote:
>> Sounds reasonable to assume that this is a GD bug.
>> My Mapserver is using GD version 2.0.35, which should
>> be the latest one.
>>
>> Håvard
>>
>> Steve Lime wrote:
>>> It's a GD bug I imagine. Have you tried the latest version of that
> lib?
>>> Steve
>>>
>>>>>> Havard Tveite <havard.tveite at umb.no> 09/21/09 4:14 AM >>>
>>> When using GD, the fill of an outlined filled ellipse symbol
>>> will "bleed" by one pixel several places outside of the
>>> outline for most symbol sizes (Mapserver 5.4.2).  See the
>>> attached (magnified) image.
>>> (AGG does not seem to have this problem)
>>>
>>> This seems to be a bug.  Has it been filed yet?
>>>
>>> Here are the most relevant parts of the map file:
>>>
>>>    SYMBOL
>>>      NAME "circle"
>>>      TYPE ellipse
>>>      FILLED true
>>>      POINTS
>>>        1 1
>>>      END
>>>    END
>>>
>>> ...
>>>
>>>    LAYER    # Circle - outline
>>>      NAME "circ"
>>>      PROJECTION
>>>        "init=epsg:32633"
>>>      END
>>>      TYPE POINT
>>>      FEATURE
>>>        POINTS
>>>          50 800
>>>        END
>>>      END
>>>      CLASS
>>>        NAME "Circle"
>>>        STYLE
>>>          SYMBOL 'circle'
>>>          SIZE 42
>>>          COLOR 0 150 200
>>>          OUTLINECOLOR 0 0 0
>>>        END
>>>      END
>>>    END #layer circle - outline
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-- 
Håvard Tveite
Department of Mathematical Sciences and Technology, UMB
Drøbakveien 31, POBox 5003, N-1432 Ås, NORWAY
Phone: +47 64965483 Fax: +47 64965401 http://www.umb.no/imt/