[mapserver-users] symbol circle (ellipse) rendered not round
but oval
Stephen Woodbridge
woodbri at swoodbridge.com
Thu Jan 14 12:25:27 EST 2010
So if I want ten pixel ellipses with a 1, 2, or 3 pixels gap how would
you specify that?
points 10 10 gap 1 (or 2 or 3)?
-Steve W
Havard Tveite wrote:
> If Thomas B. agrees, I think it would be reasonable to also
> open a bug on the gap calculation.
> In my opinion, since the word "gap" is used, the correct
> way to specify a symbol with ellipses that has the same
> gap between them as the diameter of the ellipses should be
> as follows:
>
> symbol
> name dots
> type ellipse
> points 1 1 end
> gap 1
> end
>
> or an equivalent "scaled" version such as:
>
> symbol
> name dots
> type ellipse
> points 23 23 end
> gap 23
> end
>
> The actual size of the ellipses (and the width of the gaps)
> should be determined by the SIZE in CLASS-> STYLE. If
> SIZE is 10, the ellipses should have a 10 pixel diameter
> (and should have a 10 pixel gap between them).
>
> I have been hesitant to file bugs regarding symbology, since
> the documentation on symbology is lacking and there is not
> complete agreement on how some of the things that has to do
> with symbology should work. There have also been
> discussions on changing some behaviour and mechanisms for
> symbology.
> First we have to agree on how things should work and document
> it, then we can file bugs if behaviour is not as expected.
>
> Håvard
>
> Oliver Christen wrote:
>> Hi Steve
>>
>> I followed your suggestion and opened a documentation bug
>>
>> thanks
>> Oliver
>>
>>> Hi guys,
>>>
>>> I haven't followed this whole thread but I think it should be better
>>> documented so people can understand how to use this. Please write a
>>> doc bug and put as much information in the bug about how this works
>>> as you have been able to discover.
>>>
>>> Thanks,
>>> -Steve W
>>>
>>> Oliver Christen wrote:
>>>> Thank you Håvard
>>>> I see you have changed "points 1 1 end" by "points 8 8 end".
>>>> Tell me if im wrong, but these values are only used to render the
>>>> proportions of the elipse but not it's size, is that correct?
>>>> so if I understand correctly, using larger values for the elipse
>>>> width/height refine the rendering of the vectorised dot geometry ?
>>>>
>>>> regards
>>>> Oliver
>>>>
>>>>> Dear Oliver Christen,
>>>>>
>>>>> Using Mapserver 5.6.0 and AGG rendering, you can achieve what
>>>>> you want by using a combination of ellipse size and gap size
>>>>> in the symbol definition.
>>>>> There is something strange in the calculations (a gap of
>>>>> about half the ellipse size seems to produce touching symbols),
>>>>> so in your case, you could try to use 8 as the diameter of the
>>>>> ellipses, and 20 + 4 (half the ellipse size) = 24 as the
>>>>> gap:
>>>>>
>>>>> symbol
>>>>> name dots
>>>>> type ellipse
>>>>> points 8 8 end
>>>>> gap 24
>>>>> end
>>>>>
>>>>>
>>>>> Håvard
>>>>>
>>>>> Oliver Christen wrote:
>>>>>> thank you Thomas
>>>>>>
>>>>>> so if I have a dot of, for example, 8px and I want a space pf 20px
>>>>>> between the dots, I need a gap of 20/8 = 2.5
>>>>>>
>>>>>> but as far as I can see, Mapserver doesnt like none-integer value
>>>>>> for gap.
>>>>>>
>>>>>> what should I do? :(
>>>>>>
>>>>>> 2010/1/12 thomas bonfort <thomas.bonfort at gmail.com
>>>>>> <mailto:thomas.bonfort at gmail.com>>
>>>>>>
>>>>>> gap in pixels = symbol->gap * style->size
>>>>>>
>>>>>>
>>>>>> On Tue, Jan 12, 2010 at 16:52, Oliver Christen
>>>>>> <oliver.christen at camptocamp.com
>>>>>> <mailto:oliver.christen at camptocamp.com>> wrote:
>>>>>>
>>>>>> GAP 20 is really giving unwanted result:
>>>>>> http://dev.camptocamp.com/~ochriste/tilecache9.png
>>>>>> <http://dev.camptocamp.com/%7Eochriste/tilecache9.png>
>>>>>> though using only one style instead of two seems to solve
>>>>>> the
>>>>>> oval problem (but why ???)
>>>>>> style
>>>>>> symbol "dots"
>>>>>> size 8
>>>>>> color 204 102 0
>>>>>> outlinecolor 102 51 0
>>>>>> end
>>>>>> I dont understand how GAP is supposed working:
>>>>>> with GAP 2, I had ~10px between dots,
>>>>>> with GAP 3, I had ~18px between dots,
>>>>>> with GAP 4, I had ~26px between dots
>>>>>> whats the logic ?
>>>>>>
>>>>>> ----- Original Message -----
>>>>>> *From:* thomas bonfort <mailto:thomas.bonfort at gmail.com>
>>>>>> *To:* Oliver Christen
>>>>>> <mailto:oliver.christen at camptocamp.com>
>>>>>> *Cc:* mapserver-users at lists.osgeo.org
>>>>>> <mailto:mapserver-users at lists.osgeo.org>
>>>>>> *Sent:* Tuesday, January 12, 2010 4:36 PM
>>>>>> *Subject:* Re: [mapserver-users] symbol circle (ellipse)
>>>>>> rendered not round but oval
>>>>>>
>>>>>> symbol
>>>>>> name dots
>>>>>> type ellipse
>>>>>> points 1 1 end
>>>>>> gap 20
>>>>>> end
>>>>>>
>>>>>> ...
>>>>>>
>>>>>> style
>>>>>> symbol "dots"
>>>>>> size 8
>>>>>> color r g b
>>>>>> outlinecolor r g b
>>>>>> end
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>> On Tue, Jan 12, 2010 at 16:31, Oliver Christen
>>>>>> <oliver.christen at camptocamp.com
>>>>>> <mailto:oliver.christen at camptocamp.com>> wrote:
>>>>>>
>>>>>> Hi Thomas :)
>>>>>> thanks for the answer, but sadely it didnt solve
>>>>>> my problem:
>>>>>> here are a few tests I did:
>>>>>> using GAP 20 gave me really weird result:
>>>>>>
>>>>>> http://dev.camptocamp.com/~ochriste/tilecache6_gap_20.png
>>>>>>
>>>>>> <http://dev.camptocamp.com/%7Eochriste/tilecache6_gap_20.png>
>>>>>> using PATTERN 1 22 END gave me better result, but
>>>>>> the
>>>>>> dot are still slightly oval:
>>>>>>
>>>>>> http://dev.camptocamp.com/~ochriste/tilecache7_pattern.png
>>>>>>
>>>>>> <http://dev.camptocamp.com/%7Eochriste/tilecache7_pattern.png>
>>>>>> I wondered if the visual effect may have come
>>>>>> from the
>>>>>> fact im pilling up two circle one over the other, but
>>>>>> even when trying to display only the outer or inner
>>>>>> circles, the circle are still slightly off:
>>>>>>
>>>>>> http://dev.camptocamp.com/~ochriste/tilecache4_outercircle.png
>>>>>>
>>>>>> <http://dev.camptocamp.com/%7Eochriste/tilecache4_outercircle.png>
>>>>>>
>>>>>> http://dev.camptocamp.com/~ochriste/tilecache5_innercircle.png
>>>>>>
>>>>>> <http://dev.camptocamp.com/%7Eochriste/tilecache5_innercircle.png>
>>>>>> (both at once
>>>>>>
>>>>>> http://dev.camptocamp.com/~ochriste/tilecache3_bothcircle.png
>>>>>>
>>>>>> <http://dev.camptocamp.com/%7Eochriste/tilecache3_bothcircle.png>)
>>>>>> any other idea? ^_^
>>>>>>
>>>>>> ----- Original Message -----
>>>>>> *From:* thomas bonfort
>>>>>> <mailto:thomas.bonfort at gmail.com>
>>>>>> *To:* Oliver Christen
>>>>>> <mailto:oliver.christen at camptocamp.com>
>>>>>> *Cc:* mapserver-users at lists.osgeo.org
>>>>>> <mailto:mapserver-users at lists.osgeo.org>
>>>>>> *Sent:* Tuesday, January 12, 2010 3:18 PM
>>>>>> *Subject:* Re: [mapserver-users] symbol circle
>>>>>> (ellipse) rendered not round but oval
>>>>>>
>>>>>> hi Oliver :)
>>>>>>
>>>>>> try with GAP 20 instead of STYLE 1 20 END
>>>>>> (which is
>>>>>> deprecated btw, use PATTERN now)
>>>>>>
>>>>>> cheers,
>>>>>> thomas
>>>>>>
>>>>>> On Tue, Jan 12, 2010 at 15:04, Oliver Christen
>>>>>> <oliver.christen at camptocamp.com
>>>>>> <mailto:oliver.christen at camptocamp.com>> wrote:
>>>>>>
>>>>>> hello
>>>>>>
>>>>>> I have a weird problem with symbology.
>>>>>> Im rendering a line with dots, but the
>>>>>> dots are
>>>>>> not round but slightly oval, see image
>>>>>>
>>>>>> http://dev.camptocamp.com/~ochriste/tilecache.png
>>>>>>
>>>>>> <http://dev.camptocamp.com/%7Eochriste/tilecache.png>
>>>>>>
>>>>>> Any idea what could be the cause ?
>>>>>>
>>>>>> Here is my symbol definition:
>>>>>>
>>>>>> SYMBOL
>>>>>> NAME "linie-gepunkt10"
>>>>>> TYPE ELLIPSE
>>>>>> POINTS
>>>>>> 1 1
>>>>>> END
>>>>>> STYLE
>>>>>> 1 20
>>>>>> END
>>>>>> FILLED TRUE
>>>>>> END
>>>>>>
>>>>>> and my layer's class definition:
>>>>>>
>>>>>> CLASS
>>>>>> EXPRESSION "3"
>>>>>> MAXSCALEDENOM 200001
>>>>>> STYLE
>>>>>> SYMBOL "linie-gepunkt10"
>>>>>> SIZE 10
>>>>>> COLOR 102 51 0
>>>>>> END
>>>>>> STYLE
>>>>>> SYMBOL "linie-gepunkt10"
>>>>>> SIZE 8
>>>>>> COLOR 204 102 0
>>>>>> END
>>>>>> END
>>>>>>
>>>>>> and the map outputformat:
>>>>>>
>>>>>> OUTPUTFORMAT
>>>>>> NAME png
>>>>>> DRIVER "AGG/PNG"
>>>>>> MIMETYPE "image/png"
>>>>>> IMAGEMODE RGBA
>>>>>> EXTENSION "png"
>>>>>> FORMATOPTION "INTERLACE=OFF"
>>>>>> END
>>>>>>
>>>>>> _______________________________________________
>>>>>> mapserver-users mailing list
>>>>>> mapserver-users at lists.osgeo.org
>>>>>> <mailto:mapserver-users at lists.osgeo.org>
>>>>>>
>>>>>> http://lists.osgeo.org/mailman/listinfo/mapserver-users
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>> --
>>>>> 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/
>>>>>
>>>> _______________________________________________
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>>>> http://lists.osgeo.org/mailman/listinfo/mapserver-users
>>>
>>
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>
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