[mapserver-users] symbol circle (ellipse) rendered not round
but oval
Oliver Christen
oliver.christen at camptocamp.com
Fri Jan 15 02:07:09 EST 2010
mmm, in my opinion it would be clearer if the GAP didnt depend from
anything, set the GAP to 10 would make you a spacing of 10px between each
symbols border, whatever the values of the symbol POINTS.
but that may be a change too important ?
Oliver
> Stephen Woodbridge wrote:
>> 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)?
>
> Yes, if the rendering behaviour had been according to my
> preferences,
> POINTS 10 10 END
> GAP 1 (or 2 or 3)
> should do it (if you had specified SIZE 10 in the STYLE).
> You specify the gap, and not the centre to centre distance
> between the ellipses.
>
> But currently, this is not the behaviour.
> Currently (with AGG in 5.6.0) you would have to specify:
> POINTS 10 10 END
> GAP 6 (or 7 or 8)
> to get something close (if you specify SIZE 10 in the STYLE).
>
> Something seems to be wrong when the GAP is close to
> half the diameter specified in POINTS - some of the gaps
> will be as expected, while others are larger (closer to the
> actual number specified in GAP).
>
> Håvard
>
>>
>> -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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>>
>>
>
> --
> 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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