[mapserver-users] Rendering line crossing iteslf

[thomas bonfort]

---------- Forwarded message ----------
From: thomas bonfort <thomas.bonfort at gmail.com>
Date: Wed, May 11, 2011 at 16:03
Subject: Re: SV: [mapserver-users] Rendering line crossing iteslf
To: Stephen Woodbridge <woodbri at swoodbridge.com>


Steve,
That isn't the case. The first style of all the features are rendered
in a first phase, and the following ones are rendered in a second
phase, so the order is

feature1->style1
feature2->style1
...
featuren->style1
feature1->style2
...
featuren->style2
...
...
feature1->stylem
featuren->stylem

without that, you'd get artifacts on road intersections.

--
thomas



On Wed, May 11, 2011 at 15:47, Stephen Woodbridge
<woodbri at swoodbridge.com> wrote:
> Niels-Peter,
>
> I believe that you will need to split the line at the intersection into
> multiple lines to get the display that you want. Because you line just
> crosses itself there is no intersection there. If you split the line into
> multiple segments that there will be an intersection and mapserver should
> render it is desired.
>
> -Steve W
>
> On 5/11/2011 8:18 AM, Niels-Peter Jensen wrote:
>>
>> Hi Thomas
>>
>> The bridge was used as an anology. In fact, the line feature is a bus
>> route
>> that crosses itself, and we just want to show where the route passes
>> through
>> an intersection.
>>
>> Niels-Peter
>>
>>
>> -----Oprindelig meddelelse-----
>> Fra: thomas bonfort [mailto:thomas.bonfort at gmail.com]
>> Sendt: 11. maj 2011 13:56
>> Til: Niels-Peter Jensen
>> Emne: Re: [mapserver-users] Rendering line crossing iteslf
>>
>>
>> On Wed, May 11, 2011 at 13:51, Niels-Peter Jensen<npj at i-gis.dk>  wrote:
>>>
>>> Hi Thomas
>>>
>>> Thanks for the quick answer.
>>>
>>> We cannot make the style work in the mapfile and have to place it in
>>> the symbol file. By the way, we are using Mapserver 5.4.2.
>>>
>>> But anyway, I don't think it solves our problem.
>>> We don't have any "bridge" in our line data, it is just a single line
>>> feature that crosses itself.
>>
>> then how can you distinguish the case of the bridge with the case of the
>> intersection ? applying the solution I proposed on all lines will give
>> incorrect cases everywhere you don't have a bridge, so it would not be a
>> possible solution.
>>
>> --
>> thomas
>>
>>>
>>> Regards
>>> Niels-Peter
>>>
>>>
>>> -----Oprindelig meddelelse-----
>>> Fra: thomas bonfort [mailto:thomas.bonfort at gmail.com]
>>> Sendt: 11. maj 2011 12:14
>>> Til: Niels-Peter Jensen
>>> Cc: mapserver-users at lists.osgeo.org
>>> Emne: Re: [mapserver-users] Rendering line crossing iteslf
>>>
>>>
>>> An undocumented and "not guaranteed to work in future versions" is to
>>> trick mapserver in not drawing the cached base style for bridge lines.
>>> As you are avoiding the line caching mechanism, you have to tweak the
>>> linecaps for the base style.
>>>
>>> CLASS
>>>   EXPRESSION ([bridge]=1)
>>>   STYLE
>>>   END
>>>   STYLE
>>>      color black
>>>      width 5
>>>      linecap butt
>>>   END
>>>   STYLE
>>>      color yellow
>>>      width 3
>>>      linecap round
>>>   END
>>>   STYLE
>>>      color black
>>>      width 1
>>>   END
>>> END
>>>
>>> I haven't tested this recently, so please keep in touch if this solves
>>> your problem or not.
>>>
>>> regards,
>>> thomas
>>>
>>> On Wed, May 11, 2011 at 11:40, Niels-Peter Jensen<npj at i-gis.dk>
>>> wrote:
>>>>
>>>> Hi users
>>>>
>>>> We have a problem in rendering a route based on a line feature.
>>>>
>>>> When we use the common way to do that, by using two styles, with a
>>>> thick black line that defines an outline, and a thinner defying the
>>>> road center, we will not get the desired result.
>>>>
>>>> But I want to show where routes cross ("bridge" intersection), and
>>>> not as a "normal" intersection, see the attached examples.
>>>>
>>>> As there is no outline definition on linefeatures I can't se how that
>>>> can be done in a simple way.
>>>>
>>>>
>>>> Niels-Peter
>>>> I-GIS
>>>>
>>>> _______________________________________________
>>>> mapserver-users mailing list
>>>> mapserver-users at lists.osgeo.org
>>>> http://lists.osgeo.org/mailman/listinfo/mapserver-users
>>>>
>>>>
>>>
>>>
>>
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