MIGRATION_GUIDE.TXT

[Stephen Woodbridge]

OK, I could be wrong, but this might also be a regression that was 
introduced at some point.

Does anyone else remember what the behavior used to be with this?

Assefa, if you have some older versions of mapserver already loaded can 
you try this on them also. If the behavior is consistent, then document 
it. And I'll try to update my memory :)

Thanks,
   -Steve W.

Yewondwossen Assefa wrote:
> 
> Stephen Woodbridge wrote:
>> Yewondwossen Assefa wrote:
>>> Stephen Woodbridge wrote:
>>>> I think we need to clarify this point.
>>>>
>>>>> ----------------------------------------------------
>>>>> Styling/Symbolgy changes
>>>>> ----------------------------------------------------
>>>>> Prior to MapsServer 5.0, if a pixmap symbol was used in style on a 
>>>>> Line
>>>>> Layer, the symbol was used as a brush to draw the line. In 
>>>>> MapServer 5.0,
>>>>> it is possible to draw the pixmap symbol along the line (Note that 
>>>>> this
>>>>> was available using a true type symbol). To achieve  this, the user 
>>>>> needs
>>>>> to use the parameter GAP with it's pixmap symbol definition in the 
>>>>> symbol
>>>>> file. The GAP represents the distance between the symbols. If the 
>>>>> GAP is not
>>>>> given, the pixmap symbol will be used as a brush.
>>>>
>>>> With true type symbols you can specify negative values for GAP to 
>>>> cause the symbol to align with the line segment. Is this also 
>>>> supported for pixmap symbols? This should be made explicit in here.
>>>>
>>>
>>>  The pixmap symbols (and the true type symbols) always align with the 
>>> line segment. The negative gap should have the effect of adding 
>>> 180deg to the calculated angle.
>>> I will update the guide to reflect this.
>>
>> Assefa,
>>
>> The current behavior is that with a positive gap, the symbol will 
>> always point north, when the gap is negative it will align the symbol 
>> north with the direction of the line segment. I do not think we want 
>> to eliminate either of these options. For oneway arrows along streets, 
>> you need to know if the direction of travel is A-B or B-A and use a 
>> CLASS to select a flipped symbol for the other direction. You can not 
>> change the GAP to flip the symbol on a per shape basis in the mapfile.
>>
> 
>  Steve,
> 
>  I am not sure that when using a true type fonts,  a positive gap will 
> always make the symbol point north.  Here is a test I did with a true 
> type font :
> 
>  SYMBOL
> NAME "I"
> TYPE
> TRUETYPE
> FONT "Arial"
> CHARACTER "I"
> ANTIALIAS TRUE
> GAP 15
> END
> 
>  and the STYLE looks
>     STYLE
>         SYMBOL "I"
>          SIZE 15
>         COLOR 120 120 120
>      END
> 
>  Attached is the a what it gives in Mapserver
> 
>  Looking at the result, I interpret this as being the symbol is aligned 
> with the line and does not always point north. Is that correct ?
> 
>> -Steve
>>
>>>
>>>> -Steve W
>>>>
>>>
>>>
>>
>>
> 
> 
> 
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>