MIGRATION_GUIDE.TXT

[Stephen Woodbridge]

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

> 
>> -Steve W
>>
> 
>