[fdo-trac] #218: ExpressionEngine: Length2D() calculation is not accurate for arcs

[FDO]

#218: ExpressionEngine: Length2D() calculation is not accurate for arcs
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   Reporter:  danstoica         |       Owner:  danstoica
       Type:  defect            |      Status:  new      
   Priority:  major             |   Milestone:  3.3.0    
  Component:  GenericRdbms API  |     Version:  3.3.0    
   Severity:  3                 |    Keywords:           
External_id:  1012427           |  
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 The diffence came from the fact the arcs are tessellated and the length
 was
 computed by adding up the length of individual segments. The reason doing
 so is
 that the functionality to compute the radius of the circle and the
 orientation
 of the arc is not trivial and it lives in FdoSpatialUtilityCircularArc
 which is
 not exported.

 Another approach is to avoid code duplication and compute the radius and
 the angle
 by using basic trigonometry on the circle. That is, the algorithm needs 2
 equal
 adjacent segments on the circle which are provided by tessellation.

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Ticket URL: <http://trac.osgeo.org/fdo/ticket/218>
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