[Mapguide-trac] [mapguide-trac] #1987: Hatches from DWF files renders poorly using AGG Render

[MapGuide Open Source]

#1987: Hatches from DWF files renders poorly using AGG Render
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   Reporter:  fare             |       Owner:       
       Type:  defect           |      Status:  new  
   Priority:  low              |   Milestone:       
  Component:  Drawing Service  |     Version:  2.2.0
   Severity:  trivial          |    Keywords:       
External_id:                   |  
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Comment(by fare):

 According to AGG sample page [http://www.antigrain.com/demo/] and
 "gouraud" sample there are two methods that can be used to hide this kind
 of problem - dilating the polygons and/or changing the gamma-correction
 value.

 I tried implementing the dilating polygons but didn't manage to remove
 artifacts. So I switched to gamma correction.

 I'm proposing patch that is attached. Drawing polytriangles is separated
 to another method of AGGRenderer class. Basically method is copy of method
 that is used to draw polygons but before rendering occurs gamma value is
 set to low value (test showed that value between 0.3-0.5 gives satisfying
 results) and then restored to value 1.0 once rendering is done.

 Lowering gamma value gives sharper outer edges(less anti-aliasing) but for
 me this is acceptable trade of.

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Ticket URL: <http://trac.osgeo.org/mapguide/ticket/1987#comment:4>
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