[mapguide-trac] #754: Polygon features are drawn wrong when not completely in the window

[MapGuide Open Source]

#754: Polygon features are drawn wrong when not completely in the window
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 Reporter:  waltweltonlair  |         Owner:  waltweltonlair
     Type:  defect          |        Status:  closed        
 Priority:  high            |     Milestone:  2.1           
Component:  General         |       Version:  2.0.2         
 Severity:  minor           |    Resolution:  fixed         
 Keywords:                  |   External_id:  1102648.01    
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Comment (by crispinatime):

 Hi,

 This is an interesting submission as the polygon clipping seems to be in
 its entitity to be a programming renderign utility and not a cartographic
 requirement (unlike the thick line clipping ticket).

 With my cartographic / data visualisation hat on, the map shown should
 represent a window onto the data, just like moving a picture frame over a
 raster map.  Sure we have advantages with smart label placement to
 optimise the actual window of data displayed -- but should MapGuide be
 displaying a new artificial polygon psaudo-edge at the edge of the screen?
 This implies there is data that forms vertices and edges where MapGuide
 has drawn them - but these do not exist.

 I understand why for rendering efficiency the clipping occurs but
 cartographically I personally think the polygon should just flow to the
 map edge and not show the clipped edge line.  This is obviously a change
 to existing behaviour but a future flag to not show these created clipped-
 edge-lines could be an option?  I would be interested in your / other
 thoughts.

 The second reason the whole behavious is not consistent at present in a
 final MapGuide solution is that on the basic viewer with the status-bar
 turned on the map renderign height in AJAX is not calculated correctly so
 the map always renders too 'tall' - you can see this easily because
 panning up will pull up and expose the image part that was hidden behind
 the status bar.  The end result of this is that only the clipping done is
 actually visible on the North, West, East sides of the map so the whole
 MapGuide end-user experience is inconsistent.

-- 
Ticket URL: <http://trac.osgeo.org/mapguide/ticket/754#comment:4>
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