[fusion-trac] #143: Incorrect scale displayed for maps using units other than meters

[Fusion]

#143: Incorrect scale displayed for maps using units other than meters
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 Reporter:  chrisclaydon        |         Owner:  madair  
     Type:  defect              |        Status:  assigned
 Priority:  P1                  |     Milestone:  2.0     
Component:  Widgets             |       Version:  SVN     
 Severity:  Major               |    Resolution:          
 Keywords:                      |   External_id:  1085634 
    State:  Analysis Requested  |       Browser:  All     
       Os:  All                 |  
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Comment (by chrisclaydon):

 If the data is interpreted as being in millimeters, and the Map coordinate
 system uses millimeters, and the initial extents of the map match the full
 extent of the data, the entire data set should fill the initial view.

 I dug into this a little more, and it seems that there are two separate
 issues at hand:

 1) Fusion maps the metersPerUnit value from the MG map to the nearest
 !OpenLayers unit. So it maps millimeters to inches, which throws
 everything off. I tried adding a definition for 'mm' units into
 !OpenLayers.js, and that fixed the problem for the millimeter-based map
 example.

 {{{
 OpenLayers.INCHES_PER_UNIT["mm"] = OpenLayers.INCHES_PER_UNIT.m / 1000.0;
 }}}

 It would be nice to add entries to the !OpenLayers.INCHES_PER_UNIT list on
 the fly for units that don't currently have an entry, rather than having
 to hard-code every possible supported unit...

 2) There seems to be a restriction on the maximum scale of 1:100,000,000.
 This is what prevents the kilometer-based map example from displaying the
 full data extents. I'm not sure if the restriction is imposed by Fusion or
 !OpenLayers...

-- 
Ticket URL: <http://trac.osgeo.org/fusion/ticket/143#comment:5>
Fusion <http://trac.osgeo.org/fusion>
Fusion is a web-mapping application development framework for MapServer and MapGuide OS.