[GRASS-dev] [GRASS GIS] #1697: zoom out centering problem

GRASS GIS trac at osgeo.org
Mon Aug 20 10:42:30 PDT 2012

#1697: zoom out centering problem
 Reporter:  cmbarton  |       Owner:  grass-dev@…              
     Type:  defect    |      Status:  new                      
 Priority:  normal    |   Milestone:  6.4.3                    
Component:  wxGUI     |     Version:  svn-releasebranch64      
 Keywords:            |    Platform:  All                      
      Cpu:  All       |  

Comment(by cmbarton):


 This fixes the point zoom out.

 I'm still not sure what the box zoom out is doing. As you say, it is more
 difficult to imagine what a box zoom out does. There have been discussions
 (some heated) in the past about these angels dancing on the head of a pin.

 IMHO, the most logical behavior for a zoom-out box is the inverse of a
 zoom-in box. The zoom in box adjusts the display so that the area defined
 by the box expands to fill the display window. A large box will do only a
 little zooming, while a tiny box will do a lot of zooming.

 For the inverse, the view should be adjusted so that the area that fills
 the display window shrinks and moves to fill the box (with the rest of the
 display adjusting accordingly). A large box will do a little shrinking and
 a tiny box will do a lot of shrinking. My experience is that while the
 calculations to do this are not difficult in and of themselves, it is
 conceptually complicated to imagine and figure out what the calculations

 This is sort of what is happening now, but a tiny box does not do a lot of

 Fixing the point zoom-out helps a lot though.


Ticket URL: <http://trac.osgeo.org/grass/ticket/1697#comment:3>
GRASS GIS <http://grass.osgeo.org>

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