#1697: zoom out centering problem
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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 |
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When zooming out, instead of centering the display on the point clicked
(as zoom in does), it shifts the center of the display to the point
clicked. Same with a box zoom.
#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 |
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Comment(by annakrat):
Hi,
it should be fixed in r52745 (grass 7). This bug was probably not caused
by recent changes in zooming and I didn't realize it because I use almost
only mouse wheel for zooming.
Zooming out with box seems to be quite ok for me. I'm not sure it works
perfectly but the result is what I would expect. The problem is that it's
quite difficult to imagine what zooming out with box exactly does.
#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 |
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Comment(by cmbarton):
Anna,
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
are.
This is sort of what is happening now, but a tiny box does not do a lot of
shrinking.
#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 |
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Comment(by cmbarton):
The zoom out with a single click is working well in GRASS 7. The box zoom
out is the same as before. The improvement to zoom out with a mouse click
should probably be backported to GRASS 6.x