[GRASS-dev] Re: [GRASS GIS] #106: wxgrass: zoom to computational region does not respect resolution set with g.region

[Michael Barton]

On Mar 27, 2008, at 3:10 AM, grass-dev-request at lists.osgeo.org wrote:
> Date: Thu, 27 Mar 2008 10:03:45 -0000
> From: "GRASS GIS" <trac at osgeo.org>
> Subject: [GRASS-dev] Re: [GRASS GIS] #106: wxgrass: zoom to
> 	computational region does not respect resolution set with g.region
> To: undisclosed-recipients:;
> Message-ID: <051.487a2804b30e0d4102ab7164ef71db69 at osgeo.org>
> Content-Type: text/plain; charset="utf-8"
>
> #106: wxgrass: zoom to computational region does not respect  
> resolution set with
> g.region
> -------------------------- 
> +-------------------------------------------------
>   Reporter:  mlennert     |       Owner:  martinl
>       Type:  enhancement  |      Status:  assigned
>   Priority:  major        |   Milestone:  6.4.0
>  Component:  Python       |     Version:  svn-trunk
> Resolution:               |    Keywords:  wxgrass resolution zoom
> -------------------------- 
> +-------------------------------------------------
> Changes (by mlennert):
>
>  * cc: mlennert at club.worldonline.be (removed)
>   * type:  defect => enhancement
>
> Comment:
>
>  The issue is not only the extent, but also the resolution.

Yes. This was Martin's point. We've made it so that the display  
resolution stays constant regardless of the computational region.  
This makes the display render MUCH MUCH faster. The only drawback of  
having the display region stay constant in this way is that  
d.rast.num won't work as it now is. This is probably fixable either  
by modifying d.rast.num or by tweaking the GUI. But it hasn't been as  
high a priority as other items yet.

>
>  I think it would be useful to have the same system as in gis.m,  
> i.e. with
>  one display mode aligning to window size and another mode showing the
>  exact computation region, i.e. respecting extent and resolution.

I think that these two different modes are fairly confusing to most  
users.

Martin has implemented something that I think is much more useful and  
easier to understand, and that serves the same purpose. As mentioned  
above, the display always fills the window and has a constant  
resolution. However, the computational region is shown by a red box  
outline. This means you can always tell the region in which map  
modification operations will take place, without having a very  
strange-looking map in the display window, with a lot of white space  
around it.

>
>  BTW, would also be nice to add "Zoom to default region" to the menu.

Good idea.

Michael