[GRASS5] [bug #4370] (grass) d.m: cannot zoom and pan over an 'RGB or HIS layer'

[Glynn Clements]

Michael Barton wrote:

> I don't know if that is possible or not. D.zoom is a special C-module that
> interacts with an x11 display to change region extents. In gis.m, we simply
> reset the region using g.region. This will change the zoom even if *nothing*
> is displayed.

The main issue is that d.zoom redraws the display by executing
specific commands for specific types of map.

This limits it to the types of map for which the display library
maintains a list, i.e. raster, vector, or sites (yes, lib/display
still maintains a list of sites maps, and d.zoom includes the code to
redraw them by running d.sites).

If you removed the code relating to specific map types (including the
rast= and vector= options) and just called d.redraw (or manually
executed the commands from D_get_list()), it wouldn't have this
limitation, and would be a lot simpler.

-- 
Glynn Clements <glynn at gclements.plus.com>