Panels and/or layers

Ronald Wiemer RWIEM at
Thu Jun 29 08:00:00 EDT 1995

> Greetings,
> I'm looking for a way to set up a series of GRASS panels or layers
> that can somehow be defined to the driver and subsequently
> re-displayed quickly.
> The need for this arises from a requirement that I display a large
> number of icons (hundreds of thousands) against a background of mainly
> vector data, but also potentially raster images.  Currently, if I
> change the background, I do it by erasing and re-drawing raster
> images, then vectors, and finally icons.
> Re-drawing hundreds of thousands of icons (from data extracted from a
> binary file) can take several minutes.  Since this involves re-drawing
> data that hasn't changed, it seems like there should be a fast way to
> do it, by exploiting power available in the GRASS driver.
> In poking around the GRASS source code, I found C procedures to save
> and restore panels.  But the save_panel procedure seems to save only
> that data currently on the screen.  I need to save/redraw some of the
> data and re-generate other data.  Or better: I need to segment the
> data into different panels or layers and be able re-display them at
> will.
> My goals may be achievable if I could do something like this:
>     draw vectors to a panel
>     display vector panel
>     draw icons to a panel
>     display icon panel
>    later:
>     erase screen
>     draw new vectors to the vector panel
>     display vector panel
>     re-display existing icon panel
> Can anyone offer helpful suggestions?  Thanks.
> - Bob
> ---
> Robert A. Black
> Principal Engineer
> Calspan Advanced Technology Center
> Calspan Corporation
> 4455 Genesee St.
> Buffalo, NY 14120
What you can do, is converting the sites to raster and then use 
d.rast -o to display them on any background you like.

Ronald Wiemer

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