[GRASS-dev] r.surf.contour MASKs

[Markus Metz]

Hamish wrote:
> Hi,
>
> re. r43805:
>
> +<p>
> +An existing MASK raster map is respected for both reading <em>input</em>
> +and writing <em>output</em>.
>
> is that a newly added feature or documenting an old one?
>
An old one (absent in grass 3.2, introduced in grass 4.0), but it was
not working properly in grass6 because of missing NULL support, unless
a MASK used zero and not NULL for masking.

> if new, does it help speed up the very slow searches where there
> is no input data? (e.g. when the region contains a large lake or
> partial ocean, where there are no contour lines)

Yes, it does help speed up (now that NULL cells in a MASK are skipped
as intended).

Apart from floating point support, I have not added any new features
to r.surf.contour.

Markus M