[GRASS-dev] vector display clipping

[Glynn Clements]

Anna Petrášová wrote:

> > Using this functionality for graphical clipping is problematic if you
> > use thick lines, as clipped lines will be capped at the point where
> > they're clipped. It would also affect the dash offset for dashed lines
> > (although that isn't implemented yet).
> 
> Is there any way to set different default mode without modifying the code?

No.

> > Additionally, the driver's Set_window function establishes a clip
> > region (e.g. via cairo_clip() for the cairo driver). This defaults to
> > the entire "screen", but can be overridden by setting the environment
> > variable GRASS_FRAME.
> >
> > Arguably, the code which sets up the coordinate system so that the
> > current region just fits the display (D_setup) should also set the
> > clip region to fit the current region.
> >
> > However, this is complicated slightly be the fact that there's no
> > distinction between the display "frame" (either the screen or the
> > frame set by GRASS_FRAME) and the current clip region, so setting a
> > clip region would lose the only record of the frame.
> 
> I still don't understand if the current behavior in 7 is intended and if
> so, why no vector clipping is better?

It isn't intended, it's an oversight.

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