[GRASS-dev] Re: discussion: replacing ps.map

Glynn Clements glynn at gclements.plus.com
Tue Apr 3 14:36:08 EDT 2007

Dylan Beaudette wrote:

> > > > While you can fill areas (including stroked paths) with arbitrary
> > > > patterns, those patterns won't be oriented to follow the path. If you
> > > > want complex line styles, you generally have to do most of the work
> > > > yourself.
> > >
> > > "Myself" means to edit the resulting Post Script file(?).
> >
> > I mean that the application has to draw styled lines using a sequence
> > of primitives. E.g. if you want a double line (#1000 on p39), you have
> > to draw two lines, with the correct offsets. If you want arrows, you
> > have to place and draw each arrow-head.
> >
> > IOW, you can't just set a style which the "stroke" operator will then
> > apply to a path. With the built-in line-stroking operation, the style
> > is limited to a combination of colour (or fill pattern), dash pattern,
> > caps, and joins. Any fill pattern is applied without reference to the
> > line's alignment or orientation.
> I know that there has been considerable effort to make all of these things 
> possible in GRASS-- if we do not go the route of using GMT as the hard-copy 
> rendering engine, perhaps we can learn something from their postscript 
> rendering and styling code...?

According to the section on pen attributes:


GMT doesn't appear to offer any line styles beyond those which are
provided directly by PostScript.

Glynn Clements <glynn at gclements.plus.com>

More information about the grass-dev mailing list