[GRASS-dev] discussion: replacing ps.map

[Jáchym Čepický]

Hi,

the PS driver works nice, thanks!

What about d.text.freetype ? I wonder how complicated it would be to
implement too..?

Jachym

2007/3/30, Glynn Clements <glynn at gclements.plus.com>:
>
> Glynn Clements wrote:
>
> > > > Thierry, I have a very vague memory that you said something about KerGIS
> > > > being able to directly produce vectorized output. Is this true ? How do
> > > > you do this ?
> > >
> > > By using the legacy RASTERLIB now called DRAWLIB in KerGIS. The
> > > documentation about the library is misleading. It is not raster oriented
> > > if you take juste the library that is just an API and a communication
> > > facility to monitors. The API is a drawing API: you draw not only raster
> > > images, but lines, polylines etc.
> > >
> > > In KerGIS, there is only one driver: the X11 one. And it uses the X11
> > > vector drawing XLIB functions for lines etc.
> > >
> > > In this sense, it is not difficult to implement a psdriver.
> >
> > It isn't difficult to implement, but it won't necessarily be of much
> > use given the existing API.
>
> FWIW, I've committed a basic PostScript driver to CVS.
>
> It's behaviour is similar to the PNG driver. The output file is
> controlled by $GRASS_PSFILE, defaulting to "map.ps". If
> $GRASS_TRUECOLOR == "TRUE", it will generate colour output, otherwise
> grey-scale.
>
> $GRASS_{WIDTH,HEIGHT} specify the monitor dimensions in points
> (1/72"), and all coordinates are interpreted as points. This means
> that all drawing primitives are snapped to a 1-point grid, although
> rendering will be performed at the actual device resolution.
>
> At present, there are doubtless many things which don't work
> correctly, or are sub-optimal (especially polygon filling, which
> currently uses the generic software renderer, i.e. lots of horizontal
> lines).
>
> Masked images (e.g. "d.rast -o") require level 3 PostScript; colour
> images require level 2 or a level 1 implementation which supports the
> colorimage operator. Unmasked grey-scale images should work on
> anything.
>
> Anything which doesn't explicitly specify a line width (i.e. probably
> everything except "d.vect ... width=...") will end up using a line
> width of zero, which is probably not much use on a printer.
>
> --
> Glynn Clements <glynn at gclements.plus.com>
>
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>


-- 
Jachym Cepicky
e-mail: jachym.cepicky gmail com
URL: http://les-ejk.cz
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