[GRASS-user] Rotate a map display

[Glynn Clements]

Markus Neteler wrote:

> > If you need to warp a map for a strict display purpose, IMHO it's not to
> > be performed from within grass given that this operation makes no sense
> > "geographically". Don't know what the context is, but if you just have
> > to rotate an image output of a map maybe you'd better look towards image
> > manipulation tools (e.g. imagemagick and the -rotate option, which can
> > easily be integrated in a script process).
> 
> Perhaps you can use the CAIRO driver.
> In CAIRO, I see cairo.Matrix.rotate()
> http://cairographics.org/documentation/cairomm/reference/classCairo_1_1Matrix.html
> 
> Just an untested idea, I am not familiar with the CAIRO driver in GRASS.

Even in 7.0, a lot of d.* commands are still concerning themselves
with screen coordinates, the display frame, and the u_to_d
transformation (which is offset+scale with no rotation).

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