[Qgis-developer] Viewport rotation

[Nyall Dawson]

On 20 November 2014 07:46, Sandro Santilli <strk at keybit.net> wrote:
> Hi all,
> I'm looking at implementing viewport rotation support and wondering if
> anyone has already an idea about what it would take.
>
> Could adding support in QgsMapToPixel be possibly enough to make
> navigation tools aware of rotation ? Or would it be better to plug
> another transformation in between, as if it was a reprojection ?
>

Hi Sandro,

How are you thinking of implementing this? In the map canvas only?
Ideally, I think this should be supported in the map renderer -
QgsMapRendererJob.

Currently the composer supports rotated maps, but it's a bit of a
hack. It's really just rendering the map and then rotating the result.
As a result all labels, symbology, etc also get rotated, which isn't
ideal. If support for rotating maps was added to the actual map
renderer then the composer would also benefit, as we'd be able to
properly rotate the map without messing up labels and symbology.

Nyall