[QGIS-Developer] Incremental drawing possible?

[Nyall Dawson]

On 12 July 2017 at 06:21, Andreas Neumann <a.neumann at carto.net> wrote:
> Hi Nyall,
>
> I compiled your branch / pull request. Quite impressive! I like it.
>
> Is it planned to land in master, or are there issues with this improvement?

Well - from my use case I consider it ready. But there's some
outstanding questions which need solving (see the PR discussion):

- should this be normal behavior?
- should it be enabled for all layer types? wmts only (as per
sourcepole's original implementation)? local layers only (for those of
us on crap/expensive internet connections)? rasters only? vectors
only?
- is the cpu utilisation for rendering these possibly unseen tiles an
issue? or is cpu use so cheap nowdays that it's not a factor?
- should the rendering of the adjacent tiles only begin when a pan
starts? (would lose the zoom out benefits this brings, plus add a
delay in showing the nearby area when pan starts)

My 2c: just enable it for everything and let everyone get the benefits
without any configuration hassle. But... all my workstations are at
least 4 cores and lots of memory. So I'm probably not in the best
position to make this call ;)

Nyall