R devel - May 2018 - Quartz graphic device can be extremely slow in some cases

Hello,

We?re receiving reports of extremely slow rendering by users who are using the
new geom_sf() feature in ggplot2. Importantly, this seems to be a graphics
device issue, because the exact same plot takes vastly different amounts of time
to render under different devices. We?re talking about 2 seconds vs. 100 seconds
here, so not a small effect.

In particular, the quartz device on OS X seems to be particularly slow. It
appears to be the case that geom_sf() (which draws complex polygons for maps)
hits a code-path in quartz that hasn?t been well optimized for performance.
Importantly, on the same machine where rendering a specific map with quartz
takes 100 seconds, I can render the map to pdf *and* open the pdf in Preview in
about 2 seconds, so there is no fundamental reason why it should take that long
with quartz.

For discussion and reproducible examples, please see here:
https://github.com/tidyverse/ggplot2/issues/2655
https://community.rstudio.com/t/ggplot2-geom-sf-performance/3251

Best wishes,
Claus
--
Claus Wilke
Professor and Department Chair, Integrative Biology
The University of Texas at Austin
2500 Speedway, C0930
Austin, Texas 78712
512 232 2459


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It might be related with this files:

https://github.com/wch/r-source/blob/trunk/src/library/grDevices/src/devQuartz.c

https://github.com/wch/r-source/blob/trunk/src/include/R_ext/QuartzDevice.h

Could we port some of the UNIX optimizations to previous code?

https://github.com/wch/r-source/blob/trunk/src/library/grDevices/R/unix/quartz.R