Created attachment 102599 [details]
With some pdf (exported from libreoffice impress) okular uses 100% of one cpu. After a long time it ends and loads correctly the pdf.
Other pdf viewer (e.g. evince) work as expected (loads in 1-2 sec and without using a lot of cpu).
I found that the problem seems to be this particular background.
Kde Bug: https://bugs.kde.org/show_bug.cgi?id=336656
The background contains two radial gradients, one at the top (the "glow" in the center of the green bar), and one in the center.
Both gradients are approximated by stacked circles/ellipses with slowly varying color and radius.
On a dualcore Haswell system, the background renders in about 4 seconds for me, which is not incredibly fast, but ok given the contents.
Created attachment 139669 [details] [review]
Optimize opaque fills
Stefan, nice patch!
I've pushed it together with same patch for the non X variant that pdftoppm uses by default.
Created attachment 139781 [details] [review]
Optimize opaque fills for AABGR8
Isn't that the same patch i did?
No, my original patch touched XBGR, you did _RGB, this is for _BGR.
Albert, as this patch is comparatively trivial, can you push it?