scroll paint without opengl

[totaam]

Issue migrated from trac ticket # 2295

component: client | priority: major | resolution: fixed

2019-05-10 13:00:41: antoine created the issue

---

More important since #2248 enables it in more cases.
#1320 makes this much more useful too.

Original scrolling ticket: #1232, see also #1426.

[totaam]

2019-05-10 13:09:21: antoine changed status from new to closed

[totaam]

2019-05-10 13:09:21: antoine set resolution to fixed

[totaam]

2019-05-10 13:09:21: antoine commented

---

Done in r22700.

I can no longer reproduce the visual corruption with the cairo backend, and the pixmap backend has been re-implemented by copying the whole pixmap buffer to a new backing before applying the copying, which seems to have fixed it.
It is a little bit expensive to do all this copying, but most modern computers should have enough memory bandwidth for that.