Comment 3 for bug 1329087

Hello again,

the branch starts to come together: the settings are there, most of the redundancies are gone and the deletion problem is solved by making obsolete tile items try to delete themselves whenever the event loop is idle but only doing so if their render task is already finished. (I also added overlap to the tiles to prevent rendering artifacts due to pixel rounding errors.)

There do remain two serious problem which IMHO prevent this from being universally useful: The obsolete pixmaps functionality is still missing and I am not sure how this can be implemented at all. Also updating the tiles will trigger updates to the neighboring tiles as well, hence if not all visible tiles are cached, the will continuously trigger repaints of each other which never stop. (I have not yet found a way to tell QGraphicsView to repaint one and only one item and depending on how its compositing works, this might not be possible at all. Maybe using Z ordering in between the tiles could help here.)

Best regards, Adam.