Syncronous page rendering


When using Adobe Acrobat Reader to scroll through a PDF containing many pages with the “next page” command, the software will always first completely render the current page before allowing you to switch to the next page.

The software Tracker Software PDF-XChange Viewer has an option called “syncronous rendering mode” which if enabled will also completely render the current page before allowing you switch to the next page. (only the Viewer version has that option, the Editor version does not)

When scrolling in Sumatra PDF (and any other PDF reader I know) you are able to use the “next page” command even if the current page is not rendered yet. But if you do so, you will just see a completely white and blank page.

Using Acrobat Reader you can scroll fast through a PDF document looking for some table or picture you would instantly recognize even if you only see it for 0.3sec because every single page is always rendered. (around 3 pages/sec)

Doing the same in Sumatra PDF will just show you blank white pages. (around 20 pages/sec, but all blank)

Is it possible to add an option for “syncronous scrolling” in Sumatra PDF? (or even make that the default behaviour)


We don’t have plans to do that.

In practice, most pages render very quickly. It’s only complicated pages (e.g. with lots of complex vector graphics) that take time to render.

This mode would be rather complicated to implemented and I don’t see much benefit.