Preview: Scrolling in PDFs renders at a low framerate

Originator:rix.rob
Number:rdar://20992770 Date Originated:17-May-2015 07:05 PM
Status:Open Resolved:
Product:OS X Product Version:Preview 8.0 (859.21)
Classification:Performance Reproducible:Always
 
Summary:
Scrolling in PDFs in Preview is quite laggy, rendering at a very low framerate. This made it all the more surprising to me that a trivial document-based PDFView app can scroll through the same documents quite smoothly, even in two-up continuous mode.


Steps to Reproduce:
1. Open a PDF, e.g. http://sneezy.cs.nott.ac.uk/darcs/Pig09/papers/icfp-2010-desc/icfp23l-dagand.pdf
2. Scroll it from top to bottom in single-page continuous mode. (Preview does not offer two-up continuous mode.)


Expected Results:
Scrolling as smooth as in a trivial PDFView-based app.


Actual Results:
Very low framerates (< 20fps on a top of the line 2014 MacBook Pro Retina).


Regression:
N/A


Notes:
NB: Safari scrolls this document even more slowly than Preview.

Comments


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