A rather wordy but ultimately interesting look at Parallaxing images by Paul Lewis of HTML5 Rocks:
Whether or not you like parallaxing sites is one thing, but what you can say pretty confidently is that they’re a black hole of performance. The reason for this is that browsers tend to be optimized for the case where new content appears at the top or bottom of the screen when you scroll (depending on your scroll direction) and, in general terms, the browsers work best when very little changes visually during a scroll. For a parallax site that’s rarely the case since many times large visual elements all over the page change, causing the browser to do a repaint of the whole page.
His conclusion don’t guess, test is obvious; but thankfully he also provides methods to put this idiom to practice!
H5R’s responsiveness was much better on my BlackBerry Curve (OS7) than my Dual-Core portable running Firefox 17; but looking at the article and what it tries to achieve I think that’s no surprise. The amount of code that’s pulled from syndication alone is eye-watering, thankfully it’s all very pretty!
- Unlike Facebook, Famo.us thinks HTML5 rocks. Here is why. (gigaom.com)
- Scrolling Performance (html5rocks.com)
What fascinated me was not only that the technology approach there is totally different from ours – I was most amazed just how skewed the view of HTML5 in these environments is. Repeatedly I had to answer questions that were not of technical nature but actually simple regurgitations of either marketing BS about HTML5 or marketing BS against HTML5. In any case, it was mostly about blanket statements and in order to keep my sanity I thought I answer a few here.
I have to say I’m looking forward to these!