StackOverflow2013

Note that there are some explanatory texts on larger screens.

plurals

POJerky/juttery (core-)animation in a screensaver?
text
Body
copied!<p>I've built a screensaver for Leopard which utilises core-animation. It doesn't do anything overly complicated; uses a tree of CALayers and CATextLayers to produce a "table" of data in the following structure:</p> <pre><code>- root › maincontainer › subcontainer › row [multiple] › cell [multiple] › text layer </code></pre> <p>At most there are 50 CALayers rendered on the screen at any one time.</p> <p>Once I've built the "table", I'm adding animating the "subcontainer" into view using CABasicAnimation. Again, I'm not doing anything fancy - just a simple fade-in.</p> <p>The problem is that while the animation does happen its <em>painful</em> to watch. It's jerky on my development machine which is a 3.06Ghz iMac with 4GB of RAM, and seems to chop the animation into 10 steps rather than showing a gradual change.</p> <p>It gets worse on the ppc mac-mini the screensaver is targeted for; it refuses to even play the animation, generally "tweening" from the beginning of the animation (0% opacity) to half-way (50%) then completing.</p> <p>I'm relatively new to ObjectiveC and my experience is based on using garbage-collected environments, but I can't believe I'm leaking enough memory at the point the screensaver starts to cause such problems.</p> <p>Also, I'm quite sure its not a problem with the hardware. I've tested the built-in screensavers which use core-animation, and downloaded a few free CA-based for comparison, and they run without issue on both machines.</p> <p>Information is pretty thin on Google with regards to using CA in screensavers, or using CA in general for that matter, and advice/tutorials on profiling/troubling screensavers seems to be non-existant. So any help the community can provide would be well welcomed!</p> <p><strong>--- UPDATE ---</strong></p> <p>Seems as though implicit animations help smooth things out a little. Still kinda jerky, but not as bad as trying to animate everything with explicit animations as in my solution.</p>

Querying!

Guidance

An individual column

Larger individual text columns get their own page to allow for proper reading.

SQuiL has stopped working due to an internal error.

If you are curious you may find further information in the browser console, which is accessible through the devtools (F12).

Reload