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Version checking, slowing random motion

Hello everyone,

I thought I'd share my first real Quartz Composer creation. It's a screensaver called Soundstream, and it reacts to the sound input picked up by your computer's microphone. You can find it at http:// www.pcheese.net/software/soundstream/

You may want to install it and open up the .qtz file to see some tricks I've learned, notably new version checking and adjusting the speed of random motion. I'm planning on writing up an introductory QC tutorial eventually, but here's an explanation of what I did if you're interested:

Version checking uses the RSS Feed patch to get the latest version information from the update site. A sample feed can be found at feed://www.pcheese.net/software/soundstream/version.rss (option-click the version history link on the Soundstream page to see the feed source). I like this method because people could alternately check for a new version with Safari RSS, and it doubles as a list of actual changes as well. The first item in the feed is assumed to be the latest version. If the current version number differs from the latest version, a message is displayed. There's an RSS Version Check macro patch in my composition that you can copy and paste, and it should work with few changes as long as you create the corresponding feed. You'll have to specify whether to enable the checking, the URL of the RSS feed, and the current version.

For random motion, I used the random patch with a low variability setting. To slow it down, I set the timebase of the patch to external (control-click the Random patch to change this value), then multiplied the output of a Patch Time patch by a factor of 0.7 and connected that to the new time input on the random patch.

Hopefully these tips will help people create unique and interesting compositions!
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