April 2008 - chuck-users - lists.cs.princeton.edu

Re: [chuck-users] A problem with the code
by pibsid＠suomi24.fi 19 Apr '08

19 Apr '08

A quick glance over your code suggest that the seq faults are caused by float functions that do not return anything. Try: fun float foo(){ return 0.0; //remember to return a float } The null pointer exceptions are propably caused by using SinOsc @ s[MAX_COMP]; This creates an array of null pointer SinOscs. Try without the @: SinOsc s[MAX_COMP]; -Pyry Pakkanen

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Bluetooth and Wiimote: a long-term feature request
by Inventor-66＠comcast.net 17 Apr '08

17 Apr '08

I've been researching 3-axis accelerometers and have decided to build my own joystick HID unit. This will require custom homemade circuit board construction, though not much of it, and the purchase of two $35 circuit boards from the web. So no problem, it should work great and then I can code ChucK to know the position and orientation of my guitar at any moment in time. ChucK can then do many interesting special effects to the guitar sound with that information, freeing the player from clumsy pedals and such. It should be kewl, but along the way I learned that there are many Bluetooth HID products which would have done the job without any special circuitry at all. In fact, a $50 Wiimote - the remote control for the Wii console game - is a perfect little instrument tracker plus it has buttons and such as well, but ChucK doesn't know how to talk to a Bluetooth sensor. So you can see that there is good reason to add Bluetooth HID to the list of ChucK's features. I wouldn't place it at high priority since the dev team is currently so pressured with feature requests and this is only one application. Still, I wonder if such a feature as Wiimote instrument tracking might help to popularize ChucK? Whatever, just making a feature request. I added it to the bottom of the Wiki feature request list. Keep on ChucKin'! Les Hall (Inventor)

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OSX updates =< real-time audio?
by Ge Wang 16 Apr '08

16 Apr '08

Greetings, We are experiencing some rather unfriendly real-time behavior on OS X, seemingly after doing the latest apple upgrades... here are some details, at least on my machine: * system: Macbook Pro / OS X (10.4.11) * updates: Quicktime 7.4.5 + MPB EFI Firmware Update 1.5 * symptoms: real-time audio "goes to poop", even under moderate loads. * workaround: running command line chuck in BLOCKING mode (via --blocking) seems to work, however the default CALLBACK mode seems completely hosed, even with bigger buffer sizes. This is especially problematic for the miniAudicle, which doesn't have the option currently to choose between blocking vs. callback. Has anyone else noticed similar behavior, either on Tiger or Leopard? Or is this an isolated case for my system? We'd appreciate any input! Thanks!! Best, Ge!

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low overhead interpolation trick
by Kassen 12 Apr '08

12 Apr '08

Dear ChucKists. I was running out of fingers and buttons on my joypad... who-ever decided the thumbs should share both the analogue sticks and the buttons on the top? Anyway, I picked up a tilt-sensing joypad. Sadly proper tilt sensors are relatively expensive and games devices typically get made as cheaply as possible (grumble). To cut a long story short; it sends a fury of values that are somewhere around the value that it needs to be. Result; the poll-rate gets to be a kind of noisy harmonic. So; this leads to the question of how to interpolate this mess without making complex function calls at this high poll-rate and cook the poor CPU before we get any sound made at all. Solution; as soon as I get the value the axis moved to I write that to a Step Ugen's ".next()". Then; Step my_axis => LPF my_interpolation => blackhole; //set to taste, it's latency v.s. noise //maybe a rate that's relatively prime to the poll-rate would be best? 5 => my_interpolation.freq; then my_interpolation.last() can be polled at whatever rate makes sense. It can also be chucked directly to Ugens like oscillators set to act as a FM synth (use the filter's gain to scale) or to Gain's set to multiply. Very cheap and so far quite pleasant to work with, I thought I'd share. Yours, Kas.

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Future ChucK: wish list items and one comment
by Inventor-66＠comcast.net 02 Apr '08

02 Apr '08

Dear ChucKists, I look into my crystal ball and I see the future of ChucK, AKA my wish list: o MAUI ported to PC/Linux (on the way, woohoo!) o fix noteOff () problem o String Processing: preferably inspired by Perl o File I/O: I want to save and load program settings o printf (): formatted text/numeric output. o Hierarchical Events: i.e. event when any button in an array is pressed o MAUI Expansion: Text I/O, File Browser, 2D drawing, 3D drawing, etc. o Garbage Collection o Tube Amplifier UGen o Piano STK Instrument And there is one observation I'd like to share... Aside from it's musical capabilities, the one outstanding feature of ChucK to me is the way that everything works together. ChucK is very Apple/Linux-like in the way that it seems to be so well thought out. Of the dozen or two languages I've played with over the years, ChucK has got to be the most fun and the easiest to code because stuff just plain works. So my hat's off to the dev ChucKists, us user ChucKists are having a blast with your hard work! Inventor p.s. I went retro on the Pong game with the square ball as I remember from our Pong unit we had as kids, though I agree the LED would be way cooler. Maybe make it blink all three colors...

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