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

I Put A Physics Engine In Chuck
by Zed A. Shaw 15 Dec '08

15 Dec '08

Well, I'm having fun with chuck and plan on using it for a little music like project. In order to make the project work though, I needed a physics engine in chuck, so I put one in there: http://rafb.net/p/SRbR9A13.html That's a sample from my hack in progress. I just put in Box2D_Lite for now to get the idea working, but so far it's pretty nice. Right now all I've got is a Physics UGen that lets you put in an observer and a sound source, and then set their movement. It will then determine the distance and adjust the gain. Next up is pan for left/right of observer, colliding events, and maybe a doppler effect pitch shift based on velocity. -- Zed A. Shaw http://freehackersunion.org/

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Organizing Chuck Projects
by mike clemow 14 Dec '08

14 Dec '08

Hi Chuckers, Just thought I'd plumb the depths of your collective brains (as a procrastination break) to see how you all organize larger coding projects in Chuck. I have a bunch of public classes in files and an init.ck file that Machine.add's them all in the proper order. DIY Chuck class library. It's kind of hackish, though, and I want to write a Chuck session manager application. Is that a dumb idea? How do you all organize your code? Struggling through finals, Mike -- http://michaelclemow.com http://semiotech.org

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Three cheers ( and one small frown) for Dan
by Kassen 13 Dec '08

13 Dec '08

Dear list (and Dan!) LiSa.track() is brilliant! ( See; http://wiki.cs.princeton.edu/index.php/LiSa_examples ). In the past days I've had a renewed enthusiasm for experimenting with LiSa to try to emulate turntable scratches and now turntableist techniques/gestures as well. (You can read reports and see videos excerpts of the relevant sessions here; http://steim.org/jamboree08/ there is a interesting forum starting here; http://forum.itchymuzik.com/index.php ). LiSa.track() seems especially well suited to emulating platter inertia; if I understand it all correctly a simple LPF over the tracking signal will give us most of this "for free". Brilliant stuff, loads of cheap fun with breakbeats. This will be very useful indeed to many people, I imagine. But... unless I'm completely mistaken this was nowhere to be seen in the release notes. I knew it was comming, but I had no idea it was here already. Yours, Kas. PS; //=========================== //"abstract turntableism" by Kas, hacked up in a few minutes //Remixing strongly encouraged //add your own break, tweaking may be needed SndBuf b => LiSa l => Envelope cut => dac; //add your own "break2.wav" => b.read; b.samples()::samp => l.duration; 1 => l.record; l.duration() => now; 0 => l.record; b=<l; Step unity => Envelope e => LPF f => l; //inertia (sort of) 3 => f.freq; unity.next(true); 1 => l.track; 1 => l.play; .125::l.duration() => e.duration; fun void fade() { 1=> int times; while(1) { Std.rand2(2,6) => times; (1.0/times)::e.duration() => cut.duration; repeat (times) { !(cut.value() $ int) => cut.target; cut.duration() => now; } } } spork ~fade(); 1=> int direction; while(1) { -1 *=> direction; (.125 * Std.rand2(direction, 4* direction) + e.target()) % 1 => e.target; e.duration() => now; }

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Dec10 Steim, Amsterdam (NL), presentation
by Kassen 11 Dec '08

11 Dec '08

Dear list, People in The Netherlands may be interested in my presentation at Steim in Amsterdam on December 10 as part of Steim's "Micro jamboree" http://steim.org/jamboree08/ Steim is a organisation that develops, promotes, etc, new interfaces for electronic music. I'll be talking about my sequencer (for writing house using a joystick), about ChucK, my perspectives on improvisation and the use of game devices, illustrating details by improvising some music. There should be space for debate and questions as well. Some of the other sessions may be of interest to people on this list as well. I gather that these sessions are free though reservations are necessary. ( info here; http://steim.org/jamboree08/?page_id=35 ) In case nobody in NL is around it may at least be good to know that STEIM is interested in hearing about ChucK. STEIM is a rather unique institute and I'm very happy the council reversed it's decision and STEIM will continue to get funding; I'm not aware of any other institute that is exclusively dedicated to new interfaces for improvised electronic music. Yours, Kas.

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formatting string
by Beinan Li 09 Dec '08

09 Dec '08

Dear ChucKers, I couldn't find a thorough recipe of ChucK's string in the manual. Could I format a string as I do with sprintf in C or Matlab? If so, how? Thanks. Beinan

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get whole sndbuf content as uana
by werteplus＠gmail.com 09 Dec '08

09 Dec '08

hey list! i'm trying to abuse chuck for non-realtime tasks. i want to fft a wav file, do some freaky stuff, ifft it again and save the result as wav to the disk + play it. problem with this is that fft seems to only accept incoming samples being chucked realtime. any chance to upchuck sndbuf's whole content to a uana like fft? thanks, fabb

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static strings
by Beinan Li 07 Dec '08

07 Dec '08

Dear ChucKers, 1st of all I'm a newbie to ChucK (Many thanks to Steve who brought me here). I bumped into a problem regarding static strings, which would really not have been in my way if I designed it another way, but I still feel it important enough. Here is the story. I wanted to create a function in a stand-alone .ck module to load my instrument samples from disk. So I designed my loader class in *instr_loader.ck* like this: > public class Instr_loader > { > "path/to/instrument" => static string m_p_instr; > > fun static string get_instr {return m_p_instr;} > } > For some reason I just wanted to test the static flavor of ChucK, there is really no reason to use a static member here I must confess. Then my client code *main.ck* looks like this: > Instr_loader.get_instr() => string path_instr; > when I run both .ck's, I will get: > [Instr_loader.ck]:line(3): cannot declare static non-primitive objects > (yet)... > [Instr_loader.ck]:line(3): ...(hint: declare as ref (@) & initialize > outside for now) > Then I change the code with the reference to: > "some/path" => static string @ m_p_loop > Then I run > chuck Instr_loader.ck main.ck > and get this: [Instr_loader.ck]:line(3): cannot declare references (@) of primitive type > 'string'... > [Instr_loader.ck]:line(3): ...(primitive types: 'int', 'float', 'time', > 'dur') > So is there a reason why string is not part of primitive types? BTW: it works perfectly using string as normal class member. I'm just interested in this problem here. Thank you and hope ChucK will chuck it all up~! Beinan On Sun, Dec 7, 2008 at 8:09 PM, Stephen Sinclair <sinclair(a)music.mcgill.ca> wrote: > Yeah, but you have to make it a static function of a public class. > The class model in ChucK is still a little awkward, but public classes > can be instantiated in other files. Only one public class can be > defined per file! > > Steve > > > On Sun, Dec 7, 2008 at 7:51 PM, Beinan Li <li.beinan(a)gmail.com> wrote: >> Hi Steve, >> >> Should be a newbie question: >> In ChuCK, can you define a function in a single .ck file >> and call it from another .ck like in Matlab? >> >> Thanks. >> >> Beinan >> >> >> >

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Re: [chuck-users] USB Accelerometer
by Les Hall 02 Dec '08

02 Dec '08

Hi again. Just to be clear, because I wasn't clear enough in my recent post, what I have is a prototype of the product. It is exactly like the version that Ultimarc will soon carry on their product line but at the moment the darn accelerometer chips are unavailable! Yep, we can't get the chips at this time. So they are on order. When the chips become available then the product will be added to the web page at a reasonable price. The link, www.ultimarc.com, and the sub-section on that page about the U-HID nano, describe the nano prior to having an accelerometer bolted onto it. I'll notify the list when the part becomes available and ready for purchase. Thanks, Les (Inventor)

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USB Accelerometer
by Les Hall 01 Dec '08

01 Dec '08

Good news, friends! I have received a working prototype of the USB Accelerometer that I told you all about a couple of times in recent months, and initial testing indicates that it is working perfectly. This device is about the size of two postage stamps. It comes with a five-foot (I think?) USB cable and a small wire harness that attaches to a right-angle header. The header allows the device to be programmed to receive button and potentiometer inputs as well as slow Analog and Digital inputs. It can also drive LEDs, though ChucK does not drive joystick LEDs yet. Oh yes, and it looks like an ordinary joystick so the programming interface is joy-fully easy to do in ChucK. The accelerometer is the same ADXL330 that is in the WiiMote and the ADC has enough resolution to read it accurately down to the noise floor of the device, so it is plenty sensitive. Sounds like a commercial? Yeah, well I'm excited about it - this thingamajig is the product of several months of work. I had made all the plans to DIY such a beast when I approached the company Ultimarc and suggested they might want to add it to their product line. To my amazement, Andy at ultimarc said he'd like to do just that! I was so excited then, and now it's sitting on my desk awaiting further testing! If you want to get a feel for the device, you can look up the U-HID nano on the Ultimarc web site, which is www.ultimarc.com. Just click on U-HID and then look for the baby brother of the U-HID, the U-HID nano. Our product is the U-HID nano complete with expansion port and with an accelerometer squeezed onto the little board (well, a tiny bit bigger). You can also email Andy about it, his email address is andy(a)ultimarc.com. Just one more step forward on this fun and wild adventure that we call ChucK! Les (Inventor)

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