January 2009 - chuck-users - lists.cs.princeton.edu

parent and children classes
by eduard aylon 21 Jan '09

21 Jan '09

Dear chucklist, I have a question regarding parent and children classes. I'm building a patch with operators that may have one or anoother user defined envelope (i.e. gaussian like, percussive like, etc.). I want to avoid to have to define each operator with 4 different envelopes and then connect-disconnect-reconnect. What I would like is to define a parent class EnvelopeClass from which the rest can inherit. I remember from the past that in chuck inheritance is not very "handy", so if children have different functions or members than its base class, these cannot be accessed. Does anybody have good recommendations to this problem? So the idea is: EnvelopeClass -> this is the base class GaussEnvelope -> children class that inherits from EnvelopeClass PercussiveEnvelope-> children class that inherits from EnvelopeClass now I'd like to have class Operator { SinOsc s; EnvelopeClass @ env; } and be able to assign different envelope types and be able to access their members. Maybe the example at the bottoom of the email is more explanatory. Operator op; GaussianEnvelope gaussEnv @=> op.env; Operator op2; PercussiveEnvelope percEnv @=> op2.env; and even later be able to change the type of the envelope for any operator: GaussianEnvelope gaussEnv2 @=> op2.env; From what I remember, the trick would be that parent and children classes have EXACTLY the same member vars and functions although the implementation contained in it may differ. However, a gauss envelope or a percussive envelope have very different demands, and the best would be to be able to have diffferent implementations for each but inherit from the same base class. any thoughts are very much appreciated, thanks eduard Another example could be: class operator { UGen @ ugen; } Operator op; SinOsc s @=> op.ugen; // this is fine so far but none of the functions of sinosc can be accessed 220 => op.ugen.freq; // this throws an error, as far as I remember....

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Fwd: hotswapping UGens
by Kassen 21 Jan '09

21 Jan '09

Dear all, I just noticed that I accidentally send this to the DEV list instead of the users one. That was of course a mistake. I hope this didn't bother anyone, I'll try to pay more attention on the future. Sorry, Kas. ---------- Forwarded message ---------- From: Kassen <signal.automatique(a)gmail.com> Date: 2009/1/21 Subject: hotswapping UGens To: ChucK Developer Mailing List <chuck-dev(a)lists.cs.princeton.edu> Fellow ChucKists, Inspired by Scott's explanation of casting I thought I'd try a new trick that may be quite interesting for livecoding. first run this file; ----------------------------- new UGen @=> Foo.instrument; public class Foo { static UGen @instrument; spork ~attach(); fun void attach() { while(1) { if(!instrument.isConnectedTo( dac )) instrument => dac; second => now; } } } Foo foo; new Sitar @=> foo.instrument; //your melody goes here while(second => now) 1 => (foo.instrument $ Sitar).noteOn; -------------------------------------------- Then run this to hot-swap the UGen while the original code runs; -------------- new Shakers @=> Foo.instrument; ----------------------- Sadly this does need that "attach" function as assignment breaks the link to the dac. I'm not sure I feel that's desirable behaviour but at least we can now hotswap UGens without crashing. I don't think I succeeded in that before. Yours, Kas.

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Communicating with external processes
by Andrew McPherson 21 Jan '09

21 Jan '09

Hi all, What are the ways to communicate between ChucK and external programs? Specifically, my code has a lot of parameters to adjust in real time, and a GUI would be a nice way to do that. I could put the GUI together in PD or Cocoa, but how can I transmit the data to ChucK? The two ways I have found to receive external data are MIDI and OSC. MIDI control changes can be a little coarse in terms of resolution (even with 14-bit values), and for most programs it'll need some sort of loopback driver to handle the routing. OSC seems closer to a generic way of interchanging data, but it looks like I would have to spork a different thread for each parameter I want to receive (since they'd have different addresses), and that I can only receive one value per OSC event. If I wanted, say, to receive 3 floats as part of one message, is there a way to do that? Is there a way to read directly from a pipe to another process? I'm thinking of a setup where an event is signaled when new data is available at the input. Any other thoughts on how to approach this task? Thanks much, Andrew P.S. Semi-related to the above: is there a way to wait on 2 events simultaneously? Thinking of something like these: midiEvent || oscEvent => now; // wait for whichever comes first midiEvent || 200::ms => now; // wait with a timeout

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Get the value of an Envelope
by Andrew C. Smith 20 Jan '09

20 Jan '09

I've got some flawed code here, and that's because I'm stuck. I want to dynamically change Gen17's coefficients using an Envelope to get a smooth sample-rate transition, but I can't figure out how to use the last value from an Envelope and put it into the array to assign to cheb.coefs. How would I do this? Would I need a sample rate for() control? Thanks. Andrew SinOsc drive => Gen17 cheb => dac; [1., 0.5, 0.25, 0.125, 0.06] @=> float coefs[]; 0.2 => cheb.gain; while(true) { Std.rand2(0, 4) => int coef_changed; Std.rand2f(0., 0.99) => float dest; coefs => cheb.coefs; Envelope change => coefs[coef_changed]; change.target(dest); change.duration(50::ms); 50::ms => now; }

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best way to read from HID device
by Robert Carter 20 Jan '09

20 Jan '09

Hi everyone, I'm running chuck under linux and I want to play sounds using a plastic drum pad USB HID device. Here is an article with the technical details I have assembled so far: http://www.organicdesign.co.nz/USB_human_interface_devices_with_Linux I can read data from the /dev device and this data seems to be giving correct drum hit information. The hardware appears as a HID device but i've been unable to get the chuck joystick functions to use it. I thought perhaps I could use file IO to read blocks from the device and trigger sounds from that, but I can't see how you might achieve this in chuck. I have found a small C program that reads the usb device and translates this into JACK MIDI signals but this does not seem to be a good match for chuck. Another idea was to modify this program to send OSC messages instead of JACK messages, and feed into chuck that way. Any suggestions, tricks or hacks most welcome. Rob

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Using e
by Kassen 20 Jan '09

20 Jan '09

Sorry, list, no chemicals here. I just couldn't resist the title. Last night I was answering a question on the forum that involved the constant "e". To get e in chuck we go; Math.e => float value; However to get pi we go simply; pi => float another_value; This isn't exactly a major issue, compared to some of the other issues that we have but it does strike me as somewhat inconsistent. Is there a good reason for this? If not should we consider making this consistent, for example by stuffing pi in the Math library as well? Yours, Kas.

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new [chuck~] object available
by Brad Garton 19 Jan '09

19 Jan '09

Everyone -- Version 1.4 (MaxMSP 4.x) and 1.5 (Max5) of the [chuck~] Max/MSP object are available for free download: http://music.columbia.edu/~brad/chuck~/ for Macintosh OS X (10.4 and 10.5). The new [chuck~] object is up-to-date with the latest (v 1.2.1.2) release of the ChucK language, including the LiSa live-sampling unit generators and the unit-analysis generators in the 1.2.1.2 package. [chuck~] imbeds the ChucK music-programming language in Max/MSP, bringing a sophisticated set of synthesis and signal-processing tools into the Max/MSP environment. [chuck~] also features an advanced timing and scheduling system in addition to a functional-style programming interface for algorithmic operations. Full source for the object and the language are also on-line. No Windows XP version is available at present -- sorry! This is a fun object -- enjoy it! For more information about ChucK, visit the ChucK web page: http://chuck.cs.princeton.edu/ Brad Garton, Director Columbia University Computer Music Center http://music.columbia.edu/~brad

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live coding lab == 27/02 > 01/03 == ghent/belgium
by Bram de Jong 14 Jan '09

14 Jan '09

(appologies for cross-posting in advance) Hello live coders, = summary = live coding lab+battle at resonance ghent :: call to arms+collaboration 2009, February 27 -> march 1 location: espace ladda ( http://www.espaceladda.be/ ) and art center vooruit ( http://www.vooruit.be/ ), ghent, belgium = /summary= My name is Bram de Jong (you might know me from freesound.org / smartelectronix.com / musicdsp.org) and I've been appointed as one of the chief-noisemakers for the upcoming Resonance Festival ( http://www.resonanceghent.be ) in Ghent - Belgium. In particular, I'm responsible for the live coding workshop which will take place in the "espace ladda" right next to the artcenter. There will be 3 days of intense workshopping, collaboration, battles, but the format will be completely open. Space to seat about 10-13, 2 vid projectors, big mixing desk, enough audio cables to strangle a cabbage (I'm a cat lover), headphone splitters + headphones so people can listen in on you / spy / steal your best ideas in true open source sense. On Sunday afternoon, we shall all chill out in the Café and get some proper live coding wars onto the large speakers and projection screen in a relaxed/energetic/stressed battle environment, powered by plenty of Belgian Beers. Who is invited: everyone who does live graphics+coding or live audio, if you want to join, send an email to bram(a)resonanceghent.be with some youtube-y examples of what you do, some website to look at, some art, whatever you can throw at us. What is included: we offer the space and for some of you we will be able to (help?) pay the voyage. Sleeping places will be cozy and personal (read: in someones house) rather than expensive and hotel-based. Couleur locale powered. Once we get all proposals/.. we will see who we can help. Our budget is very limited. Oooh, and we also give everyone who comes play a free entrance to the festival (Machinefabriek, Eavesdropper, Alva Noto, Move D & Benjamin Brunn, Claro Intelecto & Andy Stott, Peter Van Hoesen, Mokira / Andreas Tilliander, Echospace). What would we like you to bring: your laptop and anything you think is cool to tinker with. If you have some circuitbent cheezegraters you think sound cool, bring'm and add them to your soft/hard tweaking! We'd like you to bring crazy things. Yes. The crazier the better. Note: if you live closer (uk, de, nl, fr), chances will be greater we can pay your flight/train/bus! much love and a happy ny. - Bram -- http://www.freesound.org http://www.smartelectronix.com http://www.musicdsp.org

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Re: [chuck-users] Guitar Lab
by Les Hall 11 Jan '09

11 Jan '09

Kassen, My test user said that message.ascii worked great! Issue resolved. Les

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Re: [chuck-users] Guitar Zero
by Les Hall 10 Jan '09

10 Jan '09

Kassen, OK, I coded it up with message.ascii. Now I see what you mean about this being well thought-out and not a problem. message.ascii works fine for me, I hope it also works for my test users. We will find out in a while. Les

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