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

Doing something to all members of a class?
by Kassen 14 Mar '07

14 Mar '07

Hi, list! I'm having a bit of a issue with classes. Say I have a class that has a member that's simply a integer used for counting something. I'll have a few instances (ten or so) and they will all be counting their own little thing on their own. So far so good. Now something happens and I'd like to reset all the counters to zero after which they should be independant again. How to go about this in a efficient way? I tried writing a static function to do this but it seems I misunderstand static functions. I thought that if I'd call a static function as a member of the class (not of a particular instance) then this function would be executed for all instances. That turns out not to be true; it only gets executed a single time. To make it more confusing (to me) referencing non-static int member of the class inside of a static function makes ChucK die while complaining about a nullpointer exception. In fact it will also die if I call the same function as a member of a particular instance. When I reference the number as "this.my_number" instead of just as "my_number" ChucK is a bit nicer about it and informs that "this" isn't allowed in static functions and refuses to run at all (better then suddenly dieing with cryptic complaints!). My attempt to figure out what's going on; =========================== class Foo { int my_number; fun static void bar() { <<<my_number>>>; } } Foo A; Foo B; 1 => A.my_number; 2 => B.my_number; <<<"so far">>>; //here we die Foo.bar(); ====================== "A.bar();" as a last line would also make ChucK die, BTW. Is this a bug (the nullpointer, I mean)? Am I completely misunderstanding static functions? Is the only way to go about this to make a array of type Foo and loop over it going "0 => ArrayOfFoos[n].my_number" or something to that effect? Thanks, Kas.

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Sndbuf: Unclear Error Message
by Veli-Pekka Tätilä 13 Mar '07

13 Mar '07

Hi list, A minor gripe about error handling. When the sndbuf module cannot find a file it says in my Win XP machine (ChucK 1.2.0.7): [chuck](via sndbuf): cannot stat file '../data/snare.wav'... This is very unclear unless you are a Unix programmer. I mean, to the average musician whether or not the stat system call is used and fails is of littel relevance. Where as something like file not found, would describe the error in much more abstract terms. This is a very minor thing I know, and Unix is full of such attitude, but I still don't like it from a usability point of view. Thought I'd let you know, anyway. -- With kind regards Veli-Pekka Tätilä (vtatila(a)mail.student.oulu.fi) Accessibility, game music, synthesizers and programming: http://www.student.oulu.fi/~vtatila/

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Audio Range and Zero-crossings, Performance, Hashes and Future DIrections
by Veli-Pekka Tätilä 10 Mar '07

10 Mar '07

Hi list, I'm new here. I'm a 20 something sight-impaired programmer and musician from Finland. I've got experience using analogs both virtual and real and know how to build Reaktor patches as well as program in Java, Perl and C. Now I've picked up the basics of ChucK and read through the PDF manual that comes with the program. Looks good and certainly a great deal more accessible than recent versions of Reaktor if you're using magnification and a screen reader program. I've got a flurry of questions I'll ask here. ChucK says it is: chuck version: 1.2.0.7b (dracula) exe target: microsoft win32 1. What's the range of the audio float datatype and what would be the best way to detect zero crossings? My aim is to write a simple app that counts the samples in the low and high phases of a pulse wave and prints out the pulse width whenever it changes. If I can also get MIDi input into the app it would be quite easy to determine how pulse width in percentages changes as the function of the pulse width knob in my virtual and real analogs, whose exact values are not documented. Here's some prototypical code (this is my first real chucK script): Code: 100::ms => dur blockSize; // Processing resolution. until(adc.last() < 0) // Measure low-phase first. blockSize => now; // SAmple counters: 0 => int positive; 0 => int negative; while(true) { adc.last() => float sample; if(sample > 0) ++positive; else if(sample < 0) { ++negative; if(positive > 0) // Measured at least one cycle. <<< "Width: ", 100 * negative / (negative + positive) >>>; 0 => positive => negative; // Reset counters. } // else if // Ignore the pure 0 value. blockSize => now; } // while End code. However, when I run this, the app doesn't ever seem to get past the until loop. I'm assuming here that samples are floats or doubles from -1 to 1 as in VST, as I didn't find the range in the manual. Is this correct? IF not, it's no wonder the code won't work, <smile>. Of course the rather grainy test processing rate, ten times a sec, affects matters greatly but I don't ever seem to get negative sample values even in arbitrary audio. The adc and dac modules do work. IF I patch them together and record from the wave input I get a delayed copy of the input in the output I guess this is the audio equivalent of "cat". 2. Why is it that ChucK locks up when I try to process things at the rate of 1::samp? This is what I'd use in the working code but when I try that CPU usage peaks and I have a hard time killing ChucK. Might ChucK be polling som system wide keyboard hooks or something. I'm using a screen reader which I run together with ChucK. I do know it has blocking hooks deep in the OS both in keyboard handling and graphics i.e. GDI or DirectDraw. The OS is XP Pro SP2 English and this laptop is an HP NX8220. The reader and magnifier is Dolphin Supernova 7.03 beta 7. 3. Is there any way to decrease the latency on WIndows platforms for true realtime MIDI playback and audio processing similar to Reaktor? DirectSound latency is pretty bad as my audio machine, which isn't this laptop, would have both WDM kernel streaming and ASIO support in it. 4. How does one use the ZeroX module for detecting zero crossings? What's the value range and what is the output method of that module called i.e. which thing should I poll to detect the crossings? The manual says: Quote: Emits a single pulse at the the zero crossing in the direction of the zero crossing (see examples/zerox.ck) End quote. That path is slightly outdated, by the way. I found the example in: .\examples\basic\zeroX.ck The example uses the module patchd in the DAC directly, so I never see the values it produces in processing. 5. Continuing with modules I've discovered that there are the low level programming constructs, a few basic ugens and then fancy entities that would be instruments in Reaktor speak and remind me of Korg's physical modelling. Are additional basic modules going to be added in the future? Ideally, I'd like, in addition to implementing the constructions as program code, use ChucK as a more conventional modular synthesizer. Reaktor has got very very generic modules in it stuff like digital gates and sequential circuits, multiplexing and demultiplexing, comparators, waveshaping, variable delays, lookup tables, step sequencers and so on. YOu get the picture. While it is true that many of these things can be simulated easily and even more flexibly in program code, that doesn't feel like programming a modular synth, if you know what I mean. But then again, that might not be the aim of ChucK. Maybe I could use ChucK itself to model some of those, if that's possible, inheriting from a ugen that is. Is there example code for something like that, whose primary focus is not the audio processing itself as it often is in DSP? I'm not actually much good in higher math. 6. How do you use the array datatype in ChucK as a hash? I read that you can index the array with strings much like a Perl hash, except that numbres and strings are totally separate. If I get handed a hashtable whose keys I don't know beforehand, is there a keys or each function for iterating through the hash's keyset? Is the hash portion of the array unordered as one might expect in an implementation e.g. an array of pointers to linked-lists? Thanks for any help in advance. And sorry about these complaints, I just thought ChucK would have been a more complete piece of software than it currently is. Well, it has developed loads since I read the manual last time and decidedd back then it isn't quite ready yet, however. Now it is complete enough that I could imagine using it as a Reaktor and VSt plug substitute for some things. Another bonus is that it is available for LInux, so one of my friends whose into Linux and music could use it, too. i've already hyped the prog. I'm much more comfortable handling memory and doing processing in ChucK or Java than I am in C++, for instance. -- With kind regards Veli-Pekka Tätilä (vtatila(a)mail.student.oulu.fi) Accessibility, game music, synthesizers and programming: http://www.student.oulu.fi/~vtatila/

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key up
by Ryan Spangler 10 Mar '07

10 Mar '07

Am I missing it? I am using KBHit for key downs but I can't find a way to track key ups! I have looked all over the documentation/examples and several creative google attempts all for naught. Thanks! --------------------------------- Need Mail bonding? Go to the Yahoo! Mail Q&A for great tips from Yahoo! Answers users.

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User-Module Fundamentals AKA Extending Ugen
by Veli-Pekka Tätilä 08 Mar '07

08 Mar '07

Hi list, A quick question I'll post tonight before replying in the other thread I've started. To gain some experience in ChucK and make it feel more like Reaktor, in terms of modules, I thought I should try implementing some Reaktor modules in ChucK itself. of course, it makes no sense to create something as simple as an audio adder as we have the infix plus binary operator already in the language. So I dug up an ancient Generator module (Generator was the product before they named it Reaktor), and picked a relatively simple example namely a wave made up of series of up and down counts as folows: Quote ancient Generator manual: Multistep Oscillator 4-Ramp Oscillator for 4-ramp waveform with logarithmic pitch control and linear amplitude modulation. The level of each of the breakpoints which are connected by ramps can be set independent of the others. w P: Logarithmic event input for controlling the pitch (oscillator frequency). Value in semitones (69.0 = 440 Hz, but also see DAC Tun). 112 w A: Audio input for controlling the amplitude. The output signal moves between +A and - A. w S1: Event input for controlling the level of the first breakpoint. w S2: Event input for controlling the level of the second breakpoint. w S3: Event input for controlling the level of the third breakpoint. w S4: Event input for controlling the level of the fourth breakpoint. w Out: Audio signal output for the ramp waveform. End quote. Although in this case my aim would be to create a Multistep Oscillator n-Ramp to make it more flexible. In stead of multiple getters and setters I'll create just one with an index parameter, makes life much easier. I read that constructors having parameters are not supported, so I might as well use an initializer method to set parameters after instanciation. I've been looking into ./class/dinky.ck and it claims that one cannot yet inherit from a Ugen, ouch. Is that still true? Well if classes are duck-typed as in Perl or Ruby, i.e. common method names are good enough for polymorphism, then that's not a problem I suppose. I've been trying to grasp how a uGen operates, too, where is it documented thoroughly? The manual says all uGens have certain common parameters. But how should I implement something like: Quote manual: . .chan - (int) - returns a reference on a channel (0 ->N-1) End quote. For my class which should work like a uGen, i.e. what to return and where do I get the object I'm supposed to return? Ideally I'd like to create modules that make no difference between event and audio signals as in a true modular. Howabout modules with multiple inputs. Another thing I'm thinking of creating would be a simple multiplexer named OneOfN which has n inputs and a selectN adress bus. It connects the input addressed by selectN to the output. This is a generalization of the Reaktor modules audio switch 2, 4, 8 and event switch 2, 4, 8. Are such multi in/out modules currently feasible? Do I have to advance time in such a module, as it is a (stateless)combination circuit, not a state machine? Lastly, how do I import my classes in a project ii.e. is there some C:ish preprocessor include syntax or a Java-like classpath environment variable? I find there ar a number of things the manual and a quick glance at the examples doesn't answer adequately. Well, I'm glad we have this list. And sorry to bother you with pretty obvious newbie Qs, I mean if one has ever created an instrument, all or most of these must have been answered already, or else I'm seriously lost, <smile>. Is there a FAQ or archive? -- With kind regards Veli-Pekka Tätilä (vtatila(a)mail.student.oulu.fi) Accessibility, game music, synthesizers and programming: http://www.student.oulu.fi/~vtatila/

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Music created from a chuck example
by David Powers 03 Mar '07

03 Mar '07

This is kind of nice: http://www.restivo.org/blog/archives/63 ~David

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(no subject)
by Martin Robinson 26 Feb '07

26 Feb '07

Date: Mon, 26 Feb 2007 15:25:12 -0500 From: martin robinson <mjr(a)cc.gatech.edu> To: "ChucK Users Mailing List" <chuck-users(a)lists.cs.princeton.edu> Subject: Re: [chuck-users] Music created from a chuck example In-Reply-To: <686ba4e40702260959o7f362408g1150797f93b3dfd4(a)mail.gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Content-Disposition: inline References: <686ba4e40702260852g85fef20wc82e918135afdbc9(a)mail.gmail.com> <1172511158.45e319b6d375e(a)cubmail.cc.columbia.edu> <686ba4e40702260959o7f362408g1150797f93b3dfd4(a)mail.gmail.com> > Max/msp is WAY out of my price range, but I'd love to have something > like that in PD. I don't know if I could convince someone on the PD > list to port it though... I have a working version of chuck~ for PD (based on Brad's max/msp version), which is very close to release. There is no Windows port as of yet (Linux & Mac currently), but I hope to have that soon. I just finished porting it to ChucK 1.2.0.7 and it will be fairly easy to port to the new version of ChucK that is about to appear. I hope to make a release announcement to the list in the next week or two. martin robinson

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[OT] CMC Fün Nite for laptop improv
by garton＠columbia.edu 26 Feb '07

26 Feb '07

Hey cHUck-STers: An item of interest for the New York crowd, and I know there are a few of you. At the CMC we are starting a monthly evening of laptop/electronic performance called "CMC Fün Nite." The first one is this Thursday (March 1). See the press release below. If its not fun, its poorly named, so come out and join the fun! -------------- Press release: This coming Thursday evening (March 1) marks the inaugural event in a monthly meeting devoted to informal performance and discussion of laptop improvisation in the New York area. We're calling these "CMC fün nites" and our intention is to provide a dorkbot-like forum for artists and musicians involved in technological improvisation. This first event will feature performances and talk by: PG (Terry Pender and Brad Garton, possible video enhancements by Luke Dubois) Sam Pluta (audio and video improvisations) Nick Didkovsky (improvisational pieces by Dr. Nerve!) Please come to join us! We will be in the main space of the third floor of Prentis Hall, 632 W. 125th Street (just off Broadway). Visit the CMC web site [http://music.columbia.edu/CMC] for directions. -------------- Thanks and sorry for the clutter, brad http://music.columbia.edu/~brad

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Bufsize and miniAudicle
by Jim Credland 25 Feb '07

25 Feb '07

Hello - Just downloaded and installed chuck and it's funky GUI. It's not clear how to increase the bufsize parameter from the GUI though - I've some some serious glitching at the moment. all pointers appreciated, thanks, J. -- Jim Credland jim(a)cernproductions.com

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Creating a THX-like sound in ChucK
by Perry R Cook 22 Feb '07

22 Feb '07

Hi all, here's a little New Year's gift. After reading a posting by an STK user to the stk list about reading Andy Moorer's account of how he created the THX sound, I decided to whip one up in ChucK. As easy as one might expect. Enjoy!! PRC http://musicthing.blogspot.com/2005/05/tiny-music-makers-pt-3-thx-sound.html // THX emulator, Perry R. Cook, Jan. 8, 2007 // // F-1, B1b, F1, B2b, F2, B3b, F3, A5, F4, A6 [ 29.0, 87.5,116.0,175.0,233.0,350.0,524.0,880.0,1048,1760, 29.0, 87.5,116.0,175.0,233.0,350.0,524.0,880.0,1048,1760, 29.0, 87.5,116.0,175.0,233.0,350.0,524.0,880.0,1048,1760 ] @=> float targets[]; float initials[30]; float deltas[30]; sawosc s[30]; gain gl[30]; gain gr[30]; JCRev rl => dac.left; JCRev rr => dac.right; 0 => int i => int j; for (0 => i; i<30; i+1 => i) { std.rand2f(200.0,800.0) => initials[i] => s[i].freq; // random freqs. (targets[i] - initials[i]) / 10000.0 => deltas[i]; // 10 sample updates 0.1 => s[i].gain; std.rand2f(0.0,1.0) => gl[i].gain; // random 1.0 - gl[i].gain() => gr[i].gain; // panning s[i] => gl[i] => rl; // hook up s[i] => gr[i] => rr; // all the oscs } 10000 :: samp => now; // steady cluster while(j < 10000) { for (0 => i; i<30; i+1 => i) { initials[i] + (deltas[i]*j) => s[i].freq; // sweep freqs. } j + 1 => j; 10 :: samp => now;} while (j < 30000) { // hold chord 10 :: samp => now; j + 1 => j; } while (j < 35000) { for (0 => i; i<30; i+1 => i) { 0.1 * (35000 - j) / 10000.0 => s[i].gain; // decay gains } 10 :: samp => now; j + 1 => j; } 60000 :: samp => now; // reverb tail

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