SuperCollider CLASSES

Synth

Client-side representation of a synth node on the server
Source: /usr/local/share/SuperCollider/SCClassLibrary/Common/Control/Node.sc
Inherits from: Node : Object

Description

A Synth is the client-side representation of a synth node on the server. A Synth represents a single sound producing unit. What it does is defined in a SynthDef, which specifies what UGens are used and how they are patched together. It also specifies what inputs and outputs the Synth will have. A SynthDef is thus a kind of fixed pattern, upon which Synths are be based. (Despite this, a given SynthDef can provide a surprising amount of variation.) For more detail on SynthDefs, their construction, and how to send them to a server, see the SynthDef help file.

For more on the important distinction between client objects and server nodes, see Client vs Server. For information on creating nodes without using objects, see Node Messaging.

Order of Execution

Order of execution is a crucial issue when creating Synths which interact with each other.

    sound ->  filter

If a sound is to be passed through a filter, the synth that does the filtering must be later in the order of execution than the synth which is its input. The computer must calculate a buffer's worth of sound, and then the computer moves on to calculate a buffer's worth of the filtered version of that sound.

The actual interconnection between synth nodes is accomplished with buses. See Bus and Server Architecture for details.

See the Order of execution help file for a more detailed discussion of this important topic.

Bundling

Some of the methods below have two versions: a regular one which sends its corresponding message to the server immediately, and one which returns the message in an Array so that it can be added to a bundle. It is also possible to capture the messages generated by the regular methods using Server's automated bundling capabilities. See Server and Bundled Server Messages for more details.

Class Methods

Synth is a subclass of Node, and thus many of its most useful and important methods are documented in the Node help file.

Creation with Immediate Instantiation on the Server

Create and return a new Synth object, and immediately start the corresponding synth node on the server.

Arguments:

 defName A String or Symbol specifying the name of the SynthDef to use in creating the Synth. args An optional Array specifying initial values for the SynthDef's arguments (controls). These are specified in pairs of control name or index and value. If names are used they can be specified with either Strings or Symbols. e.g. [\frequency, 440, \amplitude, 1, ...]. Values that are arrays are sent using OSC array type-tags ($[ and$]). These values will be assigned to subsequent controls. target A target for this Synth. If target is not a Group or Synth, it will be converted as follows: If it is a Server, it will be converted to the default_group of that server. If it is nil, to the default_group of the default Server. If it is an integer, it is created relative to a group with that id. addAction one of the following Symbols: \addToHead(the default) add at the head of the group specified by target\addToTailadd at the tail of the group specified by target\addAfteradd immediately after target in its server's node order\addBeforeadd immediately before target in its server's node order\addReplacereplace target and take its place in its server's node order Note: A Synth is not a valid target for \addToHead and \addToTail.

Discussion:

s.boot;
// create a Synth at the head of the default Server's default group
// based on the SynthDef "default"
x = Synth.new("default");
s.queryAllNodes; // note the default group (ID 1)
x.free;

// Using an arrayed control
// run this block first to make the SynthDef
(
SynthDef("help-synth", {| freq = #[440, 450, 460], out = 0 |
Out.ar(out, Mix(SinOsc.ar(freq, 0, 0.1)));
)

// then this a short while later
x = Synth("help-synth", [freq: [500,501,510] ]);

x = Synth("help-synth", [freq: [500,501,510] ]);
x.set(\freq, [1,2,3] * 400 + [1,2,3], \out, 1);
x.set(\freq, [3] * 400 + [1,2,3], \out, 1);
x.free;

As new above, but creates a node which is paused. This can be started by calling run on it.

s.boot;
x = Synth.newPaused("default");
s.queryAllNodes; // see I'm here
x.run; // true is the default
x.run(false); // pause me again
x.free;

A convenience method which will create a synth node with an node ID of -1. Such a node cannot be messaged after creation. As such this method does not create an object, and returns nil. For details of its arguments see new above.

Returns:

nil

The following convenience methods correspond to the add actions of Synth.new :

*after (aNode, defName, args)

Create and return a Synth and add it immediately after aNode.

*before (aNode, defName, args)

Create and return a Synth and add it immediately before aNode.

Create and return a Synth. If aGroup is a Group add it at the head of that group. If it is a Server, add it at the head of the default_group of that server. If it is nil, add it at the head of the default_group of the default server. If it is an integer, it is created relative to a group with that id.

*tail (aGroup, defName, args)

Create and return a Synth. If aGroup is a Group add it at the tail of that group. If it is a Server, add it at the tail of the default_group of that server. If it is nil, add it at the tail of the default_group of the the default server. If it is an integer, it is created relative to a group with that id.

*replace (nodeToReplace, defName, args)

Create and return a Synth and use it to replace nodeToReplace, taking its place in its server's node order.

Creation without Instantiation on the Server

For use in message bundles it is also possible to create a Synth object in the client app without immediately creating a synth node on the server. Once done one can call methods which create messages to add to a bundle, which when sent to the server will instantiate the synth.

*basicNew (defName, server, nodeID)

Create and return a Synth object without creating a synth node on the server.

Arguments:

 defName A String or Symbol specifying the name of the SynthDef to use in creating the Synth. server An optional instance of Server. If nil this will default to the default Server. nodeID An optional node ID number. If not supplied one will be generated by the Server's NodeIDAllocator. Normally you should not need to supply an ID.

Discussion:

s.boot;
x = Synth.basicNew("default", s); // Create without sending
s.sendBundle(nil, x.newMsg;); // Now send a message; create at the head of s' default group
s.queryAllNodes;
x.free;

After creation, use instance methods newMsg, addToHeadMsg, addToTailMsg, addBeforeMsg, addAfterMsg, addReplaceMsg to instantiate this synth on the server. See Instance Methods below.

Instance Methods

Synth is a subclass of Node, and thus many of its most useful and important methods are documented in the Node help file.

-defName = value

Returns:

the name of this Synth's SynthDef.

Creation without Instantiation on the Server

Use class method basicNew to create a Synth without instantiating it on the server. Then use the following instance methods:

See *new above for details of addActions and args.

Returns:

a message of the type s_new which can be bundled. When sent to the server this message will instantiate this synth. If target is nil, it will default to the default_group of the Server specified in *basicNew when this Synth was created. The default addAction is \addToHead.

See *new above for details on args.

Returns:

a message of the type s_new which can be bundled. When sent to the server this message will instantiate this synth. If aGroup is a Group it will be added at the head of that group. If it is nil, it will be added at the head of the default_group of this Synth's server (as specified when *basicNew was called).

See *new above for details on args.

Returns:

a message of the type s_new which can be bundled. When sent to the server this message will instantiate this synth. If aGroup is a Group it will be added at the tail of that group. If it is nil, it will be added at the tail of the default_group of this Synth's server (as specified when *basicNew was called).

See *new above for details on args.

Returns:

a message of the type s_new which can be bundled. When sent to the server this message will instantiate this synth, immediately before aNode.

See *new above for details on args.

Returns:

a message of the type s_new which can be bundled. When sent to the server this message will instantiate this synth, immediately after aNode.

See *new above for details on args.

Returns:

a message of the type s_new which can be bundled. When sent to the server this message will instantiate this synth, replacing nodeToReplace in the server's node order.

Control

For further methods of controlling Synths (set, map, etc.), see the Node helpfile.

-getMsg (index)

Query the server for the current value of a Control (argument).

Arguments:

 index a control name or index (action) a Function which will be evaluated with the value passed as an argument when the reply is received.

Discussion:

s.boot;
(
SynthDef("help-Synth-get", { arg freq = 440;
Out.ar(0, SinOsc.ar(freq, 0, 0.1));
)
x = Synth("help-Synth-get");
x.set(\freq, 220 + 440.rand);
x.get(\freq, { arg value; ("freq is now:" + value + "Hz").postln; });
x.free;

-getnMsg (index, count)

Query the server for the current values of a sequential range of Controls (arguments).

Arguments:

 index a control name or index count the number of sequential controls to query, starting at index. (action) a Function which will be evaluated with an Array containing the values passed as an argument when the reply is received.

-set ( ... args)

From superclass: Node

Set the values of one or more Controls.

Discussion:

Example:

x.set(\freq, 440, \amp, 0.5)

-seti ( ... args)

Set part of an arrayed control.

Arguments:

 ... args A sequence of name, index, value triplets. nameThe name of the arrayed controlindexThe index into the arrayvalueThe new value to set, can be an array to set a range of elements.

Discussion:

NOTE: The synthdef has to be .add'ed, so that it is stored in the SynthDescLib.

Example:

(
s.waitForBoot {
SynthDef(\helpSeti, { |freqs = #[100,150,200,250]|
Out.ar(0, SinOsc.ar(freqs.poll,0,0.1).sum ! 2)
s.sync;
x = Synth(\helpSeti);
}
)
x.seti(\freqs,2,600); // set only the third element
x.seti(\freqs,1,[400,410]); // set second and third element
x.free;

Examples

// boot the default server
s = Server.default; // just to be sure
s.boot;

(
// send a synth def to server
SynthDef("tpulse", { arg out = 0,freq = 700, sawFreq = 440.0;
Out.ar(out, SyncSaw.ar(freq, sawFreq, 0.1));
)

// Here the defaults for *new will result in a Synth at the head of the default group
// of the default Server. This will use the SynthDef's default arguments;
y = Synth.new("tpulse");
y.free;

// The same done explicitly
y.free;

// With some arguments
y = Synth.new("tpulse", [\freq, 350, \sawFreq, 220]);
y.free;

// make a new synth
y = Synth("tpulse");

// pause
y.run(false);

y.run(true);

// set a control by argument name
y.set("freq", 200);

// or by index
y.set(2, 100.0);

// modulate out to bus number 1 (the right speaker)
y.set(0, 1);

//  multiple set commands in one message
y.set("out", 0, "freq",300);

// free the synth from the server
y.free;

Filtering

(
// first collect some things to play with
SynthDef("moto-rev", { arg out=0;
var x;
x = RLPF.ar(LFPulse.ar(SinOsc.kr(0.2, 0, 10, 21), [0,0.1], 0.1),
100, 0.1).clip2(0.4);
Out.ar(out, x);

SynthDef("bubbles", { arg out=0;
var f, zout;
f = LFSaw.kr(0.4, 0, 24, LFSaw.kr([8,7.23], 0, 3, 80)).midicps;
zout = CombN.ar(SinOsc.ar(f, 0, 0.04), 0.2, 0.2, 4); // echoing sine wave
Out.ar(out, zout);

SynthDef("rlpf",{ arg out=0,ffreq=600,rq=0.1;
ReplaceOut.ar( out, RLPF.ar( In.ar(out), ffreq,rq) )

SynthDef("wah", { arg out, rate = 1.5, cfreq = 1400, mfreq = 1200, rq=0.1;
var zin, zout;

zin = In.ar(out, 2);
cfreq = Lag3.kr(cfreq, 0.1);
mfreq = Lag3.kr(mfreq, 0.1);
rq   = Ramp.kr(rq, 0.1);
zout = RLPF.ar(zin, LFNoise1.kr(rate, mfreq, cfreq), rq, 10).distort
* 0.15;

// replace the incoming bus with the effected version
ReplaceOut.ar( out , zout );

SynthDef("modulate",{ arg out = 0, freq = 1, center = 440, plusMinus = 110;
Out.kr(out, SinOsc.kr(freq, 0, plusMinus, center));
)

// execute these one at a time

// y is playing on bus 0
y = Synth("moto-rev",["out",0]);

// z is reading from bus 0 and replacing that; It must be *after* y
z = Synth.after(y,"wah",["out",0]);

// stop the wah-ing
z.run(false);

// resume the wah-ing
z.run(true);

// add a rlpf after that, reading and writing to the same buss
x = Synth.after(z,"rlpf",["out",0]);

// create another rlpf after x
t = Synth.after(x,"rlpf",["out",0]);

x.set("ffreq", 400);

x.set(\ffreq, 800); // Symbols work for control names too

// Now let's modulate x's ffreq arg
// First get a control Bus
b = Bus.control(s, 1);

// now the modulator, *before* x
m = Synth.before(x, "modulate", [\out, b]);

// now map x's ffreq to b
x.map("ffreq", b);

m.set("freq", 4, "plusMinus", 20);

x.free;
z.free;
m.free;

// now place another synth after y, on the same bus
// they both write to the buss, adding their outputs
r = Synth.after(y,"bubbles",["out",0]);

y.free;

r.free;

// look at the Server window
// still see 4 Ugens and 1 synth?
// you can't hear me, but don't forget to free me
t.free;