Skip to content

Ephemeral oscModulatorNode. #1

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Open
srikumarks wants to merge 1 commit into
base: master
Choose a base branch
from
Open

Ephemeral oscModulatorNode. #1

Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
123 changes: 63 additions & 60 deletions jsaModels/jsaFM.js
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -25,67 +25,52 @@ define(
var m_modIndex = 1.0;
var m_attackTime = 0.05;
var m_releaseTime = 1.0;
var stopTime = 0.0; // will be > audioContext.currentTime if playing
var now = 0.0;

// Create the nodes and thier connections. Runs once on load [Don't know why for jsaOc we have to call this on every play(), but not for this model!]
var buildModelArchitecture = (function () {
// These must be called on every play because of the tragically short lifetime ... however, after the
// they have actally been completely deleted - a reference to gainLevelNode, for example, still returns [object AudioGainNode]
oscModulatorNode = config.audioContext.createOscillator();
m_CarrierNode = fmodOscFactory();
gainEnvNode = config.audioContext.createGainNode();
gainLevelNode = config.audioContext.createGainNode();
// Setup the fixed nodes that the FM modulator node (oscModulatorNode)
// must connect to.
// -Kumar
// -- BEGIN FIXED SETUP --
m_CarrierNode = fmodOscFactory();
gainEnvNode = config.audioContext.createGainNode();
gainLevelNode = config.audioContext.createGainNode();

console.log("in BUILD, gain level node is " + gainLevelNode );
console.log("in BUILD, gain level node is " + gainLevelNode );

// Also have to set all of their state values since they all get forgotten, too!!
gainLevelNode.gain.value = m_gainLevel;
gainEnvNode.gain.value = 0;
oscModulatorNode.type = 0; //sin
// Also have to set all of their state values since they all get forgotten, too!!
gainLevelNode.gain.value = m_gainLevel;
gainEnvNode.gain.value = 0;

oscModulatorNode.frequency.value = m_mod_freq;
m_CarrierNode.setModIndex(m_modIndex);
m_CarrierNode.setModIndex(m_modIndex);

// make the graph connections
oscModulatorNode.connect(m_CarrierNode);
m_CarrierNode.connect(gainEnvNode);
// make the graph connections
m_CarrierNode.connect(gainEnvNode);

gainEnvNode.connect(gainLevelNode);

}());

// only the misbehaving oscModulatorNode needs to be rebuilt since it is invalidated by noteOff().
var buildModelArchitectureAGAIN = function () {
oscModulatorNode = config.audioContext.createOscillator();
oscModulatorNode.frequency.value = m_mod_freq;
oscModulatorNode.connect(m_CarrierNode);
};
gainEnvNode.connect(gainLevelNode);
// -- END FIXED SETUP --

var myInterface = baseSM({},[],[gainLevelNode]);
myInterface.setAboutText("This is a simple frequency modulator with a-rate updates of the carrier frequency.")

myInterface.play = function (i_freq, i_gain) {
now = config.audioContext.currentTime;

if (stopTime <= now) { // not playing
buildModelArchitectureAGAIN();
oscModulatorNode.noteOn(now);
gainEnvNode.gain.value = 0;
} else {
gainEnvNode.gain.cancelScheduledValues(now);
}
// The rest of the code is for new starts or restarts
stopTime = config.bigNum;
oscModulatorNode.noteOff(stopTime); // "cancels" any previously set future stops, I think

// if no input, remember from last time set
m_CarrierNode.setFreq(i_freq || m_car_freq);
gainLevelNode.gain.value = i_gain || m_gainLevel;

gainEnvNode.gain.setValueAtTime(0, now);
gainEnvNode.gain.linearRampToValueAtTime(gainLevelNode.gain.value, now + m_attackTime); // go to gain level over .1 secs

var now = config.audioContext.currentTime;

// The model uses an oscillator "voice" as the input that
// controls the fmodOsc. We make one of these on every play()
// and throw it away on every release(). Note that the
// rest of the graph is not remade.
// -Kumar
if (!oscModulatorNode) {
oscModulatorNode = config.audioContext.createOscillator();
oscModulatorNode.type = 0; //sin
oscModulatorNode.frequency.value = m_mod_freq;
oscModulatorNode.connect(m_CarrierNode);
oscModulatorNode.noteOn(now);
gainLevelNode.gain.value = m_gainLevel;

gainEnvNode.gain.cancelScheduledValues(now);
gainEnvNode.gain.setValueAtTime(0, now);
gainEnvNode.gain.linearRampToValueAtTime(gainLevelNode.gain.value, now + m_attackTime); // go to gain level over .1 secs
}

if (myInterface.getNumOutConnections() === 0){
console.log("connecting MyInterface to audio context desination");
Expand Down Expand Up @@ -130,7 +115,11 @@ define(
"val": m_mod_freq
},
function (i_val) {
oscModulatorNode.frequency.value = m_mod_freq = i_val;
// Only allow control during the active period
// -Kumar
if (oscModulatorNode) {
oscModulatorNode.frequency.value = m_mod_freq = i_val;
}
}
);

Expand Down Expand Up @@ -174,16 +163,30 @@ define(
);

myInterface.release = function () {
now = config.audioContext.currentTime;
stopTime = now + m_releaseTime;

gainEnvNode.gain.cancelScheduledValues(now);
gainEnvNode.gain.setValueAtTime(gainEnvNode.gain.value, now );
gainEnvNode.gain.linearRampToValueAtTime(0, stopTime);
oscModulatorNode.noteOff(stopTime);
};
if (oscModulatorNode) {
// Good to keep these local variables instead of
// common model ones
// -Kumar
var now = config.audioContext.currentTime;
var stopTime = now + m_releaseTime;

gainEnvNode.gain.cancelScheduledValues(now);
gainEnvNode.gain.setValueAtTime(gainEnvNode.gain.value, now );
gainEnvNode.gain.linearRampToValueAtTime(0, stopTime);

// Schedule the osc node to turn off at the stop
// time and forget about the node. I think noteOff()
// can only be called once, based on an earlier discussion
// with Chris Rogers. So it is much simpler to just
// giveup the reference to the "voice" once you
// schedule a noteOff for it.
// -Kumar
oscModulatorNode.noteOff(stopTime);
oscModulatorNode = null;
}
};

return myInterface;
};
}
);
);