Parameter control envelopes are a fundamental part of electronic sound production. Mooog's adsr() method allows
you to easily apply the traditional A(ttack) D(elay) S(ustain) R(elease) envelope to any AudioParam. You
specify a base value, a peak attack value, a sustain value, and an array of durations for the phases of the envelope.
times array and
only the attack, delay, and sustain portions of the envelope will be produced. You'll then need to use one of
the other ramping functions to terminate the envelope when appropriate – remembering to set from_now:
true or the ramps will be calculated beginning at the previously scheduled event instead of the time
you callparam().
M = new Mooog();
M.track( "osc",
{ id: "saw", node_type: "Oscillator", type: "sawtooth" },
{ id: "filter", node_type: "BiquadFilter", frequency: 300, Q: 30 },
{ id: "amplitude", node_type: "Gain", gain: 0 }
);
M.node('saw').start();
$(document)
.on("mousedown", ".adsr1", function(){
M.node("filter").adsr( "frequency", { base: 300, a: 10000, s:2500, times: [0.5, 0.5, 0, 3] } );
M.node("amplitude").adsr( "gain", { base: 0, a: 1, s: 0.7, times: [0.1, 0.9, 0, 3] } );
})
.on("mousedown", ".adsr2", function(){
M.node("filter").adsr( "frequency", { base: 300, a: 10000, s:2500, times: [0.5, 0.5] } );
M.node("amplitude").adsr( "gain", { base: 0, a: 1, s: 0.7, times: [0.1, 0.9] } );
})
.on("mouseup", ".adsr2", function(){
M.node("filter").param( { frequency: 300, at: 3, ramp: "expo", from_now: true } );
M.node("amplitude").param( { gain: 0, at: 3, ramp: "expo", from_now: true } );
})
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For more information, see the section on browser support.