Tone.js/Tone/core/Param.js

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9.7 KiB
JavaScript

define(["Tone/core/Tone", "Tone/type/Type"], function(Tone){
"use strict";
/**
* @class Tone.Param wraps the native Web Audio's AudioParam to provide
* additional unit conversion functionality. It also
* serves as a base-class for classes which have a single,
* automatable parameter.
* @extends {Tone}
* @param {AudioParam} param The parameter to wrap.
* @param {Tone.Type} units The units of the audio param.
* @param {Boolean} convert If the param should be converted.
*/
Tone.Param = function(){
var options = this.optionsObject(arguments, ["param", "units", "convert"], Tone.Param.defaults);
/**
* The native parameter to control
* @type {AudioParam}
* @private
*/
this._param = this.input = options.param;
/**
* The units of the parameter
* @type {Tone.Type}
*/
this.units = options.units;
/**
* If the value should be converted or not
* @type {Boolean}
*/
this.convert = options.convert;
/**
* True if the signal value is being overridden by
* a connected signal.
* @readOnly
* @type {boolean}
* @private
*/
this.overridden = false;
if (!this.isUndef(options.value)){
this.value = options.value;
}
};
Tone.extend(Tone.Param);
/**
* Defaults
* @type {Object}
* @const
*/
Tone.Param.defaults = {
"units" : Tone.Type.Default,
"convert" : true,
"param" : undefined
};
/**
* The current value of the parameter.
* @memberOf Tone.Param#
* @type {Number}
* @name value
*/
Object.defineProperty(Tone.Param.prototype, "value", {
get : function(){
return this._toUnits(this._param.value);
},
set : function(value){
var convertedVal = this._fromUnits(value);
this._param.cancelScheduledValues(0);
this._param.value = convertedVal;
}
});
/**
* Convert the given value from the type specified by Tone.Param.units
* into the destination value (such as Gain or Frequency).
* @private
* @param {*} val the value to convert
* @return {number} the number which the value should be set to
*/
Tone.Param.prototype._fromUnits = function(val){
if (this.convert || this.isUndef(this.convert)){
switch(this.units){
case Tone.Type.Time:
return this.toSeconds(val);
case Tone.Type.Frequency:
return this.toFrequency(val);
case Tone.Type.Decibels:
return this.dbToGain(val);
case Tone.Type.NormalRange:
return Math.min(Math.max(val, 0), 1);
case Tone.Type.AudioRange:
return Math.min(Math.max(val, -1), 1);
case Tone.Type.Positive:
return Math.max(val, 0);
default:
return val;
}
} else {
return val;
}
};
/**
* Convert the parameters value into the units specified by Tone.Param.units.
* @private
* @param {number} val the value to convert
* @return {number}
*/
Tone.Param.prototype._toUnits = function(val){
if (this.convert || this.isUndef(this.convert)){
switch(this.units){
case Tone.Type.Decibels:
return this.gainToDb(val);
default:
return val;
}
} else {
return val;
}
};
/**
* the minimum output value
* @type {Number}
* @private
*/
Tone.Param.prototype._minOutput = 0.00001;
/**
* Schedules a parameter value change at the given time.
* @param {*} value The value to set the signal.
* @param {Time} time The time when the change should occur.
* @returns {Tone.Param} this
* @example
* //set the frequency to "G4" in exactly 1 second from now.
* freq.setValueAtTime("G4", "+1");
*/
Tone.Param.prototype.setValueAtTime = function(value, time){
value = this._fromUnits(value);
this._param.setValueAtTime(value, this.toSeconds(time));
return this;
};
/**
* Creates a schedule point with the current value at the current time.
* This is useful for creating an automation anchor point in order to
* schedule changes from the current value.
*
* @param {number=} now (Optionally) pass the now value in.
* @returns {Tone.Param} this
*/
Tone.Param.prototype.setRampPoint = function(now){
now = this.defaultArg(now, this.now());
var currentVal = this._param.value;
// exponentialRampToValueAt cannot ever ramp from or to 0
// More info: https://bugzilla.mozilla.org/show_bug.cgi?id=1125600#c2
if (currentVal === 0){
currentVal = this._minOutput;
}
this._param.setValueAtTime(currentVal, now);
return this;
};
/**
* Schedules a linear continuous change in parameter value from the
* previous scheduled parameter value to the given value.
*
* @param {number} value
* @param {Time} endTime
* @returns {Tone.Param} this
*/
Tone.Param.prototype.linearRampToValueAtTime = function(value, endTime){
value = this._fromUnits(value);
this._param.linearRampToValueAtTime(value, this.toSeconds(endTime));
return this;
};
/**
* Schedules an exponential continuous change in parameter value from
* the previous scheduled parameter value to the given value.
*
* @param {number} value
* @param {Time} endTime
* @returns {Tone.Param} this
*/
Tone.Param.prototype.exponentialRampToValueAtTime = function(value, endTime){
value = this._fromUnits(value);
value = Math.max(this._minOutput, value);
this._param.exponentialRampToValueAtTime(value, this.toSeconds(endTime));
return this;
};
/**
* Schedules an exponential continuous change in parameter value from
* the current time and current value to the given value over the
* duration of the rampTime.
*
* @param {number} value The value to ramp to.
* @param {Time} rampTime the time that it takes the
* value to ramp from it's current value
* @param {Time} [startTime=now] When the ramp should start.
* @returns {Tone.Param} this
* @example
* //exponentially ramp to the value 2 over 4 seconds.
* signal.exponentialRampToValue(2, 4);
*/
Tone.Param.prototype.exponentialRampToValue = function(value, rampTime, startTime){
startTime = this.toSeconds(startTime);
this.setRampPoint(startTime);
this.exponentialRampToValueAtTime(value, startTime + this.toSeconds(rampTime));
return this;
};
/**
* Schedules an linear continuous change in parameter value from
* the current time and current value to the given value over the
* duration of the rampTime.
*
* @param {number} value The value to ramp to.
* @param {Time} rampTime the time that it takes the
* value to ramp from it's current value
* @param {Time} [startTime=now] When the ramp should start.
* @returns {Tone.Param} this
* @example
* //linearly ramp to the value 4 over 3 seconds.
* signal.linearRampToValue(4, 3);
*/
Tone.Param.prototype.linearRampToValue = function(value, rampTime, startTime){
startTime = this.toSeconds(startTime);
this.setRampPoint(startTime);
this.linearRampToValueAtTime(value, startTime + this.toSeconds(rampTime));
return this;
};
/**
* Start exponentially approaching the target value at the given time with
* a rate having the given time constant.
* @param {number} value
* @param {Time} startTime
* @param {number} timeConstant
* @returns {Tone.Param} this
*/
Tone.Param.prototype.setTargetAtTime = function(value, startTime, timeConstant){
value = this._fromUnits(value);
// The value will never be able to approach without timeConstant > 0.
// http://www.w3.org/TR/webaudio/#dfn-setTargetAtTime, where the equation
// is described. 0 results in a division by 0.
value = Math.max(this._minOutput, value);
timeConstant = Math.max(this._minOutput, timeConstant);
this._param.setTargetAtTime(value, this.toSeconds(startTime), timeConstant);
return this;
};
/**
* Sets an array of arbitrary parameter values starting at the given time
* for the given duration.
*
* @param {Array} values
* @param {Time} startTime
* @param {Time} duration
* @returns {Tone.Param} this
*/
Tone.Param.prototype.setValueCurveAtTime = function(values, startTime, duration){
for (var i = 0; i < values.length; i++){
values[i] = this._fromUnits(values[i]);
}
this._param.setValueCurveAtTime(values, this.toSeconds(startTime), this.toSeconds(duration));
return this;
};
/**
* Cancels all scheduled parameter changes with times greater than or
* equal to startTime.
*
* @param {Time} startTime
* @returns {Tone.Param} this
*/
Tone.Param.prototype.cancelScheduledValues = function(startTime){
this._param.cancelScheduledValues(this.toSeconds(startTime));
return this;
};
/**
* Ramps to the given value over the duration of the rampTime.
* Automatically selects the best ramp type (exponential or linear)
* depending on the `units` of the signal
*
* @param {number} value
* @param {Time} rampTime The time that it takes the
* value to ramp from it's current value
* @param {Time} [startTime=now] When the ramp should start.
* @returns {Tone.Param} this
* @example
* //ramp to the value either linearly or exponentially
* //depending on the "units" value of the signal
* signal.rampTo(0, 10);
* @example
* //schedule it to ramp starting at a specific time
* signal.rampTo(0, 10, 5)
*/
Tone.Param.prototype.rampTo = function(value, rampTime, startTime){
rampTime = this.defaultArg(rampTime, 0);
if (this.units === Tone.Type.Frequency || this.units === Tone.Type.BPM || this.units === Tone.Type.Decibels){
this.exponentialRampToValue(value, rampTime, startTime);
} else {
this.linearRampToValue(value, rampTime, startTime);
}
return this;
};
/**
* Clean up
* @returns {Tone.Param} this
*/
Tone.Param.prototype.dispose = function(){
Tone.prototype.dispose.call(this);
this._param = null;
return this;
};
return Tone.Param;
});