javascript - 使用键盘输入时 ToneJS 的性能滞后

Question

以下代码(https://codepen.io/anon/pen/JvoVxb)播放音高，但是，我发现它们“慢”或“粘”；如果您尝试与其他音乐一起演奏，您会听到它们有点滞后，并且很难掌握正确的节奏。

直接使用 WebAudio API 时，我还没有发现这种情况(我发现 QWERTY 键盘的性能几乎与数码钢琴一样好。)我想知道这是否是一个棘手的问题使用 ToneJS(以及为什么会发生这种情况？)...或者如果我在尝试使用它创建此功能时“做错了什么”。

    var keyToPitch = { " ":" ", "z":"C3", "s":"C#3", "x":"D3", "d":"D#3", "c":"E3", "v":"F3", "g":"F#3", "b":"G3", "h":"G#3", "n":"A3", "j":"A#3", "m":"B3", ",":"C4", "q":"C4", "2":"C#4", "w":"D4", "3":"D#4", "e":"E4", "r":"F4", "5":"F#4", "t":"G4", "6":"G#4", "y":"A4", "7":"A#4", "u":"B4", "i":"C5", "9":"C#5", "o":"D5", "0":"D#5", "p":"E5", "[":"F5", "=":"F#5", "]":"G5", "Backspace":"G#5", "\\":"A5" }

    var synth = new Tone.Synth()
    synth.oscillator.type = "sawtooth"
    synth.toMaster()

    window.addEventListener('keydown', this.onkeydown) 
    window.addEventListener('keyup', this.onkeyup) 

    // This is "slow", relative to WebAudio, it's not playing the pitch in a timely fashion...  
    function onkeydown(e){
        console.log(e.key)
        synth.triggerAttack(keyToPitch[e.key])      
    }
    function onkeyup(e){
        console.log(e.key)
        synth.triggerRelease()
    }

Answer 1

根据此处的问答:https://github.com/Tonejs/Tone.js/issues/306 ，可以通过传入 currentTime 来修复代码(而不是依赖于 Tone 的默认lookahead。)

function onkeydown(e){
    synth.triggerAttack(keyToPitch[e.key], Tone.context.currentTime)      
}