带有键盘条目的ToneJS的性能滞后

Question

跟随代码( https://codepen.io/anon/pen/JvoVxb )播放音高，然而，我发现它们是“慢的”或“粘稠的”；如果你试着和其他音乐一起演奏，你会听到它们有点滞后，很难使节奏正确。

在直接使用WebAudio API时，我还没有发现这种情况(在这里，我发现QWERTY-键盘性能几乎与数字钢琴一样好)。我想知道这是否是ToneJS的一个棘手的问题(为什么会发生？)或者，如果我在尝试用它创建这个功能时“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

根据这里的Q&A：https://github.com/Tonejs/Tone.js/issues/306，代码可以通过传入currentTime来修复(而不是依赖音调的默认lookahead)。

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