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我正在尝试创建一个“每分钟节拍”(BPM)计算器,与您可以找到的一个相同(现在)为here。但出于某种原因,当我在测试歌曲的该链接上使用BPM计算器时,它会在7个按键中的实际值85.94之内获得1 BPM,并且从那里得到更准确的结果,在实际BPM的0.05内结束,而我的(基本上是同一编码的)Vue.js版本,它开始高得多(182 - > 126 - > 110)并从那里下降,但即使在60个按键后它仍然偏离了〜2 BPM,并且在一首完整的歌曲,它仍然约0.37 BPM。Vue.js计时计算不匹配普通JavaScript版本
下面的代码为the plain-JavaScript version at that link:
var count = 0;
var msecsFirst = 0;
var msecsPrevious = 0;
function ResetCount()
{
count = 0;
document.TAP_DISPLAY.T_AVG.value = "";
document.TAP_DISPLAY.T_TAP.value = "";
document.TAP_DISPLAY.T_RESET.blur();
}
function TapForBPM(e)
{
document.TAP_DISPLAY.T_WAIT.blur();
timeSeconds = new Date;
msecs = timeSeconds.getTime();
if ((msecs - msecsPrevious) > 1000 * document.TAP_DISPLAY.T_WAIT.value)
{
count = 0;
}
if (count == 0)
{
document.TAP_DISPLAY.T_AVG.value = "First Beat";
document.TAP_DISPLAY.T_TAP.value = "First Beat";
msecsFirst = msecs;
count = 1;
}
else
{
bpmAvg = 60000 * count/(msecs - msecsFirst);
document.TAP_DISPLAY.T_AVG.value = Math.round(bpmAvg * 100)/100;
document.TAP_DISPLAY.T_WHOLE.value = Math.round(bpmAvg);
count++;
document.TAP_DISPLAY.T_TAP.value = count;
}
msecsPrevious = msecs;
return true;
}
document.onkeypress = TapForBPM;
// End -->
这是我的版本:
computed: {
tappedOutBpm: function() {
let totalElapsedSeconds = (this.timeOfLastBpmKeypress - this.timeOfFirstBpmKeypress)/1000.0
let bpm = (this.numberOfTapsForBpm/totalElapsedSeconds) * 60.0
return Math.round(100*bpm)/100;
},
},
methods: {
tapForBPM: function() {
let now = new Date;
now = now.getTime();
// let now = window.performance.now()
if (this.timeOfFirstBpmKeypress === 0 || now - this.timeOfLastBpmKeypress > 5000) {
this.timeOfFirstBpmKeypress = now
this.timeOfLastBpmKeypress = now
this.numberOfTapsForBpm = 1
} else {
this.timeOfLastBpmKeypress = now
this.numberOfTapsForBpm++
}
}
}