kuu/wa1

## wa1
<!DOCTYPE html>
<html>
  <head>
    <meta charset="utf-8">
    <meta name="viewport" content="width=device-width,initial-scale=1.0,maximum-scale=1.0,minimum-scale=1.0,user-scalable=yes" />
  </head>
  <body>
    <button id="loadBtn">Load</button>
    <button id="playBtn">Play</button>
    <button id="Up">Up</button>
    <button id="Down">Down</button>
    <div id="Message"></div>
    <script>
      document.addEventListener("DOMContentLoaded", function() {
        var tLoadButton = document.getElementById('loadBtn');
        var tPlayButton = document.getElementById('playBtn');
        var tUpButton = document.getElementById('Up');
        var tDownButton = document.getElementById('Down');
        var tMessage = document.getElementById('Message');

        var AudioContext = window.AudioContext || window.webkitAudioContext;
        if (!AudioContext) {
          tMessage.innerHTML = 'Web Audio API is not supported.';
        }
        var tContext = new AudioContext();
        var tBuffer = null;
        var tSource, tStartTime, tPlayedTime = 0, tOffset = 5.5;
        var tGain = tContext.createGainNode();
        tGain.connect(tContext.destination);

        tLoadButton.addEventListener('click', function () {
          var tXHR = new XMLHttpRequest();
          tXHR.open('GET', 'bgm.mp3');
          tXHR.responseType = 'arraybuffer';

          tXHR.onreadystatechange = function() {
            if (tXHR.readyState === 4 && tXHR.status === 200) {
              tContext.decodeAudioData(
                tXHR.response,
                function (pAudioBuffer) {
                  console.log('decode success');
                  tBuffer = pAudioBuffer;
                },
                function () {
                  console.log('decode failure');
                }
              );
            }
          };
          tXHR.send();
        }, false);

        tPlayButton.addEventListener('click', function (e) {

          if (e.target.innerHTML === 'Play') {
            tSource = tContext.createBufferSource();
            tSource.buffer = tBuffer;
            tSource.connect(tGain);
            tStartTime = tContext.currentTime;
            if (tSource.start) {
              tSource.start(0, tOffset);
            } else {
              tSource.noteGrainOn(0, tOffset, tBuffer.duration);
            }
            e.target.innerHTML = 'Pause';
          } else {
            tPlayedTime = tContext.currentTime - tStartTime;
            tOffset += tPlayedTime;
            tSource.disconnect(tGain);
            tSource = null;
            e.target.innerHTML = 'Play';
          }
        }, false);

        tUpButton.addEventListener('click', function () {
          var tVol = tGain.gain.value + 0.1;
          if (tVol <= 1) {
            tGain.gain.value = tVol;
          }
        }, false);

        tDownButton.addEventListener('click', function () {
          var tVol = tGain.gain.value - 0.1;
          if (tVol >= 0) {
            tGain.gain.value = tVol;
          }
        }, false);

      }, false);
    </script>
  </body>
</html>
	<!DOCTYPE html>
	<html>
	<head>
	<meta charset="utf-8">
	<meta name="viewport" content="width=device-width,initial-scale=1.0,maximum-scale=1.0,minimum-scale=1.0,user-scalable=yes" />
	</head>
	<body>
	<button id="loadBtn">Load</button>
	<button id="playBtn">Play</button>
	<button id="Up">Up</button>
	<button id="Down">Down</button>
	<div id="Message"></div>
	<script>
	document.addEventListener("DOMContentLoaded", function() {
	var tLoadButton = document.getElementById('loadBtn');
	var tPlayButton = document.getElementById('playBtn');
	var tUpButton = document.getElementById('Up');
	var tDownButton = document.getElementById('Down');
	var tMessage = document.getElementById('Message');

	var AudioContext = window.AudioContext \|\| window.webkitAudioContext;
	if (!AudioContext) {
	tMessage.innerHTML = 'Web Audio API is not supported.';
	}
	var tContext = new AudioContext();
	var tBuffer = null;
	var tSource, tStartTime, tPlayedTime = 0, tOffset = 5.5;
	var tGain = tContext.createGainNode();
	tGain.connect(tContext.destination);

	tLoadButton.addEventListener('click', function () {
	var tXHR = new XMLHttpRequest();
	tXHR.open('GET', 'bgm.mp3');
	tXHR.responseType = 'arraybuffer';

	tXHR.onreadystatechange = function() {
	if (tXHR.readyState === 4 && tXHR.status === 200) {
	tContext.decodeAudioData(
	tXHR.response,
	function (pAudioBuffer) {
	console.log('decode success');
	tBuffer = pAudioBuffer;
	},
	function () {
	console.log('decode failure');
	}
	);
	}
	};
	tXHR.send();
	}, false);

	tPlayButton.addEventListener('click', function (e) {

	if (e.target.innerHTML === 'Play') {
	tSource = tContext.createBufferSource();
	tSource.buffer = tBuffer;
	tSource.connect(tGain);
	tStartTime = tContext.currentTime;
	if (tSource.start) {
	tSource.start(0, tOffset);
	} else {
	tSource.noteGrainOn(0, tOffset, tBuffer.duration);
	}
	e.target.innerHTML = 'Pause';
	} else {
	tPlayedTime = tContext.currentTime - tStartTime;
	tOffset += tPlayedTime;
	tSource.disconnect(tGain);
	tSource = null;
	e.target.innerHTML = 'Play';
	}
	}, false);

	tUpButton.addEventListener('click', function () {
	var tVol = tGain.gain.value + 0.1;
	if (tVol <= 1) {
	tGain.gain.value = tVol;
	}
	}, false);

	tDownButton.addEventListener('click', function () {
	var tVol = tGain.gain.value - 0.1;
	if (tVol >= 0) {
	tGain.gain.value = tVol;
	}
	}, false);

	}, false);
	</script>
	</body>
	</html>