-
Notifications
You must be signed in to change notification settings - Fork 1
/
spectrum.html
285 lines (265 loc) · 9.29 KB
/
spectrum.html
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
<html>
<head>
<title>canvasPlot.js spectrum analyzer example</title>
<link rel="stylesheet" type="text/css" href="style.css">
<script src="canvasPlot.js" type="text/javascript"></script>
<script src="mapLinear.js" type="text/javascript"></script>
<script src="mapSemiLogX.js" type="text/javascript"></script>
<script src="curveDrawerLinear.js" type="text/javascript"></script>
<script src="simplePlot.js" type="text/javascript"></script>
<script src="super.js" type="text/javascript"></script>
<script src="frameOffscreen.js" type="text/javascript"></script>
<script src="gridOffscreen.js" type="text/javascript"></script>
<script src="gridAutoLinear.js" type="text/javascript"></script>
<script src="gridAutoSemiLogX.js" type="text/javascript"></script>
<script src="gridAutoLinearOffscreen.js" type="text/javascript"></script>
<script src="gridAutoSemiLogXOffscreen.js" type="text/javascript"></script>
<script src="simplePlotOffscreen.js" type="text/javascript"></script>
<script src="canvasStretch.js" type="text/javascript"></script>
<script src="spectrumAnalyserSignal.js" type="text/javascript"></script>
<script src="simpleSpectrumAnalyser.js" type="text/javascript"></script>
<script src="simpleSpectrumAnalyserWidget.js" type="text/javascript"></script>
<script src="interpolateLinear.js" type="text/javascript"></script>
<script type="text/javascript">
function init() {
var audioCtx = new (window.AudioContext || window.webkitAudioContext)();
var osc = audioCtx.createOscillator();
var gainIn = audioCtx.createGain();
var analyser = audioCtx.createAnalyser();
var gainOut = audioCtx.createGain();
osc.connect(gainIn);
gainIn.connect(analyser);
analyser.connect(gainOut);
gainOut.connect(audioCtx.destination);
var canvas = document.getElementById("canvas");
var samples = Object.create(canvasPlot.samples);
samples.init(new Float32Array(16384), new Float32Array(16384));
var signal = Object.create(canvasPlot.spectrumAnalyserSignal);
signal.init(samples, null);
signal.analyser = analyser;
signal.updateAnalyser();
var sa = Object.create(canvasPlot.simpleSpectrumAnalyserWidget);
sa.init(canvas, null, [signal], null, null,
Object.create(canvasPlot.curveDrawerLinear));
function setValElement(name) {
var elem = document.getElementById(name);
elem.valElement = document.getElementById(name + "_val");
if (elem.valElement.innerHTML != elem.value)
elem.valElement.innerHTML = elem.value;
return elem;
}
var frequency_elem = setValElement("frequency");
var x1_elem = setValElement("x1");
var x2_elem = setValElement("x2");
var y1_elem = setValElement("y1");
var y2_elem = setValElement("y2");
var points_elem = setValElement("points");
var volume_in_elem = setValElement("volume_in");
var volume_out_elem = setValElement("volume_out");
osc.frequency.value = parseFloat(frequency_elem.value);
sa.spectrumAnalyser.xRange.min = parseFloat(x1_elem.value);
sa.spectrumAnalyser.xRange.max = parseFloat(x2_elem.value);
sa.spectrumAnalyser.yRange.min = parseFloat(y1_elem.value);
sa.spectrumAnalyser.yRange.max = parseFloat(y2_elem.value);
sa.spectrumAnalyser.points = parseInt(points_elem.value);
gainIn.gain.value = parseFloat(volume_in_elem.value) * 0.01;
gainOut.gain.value = parseFloat(volume_out_elem.value) * 0.01;
function xaxis_change () {
sa.spectrumAnalyser.linearMap = this.value == "linear";
sa.update(false);
}
var xaxis_elems = document.getElementsByName("xaxis");
for (var i = 0; i < xaxis_elems.length; i++) {
xaxis_elems[i].addEventListener("change", xaxis_change);
if (xaxis_elems[i].checked)
sa.spectrumAnalyser.linearMap =
xaxis_elems[i].value == "linear";
}
function grid_change () {
sa.spectrumAnalyser.showGrid = this.value == "visible";
sa.update(false);
}
var grid_elems = document.getElementsByName("grid");
for (var i = 0; i < grid_elems.length; i++) {
grid_elems[i].addEventListener("change", grid_change);
if (grid_elems[i].checked)
sa.spectrumAnalyser.showGrid =
grid_elems[i].value == "visible";
}
function interpolation_change () {
sa.spectrumAnalyser.interpolate =
this.value == "linear" ? canvasPlot.interpolateLinear
: null;
sa.update(false);
}
var interpolation_elems = document.getElementsByName("interpolation");
for (var i = 0; i < interpolation_elems.length; i++) {
interpolation_elems[i].addEventListener("change",
interpolation_change);
if (interpolation_elems[i].checked)
sa.spectrumAnalyser.interpolate =
interpolation_elems[i].value == "linear"
? canvasPlot.interpolateLinear : null;
}
function waveform_change () {
osc.type = this.value;
}
var waveform_elems = document.getElementsByName("waveform");
for (var i = 0; i < waveform_elems.length; i++) {
waveform_elems[i].addEventListener("change", waveform_change);
if (waveform_elems[i].checked)
osc.type = waveform_elems[i].value;
}
sa.update(false);
function input() {
if (this.valElement.innerHTML == this.value)
return;
this.valElement.innerHTML = this.value;
switch (this) {
case frequency_elem:
osc.frequency.value = parseFloat(this.value);
break;
case x1_elem:
sa.spectrumAnalyser.xRange.min =
parseFloat(this.value);
sa.update(false);
break;
case x2_elem:
sa.spectrumAnalyser.xRange.max =
parseFloat(this.value);
sa.update(false);
break;
case y1_elem:
sa.spectrumAnalyser.yRange.min =
parseFloat(this.value);
sa.update(false);
break;
case y2_elem:
sa.spectrumAnalyser.yRange.max =
parseFloat(this.value);
sa.update(false);
break;
case points_elem:
sa.spectrumAnalyser.points =
parseInt(this.value);
sa.update(false);
break;
case volume_in_elem:
gainIn.gain.value = parseFloat(this.value)
* 0.01;
break;
case volume_out_elem:
gainOut.gain.value = parseFloat(this.value)
* 0.01;
break;
}
}
frequency_elem.addEventListener("input", input);
x1_elem.addEventListener("input", input);
x2_elem.addEventListener("input", input);
y1_elem.addEventListener("input", input);
y2_elem.addEventListener("input", input);
points_elem.addEventListener("input", input);
volume_in_elem.addEventListener("input", input);
volume_out_elem.addEventListener("input", input);
osc.start();
var ctx = canvas.getContext("2d");
var lastTime;
var fps = 0;
function draw() {
requestAnimationFrame(draw);
sa.updateSignals();
ctx.clearRect(0, 0, canvas.width, canvas.height);
sa.draw();
var curTime = Date.now();
if (lastTime) {
fps = 0.1 * 1000 / (curTime - lastTime) + 0.9 * fps;
ctx.fillStyle = "black";
ctx.font = "16px sans";
ctx.fillText("FPS: " + fps.toFixed(2), 10, 26);
}
lastTime = curTime;
}
draw();
}
window.addEventListener("load", init);
</script>
</head>
<body>
<div class="canvas">
<canvas id="canvas"></canvas>
</div>
<form>
<div>
<label>x axis: </label>
<input type="radio" name="xaxis" value="logarithmic"/ checked> logarithmic
<input type="radio" name="xaxis" value="linear"/> linear
</div>
<div>
<label>grid: </label>
<input type="radio" name="grid" value="visible"/ checked> visible
<input type="radio" name="grid" value="invisible"/> invisible
</div>
<div>
<label for="x1">x1: </label>
<input type="range" id="x1" min="1" max="20000" step="0.1" value="20" />
<span id="x1_val">20</span>
<span>Hz</span>
</div>
<div>
<label for="x2">x2: </label>
<input type="range" id="x2" min="1" max="20000" step="0.1" value="20000" />
<span id="x2_val">20000</span>
<span>Hz</span>
</div>
<div>
<label for="y1">y1: </label>
<input type="range" id="y1" min="-200" max="0" step="1" value="-100" />
<span id="y1_val">-100</span>
<span>dB</span>
</div>
<div>
<label for="y2">y2: </label>
<input type="range" id="y2" min="-200" max="0" step="1" value="0" />
<span id="y2_val">0</span>
<span>dB</span>
</div>
<div>
<label>interpolation: </label>
<input type="radio" name="interpolation" value="linear"/ checked> linear
<input type="radio" name="interpolation" value="off"/> off
</div>
<div>
<label for="points">points: </label>
<input type="range" id="points" min="2" max="2000" step="1" value="1000" />
<span id="points_val">1000</span>
<span></span>
</div>
<div>
<label>waveform: </label>
<input type="radio" name="waveform" value="sine"/ checked> sine
<input type="radio" name="waveform" value="sawtooth"/> sawtooth
<input type="radio" name="waveform" value="square"/> square
<input type="radio" name="waveform" value="triangle"/> triangle
</div>
<div>
<label for="frequency">frequency: </label>
<input type="range" id="frequency" min="20" max="20000" step="0.1" value="440" />
<span id="frequency_val">440</span>
<span>Hz</span>
</div>
<div>
<label for="volume_in">volume in: </label>
<input type="range" id="volume_in" min="0" max="100" step="1" value="100" />
<span id="volume_in_val">100</span>
<span>%</span>
</div>
<div>
<label for="volume_out">volume out: </label>
<input type="range" id="volume_out" min="0" max="100" step="1" value="0" />
<span id="volume_out_val">0</span>
<span>%</span>
</div>
</form>
</body>
</html>