first app vibe

app/node_modules/three/src/audio/AudioAnalyser.js

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+/**
+ * This class can be used to analyse audio data.
+ *
+ * ```js
+ * // create an AudioListener and add it to the camera
+ * const listener = new THREE.AudioListener();
+ * camera.add( listener );
+ *
+ * // create an Audio source
+ * const sound = new THREE.Audio( listener );
+ *
+ * // load a sound and set it as the Audio object's buffer
+ * const audioLoader = new THREE.AudioLoader();
+ * audioLoader.load( 'sounds/ambient.ogg', function( buffer ) {
+ * 	sound.setBuffer( buffer );
+ * 	sound.setLoop(true);
+ * 	sound.setVolume(0.5);
+ * 	sound.play();
+ * });
+ *
+ * // create an AudioAnalyser, passing in the sound and desired fftSize
+ * const analyser = new THREE.AudioAnalyser( sound, 32 );
+ *
+ * // get the average frequency of the sound
+ * const data = analyser.getAverageFrequency();
+ * ```
+ */
+class AudioAnalyser {
+
+	/**
+	 * Constructs a new audio analyzer.
+	 *
+	 * @param {Audio} audio - The audio to analyze.
+	 * @param {number} [fftSize=2048] - The window size in samples that is used when performing a Fast Fourier Transform (FFT) to get frequency domain data.
+	 */
+	constructor( audio, fftSize = 2048 ) {
+
+		/**
+		 * The global audio listener.
+		 *
+		 * @type {AnalyserNode}
+		 */
+		this.analyser = audio.context.createAnalyser();
+		this.analyser.fftSize = fftSize;
+
+		/**
+		 * Holds the analyzed data.
+		 *
+		 * @type {Uint8Array}
+		 */
+		this.data = new Uint8Array( this.analyser.frequencyBinCount );
+
+		audio.getOutput().connect( this.analyser );
+
+	}
+
+	/**
+	 * Returns an array with frequency data of the audio.
+	 *
+	 * Each item in the array represents the decibel value for a specific frequency.
+	 * The frequencies are spread linearly from 0 to 1/2 of the sample rate.
+	 * For example, for 48000 sample rate, the last item of the array will represent
+	 * the decibel value for 24000 Hz.
+	 *
+	 * @return {Uint8Array} The frequency data.
+	 */
+	getFrequencyData() {
+
+		this.analyser.getByteFrequencyData( this.data );
+
+		return this.data;
+
+	}
+
+	/**
+	 * Returns the average of the frequencies returned by {@link AudioAnalyser#getFrequencyData}.
+	 *
+	 * @return {number} The average frequency.
+	 */
+	getAverageFrequency() {
+
+		let value = 0;
+		const data = this.getFrequencyData();
+
+		for ( let i = 0; i < data.length; i ++ ) {
+
+			value += data[ i ];
+
+		}
+
+		return value / data.length;
+
+	}
+
+}
+
+export { AudioAnalyser };