138 lines
3.4 KiB
Haxe
138 lines
3.4 KiB
Haxe
package kha.audio2;
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import kha.arrays.Float32Array;
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class ResamplingAudioChannel extends AudioChannel {
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public var sampleRate: Int;
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public function new(looping: Bool, sampleRate: Int) {
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super(looping);
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this.sampleRate = sampleRate;
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}
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public override function nextSamples(requestedSamples: Float32Array, requestedLength: Int, sampleRate: Int): Void {
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if (paused || stopped) {
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for (i in 0...requestedLength) {
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requestedSamples[i] = 0;
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}
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return;
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}
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var requestedSamplesIndex = 0;
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while (requestedSamplesIndex < requestedLength) {
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for (i in 0...min(sampleLength(sampleRate) - myPosition, requestedLength - requestedSamplesIndex)) {
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requestedSamples[requestedSamplesIndex++] = sample(myPosition++, sampleRate);
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}
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if (myPosition >= sampleLength(sampleRate)) {
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myPosition = 0;
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if (!looping) {
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stopped = true;
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break;
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}
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}
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}
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while (requestedSamplesIndex < requestedLength) {
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requestedSamples[requestedSamplesIndex++] = 0;
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}
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}
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inline function sample(position: Int, sampleRate: Int): Float {
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var even = position % 2 == 0;
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var factor = this.sampleRate / sampleRate;
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if (even) {
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position = Std.int(position / 2);
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var pos = factor * position;
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var pos1 = Math.floor(pos);
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var pos2 = Math.floor(pos + 1);
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pos1 *= 2;
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pos2 *= 2;
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var minimum = 0;
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var maximum = data.length - 1;
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maximum = maximum % 2 == 0 ? maximum : maximum - 1;
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var a = (pos1 < minimum || pos1 > maximum) ? 0 : data[pos1];
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var b = (pos2 < minimum || pos2 > maximum) ? 0 : data[pos2];
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return lerp(a, b, pos - Math.floor(pos));
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}
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else {
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position = Std.int(position / 2);
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var pos = factor * position;
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var pos1 = Math.floor(pos);
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var pos2 = Math.floor(pos + 1);
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pos1 = pos1 * 2 + 1;
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pos2 = pos2 * 2 + 1;
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var minimum = 1;
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var maximum = data.length - 1;
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maximum = maximum % 2 != 0 ? maximum : maximum - 1;
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var a = (pos1 < minimum || pos1 > maximum) ? 0 : data[pos1];
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var b = (pos2 < minimum || pos2 > maximum) ? 0 : data[pos2];
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return lerp(a, b, pos - Math.floor(pos));
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}
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}
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inline function lerp(v0: Float, v1: Float, t: Float) {
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return (1 - t) * v0 + t * v1;
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}
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inline function sampleLength(sampleRate: Int): Int {
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var value = Math.ceil(data.length * (sampleRate / this.sampleRate));
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return value % 2 == 0 ? value : value + 1;
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}
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public override function play(): Void {
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paused = false;
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stopped = false;
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kha.audio1.Audio._playAgain(this);
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}
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public override function pause(): Void {
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paused = true;
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}
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public override function stop(): Void {
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myPosition = 0;
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stopped = true;
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}
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override function get_length(): Float {
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return data.length / this.sampleRate / 2; // 44.1 khz in stereo
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}
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override function get_position(): Float {
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return myPosition / kha.audio2.Audio.samplesPerSecond / 2;
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}
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override function set_position(value: Float): Float {
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var pos = Math.round(value * kha.audio2.Audio.samplesPerSecond * 2.0);
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pos = pos % 2 == 0 ? pos : pos + 1;
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myPosition = max(min(pos, sampleLength(kha.audio2.Audio.samplesPerSecond)), 0);
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return value;
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}
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override function get_volume(): Float {
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return myVolume;
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}
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override function set_volume(value: Float): Float {
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return myVolume = value;
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}
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override function get_finished(): Bool {
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return stopped;
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}
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static inline function max(a: Int, b: Int) {
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return a > b ? a : b;
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}
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static inline function min(a: Int, b: Int) {
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return a < b ? a : b;
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}
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}
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