gameboy-sound - npm Package Compare versions

Comparing version 0.1.1 to 0.1.2

lib/gameboy-sound.js

@@ -27,3 +27,3 @@ window.AudioContext = window.AudioContext || window.webkitAudioContext;
 
-function baseChannel(ctx, dest=ctx.destination) {
+function baseChannel(/**@type{AudioContext}*/ctx, dest=ctx.destination) {
 	const gainNode = ctx.createGain();
@@ -43,5 +43,28 @@ gainNode.gain.setValueAtTime(0, ctx.currentTime);
 
+	/**
+	 * Previous hz changes are tracked and applied retroactively
+	 * to all future buffers played later on. This is to keep the
+	 * waveforms in sync to prevent popping when a new note is
+	 * played, making vibrato possible
+	 */
+	let prevHertzChanges = [];
+
 	/** @type{AudioBufferSourceNode} */
 	let currentSourceNode = null;
-	return function play({ buffer, rate, rateChanges=[], trigger=true, length=Infinity, volume=15, fade=0, left=true, right=true, time=0 }) {
+
+	/**
+	 * TODO!!!
+	 * two wrongs do make a right!
+	 * the value passed in to "hertz" is not actually the hertz of the waveform!
+	 * however, this function also calculates things wrong, in exactly the right way
+	 * so it all still works...
+	 * 
+	 * when refactoring it to use the real hertz value (maybe?),
+	 * make sure to test with vibrato to ensure that there's no popping
+	 */
+	return function play({ buffer, hertz, hertzChanges=[], trigger=true, length=Infinity, volume=15, fade=0, left=true, right=true, time=0 }) {
+		// calculate playback rate(s)
+		prevHertzChanges = prevHertzChanges.filter(x => x.time < time);
+		prevHertzChanges.push({ time, hertz });
+		// no left/right = no sound
 		if (!left && !right) {
@@ -58,6 +81,19 @@ volume = 0;
 		sourceNode.buffer = buffer;
-		sourceNode.playbackRate.setValueAtTime(rate, time)
+		for (const x of prevHertzChanges) {
+			const rate = buffer.sampleRate/buffer.length/x.hertz;
+			sourceNode.playbackRate.setValueAtTime(rate, x.time);
+		}
 		sourceNode.loop = true;
+		const prevWiggles = prevHertzChanges.reduce((sum, x, i, src) => {
+			if (i === 0) return 0;
+			return (sum + (x.time-src[i-1].time) * buffer.sampleRate/buffer.length/src[i-1].hertz);
+			// TODO "real hertz" calculations
+			// const realhertz = 1/(src[i-1].hertz * buffer.duration**2);
+			// console.log('realh',realhertz)
+			// return (sum + (x.time-src[i-1].time) * realhertz);
+		}, 0);
+		const offset = prevWiggles % buffer.duration
+		// console.log(buffer.duration, offset);
 		sourceNode.connect(gainNode);
-		sourceNode.start(time);
+		sourceNode.start(time, offset);
 		currentSourceNode = sourceNode;
@@ -80,8 +116,11 @@ // volume + envelope + length
 		// rate changes
-		rateChanges.forEach(({ rate, time }) => {
-			if (rate == null) {
+		hertzChanges.forEach(({ hertz, time }) => {
+			if (hertz == null) {
 				gainNode.gain.cancelScheduledValues(time);
 				gainNode.gain.setValueAtTime(0, time);
 			}
-			else sourceNode.playbackRate.setValueAtTime(rate, time)
+			else {
+				const rate = buffer.sampleRate/buffer.length/hertz;
+				sourceNode.playbackRate.setValueAtTime(rate, time)
+			}
 		});
@@ -115,5 +154,10 @@ // pan
 		const buffer = pulseWaves[duty];
-		const rate = 256 / (2048-freq);
+		const hertz = 2 * (2048-freq);
+		// TODO "real hertz" calculations
+		// console.log(buffer.sampleRate/buffer.length, buffer.duration)
+		// const realhertz = 1/((2 * (2048 - freq)) * buffer.duration**2);
 
-		const rateChanges = [];
+		// console.log(realhertz, realhertz*buffer.duration);
+
+		const hertzChanges = [];
 		if (sweepFactor !== 0) {
@@ -132,12 +176,12 @@ let shadowFreq = freq;
 				if (shadowFreq + dFreq >= 2048) {
-					rateChanges.push({ time: t1, rate: null });
+					hertzChanges.push({ time: t1, hertz: null });
 					break;
 				}
 
-				const rate = 256 / (2048-shadowFreq);
-				rateChanges.push({ time: t1, rate });
+				const hertz = 2 * (2048-shadowFreq);
+				hertzChanges.push({ time: t1, hertz });
 			}
 		}
 
-		ch({ buffer, rate, rateChanges, trigger, length, volume, fade, left, right, time });
+		ch({ buffer, hertz, hertzChanges, trigger, length, volume, fade, left, right, time });
 	};
@@ -163,6 +207,7 @@ }
 	return function ({ samples=defaultPCM, freq=1798, trigger, length, left, right, time }) {
+		/** @type{AudioBuffer} */
 		const buffer = (lastSamples && samples.join() === lastSamples) ?
 			cachedBuffer :
 			samplesToBuffer(samples);
-		const rate = 256 / (2048-freq);
+		const hertz = (2048-freq);
 
@@ -172,3 +217,3 @@ lastSamples = samples.join();
 
-		ch({ buffer, rate, trigger, length, left, right, time });
+		ch({ buffer, hertz, trigger, length, left, right, time });
 	};
@@ -208,9 +253,10 @@ }
 
+	const cats = upsampleAmounts.map(n=>256*n);
+	cats[cats.length-1]=Infinity;
+
 	return function ({ buzzy=false, freq=3<<7, trigger, length, volume, fade, left, right, time }) {
-		const cats = upsampleAmounts.map(n=>256*n);
-		cats[cats.length-1]=Infinity;
 		const resampleCategory = cats.findIndex(c => freq < c);
 		const buffer = resampledNoiseWaves[resampleCategory][+buzzy];
-		const rate = 0x40 / freq * upsampleAmounts[resampleCategory];
-		ch({ buffer, rate, trigger, length, volume, fade, left, right, time })
+		const hertz = (buffer.sampleRate/buffer.length) * freq / upsampleAmounts[resampleCategory] / 0x40;
+		ch({ buffer, hertz, trigger, length, volume, fade, left, right, time })
 	};
@@ -217,0 +263,0 @@ }

package.json

 {
   "name": "gameboy-sound",
-  "version": "0.1.1",
+  "version": "0.1.2",
   "description": "Easy 3 kB library for 98% accurate Gameboy audio",
@@ -5,0 +5,0 @@ "main": "lib/index.js",

No alert changes

Improved metrics

Total package byte prevSize

15965

increased by12.64%

Lines of code

315

increased by15.38%

No dependency changes