scratch-audio - npm Package Compare versions

Comparing version 0.1.0-prerelease.1500992119 to 0.1.0-prerelease.1500997011

package.json

 {
   "name": "scratch-audio",
-  "version": "0.1.0-prerelease.1500992119",
+  "version": "0.1.0-prerelease.1500997011",
   "description": "audio engine for scratch 3.0",
@@ -5,0 +5,0 @@ "main": "dist.js",

src/DrumPlayer.js

@@ -47,3 +47,16 @@ const SoundPlayer = require('./SoundPlayer');
                 const audioData = request.response;
-                this.audioContext.decodeAudioData(audioData).then(buffer => {
+                // Check for newer promise-based API
+                let loaderPromise;
+                if (this.audioContext.decodeAudioData.length === 1) {
+                    loaderPromise = this.audioContext.decodeAudioData(audioData);
+                } else {
+                    // Fall back to callback API
+                    loaderPromise = new Promise((resolve, reject) => {
+                        this.audioContext.decodeAudioData(audioData,
+                            decodedAudio => resolve(decodedAudio),
+                            error => reject(error)
+                        );
+                    });
+                }
+                loaderPromise.then(buffer => {
                     this.drumSounds[i].setBuffer(buffer);
@@ -50,0 +63,0 @@ });

src/effects/PanEffect.js

@@ -5,3 +5,2 @@ /**
 * 0 centers it, 100 puts it on the right.
-* Clamped -100 to 100
 */
@@ -15,4 +14,15 @@ class PanEffect {
         this.audioContext = audioContext;
-        this.panner = this.audioContext.createStereoPanner();
         this.value = 0;
+
+        this.input = this.audioContext.createGain();
+        this.leftGain = this.audioContext.createGain();
+        this.rightGain = this.audioContext.createGain();
+        this.channelMerger = this.audioContext.createChannelMerger(2);
+
+        this.input.connect(this.leftGain);
+        this.input.connect(this.rightGain);
+        this.leftGain.connect(this.channelMerger, 0, 0);
+        this.rightGain.connect(this.channelMerger, 0, 1);
+
+        this.set(this.value);
     }
@@ -25,27 +35,19 @@
     set (val) {
-        this.value = this.clamp(val, -100, 100);
-        this.panner.pan.value = this.value / 100;
-    }
+        this.value = val;
 
-    connect (node) {
-        this.panner.connect(node);
-    }
+        // Map the scratch effect value (-100 to 100) to (0 to 1)
+        const p = (val + 100) / 200;
 
-    /**
-    * Change the effect value
-    * @param {number} val - the value to change the effect by
-    */
-    changeBy (val) {
-        this.set(this.value + val);
+        // Use trig functions for equal-loudness panning
+        // See e.g. https://docs.cycling74.com/max7/tutorials/13_panningchapter01
+        this.leftGain.gain.value = Math.cos(p * Math.PI / 2);
+        this.rightGain.gain.value = Math.sin(p * Math.PI / 2);
     }
 
     /**
-    * Clamp the input to a range
-    * @param {number} input - the input to clamp
-    * @param {number} min - the min value to clamp to
-    * @param {number} max - the max value to clamp to
-    * @return {number} the clamped value
-    */
-    clamp (input, min, max) {
-        return Math.min(Math.max(input, min), max);
+     * Connnect this effect's output to another audio node
+     * @param {AudioNode} node - the node to connect to
+     */
+    connect (node) {
+        this.channelMerger.connect(node);
     }
@@ -52,0 +54,0 @@ }

src/index.js

@@ -36,3 +36,3 @@ const log = require('./log');
         this.effectsNode = this.audioEngine.audioContext.createGain();
-        this.effectsNode.connect(this.panEffect.panner);
+        this.effectsNode.connect(this.panEffect.input);
         this.panEffect.connect(this.audioEngine.input);
@@ -208,3 +208,14 @@
         case '':
-            loaderPromise = this.audioContext.decodeAudioData(bufferCopy);
+            // Check for newer promise-based API
+            if (this.audioContext.decodeAudioData.length === 1) {
+                loaderPromise = this.audioContext.decodeAudioData(bufferCopy);
+            } else {
+                // Fall back to callback API
+                loaderPromise = new Promise((resolve, reject) => {
+                    this.audioContext.decodeAudioData(bufferCopy,
+                        decodedAudio => resolve(decodedAudio),
+                        error => reject(error)
+                    );
+                });
+            }
             break;
@@ -211,0 +222,0 @@ case 'adpcm':

No alert changes

Improved metrics

Total package byte prevSize

602121

0.77%

Lines of code

3893

1.17%

No dependency changes