added mass sound, see #166

js/gravity-force-lab-basics/view/GFLBScreenView.js

@@ -12,6 +12,7 @@ define( require => {
   // modules
   const AccessiblePeer = require( 'SCENERY/accessibility/AccessiblePeer' );
   const Bounds2 = require( 'DOT/Bounds2' );
+  const CheckboxSoundGenerator = require( 'TAMBO/sound-generators/CheckboxSoundGenerator' );
   const Color = require( 'SCENERY/util/Color' );
   const ControlAreaNode = require( 'SCENERY_PHET/accessibility/nodes/ControlAreaNode' );
   const DefaultDirection = require( 'INVERSE_SQUARE_LAW_COMMON/view/DefaultDirection' );
@@ -35,6 +36,7 @@ define( require => {
   const ISLCGridNode = require( 'INVERSE_SQUARE_LAW_COMMON/view/ISLCGridNode' );
   const ISLCObjectEnum = require( 'INVERSE_SQUARE_LAW_COMMON/view/ISLCObjectEnum' );
   const ISLCQueryParameters = require( 'INVERSE_SQUARE_LAW_COMMON/ISLCQueryParameters' );
+  const MassSoundGenerator = require( 'GRAVITY_FORCE_LAB_BASICS/gravity-force-lab-basics/view/MassSoundGenerator' );
   const ModelViewTransform2 = require( 'PHETCOMMON/view/ModelViewTransform2' );
   const Node = require( 'SCENERY/nodes/Node' );
   const PlayAreaNode = require( 'SCENERY_PHET/accessibility/nodes/PlayAreaNode' );
@@ -209,6 +211,16 @@ define( require => {
                                               massControlsHelpTextBillionsString;
       } );
 
+      // sound generation for the mass values
+      soundManager.addSoundGenerator( new MassSoundGenerator(
+        model.object1.valueProperty,
+        model.resetInProgressProperty )
+      );
+      soundManager.addSoundGenerator( new MassSoundGenerator(
+        model.object2.valueProperty,
+        model.resetInProgressProperty )
+      );
+
       const checkboxItems = [
         {
           label: forceValuesString, property: model.showForceValuesProperty,
@@ -240,6 +252,14 @@ define( require => {
         fill: '#f1f1f2'
       } );
 
+      // sound generation for check box items
+      checkboxItems.forEach( checkboxItem => {
+        soundManager.addSoundGenerator( new CheckboxSoundGenerator(
+          checkboxItem.property,
+          model.resetInProgressProperty
+        ) );
+      } );
+
       // arrow that shows distance between the two masses
       const distanceArrowNode = new DistanceArrowNode( model, modelViewTransform, {
         tandem: tandem.createTandem( 'distanceArrowNode' ),

js/gravity-force-lab-basics/view/MassSoundGenerator.js

@@ -0,0 +1,66 @@
+// Copyright 2019, University of Colorado Boulder
+
+/**
+ * sound generator for mass changes
+ *
+ * @author John Blanco (PhET Interactive Simulations)
+ */
+define( require => {
+  'use strict';
+
+  // modules
+  const SoundClip = require( 'TAMBO/sound-generators/SoundClip' );
+  const gravityForceLabBasics = require( 'GRAVITY_FORCE_LAB_BASICS/gravityForceLabBasics' );
+  const GFLBConstants = require( 'GRAVITY_FORCE_LAB_BASICS/gravity-force-lab-basics/GFLBConstants' );
+
+  // sounds
+  const massSound = require( 'sound!GRAVITY_FORCE_LAB_BASICS/rubber-band-v2-middle-c.mp3' );
+
+  // constants
+  const PITCH_RANGE_IN_SEMI_TONES = 30;
+
+  class MassSoundGenerator extends SoundClip {
+
+    /**
+     * @param {NumberProperty} massProperty
+     * @param {BooleanProperty} resetInProgressProperty
+     * @param {Object} [options]
+     * @constructor
+     */
+    constructor( massProperty, resetInProgressProperty, options ) {
+
+      super( massSound, options );
+
+      // function for playing the mass sound
+      const massListener = mass => {
+        if ( !resetInProgressProperty.value ) {
+
+          // convert the mass to a playback rate, see the design document for an explanation
+          const massRange = GFLBConstants.MASS_RANGE;
+          const normalizedMass = ( mass - massRange.min ) / ( massRange.max - massRange.min );
+          const centerAndFlippedNormMass = ( ( 1 - normalizedMass ) - 0.5 );
+          const midiNote = PITCH_RANGE_IN_SEMI_TONES / 2 * centerAndFlippedNormMass;
+          const playbackSpeed = Math.pow( 2, midiNote / 12 );
+          this.setPlaybackRate( playbackSpeed );
+          this.play();
+        }
+      };
+      massProperty.link( massListener );
+
+      // @private {function}
+      this.disposeMassSoundGenerator = () => { massProperty.unlink( massListener ); };
+    }
+
+    /**
+     * @public
+     */
+    dispose() {
+      this.disposeMassSoundGenerator();
+      super.dispose();
+    }
+  }
+
+  gravityForceLabBasics.register( 'MassSoundGenerator', MassSoundGenerator );
+
+  return MassSoundGenerator;
+} );

sounds/license.json

@@ -0,0 +1,10 @@
+{
+  "rubber-band-v2-middle-c.mp3": {
+    "text": [
+      "Copyright 2002-2019 University of Colorado Boulder"
+    ],
+    "projectURL": "http://phet.colorado.edu",
+    "license": "contact [email protected]",
+    "notes": "created by Ashton Morris (PhET Interactive Simulations)"
+  }
+}