Move PoolScaleHeightProperty into PoolScale, see #148

js/common/model/DensityBuoyancyModel.ts

@@ -35,8 +35,6 @@ import TModel from '../../../../joist/js/TModel.js';
 import { PhetioObjectOptions } from '../../../../tandem/js/PhetioObject.js';
 import PickRequired from '../../../../phet-core/js/types/PickRequired.js';
 import PoolScale from './PoolScale.js';
-import PoolScaleHeightProperty from './PoolScaleHeightProperty.js';
-import DensityBuoyancyCommonConstants from '../DensityBuoyancyCommonConstants.js';
 
 // constants
 const BLOCK_SPACING = 0.01;
@@ -102,8 +100,7 @@ export default class DensityBuoyancyModel implements TModel {
   private spillingWaterOutOfBoat = false;
 
   // Scale for the pool and its heightProperty, if we are using it
-  public readonly poolScale: Scale | null = null;
-  public readonly poolScaleHeightProperty: NumberProperty;
+  public readonly poolScale: PoolScale | null = null;
 
   public constructor( providedOptions?: DensityBuoyancyModelOptions ) {
     const options = optionize<DensityBuoyancyModelOptions, DensityBuoyancyModelOptions>()( {
@@ -413,15 +410,9 @@ export default class DensityBuoyancyModel implements TModel {
       } );
     } );
 
-    // TODO: https://github.com/phetsims/density-buoyancy-common/issues/148 maybe create the pool scale height property in PoolScale?
-    const poolScaleTandem = tandem.createTandem( 'poolScale' );
-    this.poolScaleHeightProperty = new PoolScaleHeightProperty( DensityBuoyancyCommonConstants.POOL_SCALE_INITIAL_HEIGHT, {
-      range: new Range( 0, 1 ),
-      tandem: options.usePoolScale ? poolScaleTandem.createTandem( 'heightProperty' ) : Tandem.OPT_OUT
-    } );
     if ( options.usePoolScale ) {
 
-      this.poolScale = new PoolScale( this.engine, this.gravityProperty, poolScaleTandem );
+      this.poolScale = new PoolScale( this.engine, this.gravityProperty, tandem.createTandem( 'poolScale' ) );
 
       // Make sure to render it
       this.availableMasses.push( this.poolScale );
@@ -567,7 +558,7 @@ export default class DensityBuoyancyModel implements TModel {
     this.pool.reset();
     this.masses.forEach( mass => mass.reset() );
 
-    this.poolScaleHeightProperty && this.poolScaleHeightProperty.reset();
+    this.poolScale && this.poolScale.reset();
   }
 
   /**

js/common/model/PoolScale.ts

@@ -15,12 +15,19 @@ import Scale, { DisplayType, SCALE_HEIGHT, SCALE_WIDTH } from './Scale.js';
 import Vector2 from '../../../../dot/js/Vector2.js';
 import { Shape } from '../../../../kite/js/imports.js';
 import Tandem from '../../../../tandem/js/Tandem.js';
+import PoolScaleHeightProperty from './PoolScaleHeightProperty.js';
+import DensityBuoyancyCommonConstants from '../DensityBuoyancyCommonConstants.js';
+import Range from '../../../../dot/js/Range.js';
 
 // To prevent objects from being dragged beneath the scale, we extend the invisible part of the scale vertically downward.
 const SCALE_INVISIBLE_VERTICAL_EXTENSION_FACTOR = 8.26;
 
 export default class PoolScale extends Scale {
 
+  // Unitless value between 0 and 1 that represents how high the scale is above the bottom of the pool.
+  // See PoolScaleHeightControl for the mapping to model coordinates.
+  public readonly heightProperty: PoolScaleHeightProperty;
+
   public constructor( engine: PhysicsEngine, gravityProperty: TProperty<Gravity>, tandem: Tandem ) {
 
     const vertices = [
@@ -39,6 +46,16 @@ export default class PoolScale extends Scale {
       },
       tandem: tandem
     } );
+
+    this.heightProperty = new PoolScaleHeightProperty( DensityBuoyancyCommonConstants.POOL_SCALE_INITIAL_HEIGHT, {
+      range: new Range( 0, 1 ),
+      tandem: tandem.createTandem( 'heightProperty' )
+    } );
+  }
+
+  public override reset(): void {
+    super.reset();
+    this.heightProperty.reset();
   }
 }
 

js/common/view/DensityBuoyancyScreenView.ts

@@ -596,7 +596,7 @@ export default class DensityBuoyancyScreenView<Model extends DensityBuoyancyMode
     } );
 
     if ( model.poolScale ) {
-      this.poolScaleHeightControl = new PoolScaleHeightControl( model.poolScale, model.poolScaleHeightProperty,
+      this.poolScaleHeightControl = new PoolScaleHeightControl( model.poolScale,
         model.poolBounds, model.pool.liquidYInterpolatedProperty, this, {
           tandem: options.tandem.createTandem( 'poolScaleHeightControl' )
         } );

js/common/view/PoolScaleHeightControl.ts

@@ -9,7 +9,6 @@
 
 import densityBuoyancyCommon from '../../densityBuoyancyCommon.js';
 import Slider from '../../../../sun/js/Slider.js';
-import Property from '../../../../axon/js/Property.js';
 import optionize, { EmptySelfOptions } from '../../../../phet-core/js/optionize.js';
 import Range from '../../../../dot/js/Range.js';
 import Tandem from '../../../../tandem/js/Tandem.js';
@@ -28,6 +27,7 @@ import ArrowButton from '../../../../sun/js/buttons/ArrowButton.js';
 import Orientation from '../../../../phet-core/js/Orientation.js';
 import WithRequired from '../../../../phet-core/js/types/WithRequired.js';
 import { Shape } from '../../../../kite/js/imports.js';
+import PoolScale from '../model/PoolScale.js';
 
 // constants
 const DEFAULT_RANGE = new Range( 0, 1 );
@@ -37,7 +37,7 @@ type ScaleHeightSliderOptions = EmptySelfOptions & WithRequired<NumberControlOpt
 
 export default class PoolScaleHeightControl extends NumberControl {
 
-  public constructor( scale: Scale, heightProperty: Property<number>,
+  public constructor( poolScale: PoolScale,
                       poolBounds: Bounds3,
                       liquidYInterpolatedProperty: TReadOnlyProperty<number>,
                       modelViewTransform: THREEModelViewTransform,
@@ -55,12 +55,8 @@ export default class PoolScaleHeightControl extends NumberControl {
       mouseArea: thumbInteractionArea
     } );
 
-    // This magic number accomplishes two things:
-    // 1. matching the liquid level exactly causes blue graphical fractals on the top of the scale
-    // 2. Because the P2 engine has a non-infinite stiffness, masses overlap when contacting. This means that we want to
-    //    raise the scale up above the pool so that the block can be the same weight as when measuring with the ground scale.
-    const maxY = liquidYInterpolatedProperty.value;
     const minY = poolBounds.minY;
+    const maxY = liquidYInterpolatedProperty.value;
 
     const sliderTrackHeight = modelViewTransform.modelToViewDelta( new Vector3( SCALE_X_POSITION, maxY, poolBounds.maxZ ), new Vector3( SCALE_X_POSITION, minY, poolBounds.maxZ ) ).y;
 
@@ -94,15 +90,15 @@ export default class PoolScaleHeightControl extends NumberControl {
       }
     }, providedOptions );
 
-    super( new Property( '' ), heightProperty, DEFAULT_RANGE, options );
+    super( '', poolScale.heightProperty, DEFAULT_RANGE, options );
 
-    heightProperty.link( height => {
+    poolScale.heightProperty.link( height => {
       const currentHeight = Utils.linear( 0, 1, minY, maxY, height );
 
-      scale.matrix.set02( SCALE_X_POSITION );
-      scale.matrix.set12( currentHeight + Scale.SCALE_HEIGHT / 2 );
-      scale.writeData();
-      scale.transformedEmitter.emit();
+      poolScale.matrix.set02( SCALE_X_POSITION );
+      poolScale.matrix.set12( currentHeight + Scale.SCALE_HEIGHT / 2 );
+      poolScale.writeData();
+      poolScale.transformedEmitter.emit();
     } );
 
     thumbNode.touchArea = thumbInteractionArea.copy().rect( -10, -10, 20, 50 );