added pressure to state, see #296

js/common/model/MultipleParticleModel.js

@@ -503,10 +503,8 @@ class MultipleParticleModel extends PhetioObject {
     // remove all atoms
     this.removeAllAtoms();
 
-    // Reinitialize the model parameters, but not if this is a phet-io setState operation.
-    if ( !phet.joist.sim.isSettingPhetioStateProperty.value ) {
-      this.initializeModelParameters();
-    }
+    // Reinitialize the model parameters.
+    this.initializeModelParameters();
 
     // Set the model parameters that are dependent upon the substance being simulated.
     switch( substance ) {
@@ -549,11 +547,8 @@ class MultipleParticleModel extends PhetioObject {
         throw( new Error( 'unsupported substance' ) ); // should never happen, debug if it does
     }
 
-    // In most cases, the container size is reset at this point, but when the substance is being updated using phet-io
-    // the container size is *not* reset, since doing so may overwrite a size that was specifically set by the user.
-    if ( !phet.joist.sim.isSettingPhetioStateProperty.value ) {
-      this.containerHeightProperty.reset();
-    }
+    // Reset the container height.
+    this.containerHeightProperty.reset();
 
     // Make sure the normalized container dimensions are correct for the substance and the current non-normalize size.
     this.updateNormalizedContainerDimensions();
@@ -1457,7 +1452,8 @@ class MultipleParticleModel extends PhetioObject {
         gravitationalAcceleration: this.gravitationalAcceleration,
         normalizedLidVelocityY: this.normalizedLidVelocityY,
         heatingCoolingAmount: this.heatingCoolingAmountProperty.value,
-        moleculeDataSet: MoleculeForceAndMotionDataSetIO.toStateObject( this.moleculeDataSet )
+        moleculeDataSet: MoleculeForceAndMotionDataSetIO.toStateObject( this.moleculeDataSet ),
+        moleculeForcesAndMotionCalculatorPressure: this.moleculeForceAndMotionCalculator.pressureProperty.value
       }
     };
   }
@@ -1476,7 +1472,8 @@ class MultipleParticleModel extends PhetioObject {
       containerHeight: stateObject.private.containerHeight,
       normalizedLidVelocityY: stateObject.private.normalizedLidVelocityY,
       heatingCoolingAmount: stateObject.private.heatingCoolingAmount,
-      moleculeDataSet: MoleculeForceAndMotionDataSetIO.fromStateObject( stateObject.private.moleculeDataSet )
+      moleculeDataSet: MoleculeForceAndMotionDataSetIO.fromStateObject( stateObject.private.moleculeDataSet ),
+      moleculeForcesAndMotionCalculatorPressure: stateObject.private.moleculeForcesAndMotionCalculatorPressure
     };
   }
 
@@ -1494,10 +1491,10 @@ class MultipleParticleModel extends PhetioObject {
     this.gravitationalAcceleration = state.gravitationalAcceleration;
     this.normalizedLidVelocityY = state.normalizedLidVelocityY;
     this.moleculeDataSet = state.moleculeDataSet;
+    this.moleculeForceAndMotionCalculator.presetPressure( state.moleculeForcesAndMotionCalculatorPressure );
   }
 }
 
-
 // static constants
 MultipleParticleModel.PARTICLE_CONTAINER_WIDTH = CONTAINER_WIDTH;
 MultipleParticleModel.PARTICLE_CONTAINER_INITIAL_HEIGHT = CONTAINER_INITIAL_HEIGHT;

js/common/model/TimeSpanDataQueue.js

@@ -14,18 +14,20 @@ function TimeSpanDataQueue( length, maxTimeSpan ) {
   this.length = length;
   this.maxTimeSpan = maxTimeSpan;
 
-  // allocate a fixed-size array so that subsequent allocations are not needed
+  // @private - array where entries are kept
   this.dataQueue = new Array( length );
 
   // initialize the data array with a set of reusable objects so that subsequent allocations are not needed
   for ( let i = 0; i < length; i++ ) {
     this.dataQueue[ i ] = { deltaTime: 0, value: null };
   }
 
-  // initialize the variables used to make this thing work
+  // @public (read-only) {number} - the total of all values currently in the queue
+  this.total = 0;
+
+  // @private - variables used to make this thing work
   this.head = 0;
   this.tail = 0;
-  this.total = 0;
   this.timeSpan = 0;
 }
 
@@ -38,6 +40,7 @@ inherit( Object, TimeSpanDataQueue, {
    * span, and also updates the total value and the current time span
    * @param value
    * @param dt
+   * @public
    */
   add: function( value, dt ) {
 
@@ -61,6 +64,7 @@ inherit( Object, TimeSpanDataQueue, {
     while ( this.timeSpan > this.maxTimeSpan ) {
       const nextTail = ( this.tail + 1 ) % this.length;
       if ( nextTail === nextHead ) {
+
         // nothing more can be removed, so bail
         assert && assert( false, 'time span exceeded, but nothing appears to be in the queue - probably a bug' );
         break;
@@ -73,6 +77,7 @@ inherit( Object, TimeSpanDataQueue, {
 
   /**
    * clear all data from the queue
+   * @public
    */
   clear: function() {
     this.head = 0;

js/common/model/engine/AbstractVerletAlgorithm.js

@@ -16,7 +16,8 @@ import TimeSpanDataQueue from '../TimeSpanDataQueue.js';
 // Constants that control the pressure calculation.  The size of the pressure accumulator assumes a max sim rate of
 // 1 / 60, which derives from the standard 60 FPS rate at which browsers currently run.  May need to go up someday.
 const PRESSURE_CALC_TIME_WINDOW = 12; // in seconds, empirically determined to be responsive but not jumpy
-const PRESSURE_ACCUMULATOR_LENGTH = Math.ceil( PRESSURE_CALC_TIME_WINDOW / ( 1 / 60 ) * 1.1 );
+const NOMINAL_DT = 1 / 60; // in seconds, assuming 60 fps
+const PRESSURE_ACCUMULATOR_LENGTH = Math.ceil( PRESSURE_CALC_TIME_WINDOW / NOMINAL_DT * 1.1 );
 
 // constants that control when the container explodes
 const EXPLOSION_PRESSURE = 41; // in model units, empirically determined
@@ -45,7 +46,7 @@ function AbstractVerletAlgorithm( multipleParticleModel ) {
   // during execution of the Verlet algorithm, must be cleared by the client.
   this.lidChangedParticleVelocity = false;
 
-  // @private, moving time window queue for tracking the pressure data
+  // @private {TimeSpanDataQueue}, moving time window queue for tracking the pressure data
   this.pressureAccumulatorQueue = new TimeSpanDataQueue( PRESSURE_ACCUMULATOR_LENGTH, PRESSURE_CALC_TIME_WINDOW );
 
   // @private, tracks time above the explosion threshold
@@ -292,6 +293,31 @@ inherit( Object, AbstractVerletAlgorithm, {
     }
   },
 
+  /**
+   * This method allows the caller to set an initial value for the pressure.  It was added in support of phet-io state
+   * setting so that the pressure calculation could be set to an initial value above zero that reflected the state
+   * extracted from another instance of the simulation.
+   * @param {number} pressure
+   */
+  presetPressure: function( pressure ) {
+
+    assert && assert(
+      phet.joist.sim.isSettingPhetioStateProperty.value,
+      'this method is intended for use during state setting only'
+    );
+
+    // get rid of any accumulated values
+    this.pressureAccumulatorQueue.clear();
+
+    // calculate the instantaneous sample value needed to make the overall pressure be the needed value
+    const pressureSampleInstantaneousValue = pressure * PRESSURE_CALC_TIME_WINDOW / PRESSURE_ACCUMULATOR_LENGTH;
+
+    // add the entries to the accumulator
+    _.times( PRESSURE_ACCUMULATOR_LENGTH, () => {
+      this.pressureAccumulatorQueue.add( pressureSampleInstantaneousValue, NOMINAL_DT );
+    } );
+  },
+
   // static final
   PARTICLE_INTERACTION_DISTANCE_THRESH_SQRD: 6.25,