rename "evaporate" to "shear off" in whole sim, #247

doc/implementation-notes.md

@@ -2,6 +2,6 @@ Friction is a one-screen simulation that depicts a draggable Chemistry book on t
 part of the play area is the MagnifierNode, which shows the zoomed in part of the simulation.  Canvas is used to render
 the atoms in attempt to improve performance.  The main property modeled by the simulation and depicted in the thermometer
 is FrictionModel.vibrationAmplitudeProperty, which indicates how much the atoms are oscillating.  If an atom meets the threshold,
-it evaporates.
+it shears off.
 
 Model and screen coordinates are the same in this sim, so no model-view transform is needed.

doc/model.md

@@ -1,3 +1,3 @@
 The Friction model is qualitative.  The main property modeled by the simulation and depicted in the thermometer is the
-amplitude of oscillation of the atoms.  If an atom meets the threshold, it evaporates.  As each atom evaporates, a bit
+amplitude of oscillation of the atoms.  If an atom meets the threshold, it shears off.  As each atom shears off, a bit
 of cooling occurs.

js/friction/model/Atom.js

@@ -20,7 +20,7 @@ import IOType from '../../../../tandem/js/types/IOType.js';
 import friction from '../../friction.js';
 
 // constants
-const EVAPORATED_SPEED = 400; // speed that particles travel during evaporation, in model units per second
+const SHEAR_OFF_SPEED = 400; // speed that particles travel during shearing, in model units per second
 
 let uniqueID = 0;
 
@@ -57,8 +57,8 @@ class Atom extends PhetioObject {
     // @public (read-only) {boolean} - flag that indicates whether this atom is part of the top book
     this.isTopAtom = isTopAtom;
 
-    // @private - marked as true when the atom is evaporated
-    this.isEvaporated = false;
+    // @private - marked as true when the atom is sheared off
+    this.isShearedOff = false;
 
     // @public - the position of the atom
     this.positionProperty = new Vector2Property( initialPosition, {
@@ -70,14 +70,14 @@ class Atom extends PhetioObject {
     // @private {Vector2} - the center position, around which oscillations occur
     this.centerPosition = new Vector2( initialPosition.x, initialPosition.y );
 
-    // @private {Vector2} - velocity vector for evaporation
-    this.evaporationVelocity = new Vector2( 0, 0 );
+    // @private {Vector2} - velocity vector for shearing
+    this.shearingVelocity = new Vector2( 0, 0 );
 
     if ( this.isTopAtom ) {
 
       // move the atom's center position as the top book moves
       model.topBookPositionProperty.lazyLink( ( newPosition, oldPosition ) => {
-        if ( !this.isEvaporated && !phet.joist.sim.isSettingPhetioStateProperty.value ) {
+        if ( !this.isShearedOff && !phet.joist.sim.isSettingPhetioStateProperty.value ) {
           const deltaX = newPosition.x - oldPosition.x;
           const deltaY = newPosition.y - oldPosition.y;
           this.centerPosition.setXY( this.centerPosition.x + deltaX, this.centerPosition.y + deltaY );
@@ -95,29 +95,29 @@ class Atom extends PhetioObject {
     return {
       initialPosition: Vector2.Vector2IO,
       isTopAtom: BooleanIO,
-      isEvaporated: BooleanIO,
+      isShearedOff: BooleanIO,
       centerPosition: Vector2.Vector2IO,
-      evaporationVelocity: Vector2.Vector2IO
+      shearingVelocity: Vector2.Vector2IO
     };
   }
 
   /**
    * when the oscillation has exceeded the threshold, the atom breaks off, animates to one side of the screen, and
-   * disappears
+   * disappears.
    * @public
    */
-  evaporate() {
-    assert && assert( !this.isEvaporated, 'Atom was already evaporated' );
+  shearOff() {
+    assert && assert( !this.isShearedOff, 'Atom already sheared off' );
 
-    this.isEvaporated = true;
-    const evaporationDestinationX = this.model.width * ( dotRandom.nextBoolean() ? 1 : -1 );
-    const evaporationDestinationY = this.positionProperty.get().y -
+    this.isShearedOff = true;
+    const shearingDestinationX = this.model.width * ( dotRandom.nextBoolean() ? 1 : -1 );
+    const shearingDestinationY = this.positionProperty.get().y -
                                     this.model.distanceBetweenBooksProperty.get() * dotRandom.nextDouble();
 
-    this.evaporationVelocity.setXY(
-      evaporationDestinationX - this.positionProperty.get().x,
-      evaporationDestinationY - this.positionProperty.get().y
-    ).setMagnitude( EVAPORATED_SPEED );
+    this.shearingVelocity.setXY(
+      shearingDestinationX - this.positionProperty.get().x,
+      shearingDestinationY - this.positionProperty.get().y
+    ).setMagnitude( SHEAR_OFF_SPEED );
   }
 
   /**
@@ -126,7 +126,7 @@ class Atom extends PhetioObject {
    */
   reset() {
     this.centerPosition.set( this.initialPosition );
-    this.isEvaporated = false;
+    this.isShearedOff = false;
   }
 
   /**
@@ -143,11 +143,11 @@ class Atom extends PhetioObject {
     );
     this.positionProperty.set( newPosition );
 
-    // if evaporated, move away (but don't bother continuing once the atom is out of view)
-    if ( this.isEvaporated && Math.abs( this.centerPosition.x ) < 4 * this.model.width ) {
+    // if sheared off, move away (but don't bother continuing once the atom is out of view)
+    if ( this.isShearedOff && Math.abs( this.centerPosition.x ) < 4 * this.model.width ) {
       this.centerPosition.setXY(
-        this.centerPosition.x + this.evaporationVelocity.x * dt,
-        this.centerPosition.y + this.evaporationVelocity.y * dt
+        this.centerPosition.x + this.shearingVelocity.x * dt,
+        this.centerPosition.y + this.shearingVelocity.y * dt
       );
     }
   }