performance improvements for SpriteInstance hierarchy, #60

js/common/view/environment/BunnySelectionRectangleSprite.js

@@ -21,9 +21,8 @@ class BunnySelectionRectangleSprite extends Sprite {
 
   /**
    * @param {HTMLImageElement} maxImage - the largest bunny image
-   * @param {Object} [options]
    */
-  constructor( maxImage, options ) {
+  constructor( maxImage ) {
 
     assert && assert( maxImage instanceof HTMLImageElement, 'invalid maxImage' );
     assert && assert( maxImage.width > 0 && maxImage.height > 0, 'maxImage does not have valid dimensions' );

js/common/view/environment/BunnySelectionRectangleSpriteInstance.js

@@ -27,9 +27,7 @@ class BunnySelectionRectangleSpriteInstance extends OrganismSpriteInstance {
     assert && assert( bunny instanceof Bunny, 'invalid bunny' );
     assert && assert( sprite instanceof BunnySelectionRectangleSprite, 'invalid sprite' );
 
-    super( bunny, sprite, {
-      baseScale: NaturalSelectionConstants.BUNNY_IMAGE_SCALE
-    } );
+    super( bunny, sprite, NaturalSelectionConstants.BUNNY_IMAGE_SCALE );
   }
 }
 

js/common/view/environment/BunnySpriteInstance.js

@@ -24,9 +24,7 @@ class BunnySpriteInstance extends OrganismSpriteInstance {
     assert && assert( bunny instanceof Bunny, 'invalid bunny' );
     assert && assert( sprite instanceof Sprite, 'invalid sprite' );
 
-    super( bunny, sprite, {
-      baseScale: NaturalSelectionConstants.BUNNY_IMAGE_SCALE
-    } );
+    super( bunny, sprite, NaturalSelectionConstants.BUNNY_IMAGE_SCALE );
   }
 }
 

js/common/view/environment/OrganismSpriteInstance.js

@@ -8,68 +8,94 @@
  * @author Chris Malley (PixelZoom, Inc.)
  */
 
-import Multilink from '../../../../../axon/js/Multilink.js';
-import merge from '../../../../../phet-core/js/merge.js';
 import Sprite from '../../../../../scenery/js/util/Sprite.js';
 import SpriteInstance from '../../../../../scenery/js/util/SpriteInstance.js';
 import naturalSelection from '../../../naturalSelection.js';
 import Organism from '../../model/Organism.js';
 import XDirection from '../../model/XDirection.js';
+import NaturalSelectionUtils from '../../NaturalSelectionUtils.js';
 
 class OrganismSpriteInstance extends SpriteInstance {
 
   /**
    * @param {Organism} organism
    * @param {Sprite} sprite
-   * @param {Object} [options]
+   * @param {number} baseScale - the base amount to scale, tuned based on the PNG file dimensions
    */
-  constructor( organism, sprite, options ) {
+  constructor( organism, sprite, baseScale ) {
+    // args are validated by initialize
 
-    assert && assert( organism instanceof Organism, 'invalid organism' );
-    assert && assert( sprite instanceof Sprite, 'invalid sprite' );
+    super();
 
-    options = merge( {
-      baseScale: 1 // the base amount to scale, tuned based on the PNG file dimensions
-    }, options );
+    // Set field in super SpriteInstance. Every Organism needs to be both translated and scaled
+    // because the view is a 2D projection of a 3D model position.
+    this.transformType = SpriteInstance.TransformType.TRANSLATION_AND_SCALE;
 
-    super();
+    // @private
+    this.organismListener = this.updateMatrix.bind( this );
+
+    this.initialize( organism, sprite, baseScale );
+  }
+
+  /**
+   * Initializes the OrganismSpriteInstance. This is factored out of the constructor (and is public) in case
+   * we ever want to leverage SpriteInstance's Poolable features.
+   * @param organism
+   * @param sprite
+   * @param baseScale
+   * @protected for use by Poolable
+   */
+  initialize( organism, sprite, baseScale ) {
+
+    assert && assert( organism instanceof Organism, 'invalid organism' );
+    assert && assert( sprite instanceof Sprite, 'invalid sprite' );
+    assert && assert( NaturalSelectionUtils.isPositive( baseScale ), `invalid baseScale: ${baseScale}` );
 
     // Set fields in super SpriteInstance
     this.sprite = sprite;
-    this.transformType = SpriteInstance.TransformType.TRANSLATION_AND_SCALE;
 
     // @public (read-only)
     this.organism = organism;
 
-    // Update position and direction. Must be disposed.
-    const multilink = new Multilink(
-      [ organism.positionProperty, organism.xDirectionProperty ],
-      ( position, xDirection ) => {
+    // @private
+    this.baseScale = baseScale;
 
-        // compute scale and position, in view coordinates
-        const viewScale = options.baseScale * organism.modelViewTransform.getViewScale( position.z );
-        const viewX = organism.modelViewTransform.modelToViewX( position );
-        const viewY = organism.modelViewTransform.modelToViewY( position );
+    // Update position and direction, unlink in dispose. Do not use a Multilink or define disposeOrganismSpriteInstance
+    // because we will be creating a large number of OrganismSpriteInstance instances.
+    assert && assert( this.organismListener, 'organismListener should exist by now' );
+    this.organism.positionProperty.link( this.organismListener );
+    this.organism.xDirectionProperty.link( this.organismListener );
+  }
 
-        // update the matrix in the most efficient way possible
-        this.matrix.set00( viewScale * XDirection.toSign( xDirection ) ); // reflected to account for x direction
-        this.matrix.set11( viewScale );
-        this.matrix.set02( viewX );
-        this.matrix.set12( viewY );
-      } );
+  /**
+   * Updates the matrix to match the organism's position and xDirection.
+   * @private
+   */
+  updateMatrix() {
 
-    // @private
-    this.disposeOrganismSpriteInstance = () => {
-      multilink.dispose();
-    };
+    const position = this.organism.positionProperty.value;
+    const xDirection = this.organism.xDirectionProperty.value;
+
+    // compute scale and position, in view coordinates
+    const viewScale = this.baseScale * this.organism.modelViewTransform.getViewScale( position.z );
+    const viewX = this.organism.modelViewTransform.modelToViewX( position );
+    const viewY = this.organism.modelViewTransform.modelToViewY( position );
+
+    // update the matrix in the most efficient way possible
+    this.matrix.set00( viewScale * XDirection.toSign( xDirection ) ); // reflected to account for x direction
+    this.matrix.set11( viewScale );
+    this.matrix.set02( viewX );
+    this.matrix.set12( viewY );
+    assert && assert( this.matrix.isFinite(), 'matrix should be finite' );
   }
 
   /**
    * @public
    * @override
    */
   dispose() {
-    this.disposeOrganismSpriteInstance();
+    this.organism.positionProperty.unlink( this.organismListener );
+    this.organism.xDirectionProperty.unlink( this.organismListener );
     super.dispose && super.dispose();
   }
 }

js/common/view/environment/ShrubSpriteInstance.js

@@ -28,9 +28,7 @@ class ShrubSpriteInstance extends OrganismSpriteInstance {
     assert && assert( tenderSprite instanceof Sprite, 'invalid tenderSprite' );
     assert && assert( toughSprite instanceof Sprite, 'invalid toughSprite' );
 
-    super( shrub, isTough ? toughSprite : tenderSprite, {
-      baseScale: NaturalSelectionConstants.SHRUB_IMAGE_SCALE
-    } );
+    super( shrub, ( isTough ? toughSprite : tenderSprite ), NaturalSelectionConstants.SHRUB_IMAGE_SCALE );
 
     // @private
     this.tenderSprite = tenderSprite;

js/common/view/environment/WolfSpriteInstance.js

@@ -24,9 +24,7 @@ class WolfSpriteInstance extends OrganismSpriteInstance {
     assert && assert( wolf instanceof Wolf, 'invalid wolf' );
     assert && assert( sprite instanceof Sprite, 'invalid sprite' );
 
-    super( wolf, sprite, {
-      baseScale: NaturalSelectionConstants.WOLF_IMAGE_SCALE
-    } );
+    super( wolf, sprite, NaturalSelectionConstants.WOLF_IMAGE_SCALE );
   }
 }