From fb7bcb68aa13799bcfab7902e1ddaab383d1b48c Mon Sep 17 00:00:00 2001
From: pixelzoom <cmalley@pixelzoom.com>
Date: Tue, 26 Mar 2024 11:08:03 -0600
Subject: [PATCH] group static images together, add a comment linking to this
 issue, https://github.com/phetsims/faradays-electromagnetic-lab/issues/113

---
 js/common/view/FieldNode.ts | 56 ++++++++++++++++++++-----------------
 1 file changed, 30 insertions(+), 26 deletions(-)

diff --git a/js/common/view/FieldNode.ts b/js/common/view/FieldNode.ts
index 6b68849d..10f2494f 100644
--- a/js/common/view/FieldNode.ts
+++ b/js/common/view/FieldNode.ts
@@ -34,7 +34,6 @@ export default class FieldNode extends Sprites {
 
   public constructor( magnet: Magnet, visibleBoundsProperty: TReadOnlyProperty<Bounds2>, tandem: Tandem ) {
 
-    // A vector in the field is visualized as a compass needle.
     const sprite = new Sprite( FieldNode.getSpriteImage(
       FELColors.compassNeedleNorthColorProperty.value,
       FELColors.compassNeedleSouthColorProperty.value
@@ -81,31 +80,6 @@ export default class FieldNode extends Sprites {
     this.addLinkedElement( magnet );
   }
 
-  private static getSpriteImage( compassNeedleNorthColor: Color, compassNeedleSouthColor: Color ): SpriteImage {
-    // A vector in the field is visualized as a compass needle.
-    // Convert a CompassNeedleNode to a Sprite.
-    const compassNeedleNode = new CompassNeedleNode( {
-      northFill: compassNeedleNorthColor,
-      southFill: compassNeedleSouthColor,
-
-      // Apply a scale to increase resolution (we'll apply the inverse scale when rendering).
-      scale: COMPASS_NEEDLE_RESOLUTION_MULTIPLIER
-    } );
-
-    let spriteImage!: SpriteImage;
-
-    compassNeedleNode.toCanvas( ( canvas, x, y, width, height ) => {
-      spriteImage = new SpriteImage( canvas, new Vector2( ( x + compassNeedleNode.width / 2 ), ( y + compassNeedleNode.height / 2 ) ), {
-        // It looked too "sharp" without mipmapping at the normal view distance, so we'll have these generated.
-        mipmap: true,
-        mipmapBias: -0.7
-      } );
-    } );
-
-    assert && assert( spriteImage );
-    return spriteImage;
-  }
-
   /**
    * Rebuilds the grid to fill the visible bounds of the browser. We're not bothering with SpriteInstance pooling
    * because this happens rarely, and the time to rebuild is not noticeable.
@@ -163,6 +137,36 @@ export default class FieldNode extends Sprites {
     assert && assert( normalizedMagnitude >= 0 && normalizedMagnitude <= 1, `invalid normalizedStrength: ${normalizedMagnitude}` );
     return normalizedMagnitude;
   }
+
+  /**
+   * Gets the SpriteImage used to visualize a point in the field -- a compass needle.
+   */
+  private static getSpriteImage( compassNeedleNorthColor: Color, compassNeedleSouthColor: Color ): SpriteImage {
+
+    // Convert a CompassNeedleNode to a Sprite.
+    const compassNeedleNode = new CompassNeedleNode( {
+      northFill: compassNeedleNorthColor,
+      southFill: compassNeedleSouthColor,
+
+      // Apply a scale to increase resolution (we'll apply the inverse scale when rendering).
+      scale: COMPASS_NEEDLE_RESOLUTION_MULTIPLIER
+    } );
+
+    let spriteImage!: SpriteImage;
+
+    compassNeedleNode.toCanvas( ( canvas, x, y, width, height ) => {
+      spriteImage = new SpriteImage( canvas, new Vector2( ( x + compassNeedleNode.width / 2 ), ( y + compassNeedleNode.height / 2 ) ), {
+
+        // Mipmapping was added to address pixelation reported in https://github.com/phetsims/faradays-electromagnetic-lab/issues/113.
+        // It looked too "sharp" without mipmapping at the normal view distance, so we'll have these generated.
+        mipmap: true,
+        mipmapBias: -0.7
+      } );
+    } );
+
+    assert && assert( spriteImage );
+    return spriteImage;
+  }
 }
 
 /**