Release Navara overlay targets and sprite images on repeated globe switches

src/globe/navara/movers/moverMesh.js

@@ -217,7 +217,14 @@ function atlasTexture(atlas, encoded, onLoad) {
   const texture = cesiumSampling(new Texture(), encoded);
   const image = new Image();
   image.crossOrigin = 'anonymous';
+  const release = () => {
+    image.onload = null;
+    texture.image = null;
+    texture.removeEventListener('dispose', release);
+  };
+  texture.addEventListener('dispose', release);
   image.onload = () => {
+    image.onload = null;
     texture.image = image;
     texture.needsUpdate = true;
     onLoad();

src/globe/navara/movers/moverMesh.test.mjs

@@ -23,6 +23,37 @@ const spriteOptions = normalizeMoverSetOptions({
   },
 });
 
+test('disposing a sprite atlas drops decoded images and detaches pending load callbacks', (t) => {
+  const previous = globalThis.Image;
+  let image;
+  globalThis.Image = class {
+    constructor() { image = this; }
+  };
+  t.after(() => {
+    if (previous) globalThis.Image = previous;
+    else delete globalThis.Image;
+  });
+  const options = normalizeMoverSetOptions({
+    ...spriteOptions, sprite: {
+      sizePx: 24, atlas: { url: '/bracket.svg', cells: { a: [0, 0, 1, 1] } },
+    },
+  });
+  for (const loaded of [false, true]) {
+    let frames = 0;
+    const mover = createMoverMesh(options, createMoverStore(options), {
+      onTextureLoad: () => frames++,
+    });
+    if (loaded) {
+      image.onload();
+      assert.equal(mover.mesh.material.map.image, image);
+    }
+    mover.dispose();
+    assert.equal(image.onload, null);
+    assert.equal(mover.mesh.material.map.image, null);
+    assert.equal(frames, Number(loaded));
+  }
+});
+
 const basicShader = () => ({
   uniforms: UniformsUtils.clone(ShaderLib.basic.uniforms),
   vertexShader: ShaderLib.basic.vertexShader,

src/globe/navara/overlay.js

@@ -43,6 +43,17 @@ class GevOverlayEffectDesc extends EffectDesc {
     );
   }
 
+  onDestroy() {
+    // Navara removes the pass from its composer; our pass owns its GPU target
+    // and context event handlers until it is explicitly disposed.
+    const pass = this.raw?.rawPass;
+    try {
+      super.onDestroy();
+    } finally {
+      pass?.dispose();
+    }
+  }
+
   // Each drawn frame: the scene depth the overlays test against, then each
   // overlay's own per-frame work (pixel footprint, origin, viewport).
   update(time) {