From 9ba5a3aba94354c152937d0f86999d5589ce7416 Mon Sep 17 00:00:00 2001
From: German Khokhlov <ouchlock@gmail.com>
Date: Thu, 29 Oct 2026 19:26:47 +0400
Subject: [PATCH] fix(navara): invalidate cached glyphs after context loss

Clear the display-resource signature used by static sprite reuse when the WebGL context is lost or restored. Cover both events and verify that caching resumes after the redraw.
---
 src/globe/navara/overlayPass.js       |  6 ++++--
 src/globe/navara/overlayPass.test.mjs | 16 ++++++++++++++++
 2 files changed, 20 insertions(+), 2 deletions(-)

diff --git a/src/globe/navara/overlayPass.js b/src/globe/navara/overlayPass.js
index e3a4dd26d..d6be5dc6a 100644
--- a/src/globe/navara/overlayPass.js
+++ b/src/globe/navara/overlayPass.js
@@ -48,12 +48,14 @@ void main(){vec4 bg=texture2D(image,vUv);vec4 glyph=texture2D(glyphs,vUv);if(gly
   });
   const quad = new FullScreenQuad(composite);
   const canvas = renderer.domElement;
+  const display = { target, composite, quad, canvas, signature: null };
   const invalidate = () => {
-    target.signature = null;
+    display.signature = null;
   };
   canvas?.addEventListener('webglcontextlost', invalidate);
   canvas?.addEventListener('webglcontextrestored', invalidate);
-  return { target, composite, quad, canvas, invalidate };
+  display.invalidate = invalidate;
+  return display;
 }
 
 function staticSpriteSignature(scene, camera, renderer, width, height) {
diff --git a/src/globe/navara/overlayPass.test.mjs b/src/globe/navara/overlayPass.test.mjs
index 93d31c5fe..b5119f581 100644
--- a/src/globe/navara/overlayPass.test.mjs
+++ b/src/globe/navara/overlayPass.test.mjs
@@ -30,6 +30,7 @@ function harness() {
     pass = new GevOverlayPass(scene, new PerspectiveCamera(), overlay),
     draws = [];
   const renderer = {
+    domElement: new EventTarget(),
     autoClear: true,
     outputColorSpace: SRGBColorSpace,
     getPixelRatio: () => 1,
@@ -190,6 +191,21 @@ test('static sprite glyphs reuse their target until instance data changes', () =
   h.pass.camera.updateMatrixWorld();
   h.pass.render(h.renderer, input, output);
   assert.equal(h.draws.filter((draw) => draw.object === h.scene).length, 3);
+  for (const type of ['webglcontextlost', 'webglcontextrestored']) {
+    h.renderer.domElement.dispatchEvent(new Event(type));
+    const before = h.draws.filter((draw) => draw.object === h.scene).length;
+    h.pass.render(h.renderer, input, output);
+    assert.equal(
+      h.draws.filter((draw) => draw.object === h.scene).length,
+      before + 1,
+      `${type} invalidates the cached GPU pixels`,
+    );
+    h.pass.render(h.renderer, input, output);
+    assert.equal(
+      h.draws.filter((draw) => draw.object === h.scene).length,
+      before + 1,
+    );
+  }
   h.pass.dispose();
   texture.dispose();
   mesh.geometry.dispose();