Re-upload atlas textures after page merges

addons/addon-webgl/src/WebglRenderer.ts

@@ -29,13 +29,7 @@ import { combinedDisposable, Disposable, MutableDisposable, toDisposable } from
 import { createRenderDimensions } from 'browser/renderer/shared/RendererUtils';
 
 const enum Constants {
-  /**
-   * Upper bound on how many times `renderRows` re-runs `_updateModel` after detecting a
-   * mid-update atlas page merge. A single retry should always suffice once every glyph
-   * needed by the frame is cached; the cap exists purely as a safety net against an
-   * unexpected runaway, not as a tuned value.
-   */
-  MERGE_RETRY_LIMIT = 3
+  MERGE_RETRY_LIMIT = 32
 }
 
 export class WebglRenderer extends Disposable implements IRenderer {
@@ -385,13 +379,18 @@ export class WebglRenderer extends Disposable implements IRenderer {
       this._updateModel(start, end);
     }
 
-    // A mid-update atlas page merge shifts cached glyphs to new texture pages, leaving
-    // stale texturePage values in the vertex buffer. Re-run a full update if that happened.
+    // A mid-update atlas page merge invalidates vertex data and may not bump the host
+    // page's version, so re-run the update and force a full texture rebind.
+    let merged = false;
     let mergeRetries = 0;
     while (this._charAtlas && this._glyphRenderer.value.beginFrame() && mergeRetries++ < Constants.MERGE_RETRY_LIMIT) {
+      merged = true;
       this._clearModel(true);
       this._updateModel(0, this._terminal.rows - 1);
     }
+    if (merged) {
+      this._glyphRenderer.value.invalidateAtlasTextures();
+    }
 
     // Render
     this._rectangleRenderer.value.renderBackgrounds();