Merge PR #1056 for export regression validation

src/lib/exporter/modernFrameRenderer.test.ts

@@ -260,6 +260,34 @@ describe("ModernFrameRenderer Pixi lifecycle", () => {
 			vi.unstubAllGlobals();
 		}
 	});
+
+	it("defaults to WebGL when no backend is preferred, even when WebGPU is available", async () => {
+		pixiApplicationInstancesMock.length = 0;
+		pixiInitializationErrorsMock.length = 0;
+		// Linux Chromium exposes navigator.gpu, but Pixi's WebGPU bind-group path crashes
+		// with "Cannot read properties of undefined (reading '_resourceType')".
+		vi.stubGlobal("navigator", { gpu: {} });
+
+		try {
+			const renderer = createRenderer() as unknown as {
+				config: { preferredRenderBackend?: "webgl" | "webgpu" };
+				createPixiApplication: (
+					canvas: HTMLCanvasElement,
+				) => Promise<{ backend: "webgl" | "webgpu" }>;
+			};
+			renderer.config.preferredRenderBackend = undefined;
+
+			await expect(renderer.createPixiApplication({} as HTMLCanvasElement)).resolves
+				.toMatchObject({
+					backend: "webgl",
+				});
+
+			expect(pixiInitializationErrorsMock).toHaveLength(0);
+			expect(pixiApplicationInstancesMock).toHaveLength(1);
+		} finally {
+			vi.unstubAllGlobals();
+		}
+	});
 });
 
 describe("ModernFrameRenderer blur export path", () => {

src/lib/exporter/modernFrameRenderer.ts

@@ -623,14 +623,14 @@ export class FrameRenderer {
 		};
 
 		const preferredRenderBackend = this.config.preferredRenderBackend;
+		// WebGPU is opt-in. Linux Chromium exposes navigator.gpu, but Pixi's WebGPU
+		// bind-group path can crash mid-render with
+		// "Cannot read properties of undefined (reading '_resourceType')", which is only
+		// recoverable by restarting the whole export on a different backend.
 		const backendOrder: ExportRenderBackend[] =
-			preferredRenderBackend === "webgl"
-				? ["webgl", "webgpu"]
-				: preferredRenderBackend === "webgpu"
-					? ["webgpu", "webgl"]
-					: typeof navigator !== "undefined" && "gpu" in navigator
-						? ["webgpu", "webgl"]
-						: ["webgl"];
+			preferredRenderBackend === "webgpu"
+				? ["webgpu", "webgl"]
+				: ["webgl", "webgpu"];
 		const failures: PixiRendererAttempt[] = [];
 
 		for (const backend of backendOrder) {

src/lib/exporter/modernVideoExporter.ts

@@ -49,6 +49,7 @@ import {
 } from "@/lib/wallpapers";
 import { AudioProcessor, isAacAudioEncodingSupported } from "./audioEncoder";
 import {
+	getDefaultLightningRenderBackend,
 	normalizeLightningRuntimePlatform,
 	shouldPreferNativeAutoBackend,
 	shouldPreferNativeStaticLayoutBeforeBreeze,
@@ -604,7 +605,8 @@ export class ModernVideoExporter {
 					timelineEffects: this.config.clipRegions !== undefined,
 					width: this.config.width,
 					height: this.config.height,
-					preferredRenderBackend: undefined,
+					preferredRenderBackend:
+						this.config.preferredRenderBackend ?? getDefaultLightningRenderBackend(),
 					wallpaper: this.config.wallpaper,
 					zoomRegions: this.config.zoomRegions,
 					showShadow: this.config.showShadow,