fix(exporter): prefer WebGL before WebGPU in default/auto modern export mode on Linux

src/lib/exporter/modernFrameRenderer.test.ts

@@ -231,6 +231,67 @@ it("bypasses blur annotation compositing during gaps and clears stale composite
 });
 
 describe("ModernFrameRenderer Pixi lifecycle", () => {
+	it("tries WebGL before WebGPU in default/auto mode when both are nominally available", async () => {
+		pixiApplicationInstancesMock.length = 0;
+		pixiInitializationErrorsMock.length = 0;
+		// Default/auto mode with navigator.gpu present used to try WebGPU first, which
+		// crashed on the broken Linux path before any fallback could engage. The fix makes
+		// WebGL the first attempt in that case, so a nominally-present-but-crashing WebGPU
+		// backend no longer blocks the export.
+		vi.stubGlobal("navigator", { gpu: {} });
+
+		try {
+			const renderer = createRenderer() as unknown as {
+				config: { preferredRenderBackend?: "webgl" | "webgpu" };
+				createPixiApplication: (
+					canvas: HTMLCanvasElement,
+				) => Promise<{ backend: "webgl" | "webgpu" }>;
+			};
+
+			await expect(
+				renderer.createPixiApplication({} as HTMLCanvasElement),
+			).resolves.toMatchObject({
+				backend: "webgl",
+			});
+
+			// WebGL succeeded on the first attempt; WebGPU was never tried.
+			expect(pixiApplicationInstancesMock).toHaveLength(1);
+		} finally {
+			vi.unstubAllGlobals();
+		}
+	});
+
+	it("falls back to WebGPU when WebGL fails in default/auto mode", async () => {
+		pixiApplicationInstancesMock.length = 0;
+		pixiInitializationErrorsMock.length = 0;
+		pixiInitializationErrorsMock.push(new Error("WebGL initialization failed"));
+		vi.stubGlobal("navigator", { gpu: {} });
+
+		try {
+			const renderer = createRenderer() as unknown as {
+				config: { preferredRenderBackend?: "webgl" | "webgpu" };
+				createPixiApplication: (
+					canvas: HTMLCanvasElement,
+				) => Promise<{ backend: "webgl" | "webgpu" }>;
+			};
+
+			await expect(
+				renderer.createPixiApplication({} as HTMLCanvasElement),
+			).resolves.toMatchObject({
+				backend: "webgpu",
+			});
+
+			// WebGL failed first; WebGPU succeeded on the second attempt.
+			expect(pixiApplicationInstancesMock).toHaveLength(2);
+			// The failed WebGL attempt is destroyed; the successful WebGPU instance survives.
+			expect(pixiApplicationInstancesMock[0].destroy).not.toHaveBeenCalled();
+			expect(pixiApplicationInstancesMock[0].stage.destroy).toHaveBeenCalledTimes(1);
+			expect(pixiApplicationInstancesMock[0].renderer.destroy).toHaveBeenCalledTimes(1);
+		} finally {
+			vi.unstubAllGlobals();
+		}
+	});
+
 	it("continues to the next backend when failed-init cleanup would throw", async () => {
 		pixiApplicationInstancesMock.length = 0;
 		pixiInitializationErrorsMock.length = 0;
@@ -244,6 +305,8 @@ describe("ModernFrameRenderer Pixi lifecycle", () => {
 					canvas: HTMLCanvasElement,
 				) => Promise<{ backend: "webgl" | "webgpu" }>;
 			};
+			// Explicit `preferredRenderBackend: "webgpu"` still tries WebGPU first;
+			// the bug fix only changes the default/auto order.
 			renderer.config.preferredRenderBackend = "webgpu";
 
 			await expect(
@@ -252,6 +315,7 @@ describe("ModernFrameRenderer Pixi lifecycle", () => {
 				backend: "webgl",
 			});
 
+			// WebGPU failed first; WebGL succeeded on the second attempt.
 			expect(pixiApplicationInstancesMock).toHaveLength(2);
 			expect(pixiApplicationInstancesMock[0].destroy).not.toHaveBeenCalled();
 			expect(pixiApplicationInstancesMock[0].stage.destroy).toHaveBeenCalledTimes(1);

src/lib/exporter/modernFrameRenderer.ts

@@ -629,7 +629,7 @@ export class FrameRenderer {
 				: preferredRenderBackend === "webgpu"
 					? ["webgpu", "webgl"]
 					: typeof navigator !== "undefined" && "gpu" in navigator
-						? ["webgpu", "webgl"]
+						? ["webgl", "webgpu"]
 						: ["webgl"];
 		const failures: PixiRendererAttempt[] = [];