Don't use dirty rect putImageData option on platforms where it's buggy.

Fixes #95

src/canUseCanvasDirtyRect.ts

@@ -0,0 +1,30 @@
+/**
+ * Chrome on Windows, Android and Chrome OS appears to be buggy when using the
+ * dirty rect option of putImageData. This function returns true if we can use
+ * it.
+ * https://github.com/mihaip/infinite-mac/issues/95
+ */
+export function canUseCanvasDirtyRect(): boolean {
+    if (cached !== undefined) {
+        return cached;
+    }
+
+    cached = check();
+    return cached;
+}
+
+function check(): boolean {
+    // Ideally we'd test for this bug via putImageData and getImageData, but
+    // the read back pixels are OK (at least in simple test cases).
+    const {userAgent} = navigator;
+    if (!userAgent.includes("Chrome")) {
+        return true;
+    }
+    return (
+        !userAgent.includes("Android") &&
+        !userAgent.includes("CrOS") &&
+        !userAgent.includes("Windows")
+    );
+}
+
+let cached: boolean | undefined;

src/emulator/emulator-ui.ts

@@ -70,6 +70,7 @@ import {
     SharedMemoryEmulatorClipboard,
 } from "./emulator-ui-clipboard";
 import type {MachineDef} from "../machines";
+import {canUseCanvasDirtyRect} from "../canUseCanvasDirtyRect";
 
 export type EmulatorConfig = {
     machine: MachineDef;
@@ -652,7 +653,7 @@ export class Emulator {
         }
         this.#screenImageData.data.set(imageData);
         const dirtyRect = this.#video.consumeBlitRect();
-        if (dirtyRect) {
+        if (dirtyRect && canUseCanvasDirtyRect()) {
             this.#screenCanvasContext.putImageData(
                 this.#screenImageData,
                 0,