Join wait: animated waiting screen instead of "Not Responding"

The relay seat-wait loop (RelayRequestSeat -- the join/join_lan "patient
walk-up") blocked the window thread's message pump for its whole 30-minute
patience window: dial (2s timeout) -> Sleep(2000) -> repeat, with status
going only to the parent bat console.  Windows flagged the frozen game
window "Not Responding" until the operator started the session
(user-reported).

- BTWaitScreenPaint (L4VIDEO.cpp): a GDI waiting screen on the main window
  -- headline + detail line in the console green + a 12-segment marching
  spinner phased on the tick clock.  Pure GDI: flicker-free during the
  seat wait (no D3D presenting yet), and re-painted after each
  ExecuteIdle Present so the WaitingForEgg phase (previously a bare black
  frame) shows "WAITING FOR MISSION ASSIGNMENT" too.
- RelayWaitTick (L4NET.CPP): PeekMessage pump + paint.  The outer dial
  loop's Sleep(2000) becomes 20 pumped 100ms slices ("WAITING FOR THE
  OPERATOR'S SESSION" / "session at <ip:port> -- close this window to
  cancel"); the inner seat-reply wait pumps per 200ms select slice.

Verified live against a dead relay address: window-only PrintWindow capture
shows the animated screen, and user32 IsHungAppWindow (the API behind "Not
Responding") reports FALSE throughout the wait.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

engine/MUNGA_L4/L4NET.CPP

@@ -1506,6 +1506,24 @@ void L4NetworkManager::HostDisconnectedMessageHandler(HostDisconnectedMessage* H
 // relaySelf and everything downstream (egg self-match, HELLO) proceeds as if
 // BT_SELF had been set.  SEAT_FULL / timeout => False.
 //
+//
+// RelayWaitTick -- pump the window thread + paint the animated waiting screen
+// (join/join_lan UX fix 2026-07-22: the seat-wait loop blocked the message
+// pump for its whole 30-min patience window, so the main window showed "Not
+// Responding" until the console started the game).
+//
+static void RelayWaitTick(const char *line1, const char *line2)
+{
+	MSG msg;
+	while (PeekMessageA(&msg, NULL, 0, 0, PM_REMOVE))
+	{
+		TranslateMessage(&msg);
+		DispatchMessageA(&msg);
+	}
+	extern void BTWaitScreenPaint(const char *, const char *);
+	BTWaitScreenPaint(line1, line2);
+}
+
 Logical L4NetworkManager::RelayRequestSeat()
 {
 	//
@@ -1541,7 +1559,17 @@ Logical L4NetworkManager::RelayRequestSeat()
 			{
 				BTRelayWaitStatus("\n");
 			}
-			Sleep(2000);
+			{
+				char detail[128];
+				sprintf(detail, "session at %s:%d -- close this window to cancel",
+					inet_ntoa(relayGameAddress.sin_addr),
+					(int)ntohs(relayGameAddress.sin_port) - 1);
+				for (int slice = 0; slice < 20; ++slice)	// 2s, pumped + animated
+				{
+					RelayWaitTick("WAITING FOR THE OPERATOR'S SESSION", detail);
+					Sleep(100);
+				}
+			}
 			continue;
 		}
 		Logical got_seat = False;
@@ -1564,6 +1592,8 @@ Logical L4NetworkManager::RelayRequestSeat()
 				tv.tv_usec = 200000;
 				if (select(0, &read_set, NULL, NULL, &tv) != 1)
 				{
+					RelayWaitTick("WAITING FOR THE OPERATOR'S SESSION",
+						"requesting a seat...");
 					continue;
 				}
 				int received = recv(seat_socket, reply + have,

engine/MUNGA_L4/L4VIDEO.cpp

@@ -8772,6 +8772,66 @@ void DPLRenderer::ExecuteImplementation(RendererComplexity, RendererOrigin::Inte
 #endif
 }
 
+//
+// BTWaitScreenPaint -- the animated "waiting" screen (join/join_lan UX fix,
+// 2026-07-22).  Pure GDI over the main window: used while the relay seat-wait
+// loop blocks startup (no D3D presenting yet -> flicker-free) and re-painted
+// after each ExecuteIdle Present during WaitingForEgg (the black idle frame).
+// A 12-segment spinner phases on the tick clock; text centered above it.
+//
+void BTWaitScreenPaint(const char *line1, const char *line2)
+{
+	extern void *BTResolveMainWindow();
+	HWND wnd = (HWND)BTResolveMainWindow();
+	if (wnd == NULL)
+		return;
+	HDC dc = GetDC(wnd);
+	if (dc == NULL)
+		return;
+	RECT rc;
+	GetClientRect(wnd, &rc);
+	int w = rc.right - rc.left, h = rc.bottom - rc.top;
+	FillRect(dc, &rc, (HBRUSH)GetStockObject(BLACK_BRUSH));
+
+	static HFONT s_font = NULL, s_fontDim = NULL;
+	if (s_font == NULL)
+	{
+		s_font = CreateFontA(30, 0, 0, 0, FW_BOLD, 0, 0, 0, DEFAULT_CHARSET,
+			OUT_DEFAULT_PRECIS, CLIP_DEFAULT_PRECIS, DEFAULT_QUALITY,
+			FIXED_PITCH | FF_MODERN, "Consolas");
+		s_fontDim = CreateFontA(20, 0, 0, 0, FW_NORMAL, 0, 0, 0, DEFAULT_CHARSET,
+			OUT_DEFAULT_PRECIS, CLIP_DEFAULT_PRECIS, DEFAULT_QUALITY,
+			FIXED_PITCH | FF_MODERN, "Consolas");
+	}
+	SetBkMode(dc, TRANSPARENT);
+	HGDIOBJ old_font = SelectObject(dc, s_font);
+	SetTextColor(dc, RGB(64, 255, 64));
+	RECT r1 = { 0, h / 2 - 70, w, h / 2 - 30 };
+	DrawTextA(dc, line1, -1, &r1, DT_CENTER | DT_SINGLELINE | DT_VCENTER);
+	SelectObject(dc, s_fontDim);
+	SetTextColor(dc, RGB(24, 140, 24));
+	RECT r2 = { 0, h / 2 - 24, w, h / 2 + 8 };
+	DrawTextA(dc, line2, -1, &r2, DT_CENTER | DT_SINGLELINE | DT_VCENTER);
+	SelectObject(dc, old_font);
+
+	// the spinner: 12 segments, three brightness tiers marching clockwise
+	int cx = w / 2, cy = h / 2 + 80, r_in = 18, r_out = 34;
+	int phase = (int)((GetTickCount() / 80UL) % 12UL);
+	for (int i = 0; i < 12; ++i)
+	{
+		int age = (i - phase + 12) % 12;
+		int lum = (age == 0) ? 255 : (age < 3) ? 150 : 60;
+		HPEN pen = CreatePen(PS_SOLID, 4, RGB(lum / 4, lum, lum / 4));
+		HGDIOBJ old_pen = SelectObject(dc, pen);
+		double a = i * 3.14159265 / 6.0;
+		MoveToEx(dc, cx + (int)(r_in * cos(a)), cy + (int)(r_in * sin(a)), NULL);
+		LineTo(dc, cx + (int)(r_out * cos(a)), cy + (int)(r_out * sin(a)));
+		SelectObject(dc, old_pen);
+		DeleteObject(pen);
+	}
+	ReleaseDC(wnd, dc);
+}
+
 void DPLRenderer::ExecuteIdle()
 {
 	HRESULT hr;
@@ -8782,7 +8842,13 @@ void DPLRenderer::ExecuteIdle()
 
 	hr = mDevice->EndScene();
 
-	if (mDevice->Present(NULL, NULL, NULL, NULL) == D3DERR_DEVICELOST)
+	// WaitingForEgg is a black frame -- overlay the waiting screen (GDI,
+	// repainted after every Present; join/join_lan UX fix 2026-07-22).
+	{
+		HRESULT present_hr = mDevice->Present(NULL, NULL, NULL, NULL);
+		BTWaitScreenPaint("WAITING FOR MISSION ASSIGNMENT",
+			"the operator starts the session from the console");
+		if (present_hr == D3DERR_DEVICELOST)
 	{
 		int bbCount = mPresentParams.BackBufferCount;
 		int bbWidth = mPresentParams.BackBufferWidth;
@@ -8797,6 +8863,7 @@ void DPLRenderer::ExecuteIdle()
 		mPresentParams.BackBufferWidth = bbWidth;
 		mPresentParams.BackBufferHeight = bbHeight;
 	}
+	}
 }
 //
 //#############################################################################