implementations/Crafter.Graphics-Window.cpp

@@ -698,7 +698,20 @@ void Window::StartSync() {
 	}
     #endif
     #ifdef CRAFTER_GRAPHICS_WINDOW_WIN32
+    // While updating, the FIFO present inside Update() paces this loop to the
+    // vblank, so the PeekMessage poll is vsync-gated. While NOT updating
+    // (paused / minimized / stopped) nothing throttles the loop, and a bare
+    // PeekMessage(PM_REMOVE) spin pins a core at 100% while uselessly re-running
+    // Gamepad::Tick() (mutex + per-pad COM reads) and onBeforeUpdate every
+    // iteration. Block on the message queue instead, waking on input or after a
+    // short timeout so gamepad polling / onBeforeUpdate still tick at a sane
+    // rate (e.g. to detect a controller button asking to resume).
+    constexpr DWORD kPausedPollIntervalMs = 16;
     while(open) {
+        if (!updating) {
+            MsgWaitForMultipleObjectsEx(0, nullptr, kPausedPollIntervalMs,
+                                        QS_ALLINPUT, MWMO_INPUTAVAILABLE);
+        }
         MSG msg;
         while (PeekMessage(&msg, NULL, 0, 0, PM_REMOVE)) {
             TranslateMessage(&msg);