Add pointer lock key combo

Fixes #737

app/streaming/input/input.cpp

@@ -21,6 +21,7 @@ SdlInputHandler::SdlInputHandler(StreamingPreferences& prefs, NvComputer*, int s
       m_MousePositionLock(0),
       m_MouseWasInVideoRegion(false),
       m_PendingMouseButtonsAllUpOnVideoRegionLeave(false),
+      m_PointerRegionLockActive(false),
       m_FakeCaptureActive(false),
       m_CaptureSystemKeysMode(prefs.captureSysKeysMode),
       m_MouseCursorCapturedVisibilityState(SDL_DISABLE),
@@ -115,6 +116,11 @@ SdlInputHandler::SdlInputHandler(StreamingPreferences& prefs, NvComputer*, int s
     m_SpecialKeyCombos[KeyComboPasteText].scanCode = SDL_SCANCODE_V;
     m_SpecialKeyCombos[KeyComboPasteText].enabled = true;
 
+    m_SpecialKeyCombos[KeyComboTogglePointerRegionLock].keyCombo = KeyComboTogglePointerRegionLock;
+    m_SpecialKeyCombos[KeyComboTogglePointerRegionLock].keyCode = SDLK_l;
+    m_SpecialKeyCombos[KeyComboTogglePointerRegionLock].scanCode = SDL_SCANCODE_L;
+    m_SpecialKeyCombos[KeyComboTogglePointerRegionLock].enabled = true;
+
     m_OldIgnoreDevices = SDL_GetHint(SDL_HINT_GAMECONTROLLER_IGNORE_DEVICES);
     m_OldIgnoreDevicesExcept = SDL_GetHint(SDL_HINT_GAMECONTROLLER_IGNORE_DEVICES_EXCEPT);
 
@@ -389,15 +395,6 @@ bool SdlInputHandler::isSystemKeyCaptureActive()
 void SdlInputHandler::setCaptureActive(bool active)
 {
     if (active) {
-        // If we're in full-screen exclusive mode, grab the cursor so it can't accidentally leave our window.
-        if ((SDL_GetWindowFlags(m_Window) & SDL_WINDOW_FULLSCREEN_DESKTOP) == SDL_WINDOW_FULLSCREEN) {
-#if SDL_VERSION_ATLEAST(2, 0, 15)
-            SDL_SetWindowMouseGrab(m_Window, SDL_TRUE);
-#else
-            SDL_SetWindowGrab(m_Window, SDL_TRUE);
-#endif
-        }
-
         // If we're in relative mode, try to activate SDL's relative mouse mode
         if (m_AbsoluteMouseMode || SDL_SetRelativeMouseMode(SDL_TRUE) < 0) {
             // Relative mouse mode didn't work or was disabled, so we'll just hide the cursor
@@ -433,16 +430,11 @@ void SdlInputHandler::setCaptureActive(bool active)
         else {
             SDL_SetRelativeMouseMode(SDL_FALSE);
         }
-
-#if SDL_VERSION_ATLEAST(2, 0, 15)
-        // Allow the cursor to leave the bounds of our window again.
-        SDL_SetWindowMouseGrab(m_Window, SDL_FALSE);
-#else
-        // Allow the cursor to leave the bounds of our window again.
-        SDL_SetWindowGrab(m_Window, SDL_FALSE);
-#endif
     }
 
+    // Update mouse pointer region constraints
+    updatePointerRegionLock();
+
     // Now update the keyboard grab
     updateKeyboardGrabState();
 }

app/streaming/input/input.h

@@ -93,6 +93,8 @@ public:
 
     void updateKeyboardGrabState();
 
+    void updatePointerRegionLock();
+
     static
     QString getUnmappedGamepads();
 
@@ -106,6 +108,7 @@ private:
         KeyComboToggleCursorHide,
         KeyComboToggleMinimize,
         KeyComboPasteText,
+        KeyComboTogglePointerRegionLock,
         KeyComboMax
     };
 
@@ -156,6 +159,7 @@ private:
     SDL_atomic_t m_MousePositionUpdated;
     bool m_MouseWasInVideoRegion;
     bool m_PendingMouseButtonsAllUpOnVideoRegionLeave;
+    bool m_PointerRegionLockActive;
 
     int m_GamepadMask;
     GamepadState m_GamepadState[MAX_GAMEPADS];

app/streaming/input/keyboard.cpp

@@ -126,6 +126,13 @@ void SdlInputHandler::performSpecialKeyCombo(KeyCombo combo)
         break;
     }
 
+    case KeyComboTogglePointerRegionLock:
+        SDL_LogInfo(SDL_LOG_CATEGORY_APPLICATION,
+                    "Detected pointer region lock toggle combo");
+        m_PointerRegionLockActive = !m_PointerRegionLockActive;
+        updatePointerRegionLock();
+        break;
+
     default:
         Q_UNREACHABLE();
     }

app/streaming/input/mouse.cpp

@@ -272,3 +272,48 @@ Uint32 SdlInputHandler::mouseMoveTimerCallback(Uint32 interval, void *param)
 
     return interval;
 }
+
+void SdlInputHandler::updatePointerRegionLock()
+{
+    // Pointer region lock is irrelevant in relative mouse mode
+    if (SDL_GetRelativeMouseMode()) {
+        return;
+    }
+
+    // If we're in full-screen exclusive mode or region lock is enabled, grab the cursor so it can't accidentally leave our window.
+    if (isCaptureActive() &&
+            (m_PointerRegionLockActive ||
+            (SDL_GetWindowFlags(m_Window) & SDL_WINDOW_FULLSCREEN_DESKTOP) == SDL_WINDOW_FULLSCREEN)) {
+#if SDL_VERSION_ATLEAST(2, 0, 18)
+        SDL_Rect src, dst;
+
+        src.x = src.y = 0;
+        src.w = m_StreamWidth;
+        src.h = m_StreamHeight;
+
+        dst.x = dst.y = 0;
+        SDL_GetWindowSize(m_Window, &dst.w, &dst.h);
+
+        // Use the stream and window sizes to determine the video region
+        StreamUtils::scaleSourceToDestinationSurface(&src, &dst);
+
+        // SDL 2.0.18 lets us lock the cursor to a specific region
+        SDL_SetWindowMouseRect(m_Window, &dst);
+#elif SDL_VERSION_ATLEAST(2, 0, 15)
+        // SDL 2.0.15 only lets us lock the cursor to the whole window
+        SDL_SetWindowMouseGrab(m_Window, SDL_TRUE);
+#else
+        SDL_SetWindowGrab(m_Window, SDL_TRUE);
+#endif
+    }
+    else {
+        // Allow the cursor to leave the bounds of our video region or window
+#if SDL_VERSION_ATLEAST(2, 0, 18)
+        SDL_SetWindowMouseRect(m_Window, nullptr);
+#elif SDL_VERSION_ATLEAST(2, 0, 15)
+        SDL_SetWindowMouseGrab(m_Window, SDL_FALSE);
+#else
+        SDL_SetWindowGrab(m_Window, SDL_FALSE);
+#endif
+    }
+}

app/streaming/session.cpp

@@ -1708,6 +1708,9 @@ void Session::execInternal()
             // of recreating our decoder at the time the HDR transition happens.
             m_VideoDecoder->setHdrMode(LiGetCurrentHostDisplayHdrMode());
 
+            // After a window resize, we need to reset the pointer lock region
+            m_InputHandler->updatePointerRegionLock();
+
             SDL_AtomicUnlock(&m_DecoderLock);
             break;