SDL: Use SDL_SetWindowMouseRect to confine the mouse area

scummvm · Nov 19, 2021 · c6836c9 · c6836c9
1 parent 0b011e9
commit c6836c9
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Showing 5 changed files with 40 additions and 0 deletions.
diff --git a/backends/graphics/sdl/sdl-graphics.cpp b/backends/graphics/sdl/sdl-graphics.cpp
@@ -282,6 +282,10 @@ void SdlGraphicsManager::setSystemMousePosition(const int x, const int y) {
 	}
 }
 
+void SdlGraphicsManager::notifyActiveAreaChanged() {
+	_window->setMouseRect(_activeArea.drawRect);
+}
+
 void SdlGraphicsManager::handleResizeImpl(const int width, const int height) {
 	_forceRedraw = true;
 }

diff --git a/backends/graphics/sdl/sdl-graphics.h b/backends/graphics/sdl/sdl-graphics.h
@@ -182,6 +182,8 @@ class SdlGraphicsManager : virtual public WindowedGraphicsManager, public Common
 
 	void setSystemMousePosition(const int x, const int y) override;
 
+	void notifyActiveAreaChanged() override;
+
 	void handleResizeImpl(const int width, const int height) override;
 
 #if SDL_VERSION_ATLEAST(2, 0, 0)

diff --git a/backends/graphics/windowed.h b/backends/graphics/windowed.h
@@ -63,6 +63,7 @@ class WindowedGraphicsManager : virtual public GraphicsManager {
 		_activeArea.height = getOverlayHeight();
 		_overlayVisible = true;
 		_forceRedraw = true;
+		notifyActiveAreaChanged();
 	}
 
 	void hideOverlay() override {
@@ -74,6 +75,7 @@ class WindowedGraphicsManager : virtual public GraphicsManager {
 		_activeArea.height = getHeight();
 		_overlayVisible = false;
 		_forceRedraw = true;
+		notifyActiveAreaChanged();
 	}
 
 	bool isOverlayVisible() const override { return _overlayVisible; }
@@ -211,6 +213,7 @@ class WindowedGraphicsManager : virtual public GraphicsManager {
 			_activeArea.width = getWidth();
 			_activeArea.height = getHeight();
 		}
+		notifyActiveAreaChanged();
 	}
 
 	/**
@@ -222,6 +225,11 @@ class WindowedGraphicsManager : virtual public GraphicsManager {
 	 */
 	virtual void setSystemMousePosition(const int x, const int y) = 0;
 
+	/**
+	 * Called whenever the active area has changed.
+	 */
+	virtual void notifyActiveAreaChanged() {}
+
 	bool showMouse(bool visible) override {
 		if (_cursorVisible == visible) {
 			return visible;

diff --git a/backends/platform/sdl/sdl-window.cpp b/backends/platform/sdl/sdl-window.cpp
@@ -39,6 +39,7 @@ SdlWindow::SdlWindow() :
 #endif
 	_inputGrabState(false), _inputLockState(false)
 	{
+		memset(&grabRect, 0, sizeof(grabRect));
 
 #if SDL_VERSION_ATLEAST(2, 0, 0)
 #elif SDL_VERSION_ATLEAST(1, 2, 10)
@@ -150,6 +151,9 @@ void SdlWindow::grabMouse(bool grab) {
 #if SDL_VERSION_ATLEAST(2, 0, 0)
 	if (_window) {
 		SDL_SetWindowGrab(_window, grab ? SDL_TRUE : SDL_FALSE);
+#if SDL_VERSION_ATLEAST(2, 0, 17)
+		SDL_SetWindowMouseRect(_window, grab ? &grabRect : NULL);
+#endif
 	}
 	_inputGrabState = grab;
 #else
@@ -164,6 +168,19 @@ void SdlWindow::grabMouse(bool grab) {
 #endif
 }
 
+void SdlWindow::setMouseRect(const Common::Rect &rect) {
+	grabRect.x = rect.left;
+	grabRect.y = rect.top;
+	grabRect.w = rect.width();
+	grabRect.h = rect.height();
+
+#if SDL_VERSION_ATLEAST(2, 0, 17)
+	if (_inputGrabState || _lastFlags & fullscreenMask) {
+		SDL_SetWindowMouseRect(_window, &grabRect);
+	}
+#endif
+}
+
 bool SdlWindow::lockMouse(bool lock) {
 #if SDL_VERSION_ATLEAST(2, 0, 0)
 	SDL_SetRelativeMouseMode(lock ? SDL_TRUE : SDL_FALSE);
@@ -397,6 +414,9 @@ bool SdlWindow::createOrUpdateWindow(int width, int height, uint32 flags) {
 
 	const bool shouldGrab = (flags & SDL_WINDOW_INPUT_GRABBED) || fullscreenFlags;
 	SDL_SetWindowGrab(_window, shouldGrab ? SDL_TRUE : SDL_FALSE);
+#if SDL_VERSION_ATLEAST(2, 0, 17)
+	SDL_SetWindowMouseRect(_window, shouldGrab ? &grabRect : NULL);
+#endif
 
 	if (!_window) {
 		return false;

diff --git a/backends/platform/sdl/sdl-window.h b/backends/platform/sdl/sdl-window.h
@@ -51,6 +51,11 @@ class SdlWindow {
 	 */
 	void grabMouse(bool grab);
 
+	/**
+	 * Specify the area of the window to confine the mouse cursor.
+	 */
+	void setMouseRect(const Common::Rect &rect);
+
 	/**
 	 * Lock or unlock the mouse cursor within the window.
 	 */
@@ -124,6 +129,7 @@ class SdlWindow {
 private:
 	Common::Rect _desktopRes;
 	bool _inputGrabState, _inputLockState;
+	SDL_Rect grabRect;
 
 protected:
 	void getDisplayDpi(float *dpi, float *defaultDpi) const;