Map Qt6 device-independent coords before grabbing from physical coords.

psieg · Feb 10, 2024 · e52f5f4 · e52f5f4
1 parent e3fdd8a
commit e52f5f4
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Showing 2 changed files with 32 additions and 5 deletions.
diff --git a/Software/grab/GrabberBase.cpp b/Software/grab/GrabberBase.cpp
@@ -28,6 +28,11 @@
 #include "GrabberBase.hpp"
 #include "src/debug.h"
 #include <cmath>
+#include <QScreen>
+
+#ifdef Q_OS_WIN
+#include <windows.h>
+#endif
 
 namespace
 {
@@ -89,8 +94,18 @@ bool GrabberBase::isGrabbingStarted() const
 	return m_timer->isActive();
 }
 
-const GrabbedScreen * GrabberBase::screenOfRect(const QRect &rect) const
+const GrabbedScreen * GrabberBase::screenOfWidget(const QWidget& widget) const
 {
+#ifdef Q_OS_WIN
+	// Note that in Qt > 6 we can't use rect matching because the widget coords are in a device-independent
+	// coordinate system while the screen coords are in the physical one.
+	HMONITOR widgetMonitor = MonitorFromWindow(reinterpret_cast<HWND>(widget.winId()), MONITOR_DEFAULTTONULL);
+	for (int i = 0; i < _screensWithWidgets.size(); ++i) {
+		if (_screensWithWidgets[i].screenInfo.handle == widgetMonitor)
+			return &_screensWithWidgets[i];
+	}
+#else
+	QRect rect = widget.frameGeometry();
 	QPoint center = rect.center();
 	for (int i = 0; i < _screensWithWidgets.size(); ++i) {
 		if (_screensWithWidgets[i].screenInfo.rect.contains(center))
@@ -99,7 +114,8 @@ const GrabbedScreen * GrabberBase::screenOfRect(const QRect &rect) const
 	for (int i = 0; i < _screensWithWidgets.size(); ++i) {
 		if (_screensWithWidgets[i].screenInfo.rect.intersects(rect))
 			return &_screensWithWidgets[i];
-	}
+	};
+#endif
 	return NULL;
 }
 
@@ -145,10 +161,11 @@ void GrabberBase::grab()
 				_context->grabResult->append(qRgb(0,0,0));
 				continue;
 			}
-			QRect widgetRect = _context->grabWidgets->at(i)->frameGeometry();
+			const QWidget* widget = _context->grabWidgets->at(i);
+			QRect widgetRect = widget->frameGeometry();
 			getValidRect(widgetRect);
 
-			const GrabbedScreen *grabbedScreen = screenOfRect(widgetRect);
+			const GrabbedScreen *grabbedScreen = screenOfWidget(*widget);
 			if (grabbedScreen == NULL) {
 				DEBUG_HIGH_LEVEL << Q_FUNC_INFO << " widget is out of screen " << Debug::toString(widgetRect);
 				_context->grabResult->append(0);
@@ -157,6 +174,16 @@ void GrabberBase::grab()
 			DEBUG_HIGH_LEVEL << Q_FUNC_INFO << Debug::toString(widgetRect);
 			QRect monitorRect = grabbedScreen->screenInfo.rect;
 
+#if (QT_VERSION >= QT_VERSION_CHECK(6, 0, 0) && defined(Q_OS_WIN))
+			// Qt6 uses device independent coordinates but our captured image is in device coordinates.
+			// Move the topleft corner from its device-independent position to its pyhsical.
+			QPoint offset = widget->frameGeometry().topLeft() - widget->screen()->geometry().topLeft();
+			offset *= widget->screen()->devicePixelRatio();
+			widgetRect.moveTo(grabbedScreen->screenInfo.rect.topLeft() + offset);
+			widgetRect.setSize(widgetRect.size() * widget->screen()->devicePixelRatio());
+			DEBUG_HIGH_LEVEL << Q_FUNC_INFO << "adjusted: " << Debug::toString(widgetRect);
+#endif
+
 			QRect clippedRect = monitorRect.intersected(widgetRect);
 
 			// Checking for the 'grabme' widget position inside the monitor that is used to capture color

diff --git a/Software/grab/include/GrabberBase.hpp b/Software/grab/include/GrabberBase.hpp
@@ -121,7 +121,7 @@ public slots:
 		*/
 	virtual QList< ScreenInfo > * screensWithWidgets(QList< ScreenInfo > * result, const QList<GrabWidget *> &grabWidgets) = 0;
 	virtual bool isReallocationNeeded(const QList< ScreenInfo > &grabScreens) const;
-	const GrabbedScreen * screenOfRect(const QRect &rect) const;
+	const GrabbedScreen * screenOfWidget(const QWidget &widget) const;
 
 signals:
 	void frameGrabAttempted(GrabResult grabResult);