Native handling of relative cursor coordinates for camera control

src/Editor/CBasicViewport.cpp

@@ -2,6 +2,7 @@
 #include <Common/Math/MathUtil.h>
 #include <Core/Render/CDrawUtil.h>
 #include <Core/Render/CGraphics.h>
+#include <Editor/MacOSExtras.h>
 
 #include <QCursor>
 
@@ -264,8 +265,13 @@ void CBasicViewport::ProcessInput()
 
     if (IsMouseInputActive())
     {
+#ifdef __APPLE__
+        float XMovement = gpMouseDragCocoaEventFilter->claimX() * 0.01f;
+        float YMovement = gpMouseDragCocoaEventFilter->claimY() * 0.01f;
+#else
         float XMovement = (QCursor::pos().x() - mLastMousePos.x()) * 0.01f;
         float YMovement = (QCursor::pos().y() - mLastMousePos.y()) * 0.01f;
+#endif
 
         if ((XMovement != 0) || (YMovement != 0))
         {

src/Editor/MacOSExtras.h

@@ -0,0 +1,25 @@
+#ifndef MACOSEXTRAS_H
+#define MACOSEXTRAS_H
+#ifdef __APPLE__
+
+#include <CoreGraphics/CGBase.h>
+
+#include <QAbstractNativeEventFilter>
+#include <QString>
+
+void MacOSSetDarkAppearance();
+QString MacOSPathToDolphinBinary();
+
+class MouseDragCocoaEventFilter : public QAbstractNativeEventFilter
+{
+    CGFloat mX = 0.0, mY = 0.0;
+public:
+    bool nativeEventFilter(const QByteArray& eventType, void* message, long*) override;
+    CGFloat claimX() { CGFloat ret = mX; mX = 0.0; return ret; }
+    CGFloat claimY() { CGFloat ret = mY; mY = 0.0; return ret; }
+};
+
+extern MouseDragCocoaEventFilter* gpMouseDragCocoaEventFilter;
+
+#endif // __APPLE__
+#endif // MACOSEXTRAS_H

src/Editor/MacOSExtras.mm

@@ -1,5 +1,5 @@
 #import <AppKit/AppKit.h>
-#include <QString>
+#include "MacOSExtras.h"
 
 void MacOSSetDarkAppearance()
 {
@@ -16,3 +16,22 @@ QString MacOSPathToDolphinBinary()
         return QString::fromNSString(path) + QStringLiteral("/Contents/MacOS/Dolphin");
     return QString();
 }
+
+/* Filter to accumulate relative coordinates of middle and right mouse drags for camera control. */
+bool MouseDragCocoaEventFilter::nativeEventFilter(const QByteArray& eventType, void* message, long*)
+{
+    if (eventType == "mac_generic_NSEvent")
+    {
+        NSEvent* event = static_cast<NSEvent*>(message);
+        NSEventType evType = event.type;
+        if (evType == NSEventTypeRightMouseDragged ||
+            (evType == NSEventTypeOtherMouseDragged && event.buttonNumber == 2))
+        {
+            mX += event.deltaX;
+            mY += event.deltaY;
+        }
+    }
+    return false;
+}
+
+MouseDragCocoaEventFilter* gpMouseDragCocoaEventFilter = nullptr;

src/Editor/NDolphinIntegration.cpp

@@ -1,4 +1,5 @@
 #include "NDolphinIntegration.h"
+#include "Editor/MacOSExtras.h"
 #include "Editor/UICommon.h"
 
 #include <QFileInfo>
@@ -10,10 +11,6 @@
 #undef MoveFile
 #undef DeleteFile
 
-#if defined(__APPLE__)
-QString MacOSPathToDolphinBinary();
-#endif
-
 namespace NDolphinIntegration
 {
 

src/Editor/main.cpp

@@ -1,5 +1,6 @@
 #include "CEditorApplication.h"
 #include "CUIRelay.h"
+#include "MacOSExtras.h"
 #include "UICommon.h"
 #include <Common/Log.h>
 
@@ -11,10 +12,6 @@
 #include <QStyleFactory>
 #include <QtGlobal>
 
-#ifdef __APPLE__
-void MacOSSetDarkAppearance();
-#endif
-
 // Redirect qDebug output to the log file
 void QtLogRedirect(QtMsgType Type, const QMessageLogContext& /*rkContext*/, const QString& rkMessage)
 {
@@ -105,6 +102,9 @@ public:
         SetupPalette();
 #ifdef __APPLE__
         MacOSSetDarkAppearance();
+        MouseDragCocoaEventFilter mouseDragCocoaEventFilter;
+        gpMouseDragCocoaEventFilter = &mouseDragCocoaEventFilter;
+        qApp->installNativeEventFilter(gpMouseDragCocoaEventFilter);
 #endif
 
         // Default OpenGL format