Fixed|Mac OS X: Mouse input in OS X 10.4

No suppression interval must be used or otherwise the mouse movement will
stop for 250 ms when warping the cursor back to the center.

Another way would be to disassocate the mouse position from the cursor
and handle the native Mac mouse events to get the deltas.

doomsday/engine/portable/include/canvas.h

@@ -27,10 +27,14 @@ struct image_s; // see image.h
 #include <QGLWidget>
 
 #ifdef Q_WS_X11
-//#define LIBDENG_CANVAS_TRACK_WITH_MOUSE_MOVE_EVENTS
+//#  define LIBDENG_CANVAS_TRACK_WITH_MOUSE_MOVE_EVENTS
 //#  define LIBDENG_CANVAS_XWARPPOINTER
 #endif
 
+#ifdef MACOS_10_4
+#  define LIBDENG_CANVAS_TRACK_WITH_MOUSE_MOVE_EVENTS
+#endif
+
 /**
  * Drawing canvas with an OpenGL context and window surface. Each CanvasWindow
  * creates one Canvas instance on which to draw. Buffer swapping must be done
@@ -133,6 +137,8 @@ protected slots:
     void notifyInit();
 #ifndef LIBDENG_CANVAS_TRACK_WITH_MOUSE_MOVE_EVENTS
     void trackMousePosition(bool keepTracking = true);
+#else
+    void recenterMouse();
 #endif
 
 private:

doomsday/engine/portable/src/canvas.cpp

@@ -47,11 +47,15 @@
 #include "keycode.h"
 #include "canvas.h"
 
+#ifdef MACOS_10_4
+#  include <ApplicationServices/ApplicationServices.h>
+#endif
+
 #if (QT_VERSION < QT_VERSION_CHECK(4, 7, 0))
 #  define constBits bits
 #endif
 
-#ifdef LIBDENG_CANVAS_XWARPPOINTER
+#if defined(LIBDENG_CANVAS_XWARPPOINTER) || defined(MACOS_10_4)
 static const int MOUSE_TRACK_INTERVAL = 10; // ms
 #else
 static const int MOUSE_TRACK_INTERVAL = 1; // ms
@@ -102,6 +106,10 @@ struct Canvas::Instance
 #ifndef LIBDENG_CANVAS_TRACK_WITH_MOUSE_MOVE_EVENTS
         QTimer::singleShot(MOUSE_TRACK_INTERVAL, self, SLOT(trackMousePosition()));
 #endif
+#endif
+
+#ifdef MACOSX
+	//CGAssociateMouseAndMouseCursorPosition(false);
 #endif
     }
 
@@ -116,7 +124,9 @@ struct Canvas::Instance
         qApp->restoreOverrideCursor();
         self->setCursor(QCursor(Qt::ArrowCursor)); // Default cursor.
 #endif
-
+#ifdef MACOSX
+	//CGAssociateMouseAndMouseCursorPosition(true);
+#endif
         // Tell the mouse driver that the mouse is untrapepd.
         mouseGrabbed = false;
         Mouse_Trap(false);
@@ -443,12 +453,29 @@ void Canvas::mouseMoveEvent(QMouseEvent* ev)
     if(!delta.isNull())
     {
         Mouse_Qt_SubmitMotion(IMA_POINTER, delta.x(), delta.y());
-    }
 
-    QCursor::setPos(mapToGlobal(rect().center()));
+        d->prevMousePos = ev->pos();
+
+	QTimer::singleShot(1, this, SLOT(recenterMouse()));
+    }
+}
 
+void Canvas::recenterMouse()
+{
     // Ignore the next event, which is caused by the forced cursor move.
-    d->prevMousePos = QPoint();
+    d->prevMousePos = QPoint();    
+
+    QPoint screenPoint = mapToGlobal(rect().center()); 
+
+#ifdef MACOS_10_4
+    CGSetLocalEventsSuppressionInterval(0.0);
+#endif
+
+    QCursor::setPos(screenPoint);
+
+#ifdef MACOS_10_4
+    CGSetLocalEventsSuppressionInterval(0.25);
+#endif
 }
 #endif