From Stephan Huber,

"attached you'll find some modifications to Producer, osgGA and
osgProducer to enable Mac OS X support for

+ scrollwheels,
+ mightymouse-srollballs
+ new tracking-pads with scroll feature
+ tablet-support (pressure, proximity and pointertype) (Wacom only tested)

I think there was a bug in the windows-implementation of scroll-wheel
support (wrong order of ScrollingMotion-enum, casting problem) which is
fixed now.

The scrollwheel-code is a bit klunky across platforms, some devices on
OS X can report an absolute delta in pixel-coordinates not only the
direction, so for now there is scrollingMotion (which describes the
direction) and scrolldeltax and scrolldeltay. I decided to leave the
scrollingmotion-stuff to not break old code relying on this."

include/osgGA/EventQueue

@@ -56,6 +56,15 @@ class OSGGA_EXPORT EventQueue : public osg::Referenced
 
         /** method for adapting mouse scroll wheel events, placing this event on the back of the event queue. */
         void mouseScroll(GUIEventAdapter::ScrollingMotion sm);
+        
+        /** method for adapting mouse scroll wheel events, placing this event on the back of the event queue. */
+        void mouseScroll2D(float x, float y);
+        
+        /** method for adapting pen pressure events, placing this event on the back og the event queue.*/
+        void penPressure(float pressure);
+        
+         /** method for adapting pen proximity events, placing this event on the back og the event queue.*/
+        void penProximity(GUIEventAdapter::TabletPointerType pt, bool isEntering);
 
         /** method for updating in response to a mouse warp. Note, just moves the mouse position without creating a new event for it.*/
         void mouseWarp(float x, float y);

include/osgGA/GUIEventAdapter

@@ -50,7 +50,10 @@ public:
             KEYUP,
             FRAME,
             RESIZE,
-            SCROLL
+            SCROLL,
+            PEN_PRESSURE,
+            PEN_PROXIMITY_ENTER,
+            PEN_PROXIMITY_LEAVE
         };
 
         enum KeySymbol
@@ -231,12 +234,22 @@ public:
 
         enum ScrollingMotion 
         {
+            SCROLL_NONE,
             SCROLL_LEFT,
             SCROLL_RIGHT,
             SCROLL_UP,
-            SCROLL_DOWN
+            SCROLL_DOWN,
+            SCROLL_2D
         };
 
+        enum TabletPointerType 
+        {
+            UNKNOWN = 0,
+            PEN,
+            PUCK,
+            ERASER
+        };
+        
     public:
 
         GUIEventAdapter();
@@ -319,9 +332,30 @@ public:
 
         unsigned int getModKeyMask() const { return _modKeyMask; }
 
-
+        /// get the pressure, from a tablet input device (range 0 - 1)
+        float getPenPressure()  const { return _pressure; }
+        /// sets the pressure from a tablet
+        void setPenPressure(float pressure) { _pressure = pressure; }
+        /// get the current used tablet pointer type
+        TabletPointerType getTabletPointerType() const { return _tabletPointerType; }
+        /// set the current used tablet pointer type
+        void setTabletPointerType(TabletPointerType pt) { _tabletPointerType = pt; }
+        
         void setScrollingMotion(ScrollingMotion motion) { _scrollingMotion = motion; }
-
+        
+        /** get the scrolling x-delta */
+        float getScrollingDeltaX() const { return _scrollingDeltaX; }
+        
+        /** get the scrolling y-delta */
+        float getScrollingDeltaY() const { return _scrollingDeltaY; }
+        
+        /** sets the scrolling delta to x,y and the type of scrolling to SCROLL_2D */
+        void setScrollingMotionDelta(float x, float y) {
+            _scrollingMotion = SCROLL_2D;
+            _scrollingDeltaX = x;
+            _scrollingDeltaY = y;
+        }
+        
         ScrollingMotion getScrollingMotion() const { return _scrollingMotion; }
 
 
@@ -360,10 +394,13 @@ public:
         float _Ymin,_Ymax;
         float _mx;
         float _my;
+        float _pressure;
         unsigned int _buttonMask;
         unsigned int _modKeyMask;
         ScrollingMotion _scrollingMotion;
+        float _scrollingDeltaX, _scrollingDeltaY;
         MouseYOrientation _mouseYOrientation;
+        TabletPointerType _tabletPointerType;
 };
 
 }

include/osgProducer/KeyboardMouseCallback

@@ -37,6 +37,9 @@ class OSGPRODUCER_EXPORT KeyboardMouseCallback : public Producer::KeyboardMouseC
 
         // override KeyboardMouseCallback methods.
         virtual void mouseScroll( Producer::KeyboardMouseCallback::ScrollingMotion sm );
+        virtual void mouseScroll2D( float, float);
+        virtual void penPressure(float pressure);
+        virtual void penProximity(TabletPointerType, bool);
         virtual void mouseMotion( float mx, float my);
         virtual void passiveMouseMotion( float mx, float my);
         virtual void mouseWarp( float mx, float my);