From 214e1b81ed4f0ff79cc8693145561d2d8b92c133 Mon Sep 17 00:00:00 2001
From: Robert Osfield <robert@openscenegraph.com>
Date: Thu, 25 Jun 2009 18:31:43 +0000
Subject: [PATCH] Simplified throw rate code, and add throw rate compensation
 into zoom in/out code.

---
 include/osgGA/TrackballManipulator |  9 +--------
 src/osgGA/TrackballManipulator.cpp | 30 ++++++++++--------------------
 2 files changed, 11 insertions(+), 28 deletions(-)

diff --git a/include/osgGA/TrackballManipulator b/include/osgGA/TrackballManipulator
index 1cae1676a..061882671 100644
--- a/include/osgGA/TrackballManipulator
+++ b/include/osgGA/TrackballManipulator
@@ -148,15 +148,8 @@ class OSGGA_EXPORT TrackballManipulator : public MatrixManipulator
 
         bool _allowThrow;
         bool _thrown;
-        
 
-        /** Indicates whether "thrown" display should match rate of motion at time of throw.
-          * This is significant on systems where the delta between mouse events can be radically different
-          * from the delta in display update events.
-          */
-        bool _rate_sensitive;
-
-        /** The approximate amount of time it is currently taking to draw a frame. 
+        /** The approximate amount of time it is currently taking to draw a frame.
           * This is used to compute the delta in translation/rotation during a thrown display update.
           * It allows us to match an delta in position/rotation independent of the rendering frame rate.
           */
diff --git a/src/osgGA/TrackballManipulator.cpp b/src/osgGA/TrackballManipulator.cpp
index d01da3bef..da31ba17b 100644
--- a/src/osgGA/TrackballManipulator.cpp
+++ b/src/osgGA/TrackballManipulator.cpp
@@ -12,7 +12,6 @@ TrackballManipulator::TrackballManipulator()
     _minimumZoomScale = 0.05f;
     _allowThrow = true;
     _thrown = false;
-    _rate_sensitive = true;
 
     _distance = 1.0f;
     _trackballSize = 0.8f;
@@ -310,7 +309,12 @@ bool TrackballManipulator::calcMovement()
 
         buttonMask = _ga_t1->getButtonMask();
     }
-    
+
+
+    double throwScale =  (_thrown && _ga_t0.valid() && _ga_t1.valid()) ?
+            _delta_frame_time / (_ga_t0->getTime() - _ga_t1->getTime()) :
+            1.0;
+
     if (buttonMask==GUIEventAdapter::LEFT_MOUSE_BUTTON)
     {
 
@@ -330,15 +334,8 @@ bool TrackballManipulator::calcMovement()
 
         osg::Quat new_rotate;
 
-        if (_thrown && _rate_sensitive && _ga_t0.valid() && _ga_t1.valid())
-        {
-            // frame_time / delta_event_time
-            double rate = _delta_frame_time / (_ga_t0->getTime() - _ga_t1->getTime());
-            new_rotate.makeRotate(angle * rate,axis);
-        } else {
-            new_rotate.makeRotate(angle,axis);
-        }
-        
+        new_rotate.makeRotate(angle * throwScale,axis);
+
         _rotation = _rotation*new_rotate;
 
         return true;
@@ -350,18 +347,11 @@ bool TrackballManipulator::calcMovement()
 
         // pan model.
 
-        float scale = -0.3f*_distance;
+        float scale = -0.3f * _distance * throwScale;
 
         osg::Matrix rotation_matrix;
         rotation_matrix.makeRotate(_rotation);
 
-        if (_thrown && _rate_sensitive && _ga_t0.valid() && _ga_t1.valid())
-        {
-            // frame_time / delta_event_time
-            double rate = _delta_frame_time / (_ga_t0->getTime() - _ga_t1->getTime());
-            scale *= rate;
-        }
-
         osg::Vec3 dv(dx*scale,dy*scale,0.0f);
 
         _center += dv*rotation_matrix;
@@ -375,7 +365,7 @@ bool TrackballManipulator::calcMovement()
         // zoom model.
 
         float fd = _distance;
-        float scale = 1.0f+dy;
+        float scale = 1.0f+ dy * throwScale;
         if (fd*scale>_modelScale*_minimumZoomScale)
         {