Checked in osgParticle, writtten by Marco Jez.

include/osgParticle/RandomRateCounter

@@ -0,0 +1,57 @@
+//C++ header - Open Scene Graph - Copyright (C) 1998-2002 Robert Osfield
+//Distributed under the terms of the GNU Library General Public License (LGPL)
+//as published by the Free Software Foundation.
+//osgParticle - Copyright (C) 2002 Marco Jez
+
+#ifndef OSGPARTICLE_RANDOMRATECOUNTER_
+#define OSGPARTICLE_RANDOMRATECOUNTER_ 1
+
+#include <osgParticle/VariableRateCounter>
+
+#include <osg/CopyOp>
+#include <osg/Object>
+
+namespace osgParticle
+{
+
+    class RandomRateCounter: public VariableRateCounter {
+    public:
+        inline RandomRateCounter();
+        inline RandomRateCounter(const RandomRateCounter &copy, const osg::CopyOp &copyop = osg::CopyOp::SHALLOW_COPY);
+        
+        META_Object(RandomRateCounter);
+    
+        /// Return the number of particles to be created in this frame
+        inline int numParticlesToCreate(double dt) const;
+        
+    protected:
+        virtual ~RandomRateCounter() {}
+        
+    private:
+        mutable float np_;
+    };
+    
+    // INLINE FUNCTIONS
+    
+    inline RandomRateCounter::RandomRateCounter()
+    : VariableRateCounter(), np_(0)
+    {
+    }
+    
+    inline RandomRateCounter::RandomRateCounter(const RandomRateCounter &copy, const osg::CopyOp &copyop)
+    : VariableRateCounter(copy, copyop), np_(copy.np_)
+    {
+    }
+    
+    inline int RandomRateCounter::numParticlesToCreate(double dt) const
+    {
+        np_ += dt * getRateRange().get_random();
+        int n = static_cast<int>(np_);
+        np_ -= n;
+        return n;
+    }    
+
+}
+
+
+#endif