From Marco Jez, updates to osgParticle, with integration of changes from Tom

Jolly.

include/osgParticle/ParticleProcessor

@@ -102,6 +102,15 @@ namespace osgParticle
         /// Get the reset time of this processor.
         inline double getResetTime() const;
         
+        /**
+          Check whether the processor is alive with respect to start time and
+          life duration. Note that this method may return true even if the 
+          processor has been disabled by calling setEnabled(false). To test
+          whether the processor is actually processing particles or not, you
+          should evaluate (isEnabled() && isAlive()).
+         */
+        inline bool isAlive() const;
+        
         void traverse(osg::NodeVisitor &nv);
 
         /// Get the current local-to-world transformation matrix (valid only during cull traversal).
@@ -289,6 +298,11 @@ namespace osgParticle
         return getWorldToLocalMatrix().preMult(P) -
             getWorldToLocalMatrix().preMult(osg::Vec3(0, 0, 0));
     }
+    
+    inline bool ParticleProcessor::isAlive() const
+    {
+		return currentTime_ < (lifeTime_ + startTime_);
+    }
 
 }