Ensure non-negative particle life time, add size assertion

components/nifogre/ogrenifloader.cpp

@@ -762,8 +762,8 @@ class NIFObjectLoader
         else
             emitter->setEmissionRate(partctrl->numParticles / (partctrl->lifetime + partctrl->lifetimeRandom/2));
 
-        emitter->setTimeToLive(partctrl->lifetime,
-                               partctrl->lifetime + partctrl->lifetimeRandom);
+        emitter->setTimeToLive(std::max(0.f, partctrl->lifetime),
+                               std::max(0.f, partctrl->lifetime + partctrl->lifetimeRandom));
         emitter->setParameter("width", Ogre::StringConverter::toString(partctrl->offsetRandom.x));
         emitter->setParameter("height", Ogre::StringConverter::toString(partctrl->offsetRandom.y));
         emitter->setParameter("depth", Ogre::StringConverter::toString(partctrl->offsetRandom.z));

components/nifogre/particles.cpp

@@ -448,12 +448,14 @@ public:
         if(life_time-particle_time < mGrowTime)
         {
             Ogre::Real scale = (life_time-particle_time) / mGrowTime;
+            assert (scale >= 0);
             width *= scale;
             height *= scale;
         }
         if(particle_time < mFadeTime)
         {
             Ogre::Real scale = particle_time / mFadeTime;
+            assert (scale >= 0);
             width *= scale;
             height *= scale;
         }
@@ -479,12 +481,14 @@ public:
             if(life_time-particle_time < mGrowTime)
             {
                 Ogre::Real scale = (life_time-particle_time) / mGrowTime;
+                assert (scale >= 0);
                 width *= scale;
                 height *= scale;
             }
             if(particle_time < mFadeTime)
             {
                 Ogre::Real scale = particle_time / mFadeTime;
+                assert (scale >= 0);
                 width *= scale;
                 height *= scale;
             }