Properly clear nitro on restart, plus fix some silly code where sometimes we carefully check if (m_nitro) before using the pointer, and at other times we use the pointer without checking

git-svn-id: svn+ssh://svn.code.sf.net/p/supertuxkart/code/main/trunk@9785 178a84e3-b1eb-0310-8ba1-8eac791a3b58

src/graphics/particle_emitter.cpp

@@ -289,6 +289,13 @@ void ParticleEmitter::setPosition(const Vec3 &pos)
 
 //-----------------------------------------------------------------------------
 
+void ParticleEmitter::clearParticles()
+{
+    m_node->clearParticles();
+}
+
+//-----------------------------------------------------------------------------
+
 void ParticleEmitter::setParticleType(const ParticleKind* type)
 {   
     assert(m_magic_number == 0x58781325);

src/graphics/particle_emitter.hpp

@@ -89,7 +89,9 @@ public:
     
     void         setParticleType(const ParticleKind* p);
     
-    void resizeBox(float size);
+    void         resizeBox(float size);
+    
+    void         clearParticles();
     
     scene::IParticleSystemSceneNode* getNode() { return m_node; }
     

src/karts/kart.cpp

@@ -506,7 +506,12 @@ void Kart::reset()
     m_kart_model->setAnimation(KartModel::AF_DEFAULT);
     m_view_blocked_by_plunger = 0.0;
     m_attachment->clear();
-    m_nitro->setCreationRate(0.0f);
+    if (m_nitro)
+    {
+        m_nitro->setCreationRate(0.0f);
+        m_nitro->clearParticles();
+    }
+    
     m_zipper_fire->setCreationRate(0.0f);
     if (m_collision_particles) m_collision_particles->setCreationRate(0.0f);
     m_powerup.reset();
@@ -875,7 +880,7 @@ void Kart::update(float dt)
         }
     }  // UserConfigParams::m_graphical_effects
     
-    m_nitro->update(dt);
+    if (m_nitro) m_nitro->update(dt);
     m_zipper_fire->update(dt);
     if (m_collision_particles) m_collision_particles->update(dt);