Add nicer fire when using zippers, the proper way this time, no more by hijacking nitro

git-svn-id: svn+ssh://svn.code.sf.net/p/supertuxkart/code/main/trunk@9483 178a84e3-b1eb-0310-8ba1-8eac791a3b58

data/gfx/zipper_fire.xml

@@ -0,0 +1,30 @@
+<?xml version="1.0"?>
+<particles emitter="box" box_x="0.35" box_y="0.2" box_z="0.2">
+
+    <spreading angle="30"         />
+    
+    <velocity  x="0.0"
+               y="0.001"
+               z="-0.003"         />
+    
+    <material  file="zipper-particle.png"  />
+    
+    <!-- Amount of particles emitted per second -->
+    <rate      min="800"
+               max="1000"         />
+    
+    <!-- Minimal and maximal lifetime of a particle, in milliseconds. -->
+    <lifetime  min="100"
+               max="300"          />
+    
+    <!-- Size of the particles -->
+    <size      min="0.20"
+               max="0.40"         />
+    
+    <color     min="255 255 255"
+               max="255 255 255"  />
+    
+    <!-- How much time in milliseconds before the particle is fully faded out  -->
+    <fadeout   time="100"         />
+
+</particles>

src/graphics/particle_emitter.cpp

@@ -246,7 +246,7 @@ void ParticleEmitter::setCreationRate(float f)
     // FIXME: to work around irrlicht bug, when an emitter is paused by setting the rate
     //        to 0 results in a massive emission when enabling it back. In irrlicht 1.8
     //        the node has a method called "clearParticles" that should be cleaner than this
-    if (f == 0.0f)
+    if (f <= 0.0f)
     {
         m_emitter->grab();
         m_node->setEmitter(NULL);
@@ -262,6 +262,7 @@ void ParticleEmitter::setCreationRate(float f)
 
 int ParticleEmitter::getCreationRate()
 {
+    if (m_node->getEmitter() == NULL) return 0;
     return m_emitter->getMinParticlesPerSecond();
 }
 

src/karts/kart.cpp

@@ -102,6 +102,8 @@ Kart::Kart (const std::string& ident, Track* track, int position, bool is_first_
     m_terrain_particles    = NULL;
     m_nitro                = NULL;
     m_nitro_kind           = NULL;
+    m_zipper_fire          = NULL;
+    m_zipper_fire_kind     = NULL;
     m_slipstream           = NULL;
     m_skidmarks            = NULL;
     m_camera               = NULL;
@@ -387,6 +389,8 @@ Kart::~Kart()
     if(m_terrain_particles)      delete m_terrain_particles;
     if(m_nitro)                  delete m_nitro;
     if(m_nitro_kind)             delete m_nitro_kind;
+    if(m_zipper_fire)            delete m_zipper_fire;
+    if(m_zipper_fire_kind)       delete m_zipper_fire_kind;
     if(m_slipstream)             delete m_slipstream;
     if(m_rain)                   delete m_rain;
     if(m_sky_particles_emitter)  delete m_sky_particles_emitter;
@@ -497,6 +501,7 @@ void Kart::reset()
     m_view_blocked_by_plunger = 0.0;
     m_attachment->clear();
     m_nitro->setCreationRate(0.0f);
+    m_zipper_fire->setCreationRate(0.0f);
     m_powerup.reset();
 
     m_race_position        = m_initial_position;
@@ -842,6 +847,7 @@ void Kart::update(float dt)
     }  // UserConfigParams::m_graphical_effects
     
     m_nitro->update();
+    m_zipper_fire->update();
     
     updatePhysics(dt);
 
@@ -963,7 +969,7 @@ void Kart::update(float dt)
   */
 void Kart::showZipperFire()
 {
-    m_nitro->setCreationRate(800.0f);
+    m_zipper_fire->setCreationRate(800.0f);
 }
 
 //-----------------------------------------------------------------------------
@@ -1814,6 +1820,16 @@ void Kart::loadData(RaceManager::KartType type, bool is_first_kart,
         std::cerr << e.what() << std::endl;
     }
     
+    try
+    {
+        m_zipper_fire_kind = new ParticleKind(file_manager->getGfxFile("zipper_fire.xml"));
+        m_zipper_fire      = new ParticleEmitter(m_zipper_fire_kind, position, getNode());
+    }
+    catch (std::runtime_error& e)
+    {
+        std::cerr << e.what() << std::endl;
+    }
+    
     m_slipstream = new SlipStream(this);
 
     if(m_kart_properties->hasSkidmarks())
@@ -1920,8 +1936,7 @@ void Kart::updateGraphics(float dt, const Vec3& offset_xyz,
             float calculated_rate = m_controls.m_nitro && isOnGround() &&  m_collected_energy > 0
                                     ? (min_rate + rate*(max_rate - min_rate)) : 0;
             
-            // the std::max call is there to let nitro fade out smoothly instead of stopping sharply
-            m_nitro->setCreationRate(std::max(calculated_rate, m_nitro->getCreationRate() - dt*800.0f));
+            m_nitro->setCreationRate(calculated_rate);
             
             // the emitter box should spread from last frame's position to the current position
             // if we want nitro to be emitted in a smooth, continuous flame and not in blobs
@@ -1929,6 +1944,18 @@ void Kart::updateGraphics(float dt, const Vec3& offset_xyz,
         }
     }
 
+    if (m_zipper_fire)
+    {
+        // the std::max call is there to let fire fade out smoothly instead of stopping sharply
+        if (m_zipper_fire->getCreationRate() > 0)
+        {
+            m_zipper_fire->setCreationRate(std::max(m_zipper_fire->getCreationRate() - dt*800.0f, 0.0f));
+            
+            // the emitter box should spread from last frame's position to the current position
+            // if we want nitro to be emitted in a smooth, continuous flame and not in blobs
+            m_zipper_fire->resizeBox(std::max(0.25f, getSpeed()*dt));
+        }
+    }
     
     float speed_ratio    = getSpeed()/MaxSpeed::getCurrentMaxSpeed();
     float offset_heading = getSteerPercent()*m_kart_properties->getSkidVisual()

src/karts/kart.hpp

@@ -157,6 +157,12 @@ private:
     /** The particle kind for the nitro. */
     ParticleKind    *m_nitro_kind;
 
+    /** Graphical effect when using a zipper. */
+    ParticleEmitter *m_zipper_fire;
+    
+    /** The particle kind for the nitro. */
+    ParticleKind    *m_zipper_fire_kind;
+    
     /** Handles all slipstreaming. */
     SlipStream      *m_slipstream;