Add gravity to particles, use gravity for water splash + fix camera modes like look back

git-svn-id: svn+ssh://svn.code.sf.net/p/supertuxkart/code/main/trunk@7378 178a84e3-b1eb-0310-8ba1-8eac791a3b58

data/splash.xml

@@ -14,8 +14,8 @@
                max="1200"         />
     
     <!-- Minimal and maximal lifetime of a particle, in milliseconds. -->
-    <lifetime  min="600"
-               max="900"         />
+    <lifetime  min="1600"
+               max="1900"         />
     
     <!-- Size of the particles -->
     <size      min="0.60"
@@ -27,4 +27,6 @@
     <!-- How much time in milliseconds before the particle is fully faded out  -->
     <fadeout   time="500"        />
 
+    <gravity   strength="-0.01"
+               only-force-time="1000" />
 </particles>

src/graphics/particle_emitter.cpp

@@ -209,4 +209,12 @@ void ParticleEmitter::setParticleType(const ParticleKind* type)
                                                                                 type->getFadeoutTime());
     m_node->addAffector(af);
     af->drop();
+    
+    if (type->getGravityStrength() != 0)
+    {
+        scene::IParticleGravityAffector *gaf = m_node->createGravityAffector(core::vector3df(00.0f, type->getGravityStrength(), 0.0f),
+                                                                             type->getForceLostToGravityTime());
+        m_node->addAffector(gaf);
+        gaf->drop();
+    }
 }

src/graphics/particle_kind.cpp

@@ -47,6 +47,9 @@ ParticleKind::ParticleKind(const std::string file) : m_min_start_color(255,255,2
     m_velocity_x     = 0.001f;
     m_velocity_y     = 0.001f;
     m_velocity_z     = 0.001f;
+    m_gravity_strength = -0.03f;
+    m_force_lost_to_gravity_time = 1000;
+    
     
     // ----- Read XML file
     
@@ -189,6 +192,14 @@ ParticleKind::ParticleKind(const std::string file) : m_min_start_color(255,255,2
         
     //std::cout << "m_fadeout_time = " << m_fadeout_time << "\n";
     
+    // ------------------------------------------------------------------------
+    const XMLNode* gravity = xml->getNode("gravity");
+    if (gravity != NULL)
+    {
+        gravity->get("strength",        &m_gravity_strength);
+        gravity->get("only-force-time", &m_force_lost_to_gravity_time);
+    }
+        
     // ------------------------------------------------------------------------
     
     delete xml;

src/graphics/particle_kind.hpp

@@ -71,6 +71,12 @@ private:
     video::SColor m_min_start_color;
     video::SColor m_max_start_color;
     
+    /** Strength of gravity, not sure what the units are. Make it 0 to disable */
+    float    m_gravity_strength;
+    
+    /** Time it takes for gravity to completely replace the emission force */
+    int      m_force_lost_to_gravity_time;
+    
     /** For box emitters only */
     float m_box_x, m_box_y, m_box_z;
     
@@ -112,6 +118,13 @@ public:
     float     getVelocityX   () const { return m_velocity_x;      }
     float     getVelocityY   () const { return m_velocity_y;      }
     float     getVelocityZ   () const { return m_velocity_z;      }
+    
+    /** Get the strength of gravity, not sure what the units are. Will be 0 if disabled. */
+    float     getGravityStrength() const { return m_gravity_strength; }
+    
+    /** Get the time it takes for gravity to completely replace the emission force. Meaningless if gravity is disabled. */
+    int       getForceLostToGravityTime() const { return m_force_lost_to_gravity_time; }
+    
 };
 #endif
 

src/karts/kart.cpp

@@ -1656,7 +1656,11 @@ void Kart::updateGraphics(const Vec3& offset_xyz,
             }
             else
             {
-                if (m_camera != NULL) m_camera->setFallMode(false);
+                if (m_camera != NULL && m_camera->getMode() == Camera::CM_FALLING)
+                {
+                    m_camera->setFallMode(false);
+                }
+                
                 m_water_splash_system->setCreationRate(0);
             }
         }