Scripting : allow smoothly animating lights

src/scriptengine/script_track.cpp

@@ -228,6 +228,11 @@ namespace Scripting
                 ((TrackObjectPresentationLight*)memory)->setEnergy(energy);
             }
 
+            void animateEnergy(float energy, float duration, /** \cond DOXYGEN_IGNORE */void *memory /** \endcond */)
+            {
+                ((TrackObjectPresentationLight*)memory)->setEnergy(energy, duration);
+            }
+
             /** @} */
         }
 
@@ -358,6 +363,7 @@ namespace Scripting
 
             // Light
             r = engine->RegisterObjectMethod("Light", "void setEnergy(float)", asFUNCTION(Light::setEnergy), asCALL_CDECL_OBJLAST); assert(r >= 0);
+            r = engine->RegisterObjectMethod("Light", "void animateEnergy(float, float)", asFUNCTION(Light::animateEnergy), asCALL_CDECL_OBJLAST); assert(r >= 0);
 
             // Curve based Animation
             //fails due to insufficient visibility to scripts TODO : Decide whether to fix visibility or introduce wrappers

src/tracks/track_object_presentation.cpp

@@ -967,6 +967,11 @@ TrackObjectPresentationLight::TrackObjectPresentationLight(
     {
         m_node = NULL; // lights require shaders to work
     }
+
+    m_energy_animation_from = 0.0f;
+    m_energy_animation_to = 0.0f;
+    m_energy_animation_total_duration = 0.0f;
+    m_energy_animation_remaining_duration = 0.0f;
 }   // TrackObjectPresentationLight
 
 // ----------------------------------------------------------------------------
@@ -984,6 +989,29 @@ void TrackObjectPresentationLight::setEnergy(float energy)
     }
 }
 // ----------------------------------------------------------------------------
+void TrackObjectPresentationLight::setEnergy(float energy, float duration)
+{
+    m_energy_animation_from = m_energy;
+    m_energy_animation_to = energy;
+    m_energy_animation_total_duration = duration;
+    m_energy_animation_remaining_duration = duration;
+}
+// ----------------------------------------------------------------------------
+void TrackObjectPresentationLight::update(float dt)
+{
+    if (m_energy_animation_remaining_duration > 0.0f)
+    {
+        m_energy_animation_remaining_duration -= dt;
+        if (m_energy_animation_remaining_duration < 0.0f)
+            m_energy_animation_remaining_duration = 0.0f;
+
+        float ratio = m_energy_animation_remaining_duration / m_energy_animation_total_duration;
+
+        setEnergy(m_energy_animation_from + 
+            (m_energy_animation_to - m_energy_animation_from)*(1.0f - ratio));
+    }
+}
+// ----------------------------------------------------------------------------
 TrackObjectPresentationActionTrigger::TrackObjectPresentationActionTrigger(
                                                        const XMLNode& xml_node)
                                     :  TrackObjectPresentation(xml_node)

src/tracks/track_object_presentation.hpp

@@ -355,11 +355,18 @@ private:
     float m_distance;
     float m_energy;
 
+    float m_energy_animation_from;
+    float m_energy_animation_to;
+    float m_energy_animation_total_duration;
+    float m_energy_animation_remaining_duration;
+
 public:
     TrackObjectPresentationLight(const XMLNode& xml_node,
                                  scene::ISceneNode* parent);
     virtual ~TrackObjectPresentationLight();
     void setEnergy(float energy);
+    void setEnergy(float energy, float duration);
+    virtual void update(float dt) OVERRIDE;
 };   // TrackObjectPresentationLight
 
 // ============================================================================