flickering lights

apps/openmw/mwrender/objects.cpp

@@ -192,19 +192,43 @@ void Objects::insertLight (const MWWorld::Ptr& ptr, float r, float g, float b, f
     Ogre::Light *light = mRenderer.getScene()->createLight();
     light->setDiffuseColour (r, g, b);
 
+    ESMS::LiveCellRef<ESM::Light, MWWorld::RefData> *ref =
+        ptr.get<ESM::Light>();
+
     LightInfo info;
     info.name = light->getName();
     info.radius = radius;
     info.colour = Ogre::ColourValue(r, g, b);
-    mLights.push_back(info);
 
+    if (ref->base->data.flags & ESM::Light::Negative)
+        info.colour *= -1;
 
+    info.interior = (ptr.getCell()->cell->data.flags & ESM::Cell::Interior);
+
+    if (ref->base->data.flags & ESM::Light::Flicker)
+        info.type = LT_Flicker;
+    else if (ref->base->data.flags & ESM::Light::FlickerSlow)
+        info.type = LT_FlickerSlow;
+    else if (ref->base->data.flags & ESM::Light::Pulse)
+        info.type = LT_Pulse;
+    else if (ref->base->data.flags & ESM::Light::PulseSlow)
+        info.type = LT_PulseSlow;
+    else
+        info.type = LT_Normal;
+
+    // random starting phase for the animation
+    info.time = Ogre::Math::RangeRandom(0, 2 * M_PI);
+
+    // adjust the lights depending if we're in an interior or exterior cell
+    // quadratic means the light intensity falls off quite fast, resulting in a
+    // dark, atmospheric environment (perfect for exteriors)
+    // for interiors, we want more "warm" lights, so use linear attenuation.
     bool quadratic = false;
     if (!lightOutQuadInLin)
         quadratic = lightQuadratic;
     else
     {
-        quadratic = !mInterior;
+        quadratic = !info.interior;
     }
 
     if (!quadratic)
@@ -221,6 +245,7 @@ void Objects::insertLight (const MWWorld::Ptr& ptr, float r, float g, float b, f
     }
 
     insert->attachObject(light);
+    mLights.push_back(info);
 }
 
 bool Objects::deleteObject (const MWWorld::Ptr& ptr)
@@ -329,17 +354,8 @@ void Objects::disableLights()
     }
 }
 
-void Objects::setInterior(const bool interior)
-{
-    mInterior = interior;
-}
-
 void Objects::update(const float dt)
 {
-    // adjust the lights depending if we're in an interior or exterior cell
-    // quadratic means the light intensity falls off quite fast, resulting in a
-    // dark, atmospheric environment (perfect for exteriors)
-    // for interiors, we want more "warm" lights, so use linear attenuation.
     std::vector<LightInfo>::iterator it = mLights.begin();
     while (it != mLights.end())
     {
@@ -347,26 +363,77 @@ void Objects::update(const float dt)
         {
             Ogre::Light* light = mMwRoot->getCreator()->getLight(it->name);
 
-            bool quadratic = false;
-            if (!lightOutQuadInLin)
-                quadratic = lightQuadratic;
-            else
+            // Light animation (pulse & flicker)
+            it->time += dt;
+            const float phase = std::fmod(it->time, (32 * 2 * M_PI)) * 20;
+            float pulseConstant;
+
+            // These formulas are just guesswork, but they work pretty well
+            if (it->type == LT_Normal)
             {
-                quadratic = !mInterior;
+                // Less than 1/255 light modifier for a constant light:
+                pulseConstant = (const float)(1.0 + sin(phase) / 255.0 );
             }
-
-            if (!quadratic)
+            else if (it->type == LT_Flicker)
             {
-                float radius = it->radius * lightLinearRadiusMult;
-                float attenuation = lightLinearValue / it->radius;
-                light->setAttenuation(radius*10, 0, attenuation, 0);
+                // Let's do a 50% -> 100% sine wave pulse over 1 second:
+                // This is 75% +/- 25%
+                pulseConstant = (const float)(0.75 + sin(phase) * 0.25);
+
+                // Then add a 25% flicker variation:
+                it->resetTime -= dt;
+                if (it->resetTime < 0)
+                {
+                    it->flickerVariation = (rand() % 1000) / 1000 * 0.25;
+                    it->resetTime = 0.5;
+                }
+                if (it->resetTime > 0.25)
+                {
+                    pulseConstant = (pulseConstant+it->flickerVariation) * (1-it->resetTime * 2.0f) + pulseConstant * it->resetTime * 2.0f;
+                }
+                else
+                {
+                    pulseConstant = (pulseConstant+it->flickerVariation) * (it->resetTime * 2.0f) + pulseConstant * (1-it->resetTime * 2.0f);
+                }
             }
-            else
+            else if (it->type == LT_FlickerSlow)
+            {
+                // Let's do a 50% -> 100% sine wave pulse over 1 second:
+                // This is 75% +/- 25%
+                pulseConstant = (const float)(0.75 + sin(phase / 4.0) * 0.25);
+
+                // Then add a 25% flicker variation:
+                it->resetTime -= dt;
+                if (it->resetTime < 0)
+                {
+                    it->flickerVariation = (rand() % 1000) / 1000 * 0.25;
+                    it->resetTime = 0.5;
+                }
+                if (it->resetTime > 0.5)
+                {
+                    pulseConstant = (pulseConstant+it->flickerVariation) * (1-it->resetTime) + pulseConstant * it->resetTime;
+                }
+                else
+                {
+                    pulseConstant = (pulseConstant+it->flickerVariation) * (it->resetTime) + pulseConstant * (1-it->resetTime);
+                }
+            }
+            else if (it->type == LT_Pulse)
             {
-                float radius = it->radius * lightQuadraticRadiusMult;
-                float attenuation = lightQuadraticValue / pow(it->radius, 2);
-                light->setAttenuation(radius*10, 0, 0, attenuation);
+                // Let's do a 75% -> 125% sine wave pulse over 1 second:
+                // This is 100% +/- 25%
+                pulseConstant = (const float)(1.0 + sin(phase) * 0.25);
             }
+            else if (it->type == LT_PulseSlow)
+            {
+                // Let's do a 75% -> 125% sine wave pulse over 1 second:
+                // This is 100% +/- 25%
+                pulseConstant = (const float)(1.0 + sin(phase / 4.0) * 0.25);
+            }
+            else
+                assert(0 && "Invalid light type");
+
+            light->setDiffuseColour( it->colour * pulseConstant );
 
             ++it;
         }

apps/openmw/mwrender/objects.hpp

@@ -11,11 +11,37 @@
 namespace MWRender{
 
 /// information about light needed for rendering
+enum LightType
+{
+    // These are all mutually exclusive
+    LT_Normal=0,
+    LT_Flicker=1,
+    LT_FlickerSlow=2,
+    LT_Pulse=3,
+    LT_PulseSlow=4
+};
+
 struct LightInfo
 {
+    // Constants
     std::string name; // ogre handle
     Ogre::ColourValue colour;
     float radius;
+    bool interior; // Does this light belong to an interior or exterior cell
+    LightType type;
+
+    // Runtime variables
+	float flickerVariation; // 25% flicker variation, reset once every 0.5 seconds
+	float flickerSlowVariation; // 25% flicker variation, reset once every 1.0 seconds
+	float resetTime;
+    long double time;
+
+
+    LightInfo() :
+        flickerVariation(0), resetTime(0.5),
+        flickerSlowVariation(0), time(0), interior(true)
+    {
+    }
 };
 
 class Objects{
@@ -38,13 +64,11 @@ class Objects{
 
     static bool lightOutQuadInLin;
 
-    bool mInterior;
-
     void clearSceneNode (Ogre::SceneNode *node);
     ///< Remove all movable objects from \a node.
 
 public:
-    Objects(OEngine::Render::OgreRenderer& renderer): mRenderer (renderer), mInterior(true) {}
+    Objects(OEngine::Render::OgreRenderer& renderer): mRenderer (renderer) {}
     ~Objects(){}
     void insertBegin (const MWWorld::Ptr& ptr, bool enabled, bool static_);
     void insertMesh (const MWWorld::Ptr& ptr, const std::string& mesh);
@@ -56,9 +80,6 @@ public:
     void update (const float dt);
     ///< per-frame update
 
-    void setInterior(const bool interior);
-    ///< call this to switch from interior to exterior or vice versa
-
     Ogre::AxisAlignedBox getDimensions(MWWorld::Ptr::CellStore*);
     ///< get a bounding box that encloses all objects in the specified cell
 

apps/openmw/mwrender/renderingmanager.cpp

@@ -510,13 +510,11 @@ Shadows* RenderingManager::getShadows()
 
 void RenderingManager::switchToInterior()
 {
-    mObjects.setInterior(true);
     mRendering.getScene()->setCameraRelativeRendering(false);
 }
 
 void RenderingManager::switchToExterior()
 {
-    mObjects.setInterior(false);
     mRendering.getScene()->setCameraRelativeRendering(true);
 }
 

apps/openmw/mwworld/weather.cpp

@@ -522,7 +522,6 @@ void WeatherManager::update(float duration)
                 // re-scale to 100 percent
                 const float total = clear+cloudy+foggy+overcast+rain+thunder+ash+blight;//+snow+blizzard;
 
-                srand(time(NULL));
                 float random = ((rand()%100)/100.f) * total;
 
                 //if (random >= snow+blight+ash+thunder+rain+overcast+foggy+cloudy+clear)

components/esm/loadligh.hpp

@@ -17,7 +17,7 @@ struct Light
     {
         Dynamic = 0x001,
         Carry = 0x002, // Can be carried
-        Negative = 0x004, // Negative light?
+        Negative = 0x004, // Negative light - i.e. darkness
         Flicker = 0x008,
         Fire = 0x010,
         OffDefault = 0x020, // Off by default