Fixed terrain light priorities (fix for #139)

* lights illuminating the terrain specified in scene file are now
   always moved to front of light ordering

src/graphics/engine/lightman.cpp

@@ -236,6 +236,15 @@ bool CLightManager::SetLightEnabled(int lightRank, bool enabled)
     return true;
 }
 
+bool CLightManager::SetLightPriority(int lightRank, LightPriority priority)
+{
+    if ( (lightRank < 0) || (lightRank >= static_cast<int>( m_dynLights.size() )) )
+        return false;
+
+    m_dynLights[lightRank].priority = priority;
+    return true;
+}
+
 bool CLightManager::SetLightIncludeType(int lightRank, EngineObjectType type)
 {
     if ( (lightRank < 0) || (lightRank >= static_cast<int>( m_dynLights.size() )) )
@@ -503,6 +512,9 @@ CLightManager::LightsComparator::LightsComparator(Math::Vector eyePos, EngineObj
 
 float CLightManager::LightsComparator::GetLightWeight(const DynamicLight& dynLight)
 {
+    if (dynLight.priority == LIGHT_PRI_HIGHEST)
+        return -1.0f;
+
     bool enabled = true;
     if (!dynLight.used || !dynLight.enabled || dynLight.intensity.current == 0.0f)
         enabled = false;

src/graphics/engine/lightman.h

@@ -71,8 +71,9 @@ struct LightProgression
  */
 enum LightPriority
 {
-    LIGHT_PRI_HIGH = 1,
+    LIGHT_PRI_HIGHEST = 1, //!< always highest weight (always picked)
-    LIGHT_PRI_LOW  = 2
+    LIGHT_PRI_HIGH = 2,    //!< high weight
+    LIGHT_PRI_LOW  = 3     //!< low weight
 };
 
 /**
@@ -154,6 +155,8 @@ public:
     bool            GetLight(int lightRank, Light &light);
     //! Enables/disables the given dynamic light
     bool            SetLightEnabled(int lightRank, bool enable);
+    //! Changes the light priority
+    bool            SetLightPriority(int lightRank, LightPriority priority);
 
     //! Sets what objects are included in given dynamic light
     bool            SetLightIncludeType(int lightRank, EngineObjectType type);

src/graphics/opengl/gldevice.cpp

@@ -92,7 +92,7 @@ void CGLDevice::DebugLights()
     m_worldMat.LoadIdentity();
     UpdateModelviewMatrix();
 
-    for (int i = 0; i < m_lights.size(); ++i)
+    for (int i = 0; i < static_cast<int>( m_lights.size() ); ++i)
     {
         color.h = static_cast<float>(i) / static_cast<float>(m_lights.size());
         if (m_lightsEnabled[i])

src/object/robotmain.cpp

@@ -4784,7 +4784,10 @@ void CRobotMain::CreateScene(bool soluce, bool fixScene, bool resetObject)
 
             type = OpTypeTerrain(line, "type", Gfx::ENG_OBJTYPE_NULL);
             if (type == Gfx::ENG_OBJTYPE_TERRAIN)
+            {
+                m_lightMan->SetLightPriority(lightRank, Gfx::LIGHT_PRI_HIGHEST);
                 m_lightMan->SetLightIncludeType(lightRank, Gfx::ENG_OBJTYPE_TERRAIN);
+            }
 
             if (type == Gfx::ENG_OBJTYPE_QUARTZ)
                 m_lightMan->SetLightIncludeType(lightRank, Gfx::ENG_OBJTYPE_QUARTZ);