Enable shadow casting for terrain

Add a check to TerrainDrawable to make sure shadows are only drawn once, not once per blending pass

apps/openmw/mwrender/renderingmanager.cpp

@@ -206,7 +206,7 @@ namespace MWRender
 
         osgShadow::ShadowSettings* settings = shadowedScene->getShadowSettings();
         settings->setLightNum(0);
-        settings->setCastsShadowTraversalMask(Mask_Scene|Mask_Actor|Mask_Player);
+        settings->setCastsShadowTraversalMask(Mask_Scene|Mask_Actor|Mask_Player|Mask_Terrain);
         settings->setReceivesShadowTraversalMask(~0u);
 
         //settings->setShadowMapProjectionHint(osgShadow::ShadowSettings::PERSPECTIVE_SHADOW_MAP);

components/terrain/terraindrawable.cpp

@@ -51,6 +51,12 @@ void TerrainDrawable::cull(osgUtil::CullVisitor *cv)
     if (osg::isNaN(depth))
         return;
 
+    if (cv->getCurrentCamera()->getName() == "ShadowCamera")
+    {
+        cv->addDrawableAndDepth(this, &matrix, depth);
+        return;
+    }
+
     bool pushedLight = mLightListCallback && mLightListCallback->pushLightState(this, cv);
 
     for (PassVector::const_iterator it = mPasses.begin(); it != mPasses.end(); ++it)