When aiming at the closest kart, prefer karts on similar Y levels to karts much higher or much below

git-svn-id: svn+ssh://svn.code.sf.net/p/supertuxkart/code/main/trunk@8597 178a84e3-b1eb-0310-8ba1-8eac791a3b58

src/items/flyable.cpp

@@ -259,7 +259,8 @@ void Flyable::getClosestKart(const Kart **minKart, float *minDistSquared,
         btTransform t=kart->getTrans();
 
         Vec3 delta      = t.getOrigin()-tProjectile.getOrigin();
-        float distance2 = delta.length2();
+        // the Y distance is added again because karts above or below should not be prioritized when aiming
+        float distance2 = delta.length2() + abs(t.getOrigin().getY() - tProjectile.getOrigin().getY())*2;
 
         if(inFrontOf != NULL)
         {