Make water walking mechanics closer to original MW

apps/openmw/mwmechanics/spellcasting.cpp

@@ -223,7 +223,7 @@ namespace MWMechanics
         return 1 - resistance / 100.f;
     }
 
-    /// Check if the given affect can be applied to the target. If \a castByPlayer, emits a message box on failure.
+    /// Check if the given effect can be applied to the target. If \a castByPlayer, emits a message box on failure.
     bool checkEffectTarget (int effectId, const MWWorld::Ptr& target, const MWWorld::Ptr& caster, bool castByPlayer)
     {
         switch (effectId)

apps/openmw/mwmechanics/spellcasting.hpp

@@ -59,6 +59,8 @@ namespace MWMechanics
     float getEffectMultiplier(short effectId, const MWWorld::Ptr& actor, const MWWorld::Ptr& caster,
                               const ESM::Spell* spell = NULL, const MagicEffects* effects = NULL);
 
+    bool checkEffectTarget (int effectId, const MWWorld::Ptr& target, const MWWorld::Ptr& caster, bool castByPlayer);
+
     int getEffectiveEnchantmentCastCost (float castCost, const MWWorld::Ptr& actor);
 
     void effectTick(CreatureStats& creatureStats, const MWWorld::Ptr& actor, const MWMechanics::EffectKey& effectKey, float magnitude);

apps/openmw/mwphysics/physicssystem.cpp

@@ -985,6 +985,18 @@ namespace MWPhysics
         }
     }
 
+    bool PhysicsSystem::canMoveToWaterSurface(const MWWorld::ConstPtr &actor, const float waterlevel)
+    {
+        const Actor* physicActor = getActor(actor);
+        const float halfZ = physicActor->getHalfExtents().z();
+        const osg::Vec3f actorPosition = physicActor->getPosition();
+        const osg::Vec3f startingPosition(actorPosition.x(), actorPosition.y(), actorPosition.z() + halfZ);
+        const osg::Vec3f destinationPosition(actorPosition.x(), actorPosition.y(), waterlevel + halfZ);
+        ActorTracer tracer;
+        tracer.doTrace(physicActor->getCollisionObject(), startingPosition, destinationPosition, mCollisionWorld);
+        return (tracer.mFraction >= 1.0f);
+    }
+
     osg::Vec3f PhysicsSystem::getHalfExtents(const MWWorld::ConstPtr &actor) const
     {
         const Actor* physactor = getActor(actor);
@@ -1326,25 +1338,10 @@ namespace MWPhysics
             {
                 if (!world->isUnderwater(iter->first.getCell(), osg::Vec3f(iter->first.getRefData().getPosition().asVec3())))
                     waterCollision = true;
-                else if (physicActor->getCollisionMode())
+                else if (physicActor->getCollisionMode() && canMoveToWaterSurface(iter->first, waterlevel))
                 {
-                    const float halfZ = physicActor->getHalfExtents().z();
                     const osg::Vec3f actorPosition = physicActor->getPosition();
-                    const osg::Vec3f startingPosition(actorPosition.x(), actorPosition.y(), actorPosition.z() + halfZ);
-                    const osg::Vec3f destinationPosition(actorPosition.x(), actorPosition.y(), waterlevel + halfZ);
-                    ActorTracer tracer;
-                    tracer.doTrace(physicActor->getCollisionObject(), startingPosition, destinationPosition, mCollisionWorld);
-                    if (tracer.mFraction >= 1.0f)
-                    {
-                        waterCollision = true;
-                        physicActor->setPosition(osg::Vec3f(actorPosition.x(), actorPosition.y(), waterlevel));
-                    }
-                    else
-                    {
-                        //Remove the effect to remove the performance hit of casting in a weird spot
-                        //probably makes that Tribunal quest where the water rises a bit safer
-                        iter->first.getClass().getCreatureStats(iter->first).getActiveSpells().purgeEffect(ESM::MagicEffect::WaterWalking);
-                    }
+                    physicActor->setPosition(osg::Vec3f(actorPosition.x(), actorPosition.y(), waterlevel));            
                 }
             }
             physicActor->setCanWaterWalk(waterCollision);

apps/openmw/mwphysics/physicssystem.hpp

@@ -123,6 +123,8 @@ namespace MWPhysics
 
             bool isOnGround (const MWWorld::Ptr& actor);
 
+            bool canMoveToWaterSurface (const MWWorld::ConstPtr &actor, const float waterlevel);
+
             /// Get physical half extents (scaled) of the given actor.
             osg::Vec3f getHalfExtents(const MWWorld::ConstPtr& actor) const;
 

apps/openmw/mwworld/inventorystore.cpp

@@ -515,8 +515,8 @@ void MWWorld::InventoryStore::updateMagicEffects(const Ptr& actor)
                     MWBase::Environment::get().getWorld()->getStore().get<ESM::MagicEffect>().find (
                     effectIt->mEffectID);
 
-                // Fully resisted?
-                if (params[i].mMultiplier == 0)
+                // Fully resisted or can't be applied to target?
+                if (params[i].mMultiplier == 0 || !MWMechanics::checkEffectTarget(effectIt->mEffectID, actor, actor, actor == MWMechanics::getPlayer()))
                     continue;
 
                 float magnitude = effectIt->mMagnMin + (effectIt->mMagnMax - effectIt->mMagnMin) * params[i].mRandom;
@@ -770,6 +770,9 @@ void MWWorld::InventoryStore::visitEffectSources(MWMechanics::EffectSourceVisito
         for (std::vector<ESM::ENAMstruct>::const_iterator effectIt (enchantment.mEffects.mList.begin());
             effectIt!=enchantment.mEffects.mList.end(); ++effectIt)
         {
+            // Don't get spell icon display information for enchantments that weren't actually applied
+            if (mMagicEffects.get(MWMechanics::EffectKey(*effectIt)).getMagnitude() == 0)
+                continue;
             const EffectParams& params = mPermanentMagicEffectMagnitudes[(**iter).getCellRef().getRefId()][i];
             float magnitude = effectIt->mMagnMin + (effectIt->mMagnMax - effectIt->mMagnMin) * params.mRandom;
             magnitude *= params.mMultiplier;

apps/openmw/mwworld/worldimp.cpp

@@ -2078,11 +2078,16 @@ namespace MWWorld
         if (!cell->getCell()->hasWater())
             return true;
 
-        // Based on observations from the original engine, the depth
-        // limit at which water walking can still be cast on a target
-        // in water appears to be the same as what the highest swimmable
-        // z position would be with SwimHeightScale + 1.
-        return !isUnderwater(target, mSwimHeightScale + 1);
+        float waterlevel = cell->getWaterLevel();
+
+        // SwimHeightScale affects the upper z position an actor can swim to 
+        // while in water. Based on observation from the original engine,
+        // the upper z position you get with a +1 SwimHeightScale is the depth
+        // limit for being able to cast water walking on an underwater target.
+        if (isUnderwater(target, mSwimHeightScale + 1) || (isUnderwater(cell, target.getRefData().getPosition().asVec3()) && !mPhysics->canMoveToWaterSurface(target, waterlevel)))
+            return false; // not castable if too deep or if not enough room to move actor to surface
+        else
+            return true;
     }
 
     bool World::isOnGround(const MWWorld::Ptr &ptr) const