reworked Nif::KeyListT into Nif::CurveT

Renamed Nif:KeyListT to Nif::CurveT, moved it into its own file and
changed its implementation so that on compatible platforms, the entire
array of key-frames can be read in a single read call. Added a helper
class called Nif::CurveT::interpolator to allow other code to easily
evaluate the curve. Reworked part of the skeletonLoader code to use
the interpolator to simplify its own logic.

components/nif/curve.hpp

@@ -0,0 +1,424 @@
+#ifndef _NIF_KEYLIST_H_
+#define _NIF_KEYLIST_H_
+
+#include <cfloat>
+
+namespace Nif
+{
+
+template <typename iterator , typename predicate>
+void bubble_sort (iterator begin, iterator end, predicate const & in_order)
+{
+    if (end > begin)
+    {
+        for (iterator i = begin; i != end - 1; ++i)
+        {
+            if (in_order (*(i+0), *(i+1)))
+                continue;
+
+            for (iterator j = i; j >= begin; --j)
+            {
+                std::swap (*(j+0), *(j+1));
+
+                if (in_order (*(j+0), *(j+1)))
+                    break;
+            }
+        }
+    }
+}
+
+template <typename value_type>
+value_type linear_interpolate (float amount, value_type prev, value_type next)
+{
+    return prev + (next - prev) * amount;
+}
+
+inline
+Ogre::Quaternion linear_interpolate (float amount, Ogre::Quaternion prev, Ogre::Quaternion next)
+{
+    return Ogre::Quaternion::nlerp (amount, prev, next);
+}
+
+template<typename value_type>
+struct KeyT {
+
+    static const size_t EncodedLength =
+        NIFStream::handler <float>::EncodedLength +
+        NIFStream::handler <value_type>::EncodedLength
+        ;
+
+    float mTime;
+    value_type mValue;
+
+    void extract (NIFStream &nif)
+    {
+        nif.uncheckedRead (mTime);
+        nif.uncheckedRead (mValue);
+    }
+
+    static bool in_order (KeyT <value_type> const & l, KeyT <value_type> const & r)
+    {
+        return l.mTime < r.mTime;
+    }
+
+    template <typename derived_type>
+    struct NIFStream_handler
+    {
+        static const bool FixedLength = true;
+        static const size_t EncodedLength = derived_type::EncodedLength;
+        static const bool FileCompatibleLayout = true;
+
+        static void extract (NIFStream& Stream, KeyT <value_type> & Value)
+        {
+            static_cast <derived_type &> (Value).extract (Stream);
+        }
+    };
+};
+
+template <typename T>
+struct LinearKeyT : KeyT <T>
+{
+    static T interpolate (LinearKeyT <T> * prev, LinearKeyT <T> * next, float amount)
+    {
+        return linear_interpolate (amount, prev->mValue, next->mValue);
+    }
+};
+
+template <typename T>
+struct QuadraticKeyT : KeyT <T>
+{
+    static const size_t EncodedLength =
+        KeyT <T>::EncodedLength +
+        NIFStream::handler <T>::EncodedLength * 2
+        ;
+
+    T mForwardValue;
+    T mBackwardValue;
+
+    static T interpolate (QuadraticKeyT <T> * prev, QuadraticKeyT <T> * next, float amount)
+    {
+        return linear_interpolate (amount, prev->mValue, next->mValue);
+    }
+
+    void extract (NIFStream &nif)
+    {
+        KeyT<T>::extract (nif);
+
+        nif.uncheckedRead (mForwardValue);
+        nif.uncheckedRead (mBackwardValue);
+    }
+};
+
+template <typename T>
+struct TbcKeyT : KeyT <T>
+{
+    static const size_t EncodedLength =
+        KeyT <T>::EncodedLength +
+        NIFStream::handler <float>::EncodedLength * 3
+        ;
+
+    float mTension;
+    float mBias;
+    float mContinuity;
+
+    static T interpolate (TbcKeyT <T> * prev, TbcKeyT <T> * next, float amount)
+    {
+        return linear_interpolate (amount, prev->mValue, next->mValue);
+    }
+
+    void extract (NIFStream &nif)
+    {
+        KeyT<T>::extract (nif);
+
+        nif.uncheckedRead (mTension);
+        nif.uncheckedRead (mBias);
+        nif.uncheckedRead (mContinuity);
+    }
+};
+
+// register NIFStream extraction handlers for KeyT derivatives
+template <typename T> struct NIFStream::handler < LinearKeyT    <T> > : KeyT <T>::template NIFStream_handler < LinearKeyT    <T> > {};
+template <typename T> struct NIFStream::handler < QuadraticKeyT <T> > : KeyT <T>::template NIFStream_handler < QuadraticKeyT <T> > {};
+template <typename T> struct NIFStream::handler < TbcKeyT       <T> > : KeyT <T>::template NIFStream_handler < TbcKeyT       <T> > {};
+
+struct Curve
+{
+    static const int sLinearInterpolation    = 1;
+    static const int sQuadraticInterpolation = 2;
+    static const int sTBCInterpolation       = 3;
+};
+
+template<typename value_type>
+struct CurveT : Curve {
+
+    typedef KeyT <value_type>          BaseKey;
+    typedef TbcKeyT <value_type>       TcbKey;
+    typedef LinearKeyT <value_type>    LinearKey;
+    typedef QuadraticKeyT <value_type> QuadraticKey;
+
+    union keys {
+        LinearKey*    Linear;
+        QuadraticKey* Quadratic;
+        TcbKey*       Tcb;
+    };
+
+    class interpolator;
+
+    int mInterpolationType;
+    size_t  mSize;
+    keys    mKeys;
+
+    value_type sample (float time) const;
+
+    KeyT <value_type> const * const & keyAtIndex (size_t Index) const
+    {
+        switch (mInterpolationType)
+        {
+        case sLinearInterpolation:    return mKeys.Linear    + Index;
+        case sQuadraticInterpolation: return mKeys.Quadratic + Index;
+        case sTBCInterpolation:       return mKeys.Tcb       + Index;
+        }
+    }
+
+    void read(NIFStream *nif, bool force=false)
+    {
+        size_t count = nif->getInt();
+
+        mSize = 0;
+
+        if(count > 0 || force)
+        {
+            mInterpolationType = nif->getInt();
+
+            assert (mInterpolationType >= sLinearInterpolation && mInterpolationType <= sTBCInterpolation);
+
+            if (count > 0)
+            {
+                if(mInterpolationType == sLinearInterpolation)
+                    read_keys (nif, mKeys.Linear, count);
+                else if(mInterpolationType == sQuadraticInterpolation)
+                    read_keys (nif, mKeys.Quadratic, count);
+                else if(mInterpolationType == sTBCInterpolation)
+                    read_keys (nif, mKeys.Tcb, count);
+                else
+                    nif->file->warn("Unhandled interpolation type: "+Ogre::StringConverter::toString(mInterpolationType));
+            }
+        }
+        else
+            mInterpolationType = sLinearInterpolation;
+    }
+
+    CurveT () { init (); }
+    CurveT (CurveT <value_type> const & k) { init (k); }
+    //CurveT (CurveT <value_type> && k) { init (); swap (std::move (k)); }
+    ~CurveT () { dest (); }
+
+    operator bool () const { return mSize > 0; }
+
+    //void operator = (CurveT<value_type> && k) { swap(k); }
+    void operator = (CurveT<value_type> const & k) { dest (); init (k); }
+
+    void swap (CurveT<value_type> & k)
+    {
+        std::swap (mSize, k.mSize);
+        std::swap (mInterpolationType, k.mInterpolationType);
+        std::swap (mKeys, k.mKeys);
+    }
+
+private:
+
+    void init ()
+    {
+        mSize = 0;
+    }
+
+    void init (CurveT<value_type> const & k)
+    {
+        mInterpolationType = k.mInterpolationType;
+        switch (mInterpolationType)
+        {
+        default:
+        case sLinearInterpolation:
+            mKeys.Linear = new LinearKey [k.mSize];
+            memcpy (mKeys.Linear, k.mKeys.Linear, sizeof (LinearKey) * k.mSize);
+            mSize = k.mSize;
+            break;
+        case sQuadraticInterpolation:
+            mKeys.Quadratic = new QuadraticKey [k.mSize];
+            memcpy (mKeys.Quadratic, k.mKeys.Quadratic, sizeof (QuadraticKey) * k.mSize);
+            mSize = k.mSize;
+            break;
+        case sTBCInterpolation:
+            mKeys.Tcb = new TcbKey [k.mSize];
+            memcpy (mKeys.Tcb, k.mKeys.Tcb, sizeof (TcbKey) * k.mSize);
+            mSize = k.mSize;
+            break;
+        }
+    }
+
+    void dest ()
+    {
+        if (mSize > 0)
+        {
+            switch (mInterpolationType)
+            {
+            case sLinearInterpolation:      delete mKeys.Linear;    break;
+            case sQuadraticInterpolation:   delete mKeys.Quadratic; break;
+            case sTBCInterpolation:         delete mKeys.Tcb;       break;
+            }
+        }
+    }
+
+    template <typename T>
+    void read_keys (NIFStream *nif, T * & store, size_t count)
+    {
+        store = new T [count];
+
+        mSize = count;
+
+        nif->getArray (store, count);
+
+        //NOTE: Is this really necessary? It seems reasonable to assume that
+        //      animation data is already sorted by time...
+        //      verified no out of order frames in GOTY edition
+        bubble_sort (store, store+count, T::in_order);
+    }
+};
+
+template<typename value_type>
+class CurveT<value_type>::interpolator
+{
+    template <typename key_type>
+    struct impl
+    {
+        key_type *Cur, *End;
+
+        void init (key_type * Beg, size_t Len)
+        {
+            if (Len > 0)
+            {
+                Cur = Beg;
+                End = Beg + Len - 1;
+            }
+            else
+            {
+                Cur = End = NULL;
+            }
+        }
+
+        bool hasData () const
+        {
+            return Cur && Cur <= End;
+        }
+
+        value_type valueAt (float time)
+        {
+            while ((Cur < End) && (time >= Cur [1].mTime))
+                ++Cur;
+
+            if (Cur < End)
+            {
+                if (time > Cur->mTime)
+                {
+                    key_type * Nxt = Cur + 1;
+
+                    float offset = time - Cur->mTime;
+                    float length = Nxt->mTime - Cur->mTime;
+
+                    return key_type::interpolate (Cur, Nxt, offset / length);
+                }
+                else
+                    return Cur->mValue;
+            }
+            else
+                return End->mValue;
+        }
+
+        float curTime () const
+        {
+            return (Cur != NULL) ? Cur->Time : FLT_MIN;
+        }
+
+        float nextTime () const
+        {
+            return Cur < End ? (Cur + 1)->mTime : FLT_MAX;
+        }
+    };
+
+public:
+
+    int mInterpolationType;
+    union {
+        impl <LinearKey>    Linear;
+        impl <QuadraticKey> Quadratic;
+        impl <TcbKey>       Tcb;
+    };
+
+    interpolator (CurveT <value_type> const & Curve)
+    {
+        mInterpolationType = Curve.mInterpolationType;
+
+        switch (mInterpolationType)
+        {
+        default:
+        case Curve::sLinearInterpolation:    Linear   .init (Curve.mKeys.Linear,    Curve.mSize); break;
+        case Curve::sQuadraticInterpolation: Quadratic.init (Curve.mKeys.Quadratic, Curve.mSize); break;
+        case Curve::sTBCInterpolation:       Tcb      .init (Curve.mKeys.Tcb,       Curve.mSize); break;
+        }
+    }
+
+    // return true if there is any value(s) in this curve
+    float hasData () const
+    {
+        switch (mInterpolationType)
+        {
+        default:
+        case Curve::sLinearInterpolation:    return Linear   .hasData ();
+        case Curve::sQuadraticInterpolation: return Quadratic.hasData ();
+        case Curve::sTBCInterpolation:       return Tcb      .hasData ();
+        }
+    }
+
+    // return the timestamp of the next key-frame, or FLT_MAX if
+    // there are no more key-frames, valid if hasData returns false
+    float nextTime () const
+    {
+        switch (mInterpolationType)
+        {
+        default:
+        case Curve::sLinearInterpolation:    return Linear   .nextTime ();
+        case Curve::sQuadraticInterpolation: return Quadratic.nextTime ();
+        case Curve::sTBCInterpolation:       return Tcb      .nextTime ();
+        }
+    }
+
+    // return the value of the curve at the specified time
+    // the passed in time should never exceed the result of
+    // nextTime, not valid if hasData returns false
+    value_type valueAt (float time)
+    {
+        switch (mInterpolationType)
+        {
+        default:
+        case Curve::sLinearInterpolation:    return Linear   .valueAt (time);
+        case Curve::sQuadraticInterpolation: return Quadratic.valueAt (time);
+        case Curve::sTBCInterpolation:       return Tcb      .valueAt (time);
+        }
+    }
+};
+
+template<typename value_type>
+value_type CurveT<value_type>::sample (float time) const
+{
+    interpolator i (*this);
+    return i.valueAt (time);
+}
+
+typedef CurveT<float> FloatCurve;
+typedef CurveT<Ogre::Vector3> Vector3Curve;
+typedef CurveT<Ogre::Vector4> Vector4Curve;
+typedef CurveT<Ogre::Quaternion> QuaternionCurve;
+
+}
+
+#endif

components/nif/data.hpp

@@ -25,6 +25,7 @@
 #define OPENMW_COMPONENTS_NIF_DATA_HPP
 
 #include "controlled.hpp"
+#include "curve.hpp"
 
 #include <OgreQuaternion.h>
 #include <OgreVector3.h>
@@ -211,7 +212,7 @@ public:
 class NiPosData : public Record
 {
 public:
-    Vector3KeyList mKeyList;
+    Vector3Curve mKeyList;
 
     void read(NIFStream *nif)
     {
@@ -222,7 +223,7 @@ public:
 class NiUVData : public Record
 {
 public:
-    FloatKeyList mKeyList[4];
+    FloatCurve mKeyList[4];
 
     void read(NIFStream *nif)
     {
@@ -234,7 +235,7 @@ public:
 class NiFloatData : public Record
 {
 public:
-    FloatKeyList mKeyList;
+    FloatCurve mKeyList;
 
     void read(NIFStream *nif)
     {
@@ -284,7 +285,7 @@ public:
 class NiColorData : public Record
 {
 public:
-    Vector4KeyList mKeyList;
+    Vector4Curve mKeyList;
 
     void read(NIFStream *nif)
     {
@@ -389,7 +390,7 @@ public:
 struct NiMorphData : public Record
 {
     struct MorphData {
-        FloatKeyList mData;
+        FloatCurve mData;
         std::vector<Ogre::Vector3> mVertices;
     };
     std::vector<MorphData> mMorphs;
@@ -412,9 +413,9 @@ struct NiMorphData : public Record
 
 struct NiKeyframeData : public Record
 {
-    QuaternionKeyList mRotations;
-    Vector3KeyList mTranslations;
-    FloatKeyList mScales;
+    QuaternionCurve mRotations;
+    Vector3Curve mTranslations;
+    FloatCurve mScales;
 
     void read(NIFStream *nif)
     {

components/nif/niffile.hpp

@@ -132,81 +132,5 @@ public:
     size_t numRoots() { return roots.size(); }
 };
 
-
-template<typename T>
-struct KeyT {
-    float mTime;
-    T mValue;
-    T mForwardValue;  // Only for Quadratic interpolation
-    T mBackwardValue; // Only for Quadratic interpolation
-    float mTension;    // Only for TBC interpolation
-    float mBias;       // Only for TBC interpolation
-    float mContinuity; // Only for TBC interpolation
-};
-typedef KeyT<float> FloatKey;
-typedef KeyT<Ogre::Vector3> Vector3Key;
-typedef KeyT<Ogre::Vector4> Vector4Key;
-typedef KeyT<Ogre::Quaternion> QuaternionKey;
-
-template<typename T, T (NIFStream::*getValue)()>
-struct KeyListT {
-    typedef std::vector< KeyT<T> > VecType;
-
-    static const int sLinearInterpolation = 1;
-    static const int sQuadraticInterpolation = 2;
-    static const int sTBCInterpolation = 3;
-
-    int mInterpolationType;
-    VecType mKeys;
-
-    void read(NIFStream *nif, bool force=false)
-    {
-        size_t count = nif->getInt();
-        if(count == 0 && !force)
-            return;
-
-        mInterpolationType = nif->getInt();
-        mKeys.resize(count);
-        if(mInterpolationType == sLinearInterpolation)
-        {
-            for(size_t i = 0;i < count;i++)
-            {
-                KeyT<T> &key = mKeys[i];
-                key.mTime = nif->getFloat();
-                key.mValue = (nif->*getValue)();
-            }
-        }
-        else if(mInterpolationType == sQuadraticInterpolation)
-        {
-            for(size_t i = 0;i < count;i++)
-            {
-                KeyT<T> &key = mKeys[i];
-                key.mTime = nif->getFloat();
-                key.mValue = (nif->*getValue)();
-                key.mForwardValue = (nif->*getValue)();
-                key.mBackwardValue = (nif->*getValue)();
-            }
-        }
-        else if(mInterpolationType == sTBCInterpolation)
-        {
-            for(size_t i = 0;i < count;i++)
-            {
-                KeyT<T> &key = mKeys[i];
-                key.mTime = nif->getFloat();
-                key.mValue = (nif->*getValue)();
-                key.mTension = nif->getFloat();
-                key.mBias = nif->getFloat();
-                key.mContinuity = nif->getFloat();
-            }
-        }
-        else
-            nif->file->warn("Unhandled interpolation type: "+Ogre::StringConverter::toString(mInterpolationType));
-    }
-};
-typedef KeyListT<float,&NIFStream::getFloat> FloatKeyList;
-typedef KeyListT<Ogre::Vector3,&NIFStream::getVector3> Vector3KeyList;
-typedef KeyListT<Ogre::Vector4,&NIFStream::getVector4> Vector4KeyList;
-typedef KeyListT<Ogre::Quaternion,&NIFStream::getQuaternion> QuaternionKeyList;
-
 } // Namespace
 #endif

components/nifogre/ogrenifloader.cpp

@@ -166,9 +166,9 @@ public:
     class Value : public NodeTargetValue<Ogre::Real>
     {
     private:
-        Nif::QuaternionKeyList mRotations;
-        Nif::Vector3KeyList mTranslations;
-        Nif::FloatKeyList mScales;
+        Nif::QuaternionCurve mRotations;
+        Nif::Vector3Curve mTranslations;
+        Nif::FloatCurve mScales;
 
     public:
         Value(Ogre::Node *target, const Nif::NiKeyframeData *data)
@@ -186,68 +186,16 @@ public:
 
         virtual void setValue(Ogre::Real time)
         {
-            if(mRotations.mKeys.size() > 0)
-            {
-                if(time <= mRotations.mKeys.front().mTime)
-                    mNode->setOrientation(mRotations.mKeys.front().mValue);
-                else if(time >= mRotations.mKeys.back().mTime)
-                    mNode->setOrientation(mRotations.mKeys.back().mValue);
-                else
-                {
-                    Nif::QuaternionKeyList::VecType::const_iterator iter(mRotations.mKeys.begin()+1);
-                    for(;iter != mRotations.mKeys.end();iter++)
-                    {
-                        if(iter->mTime < time)
-                            continue;
+            if(mRotations)
+                mNode->setOrientation(mRotations.sample (time));
 
-                        Nif::QuaternionKeyList::VecType::const_iterator last(iter-1);
-                        float a = (time-last->mTime) / (iter->mTime-last->mTime);
-                        mNode->setOrientation(Ogre::Quaternion::nlerp(a, last->mValue, iter->mValue));
-                        break;
-                    }
-                }
-            }
-            if(mTranslations.mKeys.size() > 0)
-            {
-                if(time <= mTranslations.mKeys.front().mTime)
-                    mNode->setPosition(mTranslations.mKeys.front().mValue);
-                else if(time >= mTranslations.mKeys.back().mTime)
-                    mNode->setPosition(mTranslations.mKeys.back().mValue);
-                else
-                {
-                    Nif::Vector3KeyList::VecType::const_iterator iter(mTranslations.mKeys.begin()+1);
-                    for(;iter != mTranslations.mKeys.end();iter++)
-                    {
-                        if(iter->mTime < time)
-                            continue;
+            if(mTranslations)
+                mNode->setPosition(mTranslations.sample (time));
 
-                        Nif::Vector3KeyList::VecType::const_iterator last(iter-1);
-                        float a = (time-last->mTime) / (iter->mTime-last->mTime);
-                        mNode->setPosition(last->mValue + ((iter->mValue - last->mValue)*a));
-                        break;
-                    }
-                }
-            }
-            if(mScales.mKeys.size() > 0)
+            if(mScales)
             {
-                if(time <= mScales.mKeys.front().mTime)
-                    mNode->setScale(Ogre::Vector3(mScales.mKeys.front().mValue));
-                else if(time >= mScales.mKeys.back().mTime)
-                    mNode->setScale(Ogre::Vector3(mScales.mKeys.back().mValue));
-                else
-                {
-                    Nif::FloatKeyList::VecType::const_iterator iter(mScales.mKeys.begin()+1);
-                    for(;iter != mScales.mKeys.end();iter++)
-                    {
-                        if(iter->mTime < time)
-                            continue;
-
-                        Nif::FloatKeyList::VecType::const_iterator last(iter-1);
-                        float a = (time-last->mTime) / (iter->mTime-last->mTime);
-                        mNode->setScale(Ogre::Vector3(last->mValue + ((iter->mValue - last->mValue)*a)));
-                        break;
-                    }
-                }
+                float s = mScales.sample (time);
+                mNode->setScale(s, s, s);
             }
         }
     };
@@ -262,30 +210,14 @@ public:
     {
     private:
         Ogre::MaterialPtr mMaterial;
-        Nif::FloatKeyList mUTrans;
-        Nif::FloatKeyList mVTrans;
-        Nif::FloatKeyList mUScale;
-        Nif::FloatKeyList mVScale;
+        Nif::FloatCurve mUTrans;
+        Nif::FloatCurve mVTrans;
+        Nif::FloatCurve mUScale;
+        Nif::FloatCurve mVScale;
 
-        static float lookupValue(const Nif::FloatKeyList &keys, float time, float def)
+        static float lookupValue(const Nif::FloatCurve &keys, float time, float def)
         {
-            if(keys.mKeys.size() == 0)
-                return def;
-
-            if(time <= keys.mKeys.front().mTime)
-                return keys.mKeys.front().mValue;
-
-            Nif::FloatKeyList::VecType::const_iterator iter(keys.mKeys.begin()+1);
-            for(;iter != keys.mKeys.end();iter++)
-            {
-                if(iter->mTime < time)
-                    continue;
-
-                Nif::FloatKeyList::VecType::const_iterator last(iter-1);
-                float a = (time-last->mTime) / (iter->mTime-last->mTime);
-                return last->mValue + ((iter->mValue - last->mValue)*a);
-            }
-            return keys.mKeys.back().mValue;
+            return keys ? keys.sample (time) : def;
         }
 
     public:
@@ -392,18 +324,19 @@ class NIFObjectLoader
                 const Nif::NiColorData *clrdata = cl->data.getPtr();
 
                 Ogre::ParticleAffector *affector = partsys->addAffector("ColourInterpolator");
-                size_t num_colors = std::min<size_t>(6, clrdata->mKeyList.mKeys.size());
+                size_t num_colors = std::min<size_t>(6, clrdata->mKeyList.mSize);
                 for(size_t i = 0;i < num_colors;i++)
                 {
+                    Nif::Vector4Curve::BaseKey const * Key = clrdata->mKeyList.keyAtIndex (i);
                     Ogre::ColourValue color;
-                    color.r = clrdata->mKeyList.mKeys[i].mValue[0];
-                    color.g = clrdata->mKeyList.mKeys[i].mValue[1];
-                    color.b = clrdata->mKeyList.mKeys[i].mValue[2];
-                    color.a = clrdata->mKeyList.mKeys[i].mValue[3];
+                    color.r = Key->mValue[0];
+                    color.g = Key->mValue[1];
+                    color.b = Key->mValue[2];
+                    color.a = Key->mValue[3];
                     affector->setParameter("colour"+Ogre::StringConverter::toString(i),
                                            Ogre::StringConverter::toString(color));
                     affector->setParameter("time"+Ogre::StringConverter::toString(i),
-                                           Ogre::StringConverter::toString(clrdata->mKeyList.mKeys[i].mTime));
+                                           Ogre::StringConverter::toString(Key->mTime));
                 }
             }
             else if(e->recType == Nif::RC_NiParticleRotation)

components/nifogre/skeleton.cpp

@@ -10,6 +10,11 @@
 
 namespace NifOgre
 {
+template <typename value_type>
+static value_type min (value_type V0, value_type V1, value_type V2, value_type V3)
+{
+    return std::min (std::min (V0, V1), std::min (V2, V3));
+}
 
 void NIFSkeletonLoader::buildAnimation(Ogre::Skeleton *skel, const std::string &name, const std::vector<const Nif::NiKeyframeController*> &ctrls, const std::vector<std::string> &targets, float startTime, float stopTime)
 {
@@ -22,15 +27,6 @@ void NIFSkeletonLoader::buildAnimation(Ogre::Skeleton *skel, const std::string &
             continue;
         const Nif::NiKeyframeData *kf = kfc->data.getPtr();
 
-        /* Get the keyframes and make sure they're sorted first to last */
-        const Nif::QuaternionKeyList &quatkeys = kf->mRotations;
-        const Nif::Vector3KeyList &trankeys = kf->mTranslations;
-        const Nif::FloatKeyList &scalekeys = kf->mScales;
-
-        Nif::QuaternionKeyList::VecType::const_iterator quatiter = quatkeys.mKeys.begin();
-        Nif::Vector3KeyList::VecType::const_iterator traniter = trankeys.mKeys.begin();
-        Nif::FloatKeyList::VecType::const_iterator scaleiter = scalekeys.mKeys.begin();
-
         Ogre::Bone *bone = skel->getBone(targets[i]);
         // NOTE: For some reason, Ogre doesn't like the node track ID being different from
         // the bone ID
@@ -38,83 +34,30 @@ void NIFSkeletonLoader::buildAnimation(Ogre::Skeleton *skel, const std::string &
                                               anim->getNodeTrack(bone->getHandle()) :
                                               anim->createNodeTrack(bone->getHandle(), bone);
 
-        Ogre::Quaternion lastquat, curquat;
-        Ogre::Vector3 lasttrans(0.0f), curtrans(0.0f);
-        Ogre::Vector3 lastscale(1.0f), curscale(1.0f);
-        if(quatiter != quatkeys.mKeys.end())
-            lastquat = curquat = quatiter->mValue;
-        if(traniter != trankeys.mKeys.end())
-            lasttrans = curtrans = traniter->mValue;
-        if(scaleiter != scalekeys.mKeys.end())
-            lastscale = curscale = Ogre::Vector3(scaleiter->mValue);
+        Nif::QuaternionCurve::interpolator rci (kf->mRotations);
+        Nif::Vector3Curve::interpolator tci (kf->mTranslations);
+        Nif::FloatCurve::interpolator sci (kf->mScales);
 
-        bool didlast = false;
-        while(!didlast)
+        float next_timestamp = startTime;
+
+        for (;;)
         {
-            float curtime = std::numeric_limits<float>::max();
-
-            //Get latest time
-            if(quatiter != quatkeys.mKeys.end())
-                curtime = std::min(curtime, quatiter->mTime);
-            if(traniter != trankeys.mKeys.end())
-                curtime = std::min(curtime, traniter->mTime);
-            if(scaleiter != scalekeys.mKeys.end())
-                curtime = std::min(curtime, scaleiter->mTime);
-
-            curtime = std::max(curtime, startTime);
-            if(curtime >= stopTime)
-            {
-                didlast = true;
-                curtime = stopTime;
-            }
-
-            // Get the latest quaternions, translations, and scales for the
-            // current time
-            while(quatiter != quatkeys.mKeys.end() && curtime >= quatiter->mTime)
-            {
-                lastquat = curquat;
-                if(++quatiter != quatkeys.mKeys.end())
-                    curquat = quatiter->mValue;
-            }
-            while(traniter != trankeys.mKeys.end() && curtime >= traniter->mTime)
-            {
-                lasttrans = curtrans;
-                if(++traniter != trankeys.mKeys.end())
-                    curtrans = traniter->mValue;
-            }
-            while(scaleiter != scalekeys.mKeys.end() && curtime >= scaleiter->mTime)
-            {
-                lastscale = curscale;
-                if(++scaleiter != scalekeys.mKeys.end())
-                    curscale = Ogre::Vector3(scaleiter->mValue);
-            }
+            static const Ogre::Vector3 one (1,1,1);
 
             Ogre::TransformKeyFrame *kframe;
-            kframe = nodetrack->createNodeKeyFrame(curtime);
-            if(quatiter == quatkeys.mKeys.end() || quatiter == quatkeys.mKeys.begin())
-                kframe->setRotation(curquat);
-            else
-            {
-                Nif::QuaternionKeyList::VecType::const_iterator last = quatiter-1;
-                float diff = (curtime-last->mTime) / (quatiter->mTime-last->mTime);
-                kframe->setRotation(Ogre::Quaternion::nlerp(diff, lastquat, curquat));
-            }
-            if(traniter == trankeys.mKeys.end() || traniter == trankeys.mKeys.begin())
-                kframe->setTranslate(curtrans);
-            else
-            {
-                Nif::Vector3KeyList::VecType::const_iterator last = traniter-1;
-                float diff = (curtime-last->mTime) / (traniter->mTime-last->mTime);
-                kframe->setTranslate(lasttrans + ((curtrans-lasttrans)*diff));
-            }
-            if(scaleiter == scalekeys.mKeys.end() || scaleiter == scalekeys.mKeys.begin())
-                kframe->setScale(curscale);
-            else
-            {
-                Nif::FloatKeyList::VecType::const_iterator last = scaleiter-1;
-                float diff = (curtime-last->mTime) / (scaleiter->mTime-last->mTime);
-                kframe->setScale(lastscale + ((curscale-lastscale)*diff));
-            }
+            kframe = nodetrack->createNodeKeyFrame (next_timestamp);
+
+            if (rci.hasData ()) kframe->setRotation  (rci.valueAt (next_timestamp));
+            if (tci.hasData ()) kframe->setTranslate (tci.valueAt (next_timestamp));
+            if (sci.hasData ()) kframe->setScale     (sci.valueAt (next_timestamp)*one);
+
+            if (next_timestamp >= stopTime)
+                break;
+
+            next_timestamp = min (stopTime,
+                                  rci.nextTime (),
+                                  tci.nextTime (),
+                                  sci.nextTime ());
         }
     }
     anim->optimise();