/// <summary>
/// Calculates the transform that moves from A to B
/// </summary>
/// <param name="b"></param>
/// <param name="a"></param>
/// <returns></returns>
public static Transform Subtract(Transform b, Transform a)
{
return new Transform
{
Scale = b.Scale - a.Scale,
Translation = b.Translation - a.Translation,
Rotation = b.Rotation * Quaternion.Inverse(a.Rotation)
};
}
public void Update(TimeSpan elapsedTime, out Transform rootDelta)
{
rootDelta = Transform.Identity;
// Update the animation position.
ElapsedTime += TimeSpan.FromSeconds(elapsedTime.TotalSeconds * TimeFactor);
if (ElapsedTime >= Animation.Duration)
{
if (!Loop)
return;
Animation.Start();
Restart();
}
for (int i = 0; i < Animation.ChannelCount; i++)
{
IChannel channel = Animation.GetChannel(i);
//Advance frame number
_channelFrames[i] = channel.SeekToTimestamp(ElapsedTime, _channelFrames[i]);
//save root bone transform
if (Animation.RootBoneIndex == i)
{
var oldTransform = _transforms[i];
//Calculate new transform for this channel
CalculateTransform(channel, out _transforms[i]);
//Calculate the delta of the root bone
rootDelta = Transform.Subtract(_transforms[i], oldTransform);
}
else
{
//Calculate new transform for this channel
CalculateTransform(channel, out _transforms[i]);
}
}
}
public void Interpolate(ref Transform b, float amount, out Transform result)
{
result.Translation = Vector3.Lerp(Translation, b.Translation, amount);
Rotation.Nlerp(ref b.Rotation, amount, out result.Rotation);
result.Scale = Vector3.Lerp(Scale, b.Scale, amount);
}
public Transform Interpolate(Transform b, float amount)
{
Transform result;
Interpolate(ref b, amount, out result);
return result;
}
private void UpdateActiveAnimations(TimeSpan dt, out Transform fadingInRootDelta, out Transform fadingOutRootDelta)
{
fadingInRootDelta = Transform.Identity;
fadingOutRootDelta = Transform.Identity;
if (_fadingOut == null && _fadingIn == null)
InterruptClip(NextClip(), false);
if (_fadingOut == null && _fadingIn != null)
{
//DO NOT merge this into the if check above.
//The above can change the state of _fadingOut so we do need to check it twice!
_fadingOut = _fadingIn;
_fadingIn = null;
}
if (_fadingOut != null)
{
_fadingOut.Update(dt, out fadingOutRootDelta);
//Check if this animation is entering it's final phase. If so, look for another animation in the queue to start playing
if (_fadingIn == null && _fadingOut.ElapsedTime >= _fadingOut.Animation.Duration - _fadingOut.FadeOutTime && (_animationQueue.Count > 0 || !_fadingOut.Loop))
InterruptClip(NextClip(), false);
}
if (_fadingIn != null)
{
_fadingIn.Update(dt, out fadingInRootDelta);
_crossfadeElapsed += dt;
_crossfadeProgress = (float)_crossfadeElapsed.TotalSeconds / (float)_crossfadeDuration.TotalSeconds;
if (_crossfadeElapsed >= _crossfadeDuration)
{
_fadingOut = _fadingIn;
_fadingIn = null;
}
}
}
private void CalculateRootBoneDelta(ref Transform fadingOutRootDelta, ref Transform fadingInRootDelta)
{
if (_fadingOut != null && _fadingIn != null)
{
RootBoneTransfomationDelta = fadingOutRootDelta.Interpolate(fadingInRootDelta, _crossfadeProgress);
}
else if (_fadingOut != null)
{
RootBoneTransfomationDelta = fadingOutRootDelta;
}
else if (_fadingIn != null)
{
RootBoneTransfomationDelta = fadingInRootDelta;
}
else
{
throw new InvalidOperationException("No root bone motion found");
}
}
private void BuildRootBoneMatrix(ref Transform transform, out Matrix m)
{
if (!EnableRootBoneTranslationX || !EnableRootBoneTranslationY || !EnableRootBoneTranslationZ || !EnableRootBoneScale || !EnableRootBoneRotation)
{
m = (EnableRootBoneScale ? Matrix.CreateScale(transform.Scale) : Matrix.Identity) *
(EnableRootBoneRotation ? Matrix.CreateFromQuaternion(transform.Rotation) : Matrix.Identity) *
Matrix.CreateTranslation(new Vector3(
EnableRootBoneTranslationX ? transform.Translation.X : 0,
EnableRootBoneTranslationY ? transform.Translation.Y : 0,
EnableRootBoneTranslationZ ? transform.Translation.Z : 0
)
);
}
else
{
transform.ToMatrix(out m);
}
}
private void CalculateTransform(IChannel channel, out Transform transform)
{
int frameIndex = _channelFrames[channel.BoneIndex];
//frame which is greater than or equal to the current time
Keyframe b = channel.BoneTransform(frameIndex);
if (b.Time == ElapsedTime)
{
transform = b.Transform;
return;
}
//Previous frame
Keyframe a = channel.BoneTransform(frameIndex - 1);
//Interpolation factor between frames
var t = (float) ((ElapsedTime.TotalSeconds - a.Time.TotalSeconds) / (b.Time.TotalSeconds - a.Time.TotalSeconds));
//Convert linear interpolation into some other easing function
var t2 = PlaybackParameters.Interpolator(t);
//Linearly interpolate frames
transform = a.Transform.Interpolate(b.Transform, t2);
}
public void Interpolate(ref Transform b, float amount, out Transform result)
{
Vector3.Lerp(ref Translation, ref b.Translation, amount, out result.Translation);
Rotation.Nlerp(ref b.Rotation, amount, out result.Rotation);
Vector3.Lerp(ref Scale, ref b.Scale, amount, out result.Scale);
}