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);
}