/// <summary>
/// Gets the left and right key frame given the frame value.
/// </summary>
/// <param name="frame"></param>
/// <returns></returns>
public STKeyFrame[] GetFrame(float frame)
{
if (KeyFrames.Count == 0)
{
return(null);
}
STKeyFrame k1 = (STKeyFrame)KeyFrames[0], k2 = (STKeyFrame)KeyFrames[0];
foreach (STKeyFrame k in KeyFrames)
{
if (k.Frame < frame)
{
k1 = k;
}
else
{
k2 = k;
break;
}
}
return(new STKeyFrame[] { k1, k2 });
}
//Key frame setup based on
//https://github.com/gdkchan/SPICA/blob/42c4181e198b0fd34f0a567345ee7e75b54cb58b/SPICA/Formats/CtrH3D/Animation/H3DFloatKeyFrameGroup.cs
/// <summary>
/// Gets the current value at the given frame based on the interpolation the track uses and the keyframes.
/// </summary>
/// <param name="frame"></param>
/// <param name="startFrame"></param>
/// <returns></returns>
public virtual float GetFrameValue(float frame, float startFrame = 0)
{
if (KeyFrames.Count == 0)
{
return(0);
}
if (KeyFrames.Count == 1)
{
return(KeyFrames[0].Value);
}
STKeyFrame LK = KeyFrames.First();
STKeyFrame RK = KeyFrames.Last();
float Frame = frame - startFrame;
foreach (STKeyFrame keyFrame in KeyFrames)
{
if (keyFrame.Frame <= Frame)
{
LK = keyFrame;
}
if (keyFrame.Frame >= Frame && keyFrame.Frame < RK.Frame)
{
RK = keyFrame;
}
}
if (LK.Frame != RK.Frame)
{
float FrameDiff = Frame - LK.Frame;
float Weight = FrameDiff / (RK.Frame - LK.Frame);
switch (InterpolationType)
{
case STInterpoaltionType.Constant: return(LK.Value);
case STInterpoaltionType.Step: return(LK.Value);
case STInterpoaltionType.Linear: return(InterpolationHelper.Lerp(LK.Value, RK.Value, Weight));
case STInterpoaltionType.Bezier:
{
float length = RK.Frame - LK.Frame;
float inSlope = 0;
float outSlope = 0;
if (LK is STBezierKeyFrame)
{
inSlope = ((STBezierKeyFrame)LK).SlopeIn;
outSlope = ((STBezierKeyFrame)LK).SlopeOut;
}
return(InterpolationHelper.HermiteInterpolate(frame,
LK.Frame, RK.Frame,
inSlope, outSlope,
LK.Value, RK.Value));
}
case STInterpoaltionType.Hermite:
if (LK is STHermiteKeyFrame)
{
STHermiteKeyFrame hermiteKeyLK = (STHermiteKeyFrame)LK;
STHermiteKeyFrame hermiteKeyRK = (STHermiteKeyFrame)RK;
float length = RK.Frame - LK.Frame;
return(InterpolationHelper.HermiteInterpolate(frame,
hermiteKeyLK.Frame,
hermiteKeyRK.Frame,
hermiteKeyRK.TangentIn,
hermiteKeyLK.TangentOut,
hermiteKeyLK.Value,
hermiteKeyRK.Value));
}
return(InterpolationHelper.Herp(
LK.Value, RK.Value,
LK.Slope, RK.Slope,
FrameDiff,
Weight));
}
}
return(LK.Value);
}