INTERPOLATION

This returns a linear interpolation between A and B, using X as 
the percentage.  The data type returned will be the same type as the
inputs.  If X <= 0, A will be returned; if X >= 1, B will be returned.

This function uses control C [0 to 1.0] to pick a value from the 
The value returned will of the same data type as the samples.

This function returns a value picked from a spline by the scalar C.
The value returned will of the same data type as the knots, K.
The curve fits an interpolatory spline to the knot inputs.

This function returns 0, black or (0,0,0) if B < A.
This function returns 1, white or (1,1,1) if B >= A.

This function returns a smoothed pulse.
WID is the width of the pulse.
FUZ is the width of the fuzzing.
EDG is the edge to be pulsed.

This function returns a clamped linear interpolation between A and B.

This function returns 0 if X < A; 1 if X >= B;
otherwise a smooth S-curve interpolation between 0 and 1.

This function returns a smoothed value between [0,1]
based on where the edge lies in [MID-FUZ,MID+FUZ].
MID is the median value of the edge.
FUZ is the width of the fuzzing.
EDG is the edge in need of fuzzing.

This function dampens the edge from 1 to 0.
BOT is the base value of the edge.
TOP is the top value of the edge.
FUZ is the width of the dampening.
EDG is the edge in need of dampening.

This function returns a smoothed value between [0,1]
based on where the edge lies in [LO-FUZ,HI+FUZ].
LO  is the lowest value of the edge.
HI  is the greatest value of the edge.
FUZ is the width of the fuzzing.
EDG is the edge in need of fuzzing.

This function returns a filter width.