Abstract base class of interpolants over parametric samples.
The parameter domain is one dimensional, typically the time or a path along a curve defined by the data.
The sample values can have any dimensionality and derived classes may apply special interpretations to the data.
This class provides the interval seek in a Template Method, deferring the actual interpolation to derived classes.
Time complexity is `O(1)` for linear access crossing at most two points and `O(log N)` for random access,
where *N* is the number of positions.
References: [link:http://www.oodesign.com/template-method-pattern.html http://www.oodesign.com/template-method-pattern.html]
parameterPositions -- array of positions
sampleValues -- array of samples
sampleSize -- number of samples
resultBuffer -- buffer to store the interpolation results.
Note: This is not designed to be called directly.
Optional, subclass-specific settings structure.
Evaluate the interpolant at position *t*.
[link:https://github.com/mrdoob/three.js/blob/master/src/[path].js src/[path].js]