cubic-hermite-spline

### Cubic Hermite spline interpolation

Cubic Hermite spline interpolation of points / tangeants in any dimension with optional derivative computation. The interpolator can also take a knot-like vector as an optional parameter, which may be useful to enforce time at control points when used for position / velocity interpolation.## Install

`$ npm install cubic-hermite-spline`

## Example

Basic usage```
var hermite = require('cubic-hermite-spline');
var points = [
[-1, 0],
[ 0, 0],
[ 1, 0]
];
var tangents = [
[1, 1],
[0, 1],
[1, 1]
];
for(var t=0; t<1; t+=0.01) {
var point = hermite(t, points, tangents);
var tangent = hermite(t, points, tangents, null, true);
}
```

With a knot vector

```
var hermite = require('cubic-hermite-spline');
var points = [
[-1, 0],
[ 0, 0],
[ 1, 0]
];
var tangents = [
[1, 1],
[0, 1],
[1, 1]
];
var knots = [
0, 1.5, 2
];
for(var t=0; t<1; t+=0.01) {
var point = hermite(t, points, tangents);
var tangent = hermite(t, points, tangents, knots, true);
}
```

## Usage

`hermite(t, points, tangents[, knots, derivative, result])`

Computes the interpolation at `t`

for the provided set of points and tangents, and optional knots.`t`

position along the curve: in the 0, 1 range for regular use, and 0, last-knot-value when using knots`points`

vectors to interpolate`tangents`

tangents at provided points`knots`

enforced values of`t`

at provided points`derivative`

if true return the tangeant at`t`

instead of the position`result`

preallocated array in which the result will be stored (avoid GC)

**Returns**the interpolated vector