LinearSpline

new LinearSpline()

A spline that uses piecewise linear interpolation to create a curve.
Name Type Description
options.times Array.<Number> An array of strictly increasing, unit-less, floating-point times at each point. The values are in no way connected to the clock time. They are the parameterization for the curve.
options.points Array.<Cartesian3> The array of Cartesian3 control points.
Throws:
Example:
var spline = new Cesium.LinearSpline({
    times : [ 0.0, 1.5, 3.0, 4.5, 6.0 ],
    points : [
        new Cesium.Cartesian3(1235398.0, -4810983.0, 4146266.0),
        new Cesium.Cartesian3(1372574.0, -5345182.0, 4606657.0),
        new Cesium.Cartesian3(-757983.0, -5542796.0, 4514323.0),
        new Cesium.Cartesian3(-2821260.0, -5248423.0, 4021290.0),
        new Cesium.Cartesian3(-2539788.0, -4724797.0, 3620093.0)
    ]
});

var p0 = spline.evaluate(times[i]);         // equal to positions[i]
var p1 = spline.evaluate(times[i] + delta); // interpolated value when delta < times[i + 1] - times[i]
See:
Source: Core/LinearSpline.js, line 50

Members

readonlypoints :Array.<Cartesian3>

An array of Cartesian3 control points.
Source: Core/LinearSpline.js, line 97

readonlytimes :Array.<Number>

An array of times for the control points.
Source: Core/LinearSpline.js, line 83

Methods

evaluate(time, result) → Cartesian3

Evaluates the curve at a given time.
Name Type Description
time Number The time at which to evaluate the curve.
result Cartesian3 optional The object onto which to store the result.
Returns:
The modified result parameter or a new instance of the point on the curve at the given time.
Throws:
  • DeveloperError : time must be in the range [t0, tn], where t0 is the first element in the array times and tn is the last element in the array times.
Source: Core/LinearSpline.js, line 129

findTimeInterval(time) → Number

Finds an index i in times such that the parameter time is in the interval [times[i], times[i + 1]].
Name Type Description
time Number The time.
Returns:
The index for the element at the start of the interval.
Throws:
  • DeveloperError : time must be in the range [t0, tn], where t0 is the first element in the array times and tn is the last element in the array times.
Source: Core/LinearSpline.js, line 116