using Unity.UIWidgets.foundation; using Unity.UIWidgets.ui; namespace Unity.UIWidgets.physics { public class GravitySimulation : Simulation { public GravitySimulation( double acceleration, double distance, double endDistance, double velocity ) { D.assert(endDistance >= 0); this._a = acceleration; this._x = distance; this._v = velocity; this._end = endDistance; } readonly double _x; readonly double _v; readonly double _a; readonly double _end; public override double x(double time) { return this._x + this._v * time + 0.5 * this._a * time * time; } public override double dx(double time) { return this._v + time * this._a; } public override bool isDone(double time) { return this.x(time).abs() >= this._end; } } }