export var epsilon = 1e-6;
export var epsilon2 = 1e-12;
export var pi = Math.PI;
export var halfPi = pi / 2;
export var quarterPi = pi / 4;
export var tau = pi * 2;

export var degrees = 180 / pi;
export var radians = pi / 180;

export var abs = Math.abs;
export var atan = Math.atan;
export var atan2 = Math.atan2;
export var cos = Math.cos;
export var ceil = Math.ceil;
export var exp = Math.exp;
export var floor = Math.floor;
export var log = Math.log;
export var pow = Math.pow;
export var sin = Math.sin;
export var sign = Math.sign || function(x) { return x > 0 ? 1 : x < 0 ? -1 : 0; };
export var sqrt = Math.sqrt;
export var tan = Math.tan;

export function acos(x) {
  return x > 1 ? 0 : x < -1 ? pi : Math.acos(x);
}

export function asin(x) {
  return x > 1 ? halfPi : x < -1 ? -halfPi : Math.asin(x);
}

export function haversin(x) {
  return (x = sin(x / 2)) * x;
}