Function d3_geo_rotation

explainshell/web/static/js/d3.v3.js:2988–2990

(δλ, δφ, δγ)

    return forward;
  };
  function d3_geo_rotation(δλ, δφ, δγ) {
    return δλ ? δφ || δγ ? d3_geo_compose(d3_geo_rotationλ(δλ), d3_geo_rotationφγ(δφ, δγ)) : d3_geo_rotationλ(δλ) : δφ || δγ ? d3_geo_rotationφγ(δφ, δγ) : d3_geo_equirectangular;
  }
  function d3_geo_forwardRotationλ(δλ) {
    return function(λ, φ) {
      return λ += δλ, [ λ > π ? λ - 2 * π : λ < -π ? λ + 2 * π : λ, φ ];