Function resample

docs/tests/v2/es6/js/sanddance.js:116358–116449

(project, delta2)

}

function resample(project, delta2) {
  function resampleLineTo(x0, y0, lambda0, a0, b0, c0, x1, y1, lambda1, a1, b1, c1, depth, stream) {
    var dx = x1 - x0,
        dy = y1 - y0,
        d2 = dx * dx + dy * dy;

    if (d2 > 4 * delta2 && depth--) {
      var a = a0 + a1,
          b = b0 + b1,
          c = c0 + c1,
          m = (0, _math.sqrt)(a * a + b * b + c * c),
          phi2 = (0, _math.asin)(c /= m),
          lambda2 = (0, _math.abs)((0, _math.abs)(c) - 1) < _math.epsilon || (0, _math.abs)(lambda0 - lambda1) < _math.epsilon ? (lambda0 + lambda1) / 2 : (0, _math.atan2)(b, a),
          p = project(lambda2, phi2),
          x2 = p[0],
          y2 = p[1],
          dx2 = x2 - x0,
          dy2 = y2 - y0,
          dz = dy * dx2 - dx * dy2;

      if (dz * dz / d2 > delta2 // perpendicular projected distance
      || (0, _math.abs)((dx * dx2 + dy * dy2) / d2 - 0.5) > 0.3 // midpoint close to an end
      || a0 * a1 + b0 * b1 + c0 * c1 < cosMinDistance) {
        // angular distance
        resampleLineTo(x0, y0, lambda0, a0, b0, c0, x2, y2, lambda2, a /= m, b /= m, c, depth, stream);
        stream.point(x2, y2);
        resampleLineTo(x2, y2, lambda2, a, b, c, x1, y1, lambda1, a1, b1, c1, depth, stream);
      }
    }
  }

  return function (stream) {
    var lambda00, x00, y00, a00, b00, c00, // first point
    lambda0, x0, y0, a0, b0, c0; // previous point

    var resampleStream = {
      point: point,
      lineStart: lineStart,
      lineEnd: lineEnd,
      polygonStart: function () {
        stream.polygonStart();
        resampleStream.lineStart = ringStart;
      },
      polygonEnd: function () {
        stream.polygonEnd();
        resampleStream.lineStart = lineStart;
      }
    };

    function point(x, y) {
      x = project(x, y);
      stream.point(x[0], x[1]);
    }

    function lineStart() {
      x0 = NaN;
      resampleStream.point = linePoint;
      stream.lineStart();