@antv/f2/lib/deps/d3-hierarchy/src/pack/enclose.js

Charts for mobile visualization.

"use strict";

Object.defineProperty(exports, "__esModule", {
  value: true
});
exports.default = _default;
var _array = require("../array.js");
function _default(circles) {
  var i = 0,
    n = (circles = (0, _array.shuffle)(Array.from(circles))).length,
    B = [],
    p,
    e;
  while (i < n) {
    p = circles[i];
    if (e && enclosesWeak(e, p)) ++i;else e = encloseBasis(B = extendBasis(B, p)), i = 0;
  }
  return e;
}
function extendBasis(B, p) {
  var i, j;
  if (enclosesWeakAll(p, B)) return [p];

  // If we get here then B must have at least one element.
  for (i = 0; i < B.length; ++i) {
    if (enclosesNot(p, B[i]) && enclosesWeakAll(encloseBasis2(B[i], p), B)) {
      return [B[i], p];
    }
  }

  // If we get here then B must have at least two elements.
  for (i = 0; i < B.length - 1; ++i) {
    for (j = i + 1; j < B.length; ++j) {
      if (enclosesNot(encloseBasis2(B[i], B[j]), p) && enclosesNot(encloseBasis2(B[i], p), B[j]) && enclosesNot(encloseBasis2(B[j], p), B[i]) && enclosesWeakAll(encloseBasis3(B[i], B[j], p), B)) {
        return [B[i], B[j], p];
      }
    }
  }

  // If we get here then something is very wrong.
  throw new Error();
}
function enclosesNot(a, b) {
  var dr = a.r - b.r,
    dx = b.x - a.x,
    dy = b.y - a.y;
  return dr < 0 || dr * dr < dx * dx + dy * dy;
}
function enclosesWeak(a, b) {
  var dr = a.r - b.r + Math.max(a.r, b.r, 1) * 1e-9,
    dx = b.x - a.x,
    dy = b.y - a.y;
  return dr > 0 && dr * dr > dx * dx + dy * dy;
}
function enclosesWeakAll(a, B) {
  for (var i = 0; i < B.length; ++i) {
    if (!enclosesWeak(a, B[i])) {
      return false;
    }
  }
  return true;
}
function encloseBasis(B) {
  switch (B.length) {
    case 1:
      return encloseBasis1(B[0]);
    case 2:
      return encloseBasis2(B[0], B[1]);
    case 3:
      return encloseBasis3(B[0], B[1], B[2]);
  }
}
function encloseBasis1(a) {
  return {
    x: a.x,
    y: a.y,
    r: a.r
  };
}
function encloseBasis2(a, b) {
  var x1 = a.x,
    y1 = a.y,
    r1 = a.r,
    x2 = b.x,
    y2 = b.y,
    r2 = b.r,
    x21 = x2 - x1,
    y21 = y2 - y1,
    r21 = r2 - r1,
    l = Math.sqrt(x21 * x21 + y21 * y21);
  return {
    x: (x1 + x2 + x21 / l * r21) / 2,
    y: (y1 + y2 + y21 / l * r21) / 2,
    r: (l + r1 + r2) / 2
  };
}
function encloseBasis3(a, b, c) {
  var x1 = a.x,
    y1 = a.y,
    r1 = a.r,
    x2 = b.x,
    y2 = b.y,
    r2 = b.r,
    x3 = c.x,
    y3 = c.y,
    r3 = c.r,
    a2 = x1 - x2,
    a3 = x1 - x3,
    b2 = y1 - y2,
    b3 = y1 - y3,
    c2 = r2 - r1,
    c3 = r3 - r1,
    d1 = x1 * x1 + y1 * y1 - r1 * r1,
    d2 = d1 - x2 * x2 - y2 * y2 + r2 * r2,
    d3 = d1 - x3 * x3 - y3 * y3 + r3 * r3,
    ab = a3 * b2 - a2 * b3,
    xa = (b2 * d3 - b3 * d2) / (ab * 2) - x1,
    xb = (b3 * c2 - b2 * c3) / ab,
    ya = (a3 * d2 - a2 * d3) / (ab * 2) - y1,
    yb = (a2 * c3 - a3 * c2) / ab,
    A = xb * xb + yb * yb - 1,
    B = 2 * (r1 + xa * xb + ya * yb),
    C = xa * xa + ya * ya - r1 * r1,
    r = -(A ? (B + Math.sqrt(B * B - 4 * A * C)) / (2 * A) : C / B);
  return {
    x: x1 + xa + xb * r,
    y: y1 + ya + yb * r,
    r: r
  };
}