postcss,(plugins): nanocss, postcss-preset-env

1 files changed, 816 insertions, 0 deletions

diff --git a/node_modules/svgo/plugins/_path.js b/node_modules/svgo/plugins/_path.js
new file mode 100644
index 00000000..60002d7a
--- /dev/null
+++ b/node_modules/svgo/plugins/_path.js
@@ -0,0 +1,816 @@
+'use strict';
+
+/**
+ * @typedef {import('../lib/types').XastElement} XastElement
+ * @typedef {import('../lib/types').PathDataItem} PathDataItem
+ */
+
+const { parsePathData, stringifyPathData } = require('../lib/path.js');
+
+/**
+ * @type {[number, number]}
+ */
+var prevCtrlPoint;
+
+/**
+ * Convert path string to JS representation.
+ *
+ * @type {(path: XastElement) => Array<PathDataItem>}
+ */
+const path2js = (path) => {
+  // @ts-ignore legacy
+  if (path.pathJS) return path.pathJS;
+  /**
+   * @type {Array<PathDataItem>}
+   */
+  const pathData = []; // JS representation of the path data
+  const newPathData = parsePathData(path.attributes.d);
+  for (const { command, args } of newPathData) {
+    pathData.push({ command, args });
+  }
+  // First moveto is actually absolute. Subsequent coordinates were separated above.
+  if (pathData.length && pathData[0].command == 'm') {
+    pathData[0].command = 'M';
+  }
+  // @ts-ignore legacy
+  path.pathJS = pathData;
+  return pathData;
+};
+exports.path2js = path2js;
+
+/**
+ * Convert relative Path data to absolute.
+ *
+ * @type {(data: Array<PathDataItem>) => Array<PathDataItem>}
+ *
+ */
+const convertRelativeToAbsolute = (data) => {
+  /**
+   * @type {Array<PathDataItem>}
+   */
+  const newData = [];
+  let start = [0, 0];
+  let cursor = [0, 0];
+
+  for (let { command, args } of data) {
+    args = args.slice();
+
+    // moveto (x y)
+    if (command === 'm') {
+      args[0] += cursor[0];
+      args[1] += cursor[1];
+      command = 'M';
+    }
+    if (command === 'M') {
+      cursor[0] = args[0];
+      cursor[1] = args[1];
+      start[0] = cursor[0];
+      start[1] = cursor[1];
+    }
+
+    // horizontal lineto (x)
+    if (command === 'h') {
+      args[0] += cursor[0];
+      command = 'H';
+    }
+    if (command === 'H') {
+      cursor[0] = args[0];
+    }
+
+    // vertical lineto (y)
+    if (command === 'v') {
+      args[0] += cursor[1];
+      command = 'V';
+    }
+    if (command === 'V') {
+      cursor[1] = args[0];
+    }
+
+    // lineto (x y)
+    if (command === 'l') {
+      args[0] += cursor[0];
+      args[1] += cursor[1];
+      command = 'L';
+    }
+    if (command === 'L') {
+      cursor[0] = args[0];
+      cursor[1] = args[1];
+    }
+
+    // curveto (x1 y1 x2 y2 x y)
+    if (command === 'c') {
+      args[0] += cursor[0];
+      args[1] += cursor[1];
+      args[2] += cursor[0];
+      args[3] += cursor[1];
+      args[4] += cursor[0];
+      args[5] += cursor[1];
+      command = 'C';
+    }
+    if (command === 'C') {
+      cursor[0] = args[4];
+      cursor[1] = args[5];
+    }
+
+    // smooth curveto (x2 y2 x y)
+    if (command === 's') {
+      args[0] += cursor[0];
+      args[1] += cursor[1];
+      args[2] += cursor[0];
+      args[3] += cursor[1];
+      command = 'S';
+    }
+    if (command === 'S') {
+      cursor[0] = args[2];
+      cursor[1] = args[3];
+    }
+
+    // quadratic Bézier curveto (x1 y1 x y)
+    if (command === 'q') {
+      args[0] += cursor[0];
+      args[1] += cursor[1];
+      args[2] += cursor[0];
+      args[3] += cursor[1];
+      command = 'Q';
+    }
+    if (command === 'Q') {
+      cursor[0] = args[2];
+      cursor[1] = args[3];
+    }
+
+    // smooth quadratic Bézier curveto (x y)
+    if (command === 't') {
+      args[0] += cursor[0];
+      args[1] += cursor[1];
+      command = 'T';
+    }
+    if (command === 'T') {
+      cursor[0] = args[0];
+      cursor[1] = args[1];
+    }
+
+    // elliptical arc (rx ry x-axis-rotation large-arc-flag sweep-flag x y)
+    if (command === 'a') {
+      args[5] += cursor[0];
+      args[6] += cursor[1];
+      command = 'A';
+    }
+    if (command === 'A') {
+      cursor[0] = args[5];
+      cursor[1] = args[6];
+    }
+
+    // closepath
+    if (command === 'z' || command === 'Z') {
+      cursor[0] = start[0];
+      cursor[1] = start[1];
+      command = 'z';
+    }
+
+    newData.push({ command, args });
+  }
+  return newData;
+};
+
+/**
+ * @typedef {{ floatPrecision?: number, noSpaceAfterFlags?: boolean }} Js2PathParams
+ */
+
+/**
+ * Convert path array to string.
+ *
+ * @type {(path: XastElement, data: Array<PathDataItem>, params: Js2PathParams) => void}
+ */
+exports.js2path = function (path, data, params) {
+  // @ts-ignore legacy
+  path.pathJS = data;
+
+  const pathData = [];
+  for (const item of data) {
+    // remove moveto commands which are followed by moveto commands
+    if (
+      pathData.length !== 0 &&
+      (item.command === 'M' || item.command === 'm')
+    ) {
+      const last = pathData[pathData.length - 1];
+      if (last.command === 'M' || last.command === 'm') {
+        pathData.pop();
+      }
+    }
+    pathData.push({
+      command: item.command,
+      args: item.args,
+    });
+  }
+
+  path.attributes.d = stringifyPathData({
+    pathData,
+    precision: params.floatPrecision,
+    disableSpaceAfterFlags: params.noSpaceAfterFlags,
+  });
+};
+
+/**
+ * @type {(dest: Array<number>, source: Array<number>) => Array<number>}
+ */
+function set(dest, source) {
+  dest[0] = source[source.length - 2];
+  dest[1] = source[source.length - 1];
+  return dest;
+}
+
+/**
+ * Checks if two paths have an intersection by checking convex hulls
+ * collision using Gilbert-Johnson-Keerthi distance algorithm
+ * https://web.archive.org/web/20180822200027/http://entropyinteractive.com/2011/04/gjk-algorithm/
+ *
+ * @type {(path1: Array<PathDataItem>, path2: Array<PathDataItem>) => boolean}
+ */
+exports.intersects = function (path1, path2) {
+  // Collect points of every subpath.
+  const points1 = gatherPoints(convertRelativeToAbsolute(path1));
+  const points2 = gatherPoints(convertRelativeToAbsolute(path2));
+
+  // Axis-aligned bounding box check.
+  if (
+    points1.maxX <= points2.minX ||
+    points2.maxX <= points1.minX ||
+    points1.maxY <= points2.minY ||
+    points2.maxY <= points1.minY ||
+    points1.list.every((set1) => {
+      return points2.list.every((set2) => {
+        return (
+          set1.list[set1.maxX][0] <= set2.list[set2.minX][0] ||
+          set2.list[set2.maxX][0] <= set1.list[set1.minX][0] ||
+          set1.list[set1.maxY][1] <= set2.list[set2.minY][1] ||
+          set2.list[set2.maxY][1] <= set1.list[set1.minY][1]
+        );
+      });
+    })
+  )
+    return false;
+
+  // Get a convex hull from points of each subpath. Has the most complexity O(n·log n).
+  const hullNest1 = points1.list.map(convexHull);
+  const hullNest2 = points2.list.map(convexHull);
+
+  // Check intersection of every subpath of the first path with every subpath of the second.
+  return hullNest1.some(function (hull1) {
+    if (hull1.list.length < 3) return false;
+
+    return hullNest2.some(function (hull2) {
+      if (hull2.list.length < 3) return false;
+
+      var simplex = [getSupport(hull1, hull2, [1, 0])], // create the initial simplex
+        direction = minus(simplex[0]); // set the direction to point towards the origin
+
+      var iterations = 1e4; // infinite loop protection, 10 000 iterations is more than enough
+      // eslint-disable-next-line no-constant-condition
+      while (true) {
+        // eslint-disable-next-line no-constant-condition
+        if (iterations-- == 0) {
+          console.error(
+            'Error: infinite loop while processing mergePaths plugin.'
+          );
+          return true; // true is the safe value that means “do nothing with paths”
+        }
+        // add a new point
+        simplex.push(getSupport(hull1, hull2, direction));
+        // see if the new point was on the correct side of the origin
+        if (dot(direction, simplex[simplex.length - 1]) <= 0) return false;
+        // process the simplex
+        if (processSimplex(simplex, direction)) return true;
+      }
+    });
+  });
+
+  /**
+   * @type {(a: Point, b: Point, direction: Array<number>) => Array<number>}
+   */
+  function getSupport(a, b, direction) {
+    return sub(supportPoint(a, direction), supportPoint(b, minus(direction)));
+  }
+
+  // Computes farthest polygon point in particular direction.
+  // Thanks to knowledge of min/max x and y coordinates we can choose a quadrant to search in.
+  // Since we're working on convex hull, the dot product is increasing until we find the farthest point.
+  /**
+   * @type {(polygon: Point, direction: Array<number>) => Array<number>}
+   */
+  function supportPoint(polygon, direction) {
+    var index =
+        direction[1] >= 0
+          ? direction[0] < 0
+            ? polygon.maxY
+            : polygon.maxX
+          : direction[0] < 0
+          ? polygon.minX
+          : polygon.minY,
+      max = -Infinity,
+      value;
+    while ((value = dot(polygon.list[index], direction)) > max) {
+      max = value;
+      index = ++index % polygon.list.length;
+    }
+    return polygon.list[(index || polygon.list.length) - 1];
+  }
+};
+
+/**
+ * @type {(simplex: Array<Array<number>>, direction: Array<number>) => boolean}
+ */
+function processSimplex(simplex, direction) {
+  // we only need to handle to 1-simplex and 2-simplex
+  if (simplex.length == 2) {
+    // 1-simplex
+    let a = simplex[1],
+      b = simplex[0],
+      AO = minus(simplex[1]),
+      AB = sub(b, a);
+    // AO is in the same direction as AB
+    if (dot(AO, AB) > 0) {
+      // get the vector perpendicular to AB facing O
+      set(direction, orth(AB, a));
+    } else {
+      set(direction, AO);
+      // only A remains in the simplex
+      simplex.shift();
+    }
+  } else {
+    // 2-simplex
+    let a = simplex[2], // [a, b, c] = simplex
+      b = simplex[1],
+      c = simplex[0],
+      AB = sub(b, a),
+      AC = sub(c, a),
+      AO = minus(a),
+      ACB = orth(AB, AC), // the vector perpendicular to AB facing away from C
+      ABC = orth(AC, AB); // the vector perpendicular to AC facing away from B
+
+    if (dot(ACB, AO) > 0) {
+      if (dot(AB, AO) > 0) {
+        // region 4
+        set(direction, ACB);
+        simplex.shift(); // simplex = [b, a]
+      } else {
+        // region 5
+        set(direction, AO);
+        simplex.splice(0, 2); // simplex = [a]
+      }
+    } else if (dot(ABC, AO) > 0) {
+      if (dot(AC, AO) > 0) {
+        // region 6
+        set(direction, ABC);
+        simplex.splice(1, 1); // simplex = [c, a]
+      } else {
+        // region 5 (again)
+        set(direction, AO);
+        simplex.splice(0, 2); // simplex = [a]
+      }
+    } // region 7
+    else return true;
+  }
+  return false;
+}
+
+/**
+ * @type {(v: Array<number>) => Array<number>}
+ */
+function minus(v) {
+  return [-v[0], -v[1]];
+}
+
+/**
+ * @type {(v1: Array<number>, v2: Array<number>) => Array<number>}
+ */
+function sub(v1, v2) {
+  return [v1[0] - v2[0], v1[1] - v2[1]];
+}
+
+/**
+ * @type {(v1: Array<number>, v2: Array<number>) => number}
+ */
+function dot(v1, v2) {
+  return v1[0] * v2[0] + v1[1] * v2[1];
+}
+
+/**
+ * @type {(v1: Array<number>, v2: Array<number>) => Array<number>}
+ */
+function orth(v, from) {
+  var o = [-v[1], v[0]];
+  return dot(o, minus(from)) < 0 ? minus(o) : o;
+}
+
+/**
+ * @typedef {{
+ *   list: Array<Array<number>>,
+ *   minX: number,
+ *   minY: number,
+ *   maxX: number,
+ *   maxY: number
+ * }} Point
+ */
+
+/**
+ * @typedef {{
+ *   list: Array<Point>,
+ *   minX: number,
+ *   minY: number,
+ *   maxX: number,
+ *   maxY: number
+ * }} Points
+ */
+
+/**
+ * @type {(pathData: Array<PathDataItem>) => Points}
+ */
+function gatherPoints(pathData) {
+  /**
+   * @type {Points}
+   */
+  const points = { list: [], minX: 0, minY: 0, maxX: 0, maxY: 0 };
+
+  // Writes data about the extreme points on each axle
+  /**
+   * @type {(path: Point, point: Array<number>) => void}
+   */
+  const addPoint = (path, point) => {
+    if (!path.list.length || point[1] > path.list[path.maxY][1]) {
+      path.maxY = path.list.length;
+      points.maxY = points.list.length
+        ? Math.max(point[1], points.maxY)
+        : point[1];
+    }
+    if (!path.list.length || point[0] > path.list[path.maxX][0]) {
+      path.maxX = path.list.length;
+      points.maxX = points.list.length
+        ? Math.max(point[0], points.maxX)
+        : point[0];
+    }
+    if (!path.list.length || point[1] < path.list[path.minY][1]) {
+      path.minY = path.list.length;
+      points.minY = points.list.length
+        ? Math.min(point[1], points.minY)
+        : point[1];
+    }
+    if (!path.list.length || point[0] < path.list[path.minX][0]) {
+      path.minX = path.list.length;
+      points.minX = points.list.length
+        ? Math.min(point[0], points.minX)
+        : point[0];
+    }
+    path.list.push(point);
+  };
+
+  for (let i = 0; i < pathData.length; i += 1) {
+    const pathDataItem = pathData[i];
+    let subPath =
+      points.list.length === 0
+        ? { list: [], minX: 0, minY: 0, maxX: 0, maxY: 0 }
+        : points.list[points.list.length - 1];
+    let prev = i === 0 ? null : pathData[i - 1];
+    let basePoint =
+      subPath.list.length === 0 ? null : subPath.list[subPath.list.length - 1];
+    let data = pathDataItem.args;
+    let ctrlPoint = basePoint;
+
+    /**
+     * @type {(n: number, i: number) => number}
+     * TODO fix null hack
+     */
+    const toAbsolute = (n, i) => n + (basePoint == null ? 0 : basePoint[i % 2]);
+
+    switch (pathDataItem.command) {
+      case 'M':
+        subPath = { list: [], minX: 0, minY: 0, maxX: 0, maxY: 0 };
+        points.list.push(subPath);
+        break;
+
+      case 'H':
+        if (basePoint != null) {
+          addPoint(subPath, [data[0], basePoint[1]]);
+        }
+        break;
+
+      case 'V':
+        if (basePoint != null) {
+          addPoint(subPath, [basePoint[0], data[0]]);
+        }
+        break;
+
+      case 'Q':
+        addPoint(subPath, data.slice(0, 2));
+        prevCtrlPoint = [data[2] - data[0], data[3] - data[1]]; // Save control point for shorthand
+        break;
+
+      case 'T':
+        if (
+          basePoint != null &&
+          prev != null &&
+          (prev.command == 'Q' || prev.command == 'T')
+        ) {
+          ctrlPoint = [
+            basePoint[0] + prevCtrlPoint[0],
+            basePoint[1] + prevCtrlPoint[1],
+          ];
+          addPoint(subPath, ctrlPoint);
+          prevCtrlPoint = [data[0] - ctrlPoint[0], data[1] - ctrlPoint[1]];
+        }
+        break;
+
+      case 'C':
+        if (basePoint != null) {
+          // Approximate quibic Bezier curve with middle points between control points
+          addPoint(subPath, [
+            0.5 * (basePoint[0] + data[0]),
+            0.5 * (basePoint[1] + data[1]),
+          ]);
+        }
+        addPoint(subPath, [
+          0.5 * (data[0] + data[2]),
+          0.5 * (data[1] + data[3]),
+        ]);
+        addPoint(subPath, [
+          0.5 * (data[2] + data[4]),
+          0.5 * (data[3] + data[5]),
+        ]);
+        prevCtrlPoint = [data[4] - data[2], data[5] - data[3]]; // Save control point for shorthand
+        break;
+
+      case 'S':
+        if (
+          basePoint != null &&
+          prev != null &&
+          (prev.command == 'C' || prev.command == 'S')
+        ) {
+          addPoint(subPath, [
+            basePoint[0] + 0.5 * prevCtrlPoint[0],
+            basePoint[1] + 0.5 * prevCtrlPoint[1],
+          ]);
+          ctrlPoint = [
+            basePoint[0] + prevCtrlPoint[0],
+            basePoint[1] + prevCtrlPoint[1],
+          ];
+        }
+        if (ctrlPoint != null) {
+          addPoint(subPath, [
+            0.5 * (ctrlPoint[0] + data[0]),
+            0.5 * (ctrlPoint[1] + data[1]),
+          ]);
+        }
+        addPoint(subPath, [
+          0.5 * (data[0] + data[2]),
+          0.5 * (data[1] + data[3]),
+        ]);
+        prevCtrlPoint = [data[2] - data[0], data[3] - data[1]];
+        break;
+
+      case 'A':
+        if (basePoint != null) {
+          // Convert the arc to bezier curves and use the same approximation
+          // @ts-ignore no idea what's going on here
+          var curves = a2c.apply(0, basePoint.concat(data));
+          for (
+            var cData;
+            (cData = curves.splice(0, 6).map(toAbsolute)).length;
+
+          ) {
+            if (basePoint != null) {
+              addPoint(subPath, [
+                0.5 * (basePoint[0] + cData[0]),
+                0.5 * (basePoint[1] + cData[1]),
+              ]);
+            }
+            addPoint(subPath, [
+              0.5 * (cData[0] + cData[2]),
+              0.5 * (cData[1] + cData[3]),
+            ]);
+            addPoint(subPath, [
+              0.5 * (cData[2] + cData[4]),
+              0.5 * (cData[3] + cData[5]),
+            ]);
+            if (curves.length) addPoint(subPath, (basePoint = cData.slice(-2)));
+          }
+        }
+        break;
+    }
+
+    // Save final command coordinates
+    if (data.length >= 2) addPoint(subPath, data.slice(-2));
+  }
+
+  return points;
+}
+
+/**
+ * Forms a convex hull from set of points of every subpath using monotone chain convex hull algorithm.
+ * https://en.wikibooks.org/wiki/Algorithm_Implementation/Geometry/Convex_hull/Monotone_chain
+ *
+ * @type {(points: Point) => Point}
+ */
+function convexHull(points) {
+  points.list.sort(function (a, b) {
+    return a[0] == b[0] ? a[1] - b[1] : a[0] - b[0];
+  });
+
+  var lower = [],
+    minY = 0,
+    bottom = 0;
+  for (let i = 0; i < points.list.length; i++) {
+    while (
+      lower.length >= 2 &&
+      cross(lower[lower.length - 2], lower[lower.length - 1], points.list[i]) <=
+        0
+    ) {
+      lower.pop();
+    }
+    if (points.list[i][1] < points.list[minY][1]) {
+      minY = i;
+      bottom = lower.length;
+    }
+    lower.push(points.list[i]);
+  }
+
+  var upper = [],
+    maxY = points.list.length - 1,
+    top = 0;
+  for (let i = points.list.length; i--; ) {
+    while (
+      upper.length >= 2 &&
+      cross(upper[upper.length - 2], upper[upper.length - 1], points.list[i]) <=
+        0
+    ) {
+      upper.pop();
+    }
+    if (points.list[i][1] > points.list[maxY][1]) {
+      maxY = i;
+      top = upper.length;
+    }
+    upper.push(points.list[i]);
+  }
+
+  // last points are equal to starting points of the other part
+  upper.pop();
+  lower.pop();
+
+  const hullList = lower.concat(upper);
+
+  /**
+   * @type {Point}
+   */
+  const hull = {
+    list: hullList,
+    minX: 0, // by sorting
+    maxX: lower.length,
+    minY: bottom,
+    maxY: (lower.length + top) % hullList.length,
+  };
+
+  return hull;
+}
+
+/**
+ * @type {(o: Array<number>, a: Array<number>, b: Array<number>) => number}
+ */
+function cross(o, a, b) {
+  return (a[0] - o[0]) * (b[1] - o[1]) - (a[1] - o[1]) * (b[0] - o[0]);
+}
+
+/**
+ * Based on code from Snap.svg (Apache 2 license). http://snapsvg.io/
+ * Thanks to Dmitry Baranovskiy for his great work!
+ *
+ * @type {(
+ *  x1: number,
+ *  y1: number,
+ *  rx: number,
+ *  ry: number,
+ *  angle: number,
+ *  large_arc_flag: number,
+ *  sweep_flag: number,
+ *  x2: number,
+ *  y2: number,
+ *  recursive: Array<number>
+ * ) => Array<number>}
+ */
+const a2c = (
+  x1,
+  y1,
+  rx,
+  ry,
+  angle,
+  large_arc_flag,
+  sweep_flag,
+  x2,
+  y2,
+  recursive
+) => {
+  // for more information of where this Math came from visit:
+  // https://www.w3.org/TR/SVG11/implnote.html#ArcImplementationNotes
+  const _120 = (Math.PI * 120) / 180;
+  const rad = (Math.PI / 180) * (+angle || 0);
+  /**
+   * @type {Array<number>}
+   */
+  let res = [];
+  /**
+   * @type {(x: number, y: number, rad: number) => number}
+   */
+  const rotateX = (x, y, rad) => {
+    return x * Math.cos(rad) - y * Math.sin(rad);
+  };
+  /**
+   * @type {(x: number, y: number, rad: number) => number}
+   */
+  const rotateY = (x, y, rad) => {
+    return x * Math.sin(rad) + y * Math.cos(rad);
+  };
+  if (!recursive) {
+    x1 = rotateX(x1, y1, -rad);
+    y1 = rotateY(x1, y1, -rad);
+    x2 = rotateX(x2, y2, -rad);
+    y2 = rotateY(x2, y2, -rad);
+    var x = (x1 - x2) / 2,
+      y = (y1 - y2) / 2;
+    var h = (x * x) / (rx * rx) + (y * y) / (ry * ry);
+    if (h > 1) {
+      h = Math.sqrt(h);
+      rx = h * rx;
+      ry = h * ry;
+    }
+    var rx2 = rx * rx;
+    var ry2 = ry * ry;
+    var k =
+      (large_arc_flag == sweep_flag ? -1 : 1) *
+      Math.sqrt(
+        Math.abs(
+          (rx2 * ry2 - rx2 * y * y - ry2 * x * x) / (rx2 * y * y + ry2 * x * x)
+        )
+      );
+    var cx = (k * rx * y) / ry + (x1 + x2) / 2;
+    var cy = (k * -ry * x) / rx + (y1 + y2) / 2;
+    var f1 = Math.asin(Number(((y1 - cy) / ry).toFixed(9)));
+    var f2 = Math.asin(Number(((y2 - cy) / ry).toFixed(9)));
+
+    f1 = x1 < cx ? Math.PI - f1 : f1;
+    f2 = x2 < cx ? Math.PI - f2 : f2;
+    f1 < 0 && (f1 = Math.PI * 2 + f1);
+    f2 < 0 && (f2 = Math.PI * 2 + f2);
+    if (sweep_flag && f1 > f2) {
+      f1 = f1 - Math.PI * 2;
+    }
+    if (!sweep_flag && f2 > f1) {
+      f2 = f2 - Math.PI * 2;
+    }
+  } else {
+    f1 = recursive[0];
+    f2 = recursive[1];
+    cx = recursive[2];
+    cy = recursive[3];
+  }
+  var df = f2 - f1;
+  if (Math.abs(df) > _120) {
+    var f2old = f2,
+      x2old = x2,
+      y2old = y2;
+    f2 = f1 + _120 * (sweep_flag && f2 > f1 ? 1 : -1);
+    x2 = cx + rx * Math.cos(f2);
+    y2 = cy + ry * Math.sin(f2);
+    res = a2c(x2, y2, rx, ry, angle, 0, sweep_flag, x2old, y2old, [
+      f2,
+      f2old,
+      cx,
+      cy,
+    ]);
+  }
+  df = f2 - f1;
+  var c1 = Math.cos(f1),
+    s1 = Math.sin(f1),
+    c2 = Math.cos(f2),
+    s2 = Math.sin(f2),
+    t = Math.tan(df / 4),
+    hx = (4 / 3) * rx * t,
+    hy = (4 / 3) * ry * t,
+    m = [
+      -hx * s1,
+      hy * c1,
+      x2 + hx * s2 - x1,
+      y2 - hy * c2 - y1,
+      x2 - x1,
+      y2 - y1,
+    ];
+  if (recursive) {
+    return m.concat(res);
+  } else {
+    res = m.concat(res);
+    var newres = [];
+    for (var i = 0, n = res.length; i < n; i++) {
+      newres[i] =
+        i % 2
+          ? rotateY(res[i - 1], res[i], rad)
+          : rotateX(res[i], res[i + 1], rad);
+    }
+    return newres;
+  }
+};