inline code from d3-geo-projection (closes #23)

package.json

@@ -1,6 +1,6 @@
 {
   "name": "d3-geo-polygon",
-  "version": "1.6.1",
+  "version": "1.6.2",
   "description": "Clipping and geometric operations for spherical polygons.",
   "keywords": [
     "d3",

src/clip/polygon.js

@@ -18,7 +18,6 @@ export default function(geometry) {
     } else {
       return clipNone;
     }
-    polygons.forEach(polygon => (polygon.mark = geometry.mark));
 
     var clips = polygons.map(function(polygon) {
       polygon = polygon.map(ringRadians);

src/cubic.js

@@ -5,7 +5,7 @@
  *
  */
 import voronoi from "./polyhedral/voronoi";
-import { default as cube } from "../node_modules/d3-geo-projection/src/polyhedral/cube";
+import { default as cube } from "./polyhedral/cube";
 
 export default function() {
   var polygons = {

src/math.js

@@ -1,37 +1,64 @@
-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 cos = Math.cos;
 export var exp = Math.exp;
 export var floor = Math.floor;
 export var log = Math.log;
 export var max = Math.max;
 export var min = Math.min;
 export var pow = Math.pow;
-export var sin = Math.sin;
+export var round = Math.round;
 export var sign = Math.sign || function(x) { return x > 0 ? 1 : x < 0 ? -1 : 0; };
-export var sqrt = Math.sqrt;
+export var sin = Math.sin;
 export var tan = Math.tan;
 
-export function acos(x) {
-  return x > 1 ? 0 : x < -1 ? pi : Math.acos(x);
+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 sqrt1_2 = Math.SQRT1_2;
+export var sqrt2 = sqrt(2);
+export var sqrtPi = sqrt(pi);
+export var tau = pi * 2;
+export var degrees = 180 / pi;
+export var radians = pi / 180;
+
+export function sinci(x) {
+  return x ? x / Math.sin(x) : 1;
 }
 
 export function asin(x) {
   return x > 1 ? halfPi : x < -1 ? -halfPi : Math.asin(x);
 }
 
-export function haversin(x) {
-  return (x = sin(x / 2)) * x;
+export function acos(x) {
+  return x > 1 ? 0 : x < -1 ? pi : Math.acos(x);
+}
+
+export function sqrt(x) {
+  return x > 0 ? Math.sqrt(x) : 0;
+}
+
+export function tanh(x) {
+  x = exp(2 * x);
+  return (x - 1) / (x + 1);
+}
+
+export function sinh(x) {
+  return (exp(x) - exp(-x)) / 2;
+}
+
+export function cosh(x) {
+  return (exp(x) + exp(-x)) / 2;
+}
+
+export function arsinh(x) {
+  return log(x + sqrt(x * x + 1));
+}
+
+export function arcosh(x) {
+  return log(x + sqrt(x * x - 1));
 }

src/polyhedral/butterfly.js

@@ -1,7 +1,7 @@
 import {geoCentroid as centroid, geoGnomonic as gnomonic} from "d3-geo";
-import {pi} from "../../node_modules/d3-geo-projection/src/math";
+import {pi} from "../math";
 import polyhedral from "./index";
-import octahedron from "../../node_modules/d3-geo-projection/src/polyhedral/octahedron";
+import octahedron from "./octahedron";
 
 export default function(faceProjection) {
 

src/polyhedral/collignon.js

@@ -1,8 +1,8 @@
 import {geoCentroid as centroid, geoProjection as projection} from "d3-geo";
 import {geoCollignonRaw as collignonRaw} from "d3-geo-projection";
-import {pi, sqrt} from "../../node_modules/d3-geo-projection/src/math";
+import {pi, sqrt} from "../math";
 import polyhedral from "./index";
-import octahedron from "../../node_modules/d3-geo-projection/src/polyhedral/octahedron";
+import octahedron from "./octahedron";
 
 var kx = 2 / sqrt(3);
 

src/polyhedral/cube.js

@@ -0,0 +1,21 @@
+import {atan, degrees, sqrt1_2} from "../math";
+
+var phi1 = atan(sqrt1_2) * degrees;
+
+var cube = [
+  [0, phi1], [90, phi1], [180, phi1], [-90, phi1],
+  [0, -phi1], [90, -phi1], [180, -phi1], [-90, -phi1]
+];
+
+export default [
+  [0, 3, 2, 1], // N
+  [0, 1, 5, 4],
+  [1, 2, 6, 5],
+  [2, 3, 7, 6],
+  [3, 0, 4, 7],
+  [4, 5, 6, 7] // S
+].map(function(face) {
+  return face.map(function(i) {
+    return cube[i];
+  });
+});

src/polyhedral/index.js

@@ -1,7 +1,7 @@
 import {geoBounds as bounds, geoCentroid as centroid, geoInterpolate as interpolate, geoProjection as projection} from "d3-geo";
 import {default as clipPolygon} from "../clip/polygon";
-import {abs, degrees, epsilon, radians} from "../../node_modules/d3-geo-projection/src/math";
-import {default as matrix, multiply, inverse} from "../../node_modules/d3-geo-projection/src/polyhedral/matrix";
+import {abs, degrees, epsilon, radians} from "../math";
+import {default as matrix, multiply, inverse} from "./matrix";
 
 // Creates a polyhedral projection.
 //  * tree: a spanning tree of polygon faces.  Nodes are automatically

src/polyhedral/matrix.js

@@ -0,0 +1,64 @@
+import {atan2, cos, sin, sqrt} from "../math";
+
+// Note: 6-element arrays are used to denote the 3x3 affine transform matrix:
+// [a, b, c,
+//  d, e, f,
+//  0, 0, 1] - this redundant row is left out.
+
+// Transform matrix for [a0, a1] -> [b0, b1].
+export default function(a, b) {
+  var u = subtract(a[1], a[0]),
+      v = subtract(b[1], b[0]),
+      phi = angle(u, v),
+      s = length(u) / length(v);
+
+  return multiply([
+    1, 0, a[0][0],
+    0, 1, a[0][1]
+  ], multiply([
+    s, 0, 0,
+    0, s, 0
+  ], multiply([
+    cos(phi), sin(phi), 0,
+    -sin(phi), cos(phi), 0
+  ], [
+    1, 0, -b[0][0],
+    0, 1, -b[0][1]
+  ])));
+}
+
+// Inverts a transform matrix.
+export function inverse(m) {
+  var k = 1 / (m[0] * m[4] - m[1] * m[3]);
+  return [
+    k * m[4], -k * m[1], k * (m[1] * m[5] - m[2] * m[4]),
+    -k * m[3], k * m[0], k * (m[2] * m[3] - m[0] * m[5])
+  ];
+}
+
+// Multiplies two 3x2 matrices.
+export function multiply(a, b) {
+  return [
+    a[0] * b[0] + a[1] * b[3],
+    a[0] * b[1] + a[1] * b[4],
+    a[0] * b[2] + a[1] * b[5] + a[2],
+    a[3] * b[0] + a[4] * b[3],
+    a[3] * b[1] + a[4] * b[4],
+    a[3] * b[2] + a[4] * b[5] + a[5]
+  ];
+}
+
+// Subtracts 2D vectors.
+function subtract(a, b) {
+  return [a[0] - b[0], a[1] - b[1]];
+}
+
+// Magnitude of a 2D vector.
+function length(v) {
+  return sqrt(v[0] * v[0] + v[1] * v[1]);
+}
+
+// Angle between two 2D vectors.
+function angle(a, b) {
+  return atan2(a[0] * b[1] - a[1] * b[0], a[0] * b[0] + a[1] * b[1]);
+}

src/polyhedral/octahedron.js

@@ -0,0 +1,21 @@
+// TODO generate on-the-fly to avoid external modification.
+var octahedron = [
+  [0, 90],
+  [-90, 0], [0, 0], [90, 0], [180, 0],
+  [0, -90]
+];
+
+export default [
+  [0, 2, 1],
+  [0, 3, 2],
+  [5, 1, 2],
+  [5, 2, 3],
+  [0, 1, 4],
+  [0, 4, 3],
+  [5, 4, 1],
+  [5, 3, 4]
+].map(function(face) {
+  return face.map(function(i) {
+    return octahedron[i];
+  });
+});

src/polyhedral/waterman.js

@@ -1,7 +1,7 @@
 import {geoCentroid as centroid, geoGnomonic as gnomonic} from "d3-geo";
-import {asin, atan2, cos, degrees, max, min, pi, radians, sin} from "../../node_modules/d3-geo-projection/src/math";
+import {asin, atan2, cos, degrees, max, min, pi, radians, sin} from "../math";
 import polyhedral from "./index";
-import octahedron from "../../node_modules/d3-geo-projection/src/polyhedral/octahedron";
+import octahedron from "./octahedron";
 
 export default function(faceProjection) {