v1.8.1

fix geoTetrahedralLeeSouth
#28

package.json

@@ -1,6 +1,6 @@
 {
   "name": "d3-geo-polygon",
-  "version": "1.8.0",
+  "version": "1.8.1",
   "description": "Clipping and geometric operations for spherical polygons.",
   "keywords": [
     "d3",

src/intersect.js

@@ -1,12 +1,12 @@
-import {abs, acos, cos, degrees, epsilon, epsilon2, max, radians} from "./math";
+import {abs, acos, cos, degrees, epsilon, epsilon2, pi, radians} from "./math";
 import {cartesian, cartesianCross, cartesianDot, cartesianEqual, cartesianNormalizeInPlace, spherical} from "./cartesian";
 
 export function intersectSegment(from, to) {
   this.from = from, this.to = to;
   this.normal = cartesianCross(from, to);
   this.fromNormal = cartesianCross(this.normal, from);
   this.toNormal = cartesianCross(this.normal, to);
-  this.l = acos(max(0,cartesianDot(from, to)));
+  this.l = acos(cartesianDot(from, to));
 }
 
 // >> here a and b are segments processed by intersectSegment
@@ -16,7 +16,7 @@ export function intersect(a, b) {
   if (cartesianEqual(a.to, b.from) || cartesianEqual(a.to, b.to))
     return a.to;
 
-  var lc = cos(a.l + b.l) - epsilon;
+  var lc = (a.l + b.l < pi) ? cos(a.l + b.l) - epsilon : -1;
   if (cartesianDot(a.from, b.from) < lc
   || cartesianDot(a.from, b.to) < lc
   || cartesianDot(a.to, b.from) < lc

test/compare-images

@@ -12,6 +12,7 @@ for i in \
     polyhedralCollignon \
     polyhedralWaterman \
     tetrahedralLee \
+    tetrahedralLeeSouth \
     ; do
   test/render-world $i > test/output/$i.png \
       && [ "$(gm compare -metric rmse img/$i.png test/output/$i.png 2>&1)" = "Image Difference (RootMeanSquaredError):

test/compute-scale

@@ -65,6 +65,10 @@ switch (projectionName) {
     land = d3.geoGraticule().extent([[-40, -40], [80, 80]]).outline();
     break;
   }
+  // For LeeSouth
+  // case "tetrahedralLee": {
+  //  projection.angle(-30);
+  // }
 }
 
 var path = d3.geoPath()

test/render-world

@@ -3,7 +3,8 @@
 var width = 960,
     height = 500,
     projectionName = process.argv[2],
-    projectionSymbol = "geo" + projectionName[0].toUpperCase() + projectionName.slice(1);
+    projectionSymbol = "geo" + projectionName[0].toUpperCase() + projectionName.slice(1),
+    rotate, angle, translate;
 
 if (!/^[a-z0-9]+$/i.test(projectionName)) throw new Error;
 
@@ -24,13 +25,18 @@ switch (projectionName) {
   case "littrow": outline = graticule.extent([[-90, -60], [90, 60]]).outline(); break;
   case "modifiedStereographicGs50": outline = graticule.extent([[-180, 15], [-50, 75]]).outline(); break;
   case "modifiedStereographicMiller": outline = graticule.extent([[-40, -40], [80, 80]]).outline(); break;
+  case "tetrahedralLeeSouth": projectionSymbol = "geoTetrahedralLee"; rotate = [-30,0]; angle = -30; translate = [599.204, 98.0632]; break;
 }
 
 var projection = d3[projectionSymbol]().precision(0.1),
     path = d3.geoPath()
       .projection(projection)
       .context(context);
 
+if (rotate) projection.rotate(rotate);
+if (translate) projection.translate(translate);
+if (angle) projection.angle(angle);
+
 context.fillStyle = "#fff";
 context.fillRect(0, 0, width, height);