Added orthographic projection

Author: zimrick

lib/projections.js

@@ -12,7 +12,9 @@ exports.default = function (width, height, config, projectionName) {
   var rotation = config.rotation || _projectionConfig2.default.rotation;
   var precision = config.precision || _projectionConfig2.default.precision;
 
-  return projectionName === "albersUsa" ? projectionReference[projectionName]().scale(scale).translate([xOffset + width / 2, yOffset + height / 2]).precision(precision) : projectionReference[projectionName]().scale(scale).translate([xOffset + width / 2, yOffset + height / 2]).rotate(rotation).precision(precision);
+  var baseProjection = projectionReference[projectionName]().scale(scale).translate([xOffset + width / 2, yOffset + height / 2]).precision(precision);
+
+  return projectionName === "albersUsa" ? baseProjection : projectionName === "orthographic" ? baseProjection.rotate(rotation).clipAngle(90) : baseProjection.rotate(rotation);
 };
 
 var _d3GeoProjection = require("d3-geo-projection");
@@ -32,5 +34,6 @@ var projectionReference = {
   robinson: _d3GeoProjection.geoRobinson,
   winkel3: _d3GeoProjection.geoWinkel3,
   eckert4: _d3GeoProjection.geoEckert4,
-  albersUsa: _d3Geo.geoAlbersUsa
+  albersUsa: _d3Geo.geoAlbersUsa,
+  orthographic: _d3Geo.geoOrthographic
 };

src/projections.js

@@ -9,6 +9,7 @@ import {
 import {
   geoMercator,
   geoAlbersUsa,
+  geoOrthographic,
 } from "d3-geo"
 
 import defaultProjectionConfig from "./projectionConfig"
@@ -21,6 +22,7 @@ const projectionReference = {
   winkel3: geoWinkel3,
   eckert4: geoEckert4,
   albersUsa: geoAlbersUsa,
+  orthographic: geoOrthographic,
 }
 
 export default function(width, height, config, projectionName) {
@@ -31,14 +33,14 @@ export default function(width, height, config, projectionName) {
   const rotation = config.rotation || defaultProjectionConfig.rotation
   const precision = config.precision || defaultProjectionConfig.precision
 
+  const baseProjection = projectionReference[projectionName]()
+    .scale(scale)
+    .translate([ xOffset + width / 2, yOffset + height / 2 ])
+    .precision(precision)
+
   return projectionName === "albersUsa"
-    ? projectionReference[projectionName]()
-        .scale(scale)
-        .translate([ xOffset + width / 2, yOffset + height / 2 ])
-        .precision(precision)
-    : projectionReference[projectionName]()
-        .scale(scale)
-        .translate([ xOffset + width / 2, yOffset + height / 2 ])
-        .rotate(rotation)
-        .precision(precision)
+    ? baseProjection
+    : projectionName === "orthographic"
+      ? baseProjection.rotate(rotation).clipAngle(90)
+      : baseProjection.rotate(rotation)
 }