--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/toolkit/exemples/couple/javascript/d3/src/geo/azimuthal.js	Thu Apr 10 14:20:23 2014 +0200
@@ -0,0 +1,80 @@
+// TODO clip input coordinates on opposite hemisphere
+d3.geo.azimuthal = function() {
+  var mode = "orthographic", // or stereographic, gnomonic, equidistant or equalarea
+      origin,
+      scale = 200,
+      translate = [480, 250],
+      x0,
+      y0,
+      cy0,
+      sy0;
+
+  function azimuthal(coordinates) {
+    var x1 = coordinates[0] * d3_geo_radians - x0,
+        y1 = coordinates[1] * d3_geo_radians,
+        cx1 = Math.cos(x1),
+        sx1 = Math.sin(x1),
+        cy1 = Math.cos(y1),
+        sy1 = Math.sin(y1),
+        cc = mode !== "orthographic" ? sy0 * sy1 + cy0 * cy1 * cx1 : null,
+        c,
+        k = mode === "stereographic" ? 1 / (1 + cc)
+          : mode === "gnomonic" ? 1 / cc
+          : mode === "equidistant" ? (c = Math.acos(cc), c ? c / Math.sin(c) : 0)
+          : mode === "equalarea" ? Math.sqrt(2 / (1 + cc))
+          : 1,
+        x = k * cy1 * sx1,
+        y = k * (sy0 * cy1 * cx1 - cy0 * sy1);
+    return [
+      scale * x + translate[0],
+      scale * y + translate[1]
+    ];
+  }
+
+  azimuthal.invert = function(coordinates) {
+    var x = (coordinates[0] - translate[0]) / scale,
+        y = (coordinates[1] - translate[1]) / scale,
+        p = Math.sqrt(x * x + y * y),
+        c = mode === "stereographic" ? 2 * Math.atan(p)
+          : mode === "gnomonic" ? Math.atan(p)
+          : mode === "equidistant" ? p
+          : mode === "equalarea" ? 2 * Math.asin(.5 * p)
+          : Math.asin(p),
+        sc = Math.sin(c),
+        cc = Math.cos(c);
+    return [
+      (x0 + Math.atan2(x * sc, p * cy0 * cc + y * sy0 * sc)) / d3_geo_radians,
+      Math.asin(cc * sy0 - (p ? (y * sc * cy0) / p : 0)) / d3_geo_radians
+    ];
+  };
+
+  azimuthal.mode = function(x) {
+    if (!arguments.length) return mode;
+    mode = x + "";
+    return azimuthal;
+  };
+
+  azimuthal.origin = function(x) {
+    if (!arguments.length) return origin;
+    origin = x;
+    x0 = origin[0] * d3_geo_radians;
+    y0 = origin[1] * d3_geo_radians;
+    cy0 = Math.cos(y0);
+    sy0 = Math.sin(y0);
+    return azimuthal;
+  };
+
+  azimuthal.scale = function(x) {
+    if (!arguments.length) return scale;
+    scale = +x;
+    return azimuthal;
+  };
+
+  azimuthal.translate = function(x) {
+    if (!arguments.length) return translate;
+    translate = [+x[0], +x[1]];
+    return azimuthal;
+  };
+
+  return azimuthal.origin([0, 0]);
+};