Remove resampling temporary state.

d3.js

@@ -6385,15 +6385,9 @@
     function resamplePoint(point) {
       return projectPoint(point[0], point[1]);
     }
-    var λ00, φ00, λ0, sinφ0, cosφ0, x0, y0;
     function resampleLine(coordinates) {
       if (!(n = coordinates.length)) return coordinates;
-      var n, i = 0, p = coordinates[0], λ, φ, line;
-      line = [ p = projectPoint(λ00 = λ0 = p[0], φ00 = φ = p[1]) ];
-      sinφ0 = Math.sin(φ);
-      cosφ0 = Math.cos(φ);
-      x0 = p[0];
-      y0 = p[1];
+      var n, i = 0, p = coordinates[0], λ, φ, λ0, line = [ p = projectPoint(λ0 = p[0], φ = p[1]) ], sinφ0 = Math.sin(φ), cosφ0 = Math.cos(φ), x0 = p[0], y0 = p[1];
       while (++i < n) {
         p = coordinates[i];
         p = projectPoint(λ = p[0], φ = p[1]);
@@ -6403,11 +6397,12 @@
       return line;
     }
     function resamplePolygon(coordinates) {
-      var n = coordinates.length, i = -1, polygon = [], ring, p;
+      var n = coordinates.length, i = -1, polygon = [], ring, resampled, l, m, p;
       while (++i < n) {
-        polygon.push(ring = resampleLine(coordinates[i]));
-        p = projectPoint(λ00, φ00);
-        resampleLineTo(x0, y0, λ0, sinφ0, cosφ0, p[0], p[1], λ00, Math.sin(φ00), Math.cos(φ00), maxDepth, ring);
+        polygon.push(resampled = resampleLine(ring = coordinates[i]));
+        m = ring.length - 1;
+        l = resampled.length - 1;
+        resampleLineTo((p = ring[0])[0], p[1], (p = resampled[0])[0], Math.sin(p[1]), Math.cos(p[1]), (p = ring[m])[0], p[1], (p = resampled[l])[0], Math.sin(p[1]), Math.cos(p[1]), maxDepth, ring);
       }
       return polygon;
     }

src/geo/projection.js

@@ -137,16 +137,6 @@ function d3_geo_projectionMutator(projectAt) {
     return projectPoint(point[0], point[1]);
   }
 
-  // Temporary state used by resampleLine & resamplePolygon.
-  // TODO find a cleaner way to encapsulate this temporary state?
-  var λ00,
-      φ00,
-      λ0,
-      sinφ0,
-      cosφ0,
-      x0,
-      y0;
-
   // TODO rename: this is not just resampling, it also projects and transforms!
   function resampleLine(coordinates) {
     if (!(n = coordinates.length)) return coordinates;
@@ -155,11 +145,11 @@ function d3_geo_projectionMutator(projectAt) {
         p = coordinates[0],
         λ,
         φ,
-        line;
-    line = [p = projectPoint(λ00 = λ0 = p[0], φ00 = φ = p[1])];
-    sinφ0 = Math.sin(φ);
-    cosφ0 = Math.cos(φ);
-    x0 = p[0];
+        λ0,
+        line = [p = projectPoint(λ0 = p[0], φ = p[1])],
+        sinφ0 = Math.sin(φ),
+        cosφ0 = Math.cos(φ),
+        x0 = p[0],
         y0 = p[1];
     while (++i < n) {
       p = coordinates[i];
@@ -178,11 +168,18 @@ function d3_geo_projectionMutator(projectAt) {
         i = -1,
         polygon = [],
         ring,
+        resampled,
+        l,
+        m,
         p;
     while (++i < n) {
-      polygon.push(ring = resampleLine(coordinates[i]));
-      p = projectPoint(λ00, φ00); // TODO isn't this the same as ring[0]?
-      resampleLineTo(x0, y0, λ0, sinφ0, cosφ0, p[0], p[1], λ00, Math.sin(φ00), Math.cos(φ00), maxDepth, ring);
+      polygon.push(resampled = resampleLine(ring = coordinates[i]));
+      m = ring.length - 1;
+      l = resampled.length - 1;
+      resampleLineTo(
+          (p = ring[0])[0], p[1], (p = resampled[0])[0], Math.sin(p[1]), Math.cos(p[1]),
+          (p = ring[m])[0], p[1], (p = resampled[l])[0], Math.sin(p[1]), Math.cos(p[1]),
+          maxDepth, ring);
     }
     return polygon;
   }