simpler clip geo (#2248)

Author: Fil

src/style.js

@@ -352,21 +352,20 @@ const getFrameClip = memoizeClip((clipPath, context, dimensions) => {
     .attr("height", height - marginTop - marginBottom);
 });
 
-const getGeoClip = (function () {
-  const cache = new WeakMap();
-  const sphere = {type: "Sphere"};
-  return (geo, context) => {
-    let c, url;
-    if (!(c = cache.get(context))) cache.set(context, (c = new WeakMap()));
-    if (geo.type === "Sphere") geo = sphere; // coalesce all spheres.
-    if (!(url = c.get(geo))) {
-      const id = getClipId();
-      select(context.ownerSVGElement).append("clipPath").attr("id", id).append("path").attr("d", context.path()(geo));
-      c.set(geo, (url = `url(#${id})`));
-    }
-    return url;
-  };
-})();
+const geoClipCache = new WeakMap();
+const sphere = {type: "Sphere"};
+
+function getGeoClip(geo, context) {
+  let cache, url;
+  if (!(cache = geoClipCache.get(context))) geoClipCache.set(context, (cache = new WeakMap()));
+  if (geo.type === "Sphere") geo = sphere; // coalesce all spheres
+  if (!(url = cache.get(geo))) {
+    const id = getClipId();
+    select(context.ownerSVGElement).append("clipPath").attr("id", id).append("path").attr("d", context.path()(geo));
+    cache.set(geo, (url = `url(#${id})`));
+  }
+  return url;
+}
 
 // Note: may mutate selection.node!
 export function applyIndirectStyles(selection, mark, dimensions, context) {