improved NaN support

Author: DanielJDufour

package.json

@@ -50,7 +50,7 @@
     "flug": "^2.7.1"
   },
   "dependencies": {
-    "bbox-fns": "^0.19.0",
+    "bbox-fns": "^0.20.2",
     "proj4-fully-loaded": "^0.2.0",
     "proj4-merge": "^0.1.1"
   }

reproject-bbox.d.ts

@@ -8,6 +8,7 @@ export default function reprojectBoundingBox({
   bbox: [number, number, number, number] | Readonly<[number, number, number, number]>,
   density?: number | undefined,
   from: number | string,
+  nan_strategy?: "skip" | "throw" | string | undefined,
   proj4?: any,
   split?: boolean | undefined,
   to: number | string

reproject-bbox.js

@@ -11,7 +11,7 @@ if (typeof merge !== "function") {
 const CUSTOM_PROJECTION_ERROR =
   "[reproject-bbox] You passed in a value of 32767 for {{%s}}, which means a custom non-standard projection.  Please pass in a Well-Known Text or PROJ4JS String instead.";
 
-function reprojectBoundingBox({ bbox, density, from, proj4: _proj4, split = true, to }) {
+function reprojectBoundingBox({ bbox, debug_level = 0, density, from, nan_strategy = "throw", proj4: _proj4, split = true, to }) {
   if (from === 32767) throw new Error(CUSTOM_PROJECTION_ERROR.replace("{{%s}}", "from"));
   if (to === 32767) throw new Error(CUSTOM_PROJECTION_ERROR.replace("{{%s}}", "to"));
 
@@ -27,10 +27,12 @@ function reprojectBoundingBox({ bbox, density, from, proj4: _proj4, split = true
   const fwd = proj(from, to).forward;
 
   const bboxes = split ? bboxSplit(bbox, { x: [0], y: [0] }) : [bbox];
+  if (debug_level >= 2) console.log("[reproject-bbox] bboxes:", bboxes);
 
   const bboxes_reprojected = bboxes.map((bbox) => {
-    return reproject(bbox, fwd, { density });
+    return reproject(bbox, fwd, { density, nan_strategy });
   });
+  if (debug_level >= 2) console.log("[reproject-bbox] bboxes_reprojected:", bboxes_reprojected);
 
   const merged = bboxMerge(bboxes_reprojected);
 

reproject-bbox.min.js

@@ -6,19 +6,37 @@
  * @param {Array} points - an array (aka ring) of points
  * @return {bbox} bbox in form [xmin, ymin, xmax, ymax]
  */
-function bboxArray(points) {
+function bboxArray(points, { nan_strategy = "throw" } = { nan_strategy: "throw" }) {
   const count = points.length;
-  const [x, y] = points[0];
-  let xmin = x;
-  let xmax = x;
-  let ymin = y;
-  let ymax = y;
-  for (let i = 1; i < count; i++) {
+  let xmin = null;
+  let xmax = null;
+
+  let ymin = null;
+  let ymax = null;
+  for (let i = 0; i < count; i++) {
     const [x, y] = points[i];
-    if (x < xmin) xmin = x;
-    else if (x > xmax) xmax = x;
-    if (y < ymin) ymin = y;
-    else if (y > ymax) ymax = y;
+    if (isNaN(x)) {
+      if (nan_strategy === "throw") {
+        throw new Error("[bbox-fns/bbox-array] encountered point with a NaN value: [" + x + ", " + y + "]");
+      }
+    } else if (xmin === null) {
+      xmin = x;
+      xmax = x;
+    } else {
+      if (x < xmin) xmin = x;
+      else if (x > xmax) xmax = x;
+    }
+    if (isNaN(y)) {
+      if (nan_strategy === "throw") {
+        throw new Error("[bbox-fns/bbox-array] encountered point with a NaN value: [" + x + ", " + y + "]");
+      }
+    } else if (ymin === null) {
+      ymin = y;
+      ymax = y;
+    } else {
+      if (y < ymin) ymin = y;
+      else if (y > ymax) ymax = y;
+    }
   }
   return [xmin, ymin, xmax, ymax];
 }
@@ -29,10 +47,7 @@ module.exports.default = bboxArray;
 },{}],2:[function(require,module,exports){
 "use_strict";
 
-function densePolygon(
-  [xmin, ymin, xmax, ymax],
-  { density = 0 } = { density: 0 }
-) {
+function densePolygon([xmin, ymin, xmax, ymax], { density = 0 } = { density: 0 }) {
   if (typeof density === "number") density = [density, density];
 
   const [x_density, y_density] = density;
@@ -113,14 +128,14 @@ module.exports.default = merge;
 const bboxArray = require("./bbox-array.js");
 const densePolygon = require("./dense-polygon.js");
 
-function reproject(bbox, reproject, { async = false, density } = {}) {
+function reproject(bbox, fwd, { async = false, density, nan_strategy = "throw" } = {}) {
   const polygon = densePolygon(bbox, { density });
   const ring = polygon[0];
-  const reprojected = ring.map(pt => reproject(pt));
+  const reprojected = ring.map(pt => fwd(pt));
   if (async) {
-    return Promise.all(reprojected).then(points => bboxArray(points));
+    return Promise.all(reprojected).then(points => bboxArray(points, { nan_strategy }));
   } else {
-    return bboxArray(reprojected);
+    return bboxArray(reprojected, { nan_strategy });
   }
 }
 
@@ -146,12 +161,8 @@ function split(bbox, breakpoints) {
   const xbrks = breakpoints.x || [];
   const ybrks = breakpoints.y || [];
 
-  const xedges = [xmin]
-    .concat(xbrks.filter(x => x > xmin && x < xmax))
-    .concat([xmax]);
-  const yedges = [ymin]
-    .concat(ybrks.filter(y => y > ymin && y < ymax))
-    .concat([ymax]);
+  const xedges = [xmin].concat(xbrks.filter(x => x > xmin && x < xmax)).concat([xmax]);
+  const yedges = [ymin].concat(ybrks.filter(y => y > ymin && y < ymax)).concat([ymax]);
 
   const bboxes = [];
 
@@ -7634,7 +7645,7 @@ if (typeof merge !== "function") {
 const CUSTOM_PROJECTION_ERROR =
   "[reproject-bbox] You passed in a value of 32767 for {{%s}}, which means a custom non-standard projection.  Please pass in a Well-Known Text or PROJ4JS String instead.";
 
-function reprojectBoundingBox({ bbox, density, from, proj4: _proj4, split = true, to }) {
+function reprojectBoundingBox({ bbox, debug_level = 0, density, from, nan_strategy = "throw", proj4: _proj4, split = true, to }) {
   if (from === 32767) throw new Error(CUSTOM_PROJECTION_ERROR.replace("{{%s}}", "from"));
   if (to === 32767) throw new Error(CUSTOM_PROJECTION_ERROR.replace("{{%s}}", "to"));
 
@@ -7650,10 +7661,13 @@ function reprojectBoundingBox({ bbox, density, from, proj4: _proj4, split = true
   const fwd = proj(from, to).forward;
 
   const bboxes = split ? bboxSplit(bbox, { x: [0], y: [0] }) : [bbox];
+  if (debug_level >= 2) console.log("bboxes:", bboxes);
 
   const bboxes_reprojected = bboxes.map((bbox) => {
-    return reproject(bbox, fwd, { density });
+    console.log({ bbox, fwd, density, nan_strategy });
+    return reproject(bbox, fwd, { density, nan_strategy });
   });
+  if (debug_level >= 2) console.log("bboxes_reprojected:", bboxes_reprojected);
 
   const merged = bboxMerge(bboxes_reprojected);
 

test.js

@@ -71,3 +71,28 @@ test("throw error on 32767", ({ eq }) => {
   }
   eq(msg.startsWith(`[reproject-bbox] You passed in a value of 32767 for from`), true);
 });
+
+test("4326 to web mercator", ({ eq }) => {
+  const reprojected = reprojectBoundingBox({
+    bbox: [-180, -90, 180, 90],
+    density: 100,
+    from: "EPSG:4326",
+    nan_strategy: "skip",
+    split: false,
+    to: "EPSG:3857",
+  });
+  eq(reprojected, [-20037508.342789244, -26555100.29330386, 20037508.342789244, 26555100.293303788]);
+});
+
+test("4326 to web mercator (again)", ({ eq }) => {
+  const reprojected = reprojectBoundingBox({
+    bbox: [-180, -89.99928, 179.99856, 90],
+    debug_level: 0,
+    density: 100,
+    from: "EPSG:4326",
+    nan_strategy: "skip",
+    split: false,
+    to: "EPSG:3857",
+  });
+  eq(reprojected, [-20037508.342789244, -76394987.3448674, 20037348.0427225, 26555125.810017247]);
+});