v0.6.102

CHANGELOG.md

@@ -1,3 +1,6 @@
+v0.6.102
+* Added Nicolosi Globular (nicol) projection.
+
 v0.6.101
 * Added -affine fit-bbox= option, for transforming data to fit within a bounding box.
 * Improved arrow symbols.

package.json

@@ -1,6 +1,6 @@
 {
   "name": "mapshaper",
-  "version": "0.6.101",
+  "version": "0.6.102",
   "description": "A tool for editing vector datasets for mapping and GIS.",
   "keywords": [
     "shapefile",
@@ -56,7 +56,7 @@
     "iconv-lite": "^0.6.3",
     "idb-keyval": "^6.2.0",
     "kdbush": "^3.0.0",
-    "mproj": "0.0.39",
+    "mproj": "0.0.40",
     "msgpackr": "^1.10.1",
     "opn": "^5.3.0",
     "rw": "~1.3.3",

src/crs/mapshaper-proj-extents.mjs

@@ -118,7 +118,7 @@ export function getClampBBox(P) {
 }
 
 export function isCircleClippedProjection(P) {
-  return inList(P, 'stere,sterea,ups,ortho,gnom,laea,nsper,tpers,geos');
+  return inList(P, 'stere,sterea,ups,ortho,gnom,laea,nsper,tpers,geos,nicol');
 }
 
 function getPerspectiveClipAngle(P) {
@@ -143,6 +143,7 @@ export function getDefaultClipAngle(P) {
     laea: 179,
     //ortho: 89.9, // projection errors betwen lat +/-35 to 55
     ortho: 89.85, // TODO: investigate
+    nicol: 89.85,
     stere: 142,
     sterea: 142,
     ups: 10.5 // TODO: should be 6.5 deg at north pole

src/crs/mapshaper-proj-info.mjs

@@ -17,7 +17,7 @@ export function isAxisAligned(P) {
   // TODO: consider projections that may or may not be aligned,
   // depending on parameters
   if (inList(P, 'cassini,gnom,bertin1953,chamb,ob_tran,tpeqd,healpix,rhealpix,' +
-    'ocea,omerc,tmerc,etmerc')) {
+    'ocea,omerc,tmerc,etmerc,nicol')) {
     return false;
   }
   if (isAzimuthal(P)) {

www/modules.js

@@ -20279,6 +20279,7 @@ function pj_phi2(ts, e) {
 
 
 pj_add(pj_merc, 'merc', 'Mercator', 'Cyl, Sph&Ell\nlat_ts=');
+pj_add(pj_webmerc, 'webmerc', 'Web Mercator / Pseudo Mercator', 'Cyl, Ell');
 
 function pj_merc(P) {
   var EPS10 = 1e-10;
@@ -20333,6 +20334,26 @@ function pj_merc(P) {
   }
 }
 
+function pj_webmerc(P) {
+  P.k0 = 1;
+  P.inv = s_inv;
+  P.fwd = s_fwd;
+
+  function s_fwd(lp, xy) {
+    if (fabs(fabs(lp.phi) - M_HALFPI) <= EPS10) {
+      f_error();
+    }
+    xy.x = P.k0 * lp.lam;
+    xy.y = P.k0 * log(tan(M_FORTPI + 0.5 * lp.phi));
+  }
+
+  function s_inv(xy, lp) {
+    lp.phi = M_HALFPI - 2 * atan(exp(-xy.y / P.k0));
+    lp.lam = xy.x / P.k0;
+  }
+}
+
+
 
 pj_add(pj_mill, 'mill', 'Miller Cylindrical', 'Cyl, Sph');
 
@@ -20790,6 +20811,45 @@ var NITER = 9,
 }
 
 
+pj_add(pj_nicol, 'nicol', 'Nicolosi Globular', 'Misc Sph, no inv');
+
+function pj_nicol(P) {
+  P.es = 0;
+  P.fwd = s_fwd;
+
+  function s_fwd(lp, xy) {
+    var EPS = 1e-10;
+    if (fabs(lp.lam) < EPS) {
+      xy.x = 0;
+      xy.y = lp.phi;
+    } else if (fabs(lp.phi) < EPS) {
+      xy.x = lp.lam;
+      xy.y = 0;
+    } else if (fabs(fabs(lp.lam) - M_HALFPI) < EPS) {
+      xy.x = lp.lam * cos(lp.phi);
+      xy.y = M_HALFPI * sin(lp.phi);
+    } else if (fabs(fabs(lp.phi) - M_HALFPI) < EPS) {
+      xy.x = 0;
+      xy.y = lp.phi;
+    } else {
+      var tb = M_HALFPI / lp.lam - lp.lam / M_HALFPI;
+      var c = lp.phi / M_HALFPI;
+      var sp = sin(lp.phi);
+      var d = (1 - c * c) / (sp - c);
+      var r2 = tb / d;
+      r2 *= r2;
+      var m = (tb * sp / d - 0.5 * tb) / (1 + r2);
+      var n = (sp / r2 + 0.5 * d) / (1 + 1 / r2);
+      xy.x = cos(lp.phi);
+      xy.x = sqrt(m * m + xy.x * xy.x / (1 + r2));
+      xy.x = M_HALFPI * (m + (lp.lam < 0. ? -xy.x : xy.x));
+      xy.y = sqrt(n * n - (sp * sp / r2 + d * sp - 1) / (1 + 1 / r2));
+      xy.y = M_HALFPI * (n + (lp.phi < 0. ? xy.y : -xy.y));
+    }
+  }
+}
+
+
 pj_add(pj_nsper, 'nsper', 'Near-sided perspective', 'Azi, Sph\nh=');
 pj_add(pj_tpers, 'tpers', 'Tilted perspective', 'Azi, Sph\ntilt= azi= h=');