From a6ca9a8ab0e65dc34a6b637a56de526ca1cb9d72 Mon Sep 17 00:00:00 2001
From: Matthew Bloch <mbloch@nytimes.com>
Date: Wed, 19 Jul 2023 15:24:17 -0400
Subject: [PATCH] v0.6.37

---
 CHANGELOG.md                            |  3 ++
 package-lock.json                       |  4 +--
 package.json                            |  2 +-
 src/symbols/mapshaper-arrow-symbols.mjs | 38 ++++++++++++++-----------
 4 files changed, 28 insertions(+), 19 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index d335bc24..87a1fe2f 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,6 @@
+v0.6.37
+* Support for simple line symbols using `type-arrow head-length=0`.
+
 v0.6.36
 * Improved `fill-effect=sphere` gradient.
 * Sphere effect can be previewed in the web UI.
diff --git a/package-lock.json b/package-lock.json
index ba1ba11d..17ab3788 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -1,12 +1,12 @@
 {
   "name": "mapshaper",
-  "version": "0.6.36",
+  "version": "0.6.37",
   "lockfileVersion": 2,
   "requires": true,
   "packages": {
     "": {
       "name": "mapshaper",
-      "version": "0.6.36",
+      "version": "0.6.37",
       "license": "MPL-2.0",
       "dependencies": {
         "@placemarkio/tokml": "^0.3.3",
diff --git a/package.json b/package.json
index 73b1d9e8..c429fa55 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "mapshaper",
-  "version": "0.6.36",
+  "version": "0.6.37",
   "description": "A tool for editing vector datasets for mapping and GIS.",
   "keywords": [
     "shapefile",
diff --git a/src/symbols/mapshaper-arrow-symbols.mjs b/src/symbols/mapshaper-arrow-symbols.mjs
index 5049a117..f6e434b2 100644
--- a/src/symbols/mapshaper-arrow-symbols.mjs
+++ b/src/symbols/mapshaper-arrow-symbols.mjs
@@ -23,7 +23,7 @@ export function getArrowCoords(d, style) {
       headDx = size.headWidth / 2,
       stemDx = size.stemWidth / 2,
       baseDx = stemDx * (1 - stemTaper),
-      head, stem, coords, dx, dy;
+      coords, dx, dy;
 
   if (curvature) {
     // make curved stem
@@ -36,11 +36,11 @@ export function getArrowCoords(d, style) {
     dy = stemLen * Math.cos(theta / 2);
 
     if (stickArrow) {
-      stem = getCurvedStemCoords(-ax, -ay, dx, dy);
+      coords = getCurvedStemCoords(-ax, -ay, dx, dy);
     } else {
       var leftStem = getCurvedStemCoords(-ax, -ay, -stemDx + dx, dy);
       var rightStem = getCurvedStemCoords(ax, ay, stemDx + dx, dy);
-      stem = leftStem.concat(rightStem.reverse());
+      coords = leftStem.concat(rightStem.reverse());
     }
 
   } else {
@@ -48,23 +48,26 @@ export function getArrowCoords(d, style) {
     dx = 0;
     dy = stemLen;
     if (stickArrow) {
-      stem = [[0, 0], [0, stemLen]];
+      coords = [[0, 0], [0, stemLen]];
     } else {
-      stem = [[-baseDx, 0], [baseDx, 0]];
+      coords = [[-baseDx, 0], [baseDx, 0]];
     }
   }
 
   if (stickArrow) {
     // make stick arrow
-    head = [[-headDx + dx, stemLen - headLen], [dx, stemLen], [headDx + dx, stemLen - headLen]];
-    coords = [stem, head]; // MultiLineString coords
+    coords = [coords]; // MultiLineString coords
+    if (headLen > 0) {
+      coords.push([[-headDx + dx, stemLen - headLen], [dx, stemLen], [headDx + dx, stemLen - headLen]]);
+    }
   } else {
     // make filled arrow
     // coordinates go counter clockwise, starting from the leftmost head coordinate
-    head = [[stemDx + dx, dy], [headDx + dx, dy],
-        [dx, headLen + dy], [-headDx + dx, dy], [-stemDx + dx, dy]];
-    coords = stem.concat(head);
-    coords.push(stem[0].concat()); // closed path
+    coords.push([stemDx + dx, dy]);
+    if (headLen > 0) {
+      coords.push([headDx + dx, dy], [dx, headLen + dy], [-headDx + dx, dy]);
+    }
+    coords.push([-stemDx + dx, dy], coords[0].concat()); // close path
     coords = [coords]; // Polygon coords
   }
 
@@ -93,7 +96,6 @@ function calcArrowSize(d, stickArrow) {
   var totalLen = Math.max(d.radius || d.length || d.r || 0, 0),
       scale = 1,
       o = initArrowSize(d); // calc several parameters
-
   if (totalLen >= 0) {
     scale = calcScale(totalLen, o.headLen, d);
     o.stemWidth *= scale;
@@ -102,7 +104,7 @@ function calcArrowSize(d, stickArrow) {
     o.stemLen = stickArrow ? totalLen : totalLen - o.headLen;
   }
 
-  if (o.headWidth < o.stemWidth) {
+  if (o.headWidth < o.stemWidth && o.headWidth > 0) {
     stop('Arrow head must be at least as wide as the stem.');
   }
   return o;
@@ -131,14 +133,18 @@ export function initArrowSize(d) {
     headWidth: d['head-width'],
     headLen: d['head-length']
   };
-  if (!o.headWidth) {
-    if (o.headLen) {
+  if (o.headWidth === 0) {
+    o.headLen = 0;
+  } else if (o.headWidth > 0 === false) {
+    if (o.headLen > 0) {
       o.headWidth = o.headLen / sizeRatio;
+    } else if (o.headLen === 0) {
+      o.headWidth = 0;
     } else {
       o.headWidth = o.stemWidth * 3; // assumes stemWidth has been set
     }
   }
-  if (!o.headLen) {
+  if (o.headLen >= 0 === false) {
     o.headLen = o.headWidth * sizeRatio;
   }
   return o;