From 535273b9e0dc263b0f56a059245488817cacf06d Mon Sep 17 00:00:00 2001
From: Stewart Allen <stewart.allen@gmail.com>
Date: Thu, 18 Mar 2021 19:05:48 -0400
Subject: [PATCH] add smarter route planning when there are multiple tops to
 choose from

---
 src/geo/polygons.js     | 40 ++++++++++++++++++++++++++++++++++++++++
 src/mode/cam/prepare.js |  7 ++++++-
 2 files changed, 46 insertions(+), 1 deletion(-)

diff --git a/src/geo/polygons.js b/src/geo/polygons.js
index 39aac8cf..e7b324d8 100644
--- a/src/geo/polygons.js
+++ b/src/geo/polygons.js
@@ -29,6 +29,7 @@
         trimTo,
         expand,
         expand_lines,
+        route,
         union,
         inset,
         nest,
@@ -865,4 +866,43 @@
         return true;
     }
 
+    // plan a route through an array of polygon center points
+    // starting with the polygon center closest to "start"
+    function route(polys, start) {
+        let centers = [];
+        let first, minDist = Infinity;
+        for (let poly of polys) {
+            let center = poly.average();
+            let rec = {poly, center, used: false};
+            let dist = center.distTo2D(start);
+            if (dist < minDist) {
+                first = rec;
+                minDist = dist;
+            }
+            centers.push(rec);
+        }
+        first.used = true;
+        let routed = [ first ];
+        for (;;) {
+            let closest;
+            let minDist = Infinity;
+            for (let rec of centers) {
+                if (!rec.used) {
+                    let dist = rec.center.distTo2D(first.center);
+                    if (dist < minDist) {
+                        minDist = dist;
+                        closest = rec;
+                    }
+                }
+            }
+            if (!closest) {
+                break;
+            } else {
+                closest.used = true;
+                routed.push(first = closest);
+            }
+        }
+        return routed.map(r => r.poly);
+    }
+
 })();
diff --git a/src/mode/cam/prepare.js b/src/mode/cam/prepare.js
index 66cc66f4..ba872983 100644
--- a/src/mode/cam/prepare.js
+++ b/src/mode/cam/prepare.js
@@ -418,7 +418,12 @@
             }
             let ltops = tops[depth];
             let fitted = fit ? ltops.filter(poly => poly.isInside(fit, 0.01)) : ltops;
-            fitted.filter(top => !top.level_emit).forEach(top => {
+            let ftops = fitted.filter(top => !top.level_emit);
+            if (ftops.length > 1) {
+                console.log({depth, ftops});
+                ftops = POLY.route(ftops, start);
+            }
+            ftops.forEach(top => {
                 top.level_emit = true;
                 let inside = level.filter(poly => poly.isInside(top));
                 if (ease) {