From 9567a99fd9e4792d1cdf5b4daeca0fd93b4889f0 Mon Sep 17 00:00:00 2001
From: Stewart Allen <stewart.allen@gmail.com>
Date: Mon, 22 Sep 2025 00:09:41 -0400
Subject: [PATCH] fix thin wall retraction. remove point markers to allow codec
 between minion n worker

---
 src/kiri/mode/fdm/post.js    | 12 +++++++++---
 src/kiri/mode/fdm/prepare.js |  4 ++++
 2 files changed, 13 insertions(+), 3 deletions(-)

diff --git a/src/kiri/mode/fdm/post.js b/src/kiri/mode/fdm/post.js
index 21b7593c..655a569d 100644
--- a/src/kiri/mode/fdm/post.js
+++ b/src/kiri/mode/fdm/post.js
@@ -430,14 +430,13 @@ function trace_noodle(noodle, noodleWidth, minR, midR, maxR, opt = {}) {
         let parent = new Polygon();
         let inner = [];
         for (let poly of insetp.flattenTo([])) {
-            let sno = poly.parent ? shell : -shell; // shell number (- for inner/hole)
             let nupoly = poly.parent ? new Polygon() : parent;
             if (poly.parent) {
                 inner.push(nupoly);
             }
             let ltpo;
             let trace = [];
-            trace.shell = sno;
+            trace.shell = poly.parent ? shell : -shell; // shell number (- for inner/hole)
             poly.segment(minR,  true).forEachSegment((p1, p2) => {
                 let np1 = { x:(p1.x+p2.x)/2, y:(p1.y+p2.y)/2 };
                 let len = pointDist(p1, p2);
@@ -511,7 +510,7 @@ function trace_noodle(noodle, noodleWidth, minR, midR, maxR, opt = {}) {
                         // and adding that to the new trace
                         traces.push(trace);
                         let nutrace = [ trace.pop() ];
-                        nutrace.shell = sno;
+                        nutrace.shell = trace.shell;
                         // close last trace if endpoints near enough
                         if (pointDist(ltpo, trace[0] <= maxR)) {
                             trace.push(trace[0]);
@@ -551,6 +550,13 @@ function trace_noodle(noodle, noodleWidth, minR, midR, maxR, opt = {}) {
         remain.push(...ret);
     }
 
+    // remove point.segment markers for codec encoding between minion and worker
+    for (let trace of traces) {
+        for (let pt of trace) {
+            delete pt.s;
+        }
+    }
+
     return { lines, polys, remain, traces };
 }
 
diff --git a/src/kiri/mode/fdm/prepare.js b/src/kiri/mode/fdm/prepare.js
index 8c1b7499..d2bb8897 100644
--- a/src/kiri/mode/fdm/prepare.js
+++ b/src/kiri/mode/fdm/prepare.js
@@ -1126,6 +1126,10 @@ function slicePrintPath(print, slice, startPoint, offset, output, opt = {}) {
             }
             // remove emitted trace
             thin = thin.filter(t => t !== trace);
+            // retract if moving > retractDist
+            if (np && np.distTo2D(new Point(trace[0].x, trace[0].y)) > retractDist) {
+                retract();
+            }
             for (let pt of trace) {
                 np = new Point(pt.x, pt.y, z);
                 if (pt === trace[0]) {