From a4af3a916662f21a0ca7df6e1f222055d282e302 Mon Sep 17 00:00:00 2001
From: Stewart Allen <stewart.allen@gmail.com>
Date: Mon, 22 Dec 2025 10:07:10 -0500
Subject: [PATCH] fix gpu contour Y with inside only

---
 src/geo/point.js           | 12 ++++++++++++
 src/kiri/mode/cam/topo3.js | 11 +++++++----
 2 files changed, 19 insertions(+), 4 deletions(-)

diff --git a/src/geo/point.js b/src/geo/point.js
index 5751653a..f922b06f 100644
--- a/src/geo/point.js
+++ b/src/geo/point.js
@@ -126,6 +126,18 @@ class Point {
         return this;
     }
 
+    /**
+     * Swap X and Y coordinates in place
+     * @returns {Point} This point (for chaining)
+     */
+    swapXY() {
+        let p = this,
+            t = p.x;
+        p.x = p.y;
+        p.y = t;
+        return this;
+    }
+
     /**
      * Swap X and Z coordinates in place
      * @returns {Point} This point (for chaining)
diff --git a/src/kiri/mode/cam/topo3.js b/src/kiri/mode/cam/topo3.js
index ab8136d8..63999c71 100644
--- a/src/kiri/mode/cam/topo3.js
+++ b/src/kiri/mode/cam/topo3.js
@@ -182,10 +182,7 @@ export class Topo {
             for (let i=0; i<numScanlines; i++) {
                 let lineStart = i * pointsPerLine;
                 let lineData = pathData.slice(lineStart, lineStart + pointsPerLine);
-                let points = contourY
-                    ? Array.from(lineData).map((v,j) => calcPoint(i * ymult + yoff, j * xmult + xoff, v, i * xStep, j * yStep))
-                    : Array.from(lineData).map((v,j) => calcPoint(j * xmult + xoff, i * ymult + yoff, v, j * xStep, i * yStep))
-                    ;
+                let points = Array.from(lineData).map((v,j) => calcPoint(j * xmult + xoff, i * ymult + yoff, v, j * xStep, i * yStep));
                 let slice = newSlice(i);
                 let poly = newPolygon().setOpen();
                 let lines = [ ];
@@ -228,6 +225,12 @@ export class Topo {
                 if (poly.length > 1) {
                     lines.push(poly);
                 }
+                if (contourY) {
+                    for (let poly of lines)
+                    for (let p of poly.points) {
+                        p.swapXY();
+                    }
+                }
                 // raise output points when inside tab boundaries
                 if (!inside && tabsOn && clipTab.length)
                 for (let poly of lines) {