From 5e49c3191a64957ea719c4242015f16902ee0e00 Mon Sep 17 00:00:00 2001
From: Stewart Allen <stewart.allen@gmail.com>
Date: Sun, 26 Apr 2020 20:19:02 -0400
Subject: [PATCH] fix poly union bug

---
 js/geo-polygon.js     | 15 ++++++++-------
 js/geo-polygons.js    | 23 ++++++++++++++++++++---
 js/kiri-driver-sla.js | 11 +++++------
 3 files changed, 33 insertions(+), 16 deletions(-)

diff --git a/js/geo-polygon.js b/js/geo-polygon.js
index 8a2abf6d..19ab6055 100644
--- a/js/geo-polygon.js
+++ b/js/geo-polygon.js
@@ -1224,7 +1224,7 @@ var gs_base_polygon = exports;
      * @param {Polygon} poly
      * @returns {?Polygon} intersected polygon or null if no intersection
      */
-    PRO.union = function(poly) {
+    PRO.union = function(poly, min) {
         if (!this.overlaps(poly)) return null;
 
         var fillang = this.fillang && this.area() > poly.area() ? this.fillang : poly.fillang,
@@ -1235,17 +1235,18 @@ var gs_base_polygon = exports;
             clip = new clib.Clipper(),
             ctre = new clib.PolyTree(),
             sp1 = this.toClipper(),
-            sp2 = poly.toClipper();
+            sp2 = poly.toClipper(),
+            minarea = min >= 0 ? min : 0.1;
 
         clip.AddPaths(sp1, ptyp.ptSubject, true);
         clip.AddPaths(sp2, ptyp.ptClip, true);
 
         if (clip.Execute(ctyp.ctUnion, ctre, cfil.pftEvenOdd, cfil.pftEvenOdd)) {
-            poly = POLY().fromClipperTree(ctre, poly.getZ());
-            if (poly.length === 1) {
-                poly = poly[0];
-                poly.fillang = fillang;
-                return poly;
+            let union = POLY().fromClipperTreeUnion(ctre, poly.getZ(), minarea);
+            if (union.length === 1) {
+                union = union[0];
+                union.fillang = fillang;
+                return union;
             }
         }
 
diff --git a/js/geo-polygons.js b/js/geo-polygons.js
index 26dc0871..cfea45e0 100644
--- a/js/geo-polygons.js
+++ b/js/geo-polygons.js
@@ -37,6 +37,7 @@ var gs_base_polygons = exports;
         toClipper : toClipper,
         fromClipperNode : fromClipperNode,
         fromClipperTree : fromClipperTree,
+        fromClipperTreeUnion: fromClipperTreeUnion,
         cleanClipperTree : cleanClipperTree,
         fingerprintCompare: fingerprintCompare,
         fingerprint: fingerprint
@@ -82,6 +83,23 @@ var gs_base_polygons = exports;
         return polys;
     };
 
+    function fromClipperTreeUnion(tnode, z, minarea) {
+        let polys = [], poly;
+
+        tnode.m_Childs.forEach(function(child) {
+            poly = fromClipperNode(child, z);
+            if (minarea && poly.area() < minarea) {
+                return;
+            }
+            polys.push(poly);
+            if (child.m_Childs) {
+                fromClipperTreeUnion(child, z, minarea);
+            }
+        });
+
+        return polys;
+    };
+
     function cleanClipperTree(tree) {
         var clib = self.ClipperLib,
             clip = clib.Clipper;
@@ -303,10 +321,9 @@ var gs_base_polygons = exports;
      * Print.init w/ brims
      *
      * @param {Polygon[]} polys
-     * @param {number} [z]
      * @returns {Polygon[]}
      */
-     function union(polys) {
+     function union(polys, minarea) {
          if (polys.length < 2) return polys;
 
          var out = polys.slice(), i, j, union, uset = [];
@@ -315,7 +332,7 @@ var gs_base_polygons = exports;
              if (!out[i]) continue;
              for (j=i+1; j<out.length; j++) {
                  if (!out[j]) continue;
-                 union = out[i].union(out[j]);
+                 union = out[i].union(out[j], minarea);
                  if (union) {
                      out[i] = null;
                      out[j] = null;
diff --git a/js/kiri-driver-sla.js b/js/kiri-driver-sla.js
index 84d7ee90..af3cbd53 100644
--- a/js/kiri-driver-sla.js
+++ b/js/kiri-driver-sla.js
@@ -98,7 +98,7 @@ let gs_kiri_sla = exports;
                     polys.appendAll(slice.tops.map(t => t.poly.clone()));
                 });
                 // p.clone prevents inner voids from forming
-                let union = POLY.union(polys).map(p => p.clone());
+                let union = POLY.union(polys,0).map(p => p.clone());
                 let expand = POLY.expand(union, off, zoff, [], 1);
                 let lastraft;
                 for (let s=0; s<layers + gap; s++) {
@@ -165,7 +165,7 @@ let gs_kiri_sla = exports;
                     let traces = POLY.nest(POLY.flatten(slice.gatherTraces([])));
                     let trims = slice.solids.trimmed || [];
                     traces.appendAll(trims);
-                    let union = POLY.union(traces);
+                    let union = POLY.union(traces,0);
                     slice.solids.unioned = union;
                 }, "solid");
             } else {
@@ -301,8 +301,7 @@ let gs_kiri_sla = exports;
         // union support pillars
         slices.forEach(slice => {
             if (slice.supports) {
-                // todo unioning seems to be failing
-                // slice.supports = POLY.union(slice.supports);
+                slice.supports = POLY.union(slice.supports,0);
             }
         });
     }
@@ -548,14 +547,14 @@ let gs_kiri_sla = exports;
         }
 
         if (!cached) {
-            fill = POLY.union(fill);
+            fill = POLY.union(fill,0);
             fill_cache[seq_c] = fill;
         } else {
             fill = cached.slice().map(p => p.clone(true).setZ(slice.z));
         }
 
         fill = POLY.trimTo(fill, slice.tops.map(t => t.poly));
-        fill = POLY.union(slice.solids.unioned.appendAll(fill));
+        fill = POLY.union(slice.solids.unioned.appendAll(fill),0);
 
         slice.solids.unioned = fill;
     }