fix subtract

package.json

@@ -29,7 +29,7 @@
         "connect": "^3.7.0",
         "earcut": "^2.2.3",
         "express-useragent": "^1.0.13",
-        "@jscad/modeling": "^2.9.0",
+        "@jscad/modeling": "^2.9.2",
         "jszip": "^3.7.1",
         "moment": "^2.24.0",
         "pixi.js": "^4.8.9",

src/geo/csg.js

@@ -31,6 +31,9 @@ const CSG = {
     },
 
     toPositionArray(geom) {
+        if (!geom || geom.length === 0) {
+            return [].toFloat32();
+        }
         const out = [];
         const poly = jscadModeling.geometries.geom3
             .toPolygons(geom)

src/mesh/api.js

@@ -384,10 +384,10 @@ const tool = {
             return { id: m.id, matrix: m.matrix, tool: m.tool() }
         }))
         .then(data => {
-            let group = api.group.new([new mesh.model({
+            let group = api.group.new(data.map(el => new mesh.model({
                 file: `subtracted`,
-                mesh: data
-            })]).promote();
+                mesh: el
+            }) )).promote();
             api.selection.set([group]);
             api.log.emit('subtract complete').unpin();
         });

src/mesh/work.js

@@ -159,9 +159,10 @@ let model = {
             .map(a => base.CSG.fromPositionArray(a));
         let subs = [];
         for (let obj of bases) {
-            subs.appendAll(base.CSG.subtract(obj, ...tools));
+            let sub = base.CSG.subtract(obj, ...tools);
+            subs.append(base.CSG.toPositionArray(sub));
         }
-        return base.CSG.toPositionArray(subs);
+        return subs;
     },
 
     // used to generate a list for split snapping