add new slicePre()/slicePost() requirement to engine and enforce new threading/worker requirement

src/kiri/mode/fdm/work/slice.js

@@ -585,7 +585,7 @@ export function sliceOne(settings, widget, onupdate, ondone) {
         }
 
         // perform accumulation top down
-        for (let slice of stack.reverse()) {
+        for (let slice of stack.slice().reverse()) {
             let shadow = slice.shadow ?? [];
             if (devel) slice.output().setLayer("shadow", 0xff0000).addPolys(shadow);
             if (process.sliceSupportExtra) {
@@ -628,7 +628,7 @@ export function sliceOne(settings, widget, onupdate, ondone) {
 
         // trim using support part offset value
         let gaps = process.sliceSupportGap;
-        for (let slice of stack.reverse()) {
+        for (let slice of stack) {
             let clips = [
                 slice.clips,
                 gaps ? slice.up?.clips : undefined,
@@ -1162,6 +1162,7 @@ export function slicePost(settings, onupdate) {
     // assign grid_id which can be embedded in gcode and
     // used by the controller to cancel objects during print
     let { bounds } = settings;
+    if (!bounds) return;
     for (let widget of widgets) {
         let { pos, box } = widget.track;
         // calculate top/left coordinate for widget

src/kiri/run/engine.js

@@ -26,6 +26,7 @@ class Engine {
             client.setWorkPath(workURL);
             client.setPoolPath(poolURL);
             client.restart();
+            client.pool.start();
         } catch (error) {
             console.log({ error });
         }
@@ -63,11 +64,8 @@ class Engine {
     }
 
     setThreading(bool) {
-        if (bool) {
-            client.pool.start();
-        } else {
-            client.pool.stop();
-        }
+        console.log('setThreading() deprecated');
+        return this;
     }
 
     setListener(listener) {
@@ -163,6 +161,7 @@ class Engine {
             client.clear();
             client.sync([this.widget]);
             client.rotate(this.settings);
+            client.slicePre(this.settings, () => {});
             client.slice(this.settings, this.widget, msg => {
                 this.listener({ slice: msg });
                 if (msg.error) {
@@ -170,6 +169,7 @@ class Engine {
                 }
                 if (msg.done) {
                     accept(this);
+                    client.slicePost(this.settings, () => {});
                 }
             });
         });