Update layer z value

Author: remcoder

src/__tests__/job.ts

@@ -300,6 +300,61 @@ describe('.layers', () => {
     expect(layers.length).toEqual(1);
     expect(layers[0].paths.length).toEqual(4);
   });
+
+  test('layer z must equal path z', () => {
+    const job = new Job();
+
+    append_path(job, PathType.Extrusion, [
+      [5, 6, 2],
+      [5, 6, 2]
+    ]);
+
+    const layers = job.layers;
+
+    expect(layers).not.toBeNull();
+    expect(layers.length).toEqual(1);
+    expect(layers[0].z).toEqual(2);
+  });
+
+   test('layer z must equal extrusion path z', () => {
+    const job = new Job();
+
+    append_path(job, PathType.Extrusion, [
+      [5, 6, 2],
+      [5, 6, 2]
+    ]);
+
+    append_path(job, PathType.Travel, [
+      [5, 6, 4],
+      [5, 6, 4]
+    ]);
+
+    const layers = job.layers;
+
+    expect(layers).not.toBeNull();
+    expect(layers.length).toEqual(1);
+    expect(layers[0].z).toEqual(2);
+  });
+
+
+  test('layer z must equal path z, for second layer', () => {
+    const job = new Job();
+
+    append_path(job, PathType.Extrusion, [
+      [5, 6, 2],
+      [5, 6, 2]
+    ]);
+    append_path(job, PathType.Extrusion, [
+      [5, 6, 4],
+      [5, 6, 4]
+    ]);
+
+    const layers = job.layers;
+
+    expect(layers).not.toBeNull();
+    expect(layers.length).toEqual(2);
+    expect(layers[1].z).toEqual(4);
+  });
 });
 
 describe('.extrusions', () => {

src/indexers.ts

@@ -117,7 +117,13 @@ export class LayersIndexer extends Indexer {
         this.createLayer(path.vertices[2]);
       }
     }
-    this.lastLayer().paths.push(path);
+    
+    const layer = this.lastLayer();
+    if (path.travelType === PathType.Extrusion) {
+      layer.z = path.vertices[2]; // ensure the layer's Z position is updated when extruding
+    }
+
+    layer.paths.push(path);
   }
 
   /**