tweaks to xray, debug. add poly dep to mesh for topo mod

src/geo/polygon.js

@@ -1597,18 +1597,17 @@ class Polygon {
      * @param {Polygon} poly clipping mask
      * @returns {?Polygon[]}
      */
-    mask(poly, nullOnEquiv) {
+    mask(poly, nullOnEquiv, minarea) {
         let fillang = this.fillang && this.area() > poly.area() ? this.fillang : poly.fillang,
             clip = new clib.Clipper(),
             ctre = new clib.PolyTree(),
             sp1 = this.toClipper(),
             sp2 = poly.toClipper();
-
         clip.AddPaths(sp1, ptyp.ptSubject, true);
         clip.AddPaths(sp2, ptyp.ptClip, true);
 
         if (clip.Execute(ctyp.ctIntersection, ctre, cfil.pftEvenOdd, cfil.pftEvenOdd)) {
-            poly = POLY.fromClipperTree(ctre, poly.getZ());
+            poly = POLY.fromClipperTree(ctre, this.getZ(), undefined, undefined, minarea);
             poly.forEach(p => {
                 p.fillang = fillang;
             })
@@ -1779,6 +1778,29 @@ class Polygon {
 
         return null;
     }
+
+    annotate(obj = {}) {
+        Object.assign(this, obj);
+        return this;
+    }
+
+    extrude(z = 1) {
+        let poly = this.clone().setClockwise();
+        let faces = [];
+        let points = poly.points;
+        let length = points.length;
+        for (let i=0; i<length; i++) {
+            let p0 = points[i];
+            let p1 = points[(i + 1) % length];
+            faces.push(p0.x, p0.y, p0.z);
+            faces.push(p1.x, p1.y, p0.z);
+            faces.push(p1.x, p1.y, p1.z + z);
+            faces.push(p0.x, p0.y, p0.z);
+            faces.push(p1.x, p1.y, p1.z + z);
+            faces.push(p0.x, p0.y, p0.z + z);
+        }
+        return faces;
+    }
 }
 
 // use Slope.angleDiff() then re-test path mitering / rendering

src/geo/polygons.js

@@ -7,7 +7,7 @@
 // use: ext.clip2
 // use: geo.slope
 // use: geo.polygon
-gapp.register("base.polygons", [], (root, exports) => {
+gapp.register("geo.polygons", [], (root, exports) => {
 
 const { base } = root;
 const { util, config, newPoint } = base;
@@ -388,7 +388,7 @@ function subtract(setA, setB, outA, outB, z, minArea, opt = {}) {
          }
      }
 
-     let out = polys.slice(), i, j, union, uset = [];
+     let out = polys.slice(), i, j, union, uset = [], a, b;
 
      outer: for (i=0; i<out.length; i++) {
          if (!out[i]) continue;
@@ -396,6 +396,10 @@ function subtract(setA, setB, outA, outB, z, minArea, opt = {}) {
              if (!out[j]) continue;
              union = out[i].union(out[j], minarea, all);
              if (union && union.length) {
+                 if (opt.onmerge) {
+                     a = out[i];
+                     b = out[j];
+                 }
                  out[i] = null;
                  out[j] = null;
                  if (all) {
@@ -403,6 +407,9 @@ function subtract(setA, setB, outA, outB, z, minArea, opt = {}) {
                  } else {
                      out.push(union);
                  }
+                 if (opt.onmerge) {
+                     opt.onmerge(a, b, union);
+                 }
                  continue outer;
              }
          }