add new render type

src/kiri/render.js

@@ -3,18 +3,29 @@
 "use strict";
 
 (function() {
+    const KIRI = self.kiri, BASE = self.base, POLY = BASE.polygons;
+
     class Render {
         constructor() {
             this.layers = {};
         }
 
-        setLayer(layer, color) {
+        setLayer(layer, colors) {
             let layers = this.layers;
+            if (typeof(colors) === 'number') {
+                colors = {
+                    line: color,
+                    face: color
+                };
+            }
             this.current = layers[layer] = layers[layer] || {
                 lines: [],
                 polys: [],
                 faces: [],
-                color: color || 0
+                color: colors || {
+                    line: 0,
+                    face: 0
+                }
             };
             return this;
         }
@@ -44,6 +55,33 @@
             }
             return this;
         }
+
+        addFlat(polys, options) {
+            let opts = options || {};
+            let offset = opts.offset || 1;
+            if (Array.isArray(polys)) {
+                polys = POLY.flatten(polys, [], true);
+            } else {
+                polys = POLY.flatten([polys], [], true);
+            }
+            if (!polys.length) {
+                return;
+            }
+            const z = polys[0].getZ(), faces = this.current.faces;
+            polys.forEach(poly => {
+                let exp = [];
+                POLY.offset([poly],  offset/2, { z, outs: exp, flat: true });
+                POLY.offset([poly], -offset/2, { z, outs: exp, flat: true });
+                if (opts.outline) {
+                    this.addPolys(exp.clone());
+                }
+                POLY.nest(exp).forEach((poly,i) => {
+                    poly.earcut().forEach(ep => {
+                        ep.forEachPoint(p => { faces.push(p.x, p.y, p.z) });
+                    });
+                });
+            });
+        }
     }
 
     self.kiri.Render = Render;