From e94a8d4d1fa3d4112b87303eada0bb0b19e2cdac Mon Sep 17 00:00:00 2001
From: Stewart Allen <sa@grid.space>
Date: Sat, 19 Jun 2021 15:17:36 -0400
Subject: [PATCH] defer shadow creation. de-rez polys for massive shadow unions
 in some cases

---
 src/geo/polygon.js    | 16 +++++++++++++---
 src/mode/fdm/slice.js | 32 ++++++++++++++++++--------------
 2 files changed, 31 insertions(+), 17 deletions(-)

diff --git a/src/geo/polygon.js b/src/geo/polygon.js
index c12239cf..69419673 100644
--- a/src/geo/polygon.js
+++ b/src/geo/polygon.js
@@ -41,6 +41,16 @@
             return this.points.length;
         }
 
+        get deepLength() {
+            let len = this.length;
+            if (this.inner) {
+                for (let inner of this.inner) {
+                    len += inner.length;
+                }
+            }
+            return len;
+        }
+
         get bounds() {
             if (this._bounds) {
                 return this._bounds;
@@ -1420,14 +1430,14 @@
      * simplify and merge collinear. only works for single
      * non-nested polygons.  used primarily in slicer/connectLines.
      */
-    PRO.clean = function(deep, parent) {
+    PRO.clean = function(deep, parent, merge = CONF.clipperClean) {
         let clib = self.ClipperLib,
             clip = clib.Clipper,
-            clean = clip.CleanPolygon(this.toClipper()[0], CONF.clipperClean),
+            clean = clip.CleanPolygon(this.toClipper()[0], merge),
             poly = fromClipperPath(clean, this.getZ());
         if (poly.length === 0) return this;
         if (deep && this.inner) {
-            poly.inner = this.inner.map(inr => inr.clean(false, poly));
+            poly.inner = this.inner.map(inr => inr.clean(false, poly, merge));
         }
         poly.parent = parent || this.parent;
         poly.area2 = this.area2;
diff --git a/src/mode/fdm/slice.js b/src/mode/fdm/slice.js
index 9a4ac88b..fe54f5eb 100644
--- a/src/mode/fdm/slice.js
+++ b/src/mode/fdm/slice.js
@@ -259,20 +259,6 @@
                 slice.solids = [];
             });
 
-            // create shadow for clipping supports
-            let shadow = null;
-            if (!isBelt || spro.sliceSupportEnable) {
-                let alltops = slices.map(slice => slice.topPolys()).flat();
-                shadow = POLY.union(alltops,null,0.1);
-                if (spro.sliceSupportExtra) {
-                    shadow = POLY.offset(shadow, spro.sliceSupportExtra);
-                }
-                widget.shadow = shadow;
-                // slices[0].output()
-                //     .setLayer('shadow', { line: 0xff0000, check: 0xff0000 })
-                //     .addPolys(shadow);
-            }
-
             // create shells and diff inner fillable areas
             forSlices(0.0, 0.2, slice => {
                 let params = getRangeParameters(settings, slice.index);
@@ -474,6 +460,24 @@
 
             // auto support generation
             if (!isBelt && !isSynth && supportDensity && spro.sliceSupportEnable) {
+                // create shadow for clipping supports
+                let mark = Date.now();
+                let shadow = null;
+                let alltops = slices.map(slice => slice.topPolys()).flat();
+                let alllen = alltops.map(p => p.deepLength).reduce((a,v)=>a+v);
+                // console.log({alllen});
+                if (alllen > 100000) {
+                    alltops = alltops.map(p => p.clean(true, undefined, 10000));
+                    // console.log({reduced: alltops.map(p => p.deepLength).reduce((a,v)=>a+v)});
+                }
+                shadow = POLY.union(alltops,0.1,true);
+                if (spro.sliceSupportExtra) {
+                    shadow = POLY.offset(shadow, spro.sliceSupportExtra);
+                }
+                widget.shadow = shadow;
+                // slices[0].output()
+                //     .setLayer('shadow', { line: 0xff0000, check: 0xff0000 })
+                //     .addPolys(shadow);
                 forSlices(0.7, 0.8, slice => {
                     doSupport(slice, spro, shadow);
                 }, "support");