From a9e22e802f604c7fb7213eb17ae7b8bdbfddd3ea Mon Sep 17 00:00:00 2001
From: Stewart Allen <stewart.allen@gmail.com>
Date: Sat, 10 Jul 2021 22:57:32 -0400
Subject: [PATCH] enable wasm acceleration for layer diffs

---
 src/geo/polygons.js   | 2 +-
 src/mode/fdm/slice.js | 9 ++++++---
 src/mode/sla/slice.js | 5 ++++-
 3 files changed, 11 insertions(+), 5 deletions(-)

diff --git a/src/geo/polygons.js b/src/geo/polygons.js
index 4dd6107f..9ad3c305 100644
--- a/src/geo/polygons.js
+++ b/src/geo/polygons.js
@@ -314,7 +314,7 @@
             opt.prof.call = (opt.prof.call || 0) + 1;
         }
 
-        if (false && opt.wasm) {
+        if (opt.wasm && geo.wasm) {
             let oA = outA ? [] : undefined;
             let oB = outB ? [] : undefined;
             geo.wasm.js.diff(setA, setB, z, oA, oB);
diff --git a/src/mode/fdm/slice.js b/src/mode/fdm/slice.js
index c62c18f5..6195bdd9 100644
--- a/src/mode/fdm/slice.js
+++ b/src/mode/fdm/slice.js
@@ -448,7 +448,7 @@
             if (solidLayers && !vaseMode && !isSynth) {
                 profileStart("delta");
                 forSlices(0.2, 0.34, slice => {
-                    if (slice.index > 0) doDiff(slice, solidMinArea);
+                    if (slice.index > 0) doDiff(slice, solidMinArea, { wasm: useAssembly });
                 }, "layer deltas");
                 profileEnd();
                 profileStart("delta-project");
@@ -1038,10 +1038,11 @@
      * Used to calculate bridges, flats and then solid projections.
      * 'expand' is used for top offsets in SLA mode
      */
-    function doDiff(slice, minArea, sla, fakedown) {
+    function doDiff(slice, minArea, options = {}) {
         if (slice.index === 0 && !fakedown) {
             return;
         }
+        const { sla, fakedown } = options;
         const top = slice,
             down = slice.down || (fakedown ? newSlice(-1) : null),
             topInner = sla ? top.topPolys() : top.topInners(),
@@ -1056,7 +1057,9 @@
             return;
         }
 
-        POLY.subtract(topInner, downInner, bridges, flats, slice.z, minArea);
+        POLY.subtract(topInner, downInner, bridges, flats, slice.z, minArea, {
+            wasm: options.wasm
+        });
     };
 
     /**
diff --git a/src/mode/sla/slice.js b/src/mode/sla/slice.js
index e30b9200..ccf6c01d 100644
--- a/src/mode/sla/slice.js
+++ b/src/mode/sla/slice.js
@@ -144,7 +144,10 @@
             }, "shells");
             forSlices(slices, 10, (slice) => {
                 if (slice.synth) return;
-                FDM.doDiff(slice, 0.000001, true, !process.slaOpenBase);
+                FDM.doDiff(slice, 0.000001, {
+                    sla: true,
+                    fakedown: !process.slaOpenBase
+                });
             }, "delta");
             if (solidLayers) {
                 forSlices(slices, 10, (slice) => {