From 43acc4e652939eb31180bd7c33666089e2b44ede Mon Sep 17 00:00:00 2001
From: Stewart Allen <stewart.allen@gmail.com>
Date: Mon, 7 Dec 2020 21:38:39 -0500
Subject: [PATCH] improve belt rotation (still buggy)

---
 notes.md           |  1 +
 src/kiri/stack.js  |  4 ++--
 src/kiri/worker.js | 23 +++++++++++++++++------
 3 files changed, 20 insertions(+), 8 deletions(-)

diff --git a/notes.md b/notes.md
index 098ba84b..78f9eb5e 100644
--- a/notes.md
+++ b/notes.md
@@ -18,6 +18,7 @@
 
 ## `C` cosmetic, `F` functional, `P` performance, `B` bug fix
 
+* `B` normals possibly inverted on faces in 2D to 3D conversion
 * `F` right click / context menu (object deletion, etc)
 * `F` detect and report slow framerates
 * `P` duplicate objects should share same slice data unless rotated or scaled
diff --git a/src/kiri/stack.js b/src/kiri/stack.js
index 62b2286b..206c3509 100644
--- a/src/kiri/stack.js
+++ b/src/kiri/stack.js
@@ -27,8 +27,8 @@
 
         rotate(set) {
             this.view.rotation.x = -set.angle * (Math.PI/180);
-            this.view.position.y = -set.centerz + set.movez;
-            this.view.position.z = -set.movez/2;
+            this.view.position.y += -set.dy;
+            this.view.position.z += -set.dz;
         }
 
         destroy() {
diff --git a/src/kiri/worker.js b/src/kiri/worker.js
index 4322af22..12aa9616 100644
--- a/src/kiri/worker.js
+++ b/src/kiri/worker.js
@@ -75,14 +75,25 @@ KIRI.worker = {
             widget.mesh = null;
             widget.points = null;
             widget.loadVertices(widget.vertices);
-            let bbox1 = widget.getBoundingBox(true);
+            let bb1 = widget.getBoundingBox(true);
+            let zd = bb1.max.z - bb1.min.z; // z dim
+            // let cy1 = (bb1.max.y + bb1.min.y) / 2;
+            // let cz1 = (bb1.max.z + bb1.min.z) / 2;
+            widget.setPoints(null);
             widget._rotate(rotation,0,0,true);
-            widget.center();
+            widget.center(false, true);
+            let bb2 = widget.getBoundingBox(true);
+            // let cy2 = (bb2.max.y + bb2.min.y) / 2;
+            // let cz2 = (bb2.max.z + bb2.min.z) / 2;
+            // let angle = Math.atan2(cy1-cy2, cz1-cz2) * (180 / Math.PI);
             widget.rotated = true;
-            let bbox2 = widget.getBoundingBox(true);
-            let centerz = (bbox2.max.z - bbox2.min.z) / 2;
-            let movez = centerz - (bbox1.max.z - bbox1.min.z) / 2;
-            widget.rotinfo = { centerz, movez, angle: 45 };
+            let rc = Math.sin(Math.PI/4);
+            let cz = (bb2.max.z - bb2.min.z) / 2; // center z post rotate
+            let dy = cz * rc; // dy = cz rotated 45
+            let dz = dy - zd / 2;
+            // console.log({cy1,cz1,cy2,cz2,angle,cy});
+            widget.rotinfo = { angle: 45, dy, dz };
+            widget.getBoundingBox(true);
         }
 
         widget.slice(settings, function(error) {