From 43b27d18c5cbb5ae79805258422b1ff4da855b55 Mon Sep 17 00:00:00 2001
From: Val Erastov <xibyte@gmail.com>
Date: Tue, 19 Sep 2017 17:26:00 -0700
Subject: [PATCH] refactor brep-builder

---
 web/app/3d/debug.js             |  6 ++++++
 web/app/3d/tess/brep-tess.js    | 15 ++++++++++++++-
 web/app/brep/brep-builder.js    | 18 +++++++-----------
 web/app/brep/geom/impl/nurbs.js |  8 ++++++++
 4 files changed, 35 insertions(+), 12 deletions(-)

diff --git a/web/app/3d/debug.js b/web/app/3d/debug.js
index 01e8ca0c..289c5407 100644
--- a/web/app/3d/debug.js
+++ b/web/app/3d/debug.js
@@ -116,6 +116,12 @@ function addGlobalDebugActions(app) {
     AddCurve: (curve, color) => {
       __DEBUG__.AddPolyLine(curve.verb.tessellate().map(v => new Vector().set3(v)), color);
     },
+    AddNurbsCorners: (nurbs) => {
+      __DEBUG__.AddPoint(nurbs.point(0, 0), 0xff0000);
+      __DEBUG__.AddPoint(nurbs.point(1, 0), 0x00ff00);
+      __DEBUG__.AddPoint(nurbs.point(1, 1), 0x0000ff);
+      __DEBUG__.AddPoint(nurbs.point(0, 1), 0x00ffff);
+    },
     HideSolids: () => {
       app.findAllSolidsOnScene().forEach(s => s.cadGroup.traverse(o => o.visible = false));
       app.viewer.render();
diff --git a/web/app/3d/tess/brep-tess.js b/web/app/3d/tess/brep-tess.js
index 9960cfc7..1bdfd4a5 100644
--- a/web/app/3d/tess/brep-tess.js
+++ b/web/app/3d/tess/brep-tess.js
@@ -17,7 +17,13 @@ export default function(face) {
   // tessy.gluTessProperty(libtess.gluEnum.GLU_TESS_WINDING_RULE, libtess.windingRule.GLU_TESS_WINDING_POSITIVE);
   tessy.gluTessCallback(libtess.gluEnum.GLU_TESS_VERTEX_DATA, vertexCallback);
 
-  tessy.gluTessNormal(0, 0, 1);
+  const mirrored = isMirrored(face.surface);
+
+  if (mirrored) {
+    tessy.gluTessNormal(0, 0, -1);
+  } else {
+    tessy.gluTessNormal(0, 0, 1);
+  }
 
   const params = [];
   tessy.gluTessBeginPolygon(params);
@@ -87,3 +93,10 @@ function analyzeCurvature(nurbs, triangles) {
   return triangles;
 
 }
+
+function isMirrored(surface) {
+  let a = surface.point(0, 0);
+  let b = surface.point(1, 0);
+  let c = surface.point(1, 1);
+  return b.minus(a).cross(c.minus(a))._normalize().dot(surface.normalUV(0, 0)) < 0;
+}
diff --git a/web/app/brep/brep-builder.js b/web/app/brep/brep-builder.js
index c1071a9b..5fd224b7 100644
--- a/web/app/brep/brep-builder.js
+++ b/web/app/brep/brep-builder.js
@@ -43,7 +43,7 @@ export function createPrism(basePoints, height) {
     basePath.add(NurbsCurve.createLinearNurbs(basePoints[i], basePoints[j]), basePoints[i], null);
     lidPath.add(NurbsCurve.createLinearNurbs(lidPoints[i], lidPoints[j]), lidPoints[i], null);
   }
-  return enclose(basePath, lidPath, baseSurface, lidSurface, () => {});
+  return enclose(basePath, lidPath, baseSurface, lidSurface);
 }
 
 export function enclose(basePath, lidPath, basePlane, lidPlane) {
@@ -54,13 +54,10 @@ export function enclose(basePath, lidPath, basePlane, lidPlane) {
 
   const walls = [];
 
-  const baseVertices = basePath.points.map(p => new Vertex(p));
-  const lidVertices = lidPath.points.map(p => new Vertex(p));
-
   const n = basePath.points.length;
   for (let i = 0; i < n; i++) {
     let j = (i + 1) % n;
-    const wall = createWall(basePath.curves[i], lidPath.curves[i], baseVertices[j], baseVertices[i], lidVertices[i], lidVertices[j]);
+    const wall = createWall(basePath.curves[i], lidPath.curves[i]);
     walls.push(wall);
   }
   return assemble(walls, basePlane, lidPlane)
@@ -85,14 +82,14 @@ function assemble(walls, basePlane, lidPlane) {
     let next = wallEdges[j];
     let wall = walls[i];
 
-    let baseEdge = new Edge(wall.isoCurveAlignU(0), curr.halfEdge1.vertexA, next.halfEdge1.vertexA);
-    let lidEdge = new Edge(wall.isoCurveAlignU(1), curr.halfEdge1.vertexB, next.halfEdge1.vertexB);
+    let baseEdge = new Edge(wall.isoCurveAlignU(1), curr.halfEdge1.vertexB, next.halfEdge1.vertexB);
+    let lidEdge = new Edge(wall.isoCurveAlignU(0), curr.halfEdge1.vertexA, next.halfEdge1.vertexA);
 
     baseEdges.push(baseEdge);
     lidEdges.push(lidEdge);
 
     let wallFace = new Face(wall);
-    wallFace.outerLoop.halfEdges.push(baseEdge.halfEdge2, curr.halfEdge1, lidEdge.halfEdge1, next.halfEdge2);
+    wallFace.outerLoop.halfEdges.push(baseEdge.halfEdge2, curr.halfEdge2, lidEdge.halfEdge1, next.halfEdge1);
     wallFace.outerLoop.link();
     shell.faces.push(wallFace);
   }
@@ -320,12 +317,11 @@ function createBoundingNurbs(points, plane) {
   polygon = polygon.map(p => to3D._apply(p));
 
   const nurbs = new NurbsSurface(new verb.geom.ExtrudedSurface(new verb.geom.Line(
-    polygon[1].data(), polygon[0].data()), polygon[2].minus(polygon[1]).data()));
+    polygon[0].data(), polygon[1].data()), polygon[2].minus(polygon[1]).data()));
 
   return nurbs;
 }
 
-
 export function linkHalfEdges(edge, halfEdge1, halfEdge2) {
   halfEdge1.edge = edge;
   halfEdge2.edge = edge;
@@ -393,7 +389,7 @@ export function createWall(curve1, curve2) {
   if (bothClassOf(curve1, curve2, 'Line')) {
     throw 'unsupported'
   } else if (bothClassOf(curve1, curve2, 'NurbsCurve')) {
-    return new NurbsSurface(verb.geom.NurbsSurface.byLoftingCurves([curve1.verb, curve2.verb], 1));
+    return new NurbsSurface(verb.geom.NurbsSurface.byLoftingCurves([curve2.verb, curve1.verb], 1));
   } else {
     throw 'unsupported';
   }
diff --git a/web/app/brep/geom/impl/nurbs.js b/web/app/brep/geom/impl/nurbs.js
index 98d9e438..235e4218 100644
--- a/web/app/brep/geom/impl/nurbs.js
+++ b/web/app/brep/geom/impl/nurbs.js
@@ -114,6 +114,14 @@ export class NurbsSurface extends Surface {
     return normal;
   }
 
+  normalUV(u, v) {
+    let normal = new Vector().set3(this.verb.normal(u, v));
+    if (this.inverted) {
+      normal._negate();
+    }
+    return normal;
+  }
+
   normalInMiddle(point) {
     let normal = new Vector().set3(this.verb.normal(0.5, 0.5));
     if (this.inverted) {