From 8303fd1810cbae3eaa417b42441a9086809bca9b Mon Sep 17 00:00:00 2001
From: Paul Graffam <paul.graffam@isobar.com>
Date: Mon, 6 Jul 2020 17:23:59 -0400
Subject: [PATCH] Added vertex helper, fixed up mesh helper

---
 src/js/app/helpers/meshHelper.js          |  47 +++++---
 src/js/app/helpers/vertexNormalsHelper.js | 124 ++++++++++++++++++++++
 2 files changed, 156 insertions(+), 15 deletions(-)
 create mode 100644 src/js/app/helpers/vertexNormalsHelper.js

diff --git a/src/js/app/helpers/meshHelper.js b/src/js/app/helpers/meshHelper.js
index cdb2b3c..9baeb77 100644
--- a/src/js/app/helpers/meshHelper.js
+++ b/src/js/app/helpers/meshHelper.js
@@ -1,24 +1,41 @@
 import * as THREE from 'three';
+import { VertexNormalsHelper } from './vertexNormalsHelper';
 
 // Simple mesh helper that shows edges, wireframes, and face and vertex normals
 export default class MeshHelper {
   constructor(scene, mesh) {
-    const wireframe = new THREE.WireframeGeometry(mesh.geometry);
-    const wireLine = new THREE.LineSegments(wireframe);
-    wireLine.material.depthTest = false;
-    wireLine.material.opacity = 0.25;
-    wireLine.material.transparent = true;
-    mesh.add(wireLine);
+    this.mesh = mesh;
+    this.scene = scene;
 
-    const edges = new THREE.EdgesGeometry(mesh.geometry);
-    const edgesLine = new THREE.LineSegments(edges);
-    edgesLine.material.depthTest = false;
-    edgesLine.material.opacity = 0.25;
-    edgesLine.material.transparent = true;
-    mesh.add(edgesLine);
+    const wireframe = new THREE.WireframeGeometry(this.mesh.geometry);
+    this.wireLine = new THREE.LineSegments(wireframe);
+    this.wireLine.material.depthTest = false;
+    this.wireLine.material.opacity = 0.25;
+    this.wireLine.material.transparent = true;
 
-    scene.add(new THREE.BoxHelper(mesh));
-    scene.add(new THREE.FaceNormalsHelper(mesh, 2));
-    scene.add(new THREE.VertexNormalsHelper(mesh, 2));
+    const edges = new THREE.EdgesGeometry(this.mesh.geometry);
+    this.edgesLine = new THREE.LineSegments(edges);
+    this.edgesLine.material.depthTest = false;
+    this.edgesLine.material.opacity = 0.25;
+    this.edgesLine.material.transparent = true;
+
+    this.vertexHelper = new VertexNormalsHelper(this.mesh, 2);
+    this.boxHelper = new THREE.BoxHelper(this.mesh);
+  }
+
+  enable() {
+    this.mesh.add(this.wireLine);
+    this.mesh.add(this.edgesLine);
+
+    this.scene.add(this.vertexHelper);
+    this.scene.add(this.boxHelper);
+  }
+
+  disable() {
+    this.mesh.remove(this.wireLine);
+    this.mesh.remove(this.edgesLine);
+
+    this.scene.remove(this.vertexHelper);
+    this.scene.remove(this.boxHelper);
   }
 }
diff --git a/src/js/app/helpers/vertexNormalsHelper.js b/src/js/app/helpers/vertexNormalsHelper.js
new file mode 100644
index 0000000..c31c8a3
--- /dev/null
+++ b/src/js/app/helpers/vertexNormalsHelper.js
@@ -0,0 +1,124 @@
+/**
+ * @author mrdoob / http://mrdoob.com/
+ * @author WestLangley / http://github.com/WestLangley
+ */
+
+import {
+  BufferGeometry,
+  Float32BufferAttribute,
+  LineSegments,
+  LineBasicMaterial,
+  Matrix3,
+  Vector3,
+} from 'three';
+
+const _v1 = new Vector3();
+const _v2 = new Vector3();
+const _normalMatrix = new Matrix3();
+const _keys = ['a', 'b', 'c'];
+
+function VertexNormalsHelper(object, size, hex) {
+  this.object = object;
+  this.size = size !== undefined ? size : 0.1;
+
+  const color = hex !== undefined ? hex : 0xff0000;
+
+  //
+
+  let nNormals = 0;
+
+  const objGeometry = this.object.geometry;
+
+  if (objGeometry && objGeometry.isGeometry) {
+    nNormals = objGeometry.faces.length * 3;
+  } else if (objGeometry && objGeometry.isBufferGeometry) {
+    nNormals = objGeometry.attributes.normal.count;
+  }
+
+  //
+
+  const geometry = new BufferGeometry();
+  const positions = new Float32BufferAttribute(nNormals * 2 * 3, 3);
+
+  geometry.setAttribute('position', positions);
+
+  LineSegments.call(this, geometry, new LineBasicMaterial({ color: color, toneMapped: false }));
+
+  this.type = 'VertexNormalsHelper';
+
+  //
+
+  this.matrixAutoUpdate = false;
+
+  this.update();
+}
+
+VertexNormalsHelper.prototype = Object.create(LineSegments.prototype);
+VertexNormalsHelper.prototype.constructor = VertexNormalsHelper;
+
+VertexNormalsHelper.prototype.update = function () {
+  let idx;
+  this.object.updateMatrixWorld(true);
+
+  _normalMatrix.getNormalMatrix(this.object.matrixWorld);
+
+  const matrixWorld = this.object.matrixWorld;
+  const position = this.geometry.attributes.position;
+
+  //
+
+  const objGeometry = this.object.geometry;
+
+  if (objGeometry && objGeometry.isGeometry) {
+    const vertices = objGeometry.vertices;
+
+    const faces = objGeometry.faces;
+
+    idx = 0;
+
+    for (let i = 0, l = faces.length; i < l; i++) {
+      const face = faces[i];
+
+      for (let j = 0, jl = face.vertexNormals.length; j < jl; j++) {
+        const vertex = vertices[face[_keys[j]]];
+        const normal = face.vertexNormals[j];
+
+        _v1.copy(vertex).applyMatrix4(matrixWorld);
+        _v2.copy(normal).applyMatrix3(_normalMatrix).normalize().multiplyScalar(this.size).add(_v1);
+
+        position.setXYZ(idx, _v1.x, _v1.y, _v1.z);
+
+        idx = idx + 1;
+
+        position.setXYZ(idx, _v2.x, _v2.y, _v2.z);
+
+        idx = idx + 1;
+      }
+    }
+  } else if (objGeometry && objGeometry.isBufferGeometry) {
+    const objPos = objGeometry.attributes.position;
+    const objNorm = objGeometry.attributes.normal;
+
+    idx = 0;
+
+    // for simplicity, ignore index and drawcalls, and render every normal
+
+    for (var j = 0, jl = objPos.count; j < jl; j++) {
+      _v1.set(objPos.getX(j), objPos.getY(j), objPos.getZ(j)).applyMatrix4(matrixWorld);
+      _v2.set(objNorm.getX(j), objNorm.getY(j), objNorm.getZ(j));
+      _v2.applyMatrix3(_normalMatrix).normalize().multiplyScalar(this.size).add(_v1);
+
+      position.setXYZ(idx, _v1.x, _v1.y, _v1.z);
+
+      idx = idx + 1;
+
+      position.setXYZ(idx, _v2.x, _v2.y, _v2.z);
+
+      idx = idx + 1;
+    }
+  }
+
+  position.needsUpdate = true;
+};
+
+export { VertexNormalsHelper };