From fa9fa383c6e23c2b5b8f58bd6ffba3f52d52b44a Mon Sep 17 00:00:00 2001
From: Val Erastov <xibyte@gmail.com>
Date: Thu, 10 Nov 2016 22:09:50 -0800
Subject: [PATCH] stl reader

---
 web/app/3d/stl/stl-ascii-reader.js | 75 ++++++++++++++++++++++++++++++
 web/app/3d/stl/stl-reader.js       | 17 +++++++
 2 files changed, 92 insertions(+)
 create mode 100644 web/app/3d/stl/stl-ascii-reader.js
 create mode 100644 web/app/3d/stl/stl-reader.js

diff --git a/web/app/3d/stl/stl-ascii-reader.js b/web/app/3d/stl/stl-ascii-reader.js
new file mode 100644
index 00000000..c040b1a1
--- /dev/null
+++ b/web/app/3d/stl/stl-ascii-reader.js
@@ -0,0 +1,75 @@
+export function parse(buf) {
+
+  var solid = {
+    name: null,
+    faces: []    
+  };
+  var solids = [];
+  var triangle = [];
+  var normal = null;  
+  var reader = new LinesReader(buf);
+  while (reader.hasNextLine()) {
+    let line = reader.nextLine();  
+    var parts = line
+      .trim()
+      .split(' ')
+      .filter(function(part) {
+        return part !== '';
+      });
+    switch(parts[0]) {
+      case 'solid':
+        solid = {
+          name: parts.slice(1).join(' '),
+          faces: []
+        };
+        break;
+      case 'endsolid':
+        solids.push(solid);
+        break;
+      case 'facet':
+        var noramlParts = parts.slice(2);
+        if (noramlParts.length == 3) {
+          normal = noramlParts.map(Number);
+        }
+        break;
+      case 'vertex':
+        var position = parts.slice(1).map(Number);
+        triangle.push(position);
+        break;
+      case 'endfacet':
+        if (triangle.length == 3) {
+          solid.faces.push({
+            vertices: triangle,
+            normal: normal 
+          });
+        }
+        triangle = [];
+        normal = null;
+      default:
+      // skip
+    }
+  }
+  return solids;
+}
+
+function LinesReader(buf) {
+  let mark = 0;
+  let pos = 0;
+  let arr = new Uint8Array(buf);
+  this.nextLine = function() {
+    let str = "";
+    for (var i = mark; i < pos; i++) {
+      str += String.fromCharCode(arr[i]);
+    }
+    mark = pos;
+    return str;
+  };
+  this.hasNextLine = function() {
+    while (pos < arr.length) {
+      if (arr[pos ++] == 10) {
+        return true;
+      }
+    }
+    return false;
+  }
+}
\ No newline at end of file
diff --git a/web/app/3d/stl/stl-reader.js b/web/app/3d/stl/stl-reader.js
new file mode 100644
index 00000000..5ba78543
--- /dev/null
+++ b/web/app/3d/stl/stl-reader.js
@@ -0,0 +1,17 @@
+import {parse as ParseASCII} from './stl-ascii-reader'
+import {parse as ParseBinary} from './stl-binary-reader'
+
+export function ParseStl(buf) {
+  if(typeof buf === 'string') {
+    return ParseASCII(buf);
+  }
+
+  //var triangleCount = buf.readUInt32LE(80);
+  //var expectedSize = 80 + 4 + triangleCount * ((4 * 3) * 4 + 2);
+  //
+  //if(expectedSize === buf.length) {
+  //  return parseBinary(buf);
+  //}
+
+  return ParseASCII(buf);
+}