Break out parts of go() into separate functions

These things are useful separately, even to the point of including
nt3d.js into random other webpages via the javascript console as a
toolkit to manipulate and export stuff elsewhere on the web.

diff --git a/nt3d.js b/nt3d.js
index 7e0fa2540e04b9d57787802d36f2ae404efd5b30..bc11c71520157e9b708ace929d7c7ce71d5bcc6d 100644 (file)
--- a/nt3d.js
+++ b/nt3d.js
@@ -347,41 +347,20 @@ nt3d = {
                       this.point_equal(b, c, this.degenerate_face_epsilon) ||
                       this.point_equal(c, a, this.degenerate_face_epsilon);
        },
-       go: function() {
-               // Remove any previous download links
-               var old_download_link = document.getElementById("nt3d_download");
-               if (old_download_link) {
-                       old_download_link.parentNode.removeChild(old_download_link);
-               }
-
-               // Continue in a callback, so that there's not a stale download
-               // link hanging around while we process.
-               setTimeout(function(the_this) { (function() {
-
-               // Get params from form
-               var params = [];
-               for (var i = 0; i < this.user_params.length; i++) {
-                       var as_string = this.form.elements["param"+i].value;
-                       var as_num = +as_string;
-                       params[i] = isNaN(as_num) ? as_string : as_num;
-               }
-
-               // Run user_function
-               this.points = this.user_function.apply(null, params);
-
+       validate: function(points) {
                // Do a little validation
-               if (this.points.length % 3 != 0) {
+               if (points.length % 3 != 0) {
                        alert("Points list length not divisble by 3!");
                }
                var nan_count = 0;
                var nan_point_count = 0;
                var nan_face_count = 0;
-               for (var i = 0; i < this.points.length/3; i++) {
+               for (var i = 0; i < points.length/3; i++) {
                        var nan_in_face = false;
                        for (var j = 0; j < 3; j++) {
                                var nan_in_point = false;
                                for (var k = 0; k < 3; k++) {
-                                       if (isNaN(this.points[i*3+j][k])) {
+                                       if (isNaN(points[i*3+j][k])) {
                                                nan_count++;
                                                nan_in_point = true;
                                                nan_in_face = true;
@@ -392,16 +371,17 @@ nt3d = {
                        if (nan_in_face) nan_face_count ++;
                }
                if (nan_count != 0) {
-                       alert(nan_count + " NaNs in " + nan_point_count + " points in " + nan_face_count + " faces (" + (100 * nan_face_count / (this.points.length/3)) + "% of faces).");
+                       alert(nan_count + " NaNs in " + nan_point_count + " points in " + nan_face_count + " faces (" + (100 * nan_face_count / (points.length/3)) + "% of faces).");
                }
-
-               // Remove degenerate faces
+       },
+       remove_degenerate_faces: function(points) {
+               // Note: This modifies points
                var degenerate_face_count = 0;
-               for (var i = 0; i < this.points.length/3; i++) {
-                       if (this.is_degenerate(this.points[i*3+0], 
-                                              this.points[i*3+1], 
-                                              this.points[i*3+2])) {
-                               this.points.splice(i*3, 3);
+               for (var i = 0; i < points.length/3; i++) {
+                       if (this.is_degenerate(points[i*3+0], 
+                                              points[i*3+1], 
+                                              points[i*3+2])) {
+                               points.splice(i*3, 3);
                                i--;
                                degenerate_face_count ++;
                        }
@@ -409,15 +389,16 @@ nt3d = {
                if (degenerate_face_count != 0) {
                        console.log("Removed " + degenerate_face_count + " degenerate faces");
                }
-
-               // Make STL
-               this.stl = "solid " + this.user_function.name + "\n";
-               for (var i = 0; i < this.points.length/3; i++) {
-                       var a = this.points[i*3+0];
-                       var b = this.points[i*3+1];
-                       var c = this.points[i*3+2];
+               return points;
+       },
+       to_stl: function(points, name) {
+               var stl = "solid " + name + "\n";
+               for (var i = 0; i < points.length/3; i++) {
+                       var a = points[i*3+0];
+                       var b = points[i*3+1];
+                       var c = points[i*3+2];
                        var normal = this.normal(a, b, c);
-                       this.stl += "facet normal " + normal[0] + " " + normal[1] + " " + normal[2] + "\n" +
+                       stl += "facet normal " + normal[0] + " " + normal[1] + " " + normal[2] + "\n" +
                                "outer loop\n" +
                                "vertex " + a[0] + " " + a[1] + " " + a[2] + "\n"+
                                "vertex " + b[0] + " " + b[1] + " " + b[2] + "\n"+
@@ -425,8 +406,35 @@ nt3d = {
                                "endloop\n" +
                                "endfacet\n";
                }
-               this.stl += "endsolid " + this.user_function.name + "\n";
+               stl += "endsolid " + name + "\n";
+               return stl;
+       },
+       go: function() {
+               // Remove any previous download links
+               var old_download_link = document.getElementById("nt3d_download");
+               if (old_download_link) {
+                       old_download_link.parentNode.removeChild(old_download_link);
+               }
+
+               // Continue in a callback, so that there's not a stale download
+               // link hanging around while we process.
+               setTimeout(function(the_this) { (function() {
+
+               // Get params from form
+               var params = [];
+               for (var i = 0; i < this.user_params.length; i++) {
+                       var as_string = this.form.elements["param"+i].value;
+                       var as_num = +as_string;
+                       params[i] = isNaN(as_num) ? as_string : as_num;
+               }
+
+               this.points = this.user_function.apply(null, params);
+
+               this.validate(this.points);
+
+               this.remove_degenerate_faces(this.points);
 
+               this.stl = this.to_stl(this.points, this.user_function.name);
 
                // Offer result as download
                var download_link = document.createElement("a");