A helper function for generating pathnormals

diff --git a/nt3d.js b/nt3d.js
index fd57824388105fcb27341886c2eea12261f44813..62d898e6ae7a64d03a9a5a29464b12328aa1b121 100644 (file)
--- a/nt3d.js
+++ b/nt3d.js
@@ -83,6 +83,14 @@ nt3d = {
                        return nt3d.sub(path[i+1], path[i-1]);
                };
        },
+       pathnormals_from_point: function(path, p) {
+               // Use this with any point that is not on any path tangent line
+               var pathnormals = [];
+               for (var i = 0; i < path.length; i++) {
+                       pathnormals.push(this.sub(path[i], p));
+               }
+               return pathnormals;
+       },
        to_function: function(thing, make_indexer) {
                // If thing is a point, just yield thing every time.
                // If thing is a list of points && make_indexer, index into thing.