Fix extrusion bug that removed the last element in a user-supplied list representing a shape.

Author: BruceSherwood

lib/glow/extrude.js

@@ -795,15 +795,14 @@ function extrusion(args) {
     	var slist = []
         for (var i=0; i<contour.length; i++) slist.push(vec(contour[i][0], contour[i][1], 0))
         var shape_closed = slist[slist.length-1].equals(slist[0])
-        if (!shape_closed) new Error("An extrusion shape must be a closed curve.")
+        if (!shape_closed) throw new Error("An extrusion shape must be a closed curve.")
     	shapeinfo = []
         var out = vec(0,0,1)
         var L = slist.length
         var firstsharp = null
         var totallength = 0
         var vs = [], lengths=[], i, v
 
-        
         // Identify that corner of the shape that is the lowest point (minimum y)
         var miny, minyi
         for (i=0; i<L-1; i++) { // create list of vectors, calculate total length of the shape
@@ -980,10 +979,10 @@ function extrusion(args) {
     function tessellate(contours) {
     	// Use the poly2tri.js library to divide a 2D shape with possible holes into triangles.
     	// Not called if the path is closed (so no end caps need to be displayed).
-        var i, j
+        var i, j, endsave=null
         var c = contours[0]
         // poly2tri.js does not accept duplicate points:
-        if (c[0][0] === c[c.length-1][0] && c[0][1] === c[c.length-1][1]) c.pop()
+        if (c[0][0] === c[c.length-1][0] && c[0][1] === c[c.length-1][1]) endsave = c.pop()
 
         // Create poly2tri.js element for outer contour:
         var pts = []
@@ -998,6 +997,7 @@ function extrusion(args) {
             for (i=0; i<contours[j].length; i++) pts.push(new Point(c[i][0], c[i][1]))
             swctx.addHole(pts)
         }
+        if (endsave !== null) c.push(endsave) // restore last contour point
 
         function texpos(p) { // evalulate texture coordinates, using bounding box info
         	var x=p.x, y=p.y