From 4be3ce9901d4c740064946611959dafdcdaec45e Mon Sep 17 00:00:00 2001
From: Zach Beane <xach@xach.com>
Date: Tue, 14 Oct 2014 19:46:08 -0400
Subject: [PATCH] Fix up ellipse arc approximation.

The previous version could blow the stack.
---
 arc.lisp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arc.lisp b/arc.lisp
index f74feee..6291c5d 100644
--- a/arc.lisp
+++ b/arc.lisp
@@ -132,7 +132,7 @@
   (cond ((< eta2 eta1)
          (error "approximate-arc: eta2 must be bigger than eta1"))
         ((> eta2 (+ eta1 (/ pi 2) (* eta2 long-float-epsilon)))
-         (let ((etamid (+ eta1 (/ pi 2))))
+         (let ((etamid (+ eta1 (/ pi 2) (* eta2 long-float-epsilon))))
            (nconc
             (approximate-arc cx cy a b theta eta1 etamid err)
             (approximate-arc cx cy a b theta etamid eta2 err))))