Patch: Small change to push-matrix

[elliottslaughter]

Hi,

I made a small change to push-matrix on my local copy that I'm hoping you'll integrate into penumbra.

diff --git a/src/penumbra/opengl.clj b/src/penumbra/opengl.clj
index 68bc81a..dc8dfa3 100644
--- a/src/penumbra/opengl.clj
+++ b/src/penumbra/opengl.clj
@@ -88,9 +88,9 @@

 (defmacro push-matrix [& body]
   `(binding [*transform-matrix* (if *inside-begin-end* (atom @*transform-matrix*) *transform-matrix*)]
-    (if (not *inside-begin-end*) (gl-push-matrix))
-    ~@body
-    (if (not *inside-begin-end*) (gl-pop-matrix))))
+     (try (if (not *inside-begin-end*) (gl-push-matrix))
+          ~@body
+          (finally (if (not *inside-begin-end*) (gl-pop-matrix))))))

 (gl-facade-import glVertex3d vertex)
 (gl-facade-import glNormal3d normal)

Basically, I found myself in a situation where I actually cared what the return value of body of push-matrix was. The try block has the nice property that it returns that value. Coincidentally, it will also ensure the matrix gets popped in case an error occurs inside the body.

Thanks.

[ztellman]

Done and done.