[example] fiddling with the example

1 files changed, 5 insertions, 0 deletions

diff --git a/src/canvas-language.lisp b/src/canvas-language.lisp
index 24a3394..b77ad02 100644
--- a/src/canvas-language.lisp
+++ b/src/canvas-language.lisp
@@ -27,6 +27,11 @@
 (defun canvas-pen-color (r g b a)
   (setf *current-pen-color* (mapcar #'colfix (list r g b a))))
 
+(defun canvas-pen-color-function (fn)
+  (setf *current-pen-color-function*
+        (lambda (x y)
+          (mapcar #'colfix (funcall fn x y)))))
+
 (defun canvas-pen-width (n)
   (setf *current-pen-width* (round n)))