[add] bezier curve surrport

1 files changed, 12 insertions, 0 deletions

diff --git a/src/grid-geometry.lisp b/src/grid-geometry.lisp
index 218cdf2..b23b207 100644
--- a/src/grid-geometry.lisp
+++ b/src/grid-geometry.lisp
@@ -99,3 +99,15 @@ top right corners of the bounding box for POLY "
            (loop for ,y from (- ,sy ,rad)  to (+ ,sy ,rad) do
              (when (,comparator ,rad (round (euclidean-dist ,x ,y ,sx ,sy)))
                ,@body)))))))
+
+
+(defmacro with-grid-bezier
+    ((x y) (control-pts &key (step 0.001)) &body body)
+  (with-gensyms (fn points a)
+    `(let* ((,points
+              ,control-pts)
+            (,fn
+              (apply #'bezier-lambda ,points)))
+       (loop for ,a from 0.0 to 1.0 by ,step
+             for (,x ,y) = (mapcar #'round (funcall ,fn ,a))
+             do ,@body))))