X-Git-Url: http://git.kpe.io/?a=blobdiff_plain;f=convert.lisp;h=f663cf8fc98e1651357ea99a0cc8edb70b8ded8f;hb=d01611bf419081fd99767c816a4603496b0da247;hp=f6daab1836fce334f8652dd5fdaca3ea06fb6355;hpb=aa668443cbb520ebd5dd1d007c19aab2316562e5;p=cl-photo.git

diff --git a/convert.lisp b/convert.lisp
index f6daab1..f663cf8 100755
--- a/convert.lisp
+++ b/convert.lisp
@@ -9,8 +9,11 @@
 ;;;;
 ;;;; $Id$
 ;;;;
-;;;; This file, part of cl-photo, is Copyright (c) 2005 by Kevin Rosenberg.
-;;;; Rights of modification and redistribution are in the LICENSE file.
+;;;; This file, part of cl-photo, is Copyright (c) 2005 by Kevin M. Rosenberg
+;;;;
+;;;; cl-photo users are granted the rights to distribute and use this software
+;;;; as governed by the terms of the GNU General Public License v2
+;;;; (http://www.gnu.org/licenses/gpl.html)
 ;;;;
 ;;;; *************************************************************************
 
@@ -43,6 +46,28 @@
 (defun inches->mm (d)
   (* d +inches->mm+))
 
+(declaim (inline mm->inches))
+(defun mm->inches (d)
+  (/ d +inches->mm+))
+
+(defun length->mm (d units)
+  "Convert a length in units to mm."
+  (ecase units
+    (:mm d)
+    (:inches (inches->mm d))
+    (:feet (* 12 (inches->mm d)))
+    (:yards (* 36 (inches->mm d)))
+    (:meters (* 1000 d))))
+
+(defun mm->length (d units)
+  "Convert a number of mm to units."
+  (ecase units
+    (:mm d)
+    (:inches (mm->inches d))
+    (:feet (/ (mm->inches d) 12))
+    (:yards (/ (mm->inches d) 36))
+    (:meters (/ d 1000))))
+
 (defun format-dimensions (format)
   "Returns format dimensions in mm."
   (ecase format