X-Git-Url: https://git.jsancho.org/?a=blobdiff_plain;f=src%2Fgacela_misc.scm;h=a9393ca89607d52e3d75ea42700753ec9f6c44d6;hb=e562aad852e11b0ac7f9d94f65bff8b984240d02;hp=d486b2650b734a2bea3ef7b977f42898ad7ef480;hpb=75d1bbb394aa23715811cac3da7ad6b202df26cf;p=gacela.git

diff --git a/src/gacela_misc.scm b/src/gacela_misc.scm
index d486b26..a9393ca 100644
--- a/src/gacela_misc.scm
+++ b/src/gacela_misc.scm
@@ -15,12 +15,40 @@
 ;;; along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 
+
+;;; Additional modules
+
+(use-modules (srfi srfi-1))
+
+
+;;; Constants
+
+(define *pi* (* (asin 1) 2))
+
+
+;;; Functions
+
 (define (nearest-power-of-two n)
   (define (power p n)
     (cond ((> (* p 2) n) p)
 	  (else (power (* p 2) n))))
   (power 1 n))
 
+(define (degrees-to-radians angle)
+  (/ (* angle *pi*) 180))
+
+(define (radians-to-degrees angle)
+  (/ (* angle 180) *pi*))
+
 (define-macro (pushnew elem list)
   `(cond ((not (find (lambda (e) (eq? e ,elem)) ,list))
 	  (set! ,list (cons ,elem ,list)))))
+
+(define (assoc-multiple-set! alist . pairs)
+  (define (amset! alist pairs)
+    (cond ((< (length pairs) 2)
+	   alist)
+	  (else
+	   (assoc-set! alist (car pairs) (cadr pairs))
+	   (amset! alist (cddr pairs)))))
+  (amset! alist pairs))