2016-05-31 09:07:00

1 files changed, 38 insertions, 0 deletions

diff --git a/metapost/context/base/mpiv/mp-abck.mpiv b/metapost/context/base/mpiv/mp-abck.mpiv
index abd7d8848..68706b1d9 100644
--- a/metapost/context/base/mpiv/mp-abck.mpiv
+++ b/metapost/context/base/mpiv/mp-abck.mpiv
@@ -267,3 +267,41 @@ enddef ;
 def anchor_box (expr n,x,y,w,h,d) =
     currentpicture := currentpicture shifted (-x,-y) ;
 enddef ;
+
+vardef shaped (suffix p) =
+    save l ; pair l[] ;
+    save r ; pair r[] ;
+    save i ; i := 1 ;
+    save n ; n := 0 ;
+    forever :
+        exitif unknown p[i] ;
+        n := n + 1 ;
+        l[n] := ulcorner p[i] ;
+        r[n] := urcorner p[i] ;
+        n := n + 1 ;
+        l[n] := llcorner p[i] ;
+        r[n] := lrcorner p[i] ;
+        i := i + 1 ;
+    endfor ;
+    for i = 3 upto n :
+        if xpart r[i] < xpart r[i-1] :
+            r[i] := (xpart r[i],ypart r[i-1]) ;
+        elseif xpart r[i] > xpart r[i-1] :
+            r[i] := (xpart r[i],ypart r[i-1]) ;
+        fi ;
+        if xpart l[i] < xpart l[i-1] :
+            l[i] := (xpart l[i],ypart l[i-1]) ;
+        elseif xpart l[i] > xpart l[i-1] :
+            l[i] := (xpart l[i],ypart l[i-1]) ;
+        fi ;
+    endfor ;
+    if n > 0 :
+        simplified (
+            for i = 1 upto   n : r[i] -- endfor
+            for i = n downto 1 : l[i] -- endfor
+            cycle
+        )
+    else :
+        origin -- cycle
+    fi
+enddef ;