1 files changed, 88 insertions, 0 deletions
diff --git a/metapost/context/base/mp-fobg.mp b/metapost/context/base/mp-fobg.mp
new file mode 100644
index 000000000..712efe751
--- /dev/null
+++ b/metapost/context/base/mp-fobg.mp
@@ -0,0 +1,88 @@
+%D \module
+%D   [       file=mp-fobg.mp,
+%D        version=2004.03.12,
+%D          title=\CONTEXT\ \METAPOST\ graphics,
+%D       subtitle=Formatting Objects,
+%D         author=Hans Hagen,
+%D           date=\currentdate,
+%D      copyright={PRAGMA / Hans Hagen \& Ton Otten}]
+%C
+%C This module is part of the \CONTEXT\ macro||package and is
+%C therefore copyrighted by \PRAGMA. See licen-en.pdf for
+%C details.
+
+if unknown context_tool :    input mp-tool ; fi ;
+if   known context_fobg : endinput         ; fi ;
+
+boolean context_fobg ; context_fobg := true ;
+
+FoNone   := 0 ; FoHidden := 1 ; FoDotted := 2 ; FoDashed := 3 ; FoSolid  := 4 ;
+FoDouble := 5 ; FoGroove := 6 ; FoRidge  := 7 ; FoInset  := 8 ; FoOutset := 9 ;
+FoAll    := 0 ; FoTop    := 1 ; FoBottom := 2 ; FoLeft   := 3 ; FoRight  := 4 ;
+FoMedium := .5pt ; FoThin := FoMedium/2 ; FoThick := FoMedium*2 ;
+
+color FoBackgroundColor, FoNoColor, FoLineColor[] ; FoNoColor := (-1,-1,-1) ;
+numeric FoLineWidth[], FoLineStyle[] ;
+boolean FoFrame, FoBackground, FoSplit ;
+
+FoFrame := FoBackground := FoSplit := false ;
+FoBackgroundColor := white ;
+FoDashFactor := .5 ;
+FoDotFactor := .375 ;
+
+for i = FoAll upto FoRight :
+  FoLineColor[i] := black ;
+  FoLineWidth[i] := .5pt ;
+  FoLineStyle[i] := FoNone ;
+endfor ;
+
+def DrawFoFrame(expr n, p) =
+  drawoptions(withcolor FoLineColor[n] withpen pencircle scaled FoLineWidth[n]) ;
+  if     FoLineStyle[n] = FoNone   :
+    % nothing
+  elseif FoLineStyle[n] = FoHidden :
+    % nothing
+  elseif FoLineStyle[n] = FoDotted :
+    draw p dashed (withdots scaled (FoDotFactor*FoLineWidth[n])) ;
+  elseif FoLineStyle[n] = FoDashed :
+    draw p dashed (evenly scaled (FoDashFactor*FoLineWidth[n])) ;
+  elseif FoLineStyle[n] = FoSolid  :
+    draw p ;
+  elseif FoLineStyle[n] = FoDouble :
+    draw p enlarged  FoLineWidth[n] ; draw p enlarged -FoLineWidth[n] ;
+  elseif FoLineStyle[n] = FoGroove :
+    draw p ;
+    draw p withpen pencircle scaled .5FoLineWidth[n] withcolor (inverted FoLineColor[n] softened .5) ;
+  elseif FoLineStyle[n] = FoRidge  :
+    draw p withcolor  (inverted FoLineColor[n] softened .5) ;
+    draw p withpen pencircle scaled .5FoLineWidth[n] ;
+  elseif FoLineStyle[n] = FoInset  :
+    draw p ; draw p inset 2.5FoLineWidth[n] ;
+  elseif FoLineStyle[n] = FoOutset :
+    draw p ; draw p outset 2.5FoLineWidth[n] ;
+ fi ;
+enddef ;
+
+primarydef p outset d =
+  ((lrcorner p -- urcorner p -- ulcorner p -- llcorner p -- cycle)
+      shifted (d*(-1,1)) cutbefore topboundary p) cutafter leftboundary p
+enddef ;
+
+primarydef p inset d =
+  ((ulcorner p -- llcorner p -- lrcorner p -- urcorner p -- cycle)
+      shifted (d*(1,-1)) cutbefore bottomboundary p) cutafter rightboundary p
+enddef ;
+
+vardef equalpaths(expr p, q) =
+  if length(p) = length(q) :
+    save ok ; boolean ok ; ok := true ;
+    for i = 0 upto length(p)-1 :
+      ok := ok and (round(point i of p) = round(point i of q)) ;
+    endfor ;
+    ok
+  else :
+    false
+  fi
+enddef ;
+
+endinput ;