beta 2011.10.05 23:32

5 files changed, 1291 insertions, 355 deletions

diff --git a/metapost/context/base/metafun.mpiv b/metapost/context/base/metafun.mpiv
index 89a7c3935..c58d5dc15 100644
--- a/metapost/context/base/metafun.mpiv
+++ b/metapost/context/base/metafun.mpiv
@@ -17,21 +17,21 @@
 %D copy.
 
 input mp-base.mpiv ;
-input mp-tool.mp ;
+input mp-tool.mp   ;
 input mp-core.mpiv ;
-input mp-page.mp ;
-input mp-text.mp ;
-input mp-txts.mp ;
-input mp-shap.mp ;
-input mp-butt.mp ;
-input mp-char.mp ;
-input mp-step.mp ;
-input mp-grph.mp ;
-input mp-figs.mp ;
+input mp-page.mp   ;
+input mp-text.mp   ;
+input mp-txts.mp   ;
+input mp-butt.mp   ;
+%     mp-shap.mp   ; % there no need to always load this
+%     mp-char.mp   ; % there no need to always load this
+input mp-step.mp   ; % there no need to always load this (todo)
+input mp-grph.mp   ;
+input mp-figs.mp   ;
 input mp-mlib.mpiv ;
-input mp-chem.mpiv ;
-input mp-grid.mp ;
-input mp-func.mp ;
+input mp-chem.mpiv ; % there no need to always load this (todo)
+input mp-grid.mp   ;
+input mp-func.mp   ;
 
 string metafunversion ;
 
diff --git a/metapost/context/base/mp-butt.mp b/metapost/context/base/mp-butt.mp
index cf580211e..3ae3dc983 100644
--- a/metapost/context/base/mp-butt.mp
+++ b/metapost/context/base/mp-butt.mp
@@ -1,6 +1,6 @@
 %D \module
 %D   [       file=mp-butt.mp,
-%D        version=2000.05.31, 
+%D        version=2000.05.31,
 %D          title=\CONTEXT\ \METAPOST\ graphics,
 %D       subtitle=buttons,
 %D         author=Hans Hagen,
@@ -8,68 +8,64 @@
 %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. 
+%C therefore copyrighted by \PRAGMA. See licen-en.pdf for
+%C details.
 
-if unknown context_tool :    input mp-tool ; fi ; 
-if   known context_butt : endinput         ; fi ; 
+if unknown context_tool :    input mp-tool ; fi ;
+if   known context_butt : endinput         ; fi ;
 
-boolean context_butt ; context_butt := true ; 
+boolean context_butt ; context_butt := true ;
 
-def some_button (expr button_type    , 
-                      button_size    ,
-                      button_linecolor , 
-                      button_fillcolor ) = 
+def some_button (expr button_type, button_size, button_linecolor, button_fillcolor) =
 
-  numeric button_linewidth ; button_linewidth := button_size/10 ;
+    numeric button_linewidth ; button_linewidth := button_size/10 ;
 
-  drawoptions (withpen pencircle scaled button_linewidth 
-               withcolor button_linecolor) ;
+    drawoptions (withpen pencircle scaled button_linewidth withcolor button_linecolor) ;
 
-  path p    ; p := unitsquare scaled button_size ;
-  numeric d ; d := button_size ;
-  numeric l ; l := button_linewidth ;
+    path p    ; p := unitsquare scaled button_size ;
+    numeric d ; d := button_size ;
+    numeric l ; l := button_linewidth ;
 
-  fill p withcolor button_fillcolor ; draw p ;
+    fill p withcolor button_fillcolor ; draw p ;
 
-  if     button_type=101 : 
-    draw (d-2l,2l)--(2l,.5d)--(d-2l,d-2l)--cycle ;
-  elseif button_type=102 : 
-    draw (2l,2l)--(d-2l,.5d)--(2l,d-2l)--cycle ;
-  elseif button_type=103 : 
-    for i=2l step 2l until d-2l :
-      draw (2l,i)--(2l  ,i) ;
-      draw (4l,i)--(d-2l,i) ;
-    endfor ;
-  elseif button_type=104 : 
-    for i=2l step 2l until d-2l :
-      draw (2l   ,i)--(d/2-l,i) ;
-      draw (d/2+l,i)--(d-2l ,i) ;
-    endfor ;
-  elseif button_type=105 : 
-    fill fullcircle scaled (.2d) shifted (.5d,.7d) ; 
-    fill fullcircle xscaled (.6d) yscaled d shifted (.5d,0) ; 
-    clip currentpicture to p ;
-    draw p ; 
-  elseif button_type=106 :
-    draw (2l,2l)--(d-2l,d-2l) ;
-    draw (d-2l,2l)--(2l,d-2l) ;
-  elseif button_type=107 :
-    p := (3l,d-2l)--(d-3l,d-2l)--(.5d,4l)--cycle ; 
-    fill p ; draw p ; 
-    draw (.5d,2l) ; 
-  elseif button_type=108 : 
-    draw (.5d,2l)--(d-2l,d-2l)--(2l,d-2l)--cycle ; 
-  elseif button_type=109 : 
-    draw (.5d,d-2l)--(d-2l,2l)--(2l,2l)--cycle ; 
-  elseif button_type=110 : 
-    button_linewidth := button_linewidth/2 ;  
-    draw p enlarged (-2l,-l) ;
-    for i=2l step l until d-2l : 
-      draw (3l,i)--(d-3l,i) ; 
-    endfor ; 
-  fi ; 
+    if     button_type = 101 :
+        draw (d-2l,2l)--(2l,.5d)--(d-2l,d-2l)--cycle ;
+    elseif button_type = 102 :
+        draw (2l,2l)--(d-2l,.5d)--(2l,d-2l)--cycle ;
+    elseif button_type = 103 :
+        for i=2l step 2l until d-2l :
+            draw (2l,i)--(2l  ,i) ;
+            draw (4l,i)--(d-2l,i) ;
+        endfor ;
+    elseif button_type = 104 :
+        for i=2l step 2l until d-2l :
+            draw (2l   ,i)--(d/2-l,i) ;
+            draw (d/2+l,i)--(d-2l ,i) ;
+        endfor ;
+    elseif button_type = 105 :
+        fill fullcircle scaled (.2d) shifted (.5d,.7d) ;
+        fill fullcircle xscaled (.6d) yscaled d shifted (.5d,0) ;
+        clip currentpicture to p ;
+        draw p ;
+    elseif button_type = 106 :
+        draw (2l,2l)--(d-2l,d-2l) ;
+        draw (d-2l,2l)--(2l,d-2l) ;
+    elseif button_type = 107 :
+        p := (3l,d-2l)--(d-3l,d-2l)--(.5d,4l)--cycle ;
+        fill p ; draw p ;
+        draw (.5d,2l) ;
+    elseif button_type = 108 :
+        draw (.5d,2l)--(d-2l,d-2l)--(2l,d-2l)--cycle ;
+    elseif button_type = 109 :
+        draw (.5d,d-2l)--(d-2l,2l)--(2l,2l)--cycle ;
+    elseif button_type = 110 :
+        button_linewidth := button_linewidth/2 ;
+        draw p enlarged (-2l,-l) ;
+        for i=2l step l until d-2l :
+            draw (3l,i)--(d-3l,i) ;
+        endfor ;
+    fi ;
 
-enddef ; 
+enddef ;
 
-endinput ; 
+endinput ;
diff --git a/metapost/context/base/mp-char.mp b/metapost/context/base/mp-char.mp
index fd9e33848..3a7a1d939 100644
--- a/metapost/context/base/mp-char.mp
+++ b/metapost/context/base/mp-char.mp
@@ -111,6 +111,7 @@ def new_chart =
   color   xydraw   [][] ;
   numeric xyline   [][] ;
   boolean xypeep   [][] ;
+  picture xypicture[][] ;
 
   numeric cpath         ; cpath := 0 ;
   path    cpaths    []  ;
@@ -233,6 +234,15 @@ def flush_shapes =
   endfor ;
 enddef ;
 
+def flush_pictures =
+  for x=1 upto max_x :
+    for y=1 upto max_y :
+      flush_picture (x, y) ;
+    endfor ;
+  endfor ;
+enddef ;
+
+
 def draw_connection_point (expr x, y, z) =
   pickup pencircle scaled if (z=0): 2 fi xyline[x][y] ;
   drawdot xy_bottom(x,y,z,false) scaled_to_grid withcolor (1,0,0) ;
@@ -450,6 +460,16 @@ def draw_midpoint (expr n) =
   endgroup ;
 enddef ;
 
+def flush_picture(expr x, y) =
+    if known xypicture[x][y]:
+        draw xypicture[x][y] shifted xy_offset((x+0.5)*grid_width,(max_y-y+1.5)*grid_height) ;
+    fi ;
+enddef ;
+
+def chart_draw_picture(expr x, y, p) =
+    xypicture[x][y] := p ;
+enddef ;
+
 boolean reverse_connection ; reverse_connection := false ;
 
 vardef up_on_grid (expr n) =
@@ -911,6 +931,7 @@ enddef ;
 def end_chart =
   flush_shapes ;
   flush_connections ;
+  flush_pictures ;
   cmin_x := cmin_x ;
   cmax_x := cmin_x+cmax_x ;
   cmin_y := cmin_y-1 ;
diff --git a/metapost/context/base/mp-flow.mpiv b/metapost/context/base/mp-flow.mpiv
new file mode 100644
index 000000000..c134f28d8
--- /dev/null
+++ b/metapost/context/base/mp-flow.mpiv
@@ -0,0 +1,1020 @@
+%D \module
+%D   [       file=mp-char.mp,
+%D        version=2011.10.1, % 1998.10.10,
+%D          title=\CONTEXT\ \METAPOST\ graphics,
+%D       subtitle=charts,
+%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.
+
+%D This is ancient code .. but I see no need to rewrite it.
+
+if unknown context_tool :    input mp-tool ; fi ;
+if unknown context_shap :    input mp-shap ; fi ;
+if   known context_flow : endinput         ; fi ;
+
+boolean context_flow ; context_flow := true ;
+
+%D settings
+
+numeric flow_grid_width             ; flow_grid_width             := 60pt ;
+numeric flow_shape_width            ; flow_shape_width            := 45pt ;
+numeric flow_grid_height            ; flow_grid_height            := 40pt ;
+numeric flow_shape_height           ; flow_shape_height           := 30pt ;
+numeric flow_chart_offset           ; flow_chart_offset           :=  2pt ;
+color   flow_chart_background_color ; flow_chart_background_color := white ;
+boolean flow_show_mid_points        ; flow_show_mid_points        := false ;
+boolean flow_show_con_points        ; flow_show_con_points        := false ;
+boolean flow_show_all_points        ; flow_show_all_points        := false ;
+numeric flow_shape_line_width       ; flow_shape_line_width       := 2pt ;
+color   flow_shape_line_color       ; flow_shape_line_color       := .5white ;
+color   flow_shape_fill_color       ; flow_shape_fill_color       := .9white ;
+color   flow_connection_line_color  ; flow_connection_line_color  := .2white ;
+
+numeric flow_connection_line_width  ; flow_connection_line_width  := flow_shape_line_width ;
+
+numeric flow_connection_smooth_size ; flow_connection_smooth_size := 5pt ;
+numeric flow_connection_arrow_size  ; flow_connection_arrow_size  := 4pt ;
+numeric flow_connection_dash_size   ; flow_connection_dash_size   := 3pt ;
+
+numeric flow_max_x                  ; flow_max_x                  := 6 ;
+numeric flow_max_y                  ; flow_max_y                  := 4 ;
+
+boolean flow_smooth                 ; flow_smooth                 := true ;
+boolean flow_peepshape              ; flow_peepshape              := false ;
+boolean flow_arrowtip               ; flow_arrowtip               := true ;
+boolean flow_dashline               ; flow_dashline               := false ;
+boolean flow_forcevalid             ; flow_forcevalid             := false ;
+boolean flow_touchshape             ; flow_touchshape             := false ;
+boolean flow_showcrossing           ; flow_showcrossing           := false ;
+boolean flow_reverse_y              ; flow_reverse_y              := true ;
+
+picture flow_dash_pattern           ; flow_dash_pattern           := nullpicture ;
+
+numeric flow_shape_node             ; flow_shape_node             :=  0 ;
+numeric flow_shape_action           ; flow_shape_action           := 24 ;
+numeric flow_shape_procedure        ; flow_shape_procedure        :=  5 ;
+numeric flow_shape_product          ; flow_shape_product          := 12 ;
+numeric flow_shape_decision         ; flow_shape_decision         := 14 ;
+numeric flow_shape_archive          ; flow_shape_archive          := 19 ;
+numeric flow_shape_loop             ; flow_shape_loop             := 35 ;
+numeric flow_shape_wait             ; flow_shape_wait             :=  6 ;
+numeric flow_shape_subprocedure     ; flow_shape_subprocedure     := 20 ;
+numeric flow_shape_singledocument   ; flow_shape_singledocument   := 32 ;
+numeric flow_shape_multidocument    ; flow_shape_multidocument    := 33 ;
+numeric flow_shape_right            ; flow_shape_right            := 66 ;
+numeric flow_shape_left             ; flow_shape_left             := 67 ;
+numeric flow_shape_up               ; flow_shape_up               := 68 ;
+numeric flow_shape_down             ; flow_shape_down             := 69 ;
+
+% vardef some_shape_path (expr type) == imported from mp-shap
+
+def flow_show_shapes(expr n) =
+    flow_begin_chart(n,8,10) ;
+    flow_show_con_points := true ;
+    for i=0 upto 7 :
+        for j=0 upto 9 :
+            flow_new_shape(i+1,j+1,i*10+j);
+        endfor ;
+    endfor ;
+    flow_end_chart ;
+enddef ;
+
+%D connections
+
+def flow_new_chart =
+
+    flow_grid_width             := 60pt ;
+    flow_shape_width            := 45pt ;
+    flow_grid_height            := 40pt ;
+    flow_shape_height           := 30pt ;
+    flow_chart_offset           :=  2pt ;
+    flow_chart_background_color := white ;
+    flow_show_mid_points        := false ;
+    flow_show_con_points        := false ;
+    flow_show_all_points        := false ;
+    flow_shape_line_width       := 2pt ;
+    flow_shape_line_color       := .5white ;
+    flow_shape_fill_color       := .9white ;
+    flow_connection_line_color  := .2white ;
+    flow_connection_line_width  := flow_shape_line_width ;
+    flow_connection_smooth_size := 5pt ;
+    flow_connection_arrow_size  := 4pt ;
+    flow_connection_dash_size   := 3pt ;
+
+    flow_max_x                  := 6 ;
+    flow_max_y                  := 4 ;
+
+    flow_smooth                 := true  ;
+    flow_peepshape              := false ;
+    flow_arrowtip               := true  ;
+    flow_dashline               := false ;
+    flow_forcevalid             := false ;
+    flow_touchshape             := false ;
+    flow_showcrossing           := false ;
+    flow_reverse_y              := true ;
+
+    flow_dash_pattern           := nullpicture ;
+
+    numeric flow_xypoint       ; flow_xypoint := 0 ;
+    numeric flow_cpath         ; flow_cpath   := 0 ;
+
+    pair    flow_xypoints []   ;
+    boolean flow_xyfree   [][] ;
+    path    flow_xypath   [][] ;
+    numeric flow_xysx     [][] ;
+    numeric flow_xysy     [][] ;
+    color   flow_xyfill   [][] ;
+    color   flow_xydraw   [][] ;
+    numeric flow_xyline   [][] ;
+    boolean flow_xypeep   [][] ;
+    picture flow_xytext   [][] ;
+    picture flow_xylabel_l[][] ;
+    picture flow_xylabel_r[][] ;
+    picture flow_xylabel_t[][] ;
+    picture flow_xylabel_b[][] ;
+    picture flow_xyexit_l [][] ;
+    picture flow_xyexit_r [][] ;
+    picture flow_xyexit_t [][] ;
+    picture flow_xyexit_b [][] ;
+    path    flow_cpaths   []   ;
+    numeric flow_cline    []   ;
+    color   flow_ccolor   []   ;
+    boolean flow_carrow   []   ;
+    boolean flow_cdash    []   ;
+    boolean flow_ccross   []   ;
+
+    picture flow_tpicture[][]  ;
+    picture flow_bpicture[][]  ;
+    picture flow_lpicture[][]  ;
+    picture flow_rpicture[][]  ;
+
+    predefined_shapes[61] := (fullcircle scaled (1.5*predefined_shapes_yradius) xscaled (flow_grid_height/flow_grid_width)) ;
+    predefined_shapes[62] := (fullcircle scaled (2.0*predefined_shapes_yradius) xscaled (flow_grid_height/flow_grid_width)) ;
+
+enddef ;
+
+flow_new_chart ;
+
+def flow_y_pos(expr y) =
+    if flow_reverse_y :
+        flow_max_y + 1 - y
+    else :
+        y
+    fi
+enddef ;
+
+def flow_initialize_grid(expr maxx, maxy) =
+    flow_max_x := maxx ;
+    flow_max_y := maxy ;
+    flow_dsp_x := 0 ;
+    flow_dsp_y := 0 ;
+    for x=1 upto flow_max_x :
+        for y=1 upto flow_max_y :
+            flow_xyfree[x][y] := true ;
+            flow_xyfill[x][y] := flow_shape_fill_color ;
+            flow_xydraw[x][y] := flow_shape_line_color ;
+            flow_xyline[x][y] := flow_shape_line_width ;
+        endfor ;
+    endfor ;
+enddef ;
+
+def flow_scaled_to_grid =
+    xscaled flow_grid_width yscaled flow_grid_height
+enddef ;
+
+def flow_xy_offset(expr x, y) =
+    (x+.5,y+.5)
+enddef ;
+
+def flow_draw_shape(expr x, yy, p, sx, sy) =
+    begingroup ;
+        save y ; numeric y ;
+        y := flow_y_pos(yy) ;
+        flow_xypath [x][y] := (p xscaled sx yscaled sy) shifted flow_xy_offset(x,y) ;
+        flow_xyfree [x][y] := false ;
+        flow_xysx   [x][y] := sx ;
+        flow_xysy   [x][y] := sy ;
+        flow_xyfill [x][y] := flow_shape_fill_color ;
+        flow_xydraw [x][y] := flow_shape_line_color ;
+        flow_xyline [x][y] := flow_shape_line_width ;
+        flow_xypeep [x][y] := flow_peepshape ;
+    endgroup ;
+enddef ;
+
+vardef flow_i_point (expr x, y, p, t) =
+    begingroup ;
+        save q, ok ; pair q ; boolean ok ;
+        q := flow_xypath[x][y] intersection_point ((p) shifted flow_xy_offset(x,y)) ;
+        ok := true ;
+        if not ok :
+            message (t & " of shape (" & decimal x & "," & decimal y & ") limited") ;
+        fi ;
+        q
+    endgroup
+enddef ;
+
+vardef flow_trimmed (expr x, y, z, t) =
+    if flow_touchshape and t :
+        flow_xyline[x][y]/z
+    else :
+        epsilon
+    fi
+enddef ;
+
+numeric flow_zfactor ; flow_zfactor := 1/3 ;
+
+vardef flow_xy_bottom (expr x, y, z, t) =
+    flow_i_point(x, y, ((0,0)--(0,-2)) shifted (flow_zfactor*z*flow_xysx[x][y],0), "bottom")
+    shifted(0,-flow_trimmed(x,y,flow_grid_height,t))
+enddef ;
+
+vardef flow_xy_top (expr x, y, z, t) =
+    flow_i_point (x, y, ((0,0)--(0,2))  shifted (flow_zfactor*z*flow_xysx[x][y],0), "top")
+    shifted(0,flow_trimmed(x,y,flow_grid_height,t))
+enddef ;
+
+vardef flow_xy_left (expr x, y, z, t) =
+    flow_i_point (x, y, ((0,0)--(-2,0)) shifted (0,flow_zfactor*z*flow_xysy[x][y]), "left")
+    shifted(-flow_trimmed(x,y,flow_grid_width,t),0)
+enddef ;
+
+vardef flow_xy_right (expr x, y, z, t) =
+    flow_i_point (x, y, ((0,0)--(2,0))  shifted (0,flow_zfactor*z*flow_xysy[x][y]), "right")
+    shifted(flow_trimmed(x,y,flow_grid_width,t),0)
+enddef ;
+
+def flow_flush_shapes =
+    for x=1 upto flow_max_x :
+        for y=1 upto flow_max_y :
+            flow_flush_shape(x, y) ;
+        endfor ;
+    endfor ;
+enddef ;
+
+def flow_flush_pictures =
+    for x=1 upto flow_max_x :
+        for y=1 upto flow_max_y :
+            flow_flush_picture(x, y) ;
+        endfor ;
+    endfor ;
+enddef ;
+
+def flow_draw_connection_point(expr x, y, z) =
+    pickup pencircle scaled if (z=0): 2 fi flow_xyline[x][y] ;
+    drawdot flow_xy_bottom(x,y,z,false) flow_scaled_to_grid withcolor (1,0,0) ;
+    drawdot flow_xy_top   (x,y,z,false) flow_scaled_to_grid withcolor (0,1,0) ;
+    drawdot flow_xy_left  (x,y,z,false) flow_scaled_to_grid withcolor (0,0,1) ;
+    drawdot flow_xy_right (x,y,z,false) flow_scaled_to_grid withcolor (1,1,0) ;
+enddef ;
+
+def flow_flush_shape(expr x, yy) =
+    begingroup ;
+        save y ; numeric y ;
+        y := flow_y_pos(yy) ;
+        if not flow_xyfree[x][y] :
+            pickup pencircle scaled flow_xyline[x][y] ;
+            if flow_xypeep[x][y] :
+                fill (flow_xypath[x][y] peepholed (unitsquare shifted (x,y)))
+                    flow_scaled_to_grid withpen pencircle scaled 0
+                    withcolor flow_chart_background_color ;
+            else :
+                fill flow_xypath[x][y] flow_scaled_to_grid withcolor flow_xyfill[x][y] ;
+            fi ;
+            draw flow_xypath[x][y] flow_scaled_to_grid withcolor flow_xydraw[x][y] ;
+            if flow_show_con_points or flow_show_all_points :
+                flow_draw_connection_point(x, y, 0) ;
+            fi ;
+            if flow_show_all_points :
+                for i=-1 upto 1 :
+                    flow_draw_connection_point(x, y, i) ;
+                endfor ;
+            fi ;
+        fi ;
+    endgroup ;
+enddef ;
+
+vardef flow_points_initialized(expr xfrom, yfrom, xto, yto, n) =
+    if not flow_xyfree[xfrom][yfrom] and not flow_xyfree[xto][yto] :
+        flow_xypoint := n ; true
+    else :
+        flow_xypoint := 0 ; false
+    fi
+enddef ;
+
+def flow_collapse_points = % this is now an mp-tool macro
+    begingroup ;
+        % remove redundant points
+        save n ; numeric n ;
+        n := 1 ;
+        for i=2 upto flow_xypoint :
+            if not (flow_xypoints[i] = flow_xypoints[n]) :
+                n := n + 1 ;
+                flow_xypoints[n] := flow_xypoints[i]
+            fi ;
+        endfor ;
+        flow_xypoint := n ;
+        % make straight lines
+        if flow_xypoints[2] = flow_xypoints[flow_xypoint-1] :
+            flow_xypoints[3] := flow_xypoints[flow_xypoint] ;
+            flow_xypoint := 3 ;
+        fi ;
+    endgroup ;
+enddef ;
+
+vardef flow_smooth_connection(expr a,b) =
+    if ypart a = ypart b :
+        a shifted (  if xpart a >= xpart b : - fi (flow_connection_smooth_size/flow_grid_width ),0)
+    else :
+        a shifted (0,if ypart a >= ypart b : - fi (flow_connection_smooth_size/flow_grid_height)  )
+    fi
+enddef ;
+
+vardef flow_trim_points =
+    begingroup
+        save p, a, b, d, i ; numeric a, b ; path p ; pair d ;
+        p := for i=1 upto flow_xypoint-1 : flow_xypoints[i]-- endfor flow_xypoints[flow_xypoint] ;
+        if flow_touchshape :
+            a := flow_shape_line_width/flow_grid_width ;
+            b := flow_shape_line_width/flow_grid_height ;
+        else :
+            a := epsilon ;
+            b := epsilon ;
+        fi ;
+        d := direction infinity of p ;
+        flow_xypoints[flow_xypoint] := flow_xypoints[flow_xypoint] shifted
+        if     xpart d < 0 : (+a,0) ;
+        elseif xpart d > 0 : (-a,0) ;
+        elseif ypart d < 0 : (0,+b) ;
+        elseif ypart d > 0 : (0,-b) ;
+        else               : origin ;
+        fi ;
+        d := direction 0 of p ;
+        flow_xypoints[1] := flow_xypoints[1] shifted
+        if     xpart d < 0 : (-a,0) ;
+        elseif xpart d > 0 : (+a,0) ;
+        elseif ypart d < 0 : (0,-b) ;
+        elseif ypart d > 0 : (0,+b) ;
+        else               : origin ;
+        fi ;
+    endgroup
+enddef ;
+
+vardef flow_trim_points = enddef ;
+
+vardef flow_connection_path =
+    if flow_reverse_connection : reverse fi (flow_xypoints[1] --
+    for i=2 upto flow_xypoint-1 :
+        if flow_smooth :
+            flow_smooth_connection(flow_xypoints[i],flow_xypoints[i-1]) ..
+            controls flow_xypoints[i] and flow_xypoints[i] ..
+            flow_smooth_connection(flow_xypoints[i],flow_xypoints[i+1]) --
+        else :
+            flow_xypoints[i] --
+        fi
+    endfor
+    flow_xypoints[flow_xypoint])
+enddef ;
+
+def flow_draw_connection =
+    if flow_xypoint > 0 :
+        flow_collapse_points ;
+        flow_trim_points ;
+        flow_cpath := flow_cpath + 1 ;
+        flow_cpaths[flow_cpath] := flow_connection_path flow_scaled_to_grid ;
+        flow_cline[flow_cpath]  := flow_connection_line_width ;
+        flow_ccolor[flow_cpath] := flow_connection_line_color ;
+        flow_carrow[flow_cpath] := flow_arrowtip ;
+        flow_cdash[flow_cpath]  := flow_dashline ;
+        flow_ccross[flow_cpath] := flow_showcrossing ;
+    else :
+        message("no connection defined") ;
+    fi ;
+    flow_reverse_connection := false ;
+enddef ;
+
+def flow_flush_connections = % protect locals
+    begingroup ;
+    save ip, crossing, cp ; numeric ip ; boolean crossing ; path cp ;
+    ahlength := flow_connection_arrow_size ;
+    flow_dash_pattern := dashpattern(on flow_connection_dash_size off flow_connection_dash_size) ;
+    for i=1 upto flow_cpath :
+        if flow_ccross[i] :
+            crossing := false ;
+            for j=1 upto i :
+                if not  (point infinity of flow_cpaths[i] = point infinity of flow_cpaths[j]) :
+                    ip := flow_cpaths[i] intersection_point flow_cpaths[j] ;
+                    if intersection_found : crossing := true fi ;
+                fi ;
+            endfor ;
+            if crossing :
+                pickup pencircle scaled 2flow_cline[i] ;
+                cp := flow_cpaths[i] ;
+                cp := cp cutbefore point .05 length cp of cp ;
+                cp := cp cutafter  point .95 length cp of cp ;
+                draw cp withcolor flow_chart_background_color ;
+            fi ;
+        fi ;
+        pickup pencircle scaled flow_cline[i] ;
+        if flow_carrow[i] :
+            if flow_cdash[i] :
+                drawarrow flow_cpaths[i] withcolor flow_ccolor[i] dashed flow_dash_pattern ;
+            else :
+                drawarrow flow_cpaths[i] withcolor flow_ccolor[i] ;
+            fi ;
+        else :
+            if flow_cdash[i] :
+                draw flow_cpaths[i] withcolor flow_ccolor[i] dashed flow_dash_pattern ;
+            else :
+                draw flow_cpaths[i] withcolor flow_ccolor[i] ;
+            fi ;
+        fi ;
+        flow_draw_midpoint(i) ;
+    endfor ;
+    endgroup ;
+enddef ;
+
+def flow_draw_midpoint (expr n) =
+    begingroup
+        save p ; pair p ;
+        p := point .5*length(flow_cpaths[n]) of flow_cpaths[n];
+        pickup pencircle scaled 2flow_cline[n] ;
+        if flow_show_mid_points :
+            drawdot p withcolor .7white ;
+        fi ;
+    endgroup ;
+enddef ;
+
+def flow_flush_picture(expr x, yy) =
+    begingroup ; save y ; numeric y ;
+    y := flow_y_pos(yy) ;
+    if known flow_xytext[x][y] :
+        begingroup ;
+            % flow_xypath[x][y]
+            save p, offset ; path p ; pair offset ;
+            offset := flow_xy_offset((x+0.5)*flow_grid_width,(flow_max_y-y+1.5)*flow_grid_height) ;
+            offset := offset shifted (-flow_xyline[x][y]/4,-flow_xyline[x][y]/4) ; % terrible hack (some compensation)
+            p := fullsquare
+                xscaled flow_grid_width
+                yscaled flow_grid_height
+                shifted offset ;
+            if known flow_xytext[x][y]:
+                draw flow_xytext[x][y] shifted offset ;
+            fi ;
+            if known flow_xylabel_t[x][y] :
+                label.urt(flow_xylabel_t[x][y],0.5[ulcorner p,urcorner p]) ;
+            fi ;
+            if known flow_xylabel_b[x][y] :
+                label.lrt(flow_xylabel_b[x][y],0.5[llcorner p,lrcorner p]) ;
+            fi ;
+            if known flow_xylabel_l[x][y] :
+                label.ulft(flow_xylabel_l[x][y],0.5[ulcorner p,llcorner p]) ;
+            fi ;
+            if known flow_xylabel_r[x][y] :
+                label.urt (flow_xylabel_r[x][y],0.5[urcorner p,lrcorner p]) ;
+            fi ;
+            if known flow_xyexit_t[x][y] :
+                label.top(flow_xyexit_t[x][y],0.5[ulcorner p,urcorner p] shifted (0, flow_grid_height/2)) ;
+            fi ;
+            if known flow_xyexit_b[x][y] :
+                label.bot(flow_xyexit_b[x][y],0.5[llcorner p,lrcorner p] shifted (0,-flow_grid_height/2)) ;
+            fi ;
+            if known flow_xyexit_l[x][y] :
+                label.lft(flow_xyexit_l[x][y],0.5[ulcorner p,llcorner p] shifted (-flow_grid_width/2,0)) ;
+            fi ;
+            if known flow_xyexit_r[x][y] :
+                label.rt (flow_xyexit_r[x][y],0.5[urcorner p,lrcorner p] shifted ( flow_grid_width/2,0)) ;
+            fi ;
+        endgroup ;
+    fi ;
+    endgroup ;
+enddef ;
+
+def flow_chart_draw_text(expr x, y, p) =
+    flow_xytext[x][y] := p ;
+enddef ;
+
+def flow_chart_draw_label_t(expr x, y, p) = flow_xylabel_t[x][y] := p ; enddef ;
+def flow_chart_draw_label_b(expr x, y, p) = flow_xylabel_b[x][y] := p ; enddef ;
+def flow_chart_draw_label_l(expr x, y, p) = flow_xylabel_l[x][y] := p ; enddef ;
+def flow_chart_draw_label_r(expr x, y, p) = flow_xylabel_r[x][y] := p ; enddef ;
+
+def flow_chart_draw_exit_t (expr x, y, p) = flow_xyexit_t [x][y] := p ; enddef ;
+def flow_chart_draw_exit_b (expr x, y, p) = flow_xyexit_b [x][y] := p ; enddef ;
+def flow_chart_draw_exit_l (expr x, y, p) = flow_xyexit_l [x][y] := p ; enddef ;
+def flow_chart_draw_exit_r (expr x, y, p) = flow_xyexit_r [x][y] := p ; enddef ;
+
+boolean flow_reverse_connection ; flow_reverse_connection := false ;
+
+vardef flow_up_on_grid (expr n) =
+    (xpart flow_xypoints[n],(ypart flow_xypoints[n]+1) div 1)
+enddef ;
+
+vardef flow_down_on_grid (expr n) =
+    (xpart flow_xypoints[n],(ypart flow_xypoints[n]) div 1)
+enddef ;
+
+vardef flow_left_on_grid (expr n) =
+    ((xpart flow_xypoints[n]) div 1, ypart flow_xypoints[n])
+enddef ;
+
+vardef flow_right_on_grid (expr n) =
+    ((xpart flow_xypoints[n]+1) div 1, ypart flow_xypoints[n])
+enddef ;
+
+vardef flow_x_on_grid (expr n, xfrom, xto, zfrom) =
+    if (xfrom = xto) and not (zfrom = 0) :
+        if (zfrom=1) : flow_right_on_grid(2) else : flow_left_on_grid(2) fi
+    elseif xpart flow_xypoints[1] < xpart flow_xypoints[6] :
+        flow_right_on_grid(n)
+    else :
+        flow_left_on_grid(n)
+    fi
+enddef ;
+
+vardef y_on_grid (expr n, yfrom, yto, zfrom) =
+    if (yfrom = yto) and not (zfrom = 0) :
+        if (zfrom = 1) : flow_up_on_grid(2) else : flow_down_on_grid(2) fi
+    elseif ypart flow_xypoints[1] < ypart flow_xypoints[6] :
+        flow_up_on_grid(n)
+    else :
+        flow_down_on_grid(n)
+    fi
+enddef ;
+
+vardef flow_xy_on_grid (expr n, m) =
+    (xpart flow_xypoints[n], ypart flow_xypoints[m])
+enddef ;
+
+vardef flow_down_to_grid (expr a,b) =
+    (xpart flow_xypoints[a], ypart flow_xypoints[if ypart flow_xypoints[a]<ypart flow_xypoints[b] : a else : b fi])
+enddef ;
+
+vardef flow_up_to_grid (expr a,b) =
+    (xpart flow_xypoints[a], ypart flow_xypoints[if ypart flow_xypoints[a]>ypart flow_xypoints[b] : a else : b fi])
+enddef ;
+
+vardef flow_left_to_grid (expr a,b) =
+    (xpart flow_xypoints[if xpart flow_xypoints[a]<xpart flow_xypoints[b] : a else : b fi], ypart flow_xypoints[a])
+enddef ;
+
+vardef flow_right_to_grid (expr a,b) =
+    (xpart flow_xypoints[if xpart flow_xypoints[a]>xpart flow_xypoints[b] : a else : b fi], ypart flow_xypoints[a])
+enddef ;
+
+vardef flow_valid_connection (expr xfrom, yfrom, xto, yto) =
+    begingroup ;
+        save ok, vc, pp ; boolean ok ; pair vc ; path pp ;
+        save flow_xyfirst, flow_xylast ; pair flow_xyfirst, flow_xylast ;
+        % check for slanted lines
+        ok := true ;
+        for i=1 upto flow_xypoint-1 :
+            if not ((xpart flow_xypoints[i]=xpart flow_xypoints[i+1]) or (ypart flow_xypoints[i]=ypart flow_xypoints[i+1])) :
+                ok := false ;
+            fi ;
+        endfor ;
+        if not ok :
+            % message("slanted");
+            false
+        elseif flow_forcevalid :
+            % message("force");
+            true
+        elseif (xfrom=xto) and (yfrom=yto) :
+            % message("self");
+            false
+        else :
+            % check for crossing shapes
+            flow_xyfirst := flow_xypoints[1] ;
+            flow_xylast := flow_xypoints[flow_xypoint] ;
+            flow_trim_points ;
+            pp := for i=1 upto flow_xypoint-1 : flow_xypoints[i]-- endfor flow_xypoints[flow_xypoint] ;
+            flow_xypoints[1] := flow_xyfirst ;
+            flow_xypoints[flow_xypoint] := flow_xylast ;
+            for i=1 upto flow_max_x :
+                for j=1 upto flow_max_y :                % was bug: xfrom,yto
+                    if not ( ( (i,j)=(xfrom,yfrom) ) or ( (i,j)=(xto,yto) ) ) :
+                        if not flow_xyfree[i][j] :
+                            vc := pp intersection_point flow_xypath[i][j] ;
+                            if intersection_found :
+                                ok := false
+                            fi ;
+                        fi ;
+                    fi ;
+                endfor ;
+            endfor ;
+            % if not ok: message("crossing") ; fi ;
+            ok
+        fi
+    endgroup
+enddef ;
+
+def flow_connect_top_bottom (expr xfrom, yyfrom, zfrom) (expr xto, yyto, zto) =
+    yfrom := flow_y_pos(yyfrom) ;
+    yto := flow_y_pos(yyto) ;
+    if flow_points_initialized(xfrom,yfrom,xto,yto,6) :
+        flow_xypoints[1] := flow_xy_top(xfrom,yfrom,zfrom,true) ;
+        flow_xypoints[6] := flow_xy_bottom(xto,yto,zto,true) ;
+        flow_xypoints[2] := flow_up_on_grid(1) ;
+        flow_xypoints[5] := flow_down_on_grid(6) ;
+        flow_xypoints[3] := flow_up_to_grid(2,5) ;
+        flow_xypoints[4] := flow_up_to_grid(2,5) ;
+        if not flow_valid_connection(xfrom,yfrom,xto,yto) :
+            flow_xypoints[3] := flow_x_on_grid(2,xfrom,xto,zfrom) ;
+            flow_xypoints[4] := flow_xy_on_grid(3,5) ;
+        fi ;
+        %%%% begin experiment
+        flow_xypoints[3] := flow_xypoints[3] shifted (flow_dsp_x,0) ;
+        flow_xypoints[4] := flow_xypoints[4] shifted (flow_dsp_x,0) ;
+        if flow_dsp_y>0 :
+            flow_xypoints[2] := flow_xypoints[2] shifted (0,flow_dsp_y) ;
+            flow_xypoints[3] := flow_xypoints[3] shifted (0,flow_dsp_y) ;
+        elseif flow_dsp_y<0 :
+            flow_xypoints[4] := flow_xypoints[4] shifted (0,flow_dsp_y) ;
+            flow_xypoints[5] := flow_xypoints[5] shifted (0,flow_dsp_y) ;
+        fi
+        %%%% end experiment
+        flow_draw_connection ;
+    fi ;
+enddef ;
+
+def flow_connect_left_right (expr xfrom,yyfrom,zfrom) (expr xto,yyto,zto) =
+    yfrom := flow_y_pos(yyfrom) ;
+    yto := flow_y_pos(yyto) ;
+    if flow_points_initialized(xfrom,yfrom,xto,yto,6) :
+        flow_xypoints[1] := flow_xy_left(xfrom,yfrom,zfrom,true) ;
+        flow_xypoints[6] := flow_xy_right(xto,yto,zto,true) ;
+        flow_xypoints[2] := flow_left_on_grid(1) ;
+        flow_xypoints[5] := flow_right_on_grid(6) ;
+        flow_xypoints[3] := flow_left_to_grid(2,5) ;
+        flow_xypoints[4] := flow_left_to_grid(2,5) ;
+        if not flow_valid_connection(xfrom,yfrom,xto,yto) :
+            flow_xypoints[3] := flow_y_on_grid(2,yfrom,yto,zfrom) ;
+            flow_xypoints[4] := flow_xy_on_grid(5,3) ;
+        fi ;
+        flow_draw_connection ;
+  fi ;
+enddef ;
+
+def flow_connect_left_top (expr xfrom,yyfrom,zfrom) (expr xto,yyto,zto) =
+    yfrom := flow_y_pos(yyfrom) ;
+    yto := flow_y_pos(yyto) ;
+    if flow_points_initialized(xfrom,yfrom,xto,yto,5) :
+        flow_xypoints[1] := flow_xy_left(xfrom,yfrom,zfrom,true) ;
+        flow_xypoints[5] := flow_xy_top(xto,yto,zto,true) ;
+        flow_xypoints[2] := flow_left_on_grid(1) ;
+        flow_xypoints[4] := flow_up_on_grid(5) ;
+        flow_xypoints[3] := flow_left_to_grid(2,5) ;
+        if not flow_valid_connection(xfrom,yfrom,xto,yto) :
+            flow_xypoints[3] := flow_xy_on_grid(2,4) ;
+        fi ;
+        flow_draw_connection ;
+    fi ;
+enddef ;
+
+def flow_connect_left_bottom (expr xfrom,yyfrom,zfrom) (expr xto,yyto,zto) =
+    yfrom := flow_y_pos(yyfrom) ;
+    yto := flow_y_pos(yyto) ;
+    if flow_points_initialized(xfrom,yfrom,xto,yto,5) :
+        flow_xypoints[1] := flow_xy_left(xfrom,yfrom,zfrom,true) ;
+        flow_xypoints[5] := flow_xy_bottom(xto,yto,zto,true) ;
+        flow_xypoints[2] := flow_left_on_grid(1) ;
+        flow_xypoints[4] := flow_down_on_grid(5) ;
+        flow_xypoints[3] := flow_left_to_grid(2,5) ;
+        if not flow_valid_connection(xfrom,yfrom,xto,yto) :
+            flow_xypoints[3] := flow_xy_on_grid(2,4) ;
+        fi ;
+        flow_draw_connection ;
+    fi ;
+enddef ;
+
+def flow_connect_right_top (expr xfrom,yyfrom,zfrom) (expr xto,yyto,zto) =
+    yfrom := flow_y_pos(yyfrom) ;
+    yto := flow_y_pos(yyto) ;
+    if flow_points_initialized(xfrom,yfrom,xto,yto,5) :
+        flow_xypoints[1] := flow_xy_right(xfrom,yfrom,zfrom,true) ;
+        flow_xypoints[5] := flow_xy_top(xto,yto,zto,true) ;
+        flow_xypoints[2] := flow_right_on_grid(1) ;
+        flow_xypoints[4] := flow_up_on_grid(5) ;
+        flow_xypoints[3] := flow_right_to_grid(2,5) ;
+        if not flow_valid_connection(xfrom,yfrom,xto,yto) :
+            flow_xypoints[3] := flow_xy_on_grid(2,4) ;
+        fi ;
+        flow_draw_connection ;
+    fi ;
+enddef ;
+
+def flow_connect_right_bottom (expr xfrom,yyfrom,zfrom) (expr xto,yyto,zto) =
+    yfrom := flow_y_pos(yyfrom) ;
+    yto := flow_y_pos(yyto) ;
+    if flow_points_initialized(xfrom,yfrom,xto,yto,5) :
+        flow_xypoints[1] := flow_xy_right(xfrom,yfrom,zfrom,true) ;
+        flow_xypoints[5] := flow_xy_bottom(xto,yto,zto,true) ;
+        flow_xypoints[2] := flow_right_on_grid(1) ;
+        flow_xypoints[4] := flow_down_on_grid(5) ;
+        flow_xypoints[3] := flow_right_to_grid(2,5) ;
+        if not flow_valid_connection(xfrom,yfrom,xto,yto) :
+            flow_xypoints[3] := flow_xy_on_grid(2,4) ;
+        fi ;
+        %%%% begin experiment
+        flow_xypoints[2] := flow_xypoints[2] shifted (flow_dsp_x,0) ;
+        flow_xypoints[3] := flow_xypoints[3] shifted (flow_dsp_x,0) ;
+        if flow_dsp_y>0 :
+          flow_xypoints[3] := flow_xypoints[3] shifted (0,-flow_dsp_y) ;
+          flow_xypoints[4] := flow_xypoints[4] shifted (0,-flow_dsp_y) ;
+        elseif flow_dsp_y<0 :
+          flow_xypoints[3] := flow_xypoints[3] shifted (0,flow_dsp_y) ;
+          flow_xypoints[4] := flow_xypoints[4] shifted (0,flow_dsp_y) ;
+        fi
+        %%%% end experiment
+        flow_draw_connection ;
+    fi ;
+enddef ;
+
+def flow_connect_left_left (expr xfrom,yyfrom,zfrom) (expr xto,yyto,zto) =
+    yfrom := flow_y_pos(yyfrom) ;
+    yto := flow_y_pos(yyto) ;
+    if flow_points_initialized(xfrom,yfrom,xto,yto,6) :
+        flow_xypoints[1] := flow_xy_left(xfrom,yfrom,zfrom,true) ;
+        flow_xypoints[6] := flow_xy_left(xto,yto,zto,true) ;
+        flow_xypoints[2] := flow_left_on_grid(1) ;
+        flow_xypoints[5] := flow_left_on_grid(6) ;
+        flow_xypoints[3] := flow_left_to_grid(2,5) ;
+        flow_xypoints[4] := flow_left_to_grid(5,2) ;
+        if not flow_valid_connection(xfrom,yfrom,xto,yto) :
+            flow_xypoints[3] := flow_y_on_grid(2,yfrom,yto,zfrom) ;
+            flow_xypoints[4] := flow_xy_on_grid(5,3) ;
+        fi ;
+        flow_draw_connection ;
+    fi ;
+enddef ;
+
+def flow_connect_right_right (expr xfrom,yyfrom,zfrom) (expr xto,yyto,zto) =
+    yfrom := flow_y_pos(yyfrom) ;
+    yto := flow_y_pos(yyto) ;
+    if flow_points_initialized(xfrom,yfrom,xto,yto,6) :
+        flow_xypoints[1] := flow_xy_right(xfrom,yfrom,zfrom,true) ;
+        flow_xypoints[6] := flow_xy_right(xto,yto,zto,true) ;
+        flow_xypoints[2] := flow_right_on_grid(1) ;
+        flow_xypoints[5] := flow_right_on_grid(6) ;
+        flow_xypoints[3] := flow_right_to_grid(2,5) ;
+        flow_xypoints[4] := flow_right_to_grid(5,2) ;
+        if not flow_valid_connection(xfrom,yfrom,xto,yto) :
+          flow_xypoints[3] := flow_y_on_grid(2,yfrom,yto,zfrom) ;
+          flow_xypoints[4] := flow_xy_on_grid(5,3) ;
+        fi ;
+        flow_draw_connection ;
+    fi ;
+enddef ;
+
+def flow_connect_top_top (expr xfrom,yyfrom,zfrom) (expr xto,yyto,zto) =
+    yfrom := flow_y_pos(yyfrom) ;
+    yto := flow_y_pos(yyto) ;
+    if flow_points_initialized(xfrom,yfrom,xto,yto,6) :
+        flow_xypoints[1] := flow_xy_top(xfrom,yfrom,zfrom,true) ;
+        flow_xypoints[6] := flow_xy_top(xto,yto,zto,true) ;
+        flow_xypoints[2] := flow_up_on_grid(1) ;
+        flow_xypoints[5] := flow_up_on_grid(6) ;
+        flow_xypoints[3] := flow_up_to_grid(2,5) ;
+        flow_xypoints[4] := flow_up_to_grid(5,2) ;
+        if not flow_valid_connection(xfrom,yfrom,xto,yto) :
+            flow_xypoints[3] := flow_x_on_grid(2,xfrom,xto,zfrom) ;
+            flow_xypoints[4] := flow_xy_on_grid(3,5) ;
+        fi ;
+        flow_draw_connection ;
+    fi ;
+enddef ;
+
+def flow_connect_bottom_bottom (expr xfrom,yyfrom,zfrom) (expr xto,yyto,zto) =
+    yfrom := flow_y_pos(yyfrom) ;
+    yto := flow_y_pos(yyto) ;
+    if flow_points_initialized(xfrom,yfrom,xto,yto,6) :
+        flow_xypoints[1] := flow_xy_bottom(xfrom,yfrom,zfrom,true) ;
+        flow_xypoints[6] := flow_xy_bottom(xto,yto,zto,true) ;
+        flow_xypoints[2] := flow_down_on_grid(1) ;
+        flow_xypoints[5] := flow_down_on_grid(6) ;
+        flow_xypoints[3] := flow_down_to_grid(2,5) ;
+        flow_xypoints[4] := flow_down_to_grid(5,2) ;
+        if not flow_valid_connection(xfrom,yfrom,xto,yto) :
+            flow_xypoints[3] := flow_x_on_grid(2,xfrom,xto,zfrom) ;
+            flow_xypoints[4] := flow_xy_on_grid(3,5) ;
+        fi ;
+        %%%% begin experiment
+        flow_xypoints[3] := flow_xypoints[3] shifted (flow_dsp_x,0) ;
+        flow_xypoints[4] := flow_xypoints[4] shifted (flow_dsp_x,0) ;
+        if flow_dsp_y<0 :
+            flow_xypoints[2] := flow_xypoints[2] shifted (0,-flow_dsp_y) ;
+            flow_xypoints[3] := flow_xypoints[3] shifted (0,-flow_dsp_y) ;
+        elseif flow_dsp_y>0 :
+            flow_xypoints[4] := flow_xypoints[4] shifted (0,flow_dsp_y) ;
+            flow_xypoints[5] := flow_xypoints[5] shifted (0,flow_dsp_y) ;
+        fi
+        %%%% end experiment
+        flow_draw_connection ;
+    fi ;
+enddef ;
+
+def flow_connect_bottom_top (expr xfrom,yfrom,zfrom) (expr xto,yto,zto) =
+    flow_reverse_connection := true ;
+    flow_connect_top_bottom (xto,yto,zto) (xfrom,yfrom,zfrom) ;
+enddef ;
+
+def flow_connect_right_left (expr xfrom,yfrom,zfrom) (expr xto,yto,zto) =
+    flow_reverse_connection := true ;
+    flow_connect_left_right (xto,yto,zto) (xfrom,yfrom,zfrom) ;
+enddef ;
+
+def flow_connect_top_left (expr xfrom,yfrom,zfrom) (expr xto,yto,zto) =
+    flow_reverse_connection := true ;
+    flow_connect_left_top(xto,yto,zto) (xfrom,yfrom,zfrom) ;
+enddef ;
+
+def flow_connect_bottom_left (expr xfrom,yfrom,zfrom) (expr xto,yto,zto) =
+    flow_reverse_connection := true ;
+    flow_connect_left_bottom (xto,yto,zto) (xfrom,yfrom,zfrom) ;
+enddef ;
+
+def flow_connect_top_right (expr xfrom,yfrom,zfrom) (expr xto,yto,zto) =
+    flow_reverse_connection := true ;
+    flow_connect_right_top (xto,yto,zto) (xfrom,yfrom,zfrom) ;
+enddef ;
+
+def flow_connect_bottom_right (expr xfrom,yfrom,zfrom) (expr xto,yto,zto) =
+    flow_reverse_connection := true ;
+    flow_connect_right_bottom (xto,yto,zto) (xfrom,yfrom,zfrom) ;
+enddef ;
+
+def flow_draw_test_shape(expr x, y) =
+    flow_draw_shape(x,y,fullcircle, .7, .7) ;
+enddef ;
+
+def flow_draw_test_shapes =
+    for i=1 upto flow_max_x :
+        for j=1 upto flow_max_y :
+            flow_draw_test_shape(i,j) ;
+        endfor ;
+    endfor ;
+enddef;
+
+def flow_draw_test_area =
+    pickup pencircle scaled .5flow_shape_line_width ;
+    draw (unitsquare xscaled flow_max_x yscaled flow_max_y shifted (1,1)) flow_scaled_to_grid withcolor blue ;
+enddef ;
+
+def flow_show_connection(expr n, m) =
+
+    flow_begin_chart(100+n,6,6) ;
+
+        flow_draw_test_area ;
+
+        flow_smooth   := true ;
+        flow_arrowtip := true ;
+        flow_dashline := true ;
+
+        flow_draw_test_shape(2,2) ; flow_draw_test_shape(4,5) ;
+        flow_draw_test_shape(3,3) ; flow_draw_test_shape(5,1) ;
+        flow_draw_test_shape(2,5) ; flow_draw_test_shape(1,3) ;
+        flow_draw_test_shape(6,2) ; flow_draw_test_shape(4,6) ;
+
+        if     (m=1) :
+            flow_connect_top_bottom (2,2,0) (4,5,0) ;
+            flow_connect_top_bottom (3,3,0) (5,1,0) ;
+            flow_connect_top_bottom (2,5,0) (1,3,0) ;
+            flow_connect_top_bottom (6,2,0) (4,6,0) ;
+        elseif (m=2) :
+            flow_connect_top_top (2,2,0) (4,5,0) ;
+            flow_connect_top_top (3,3,0) (5,1,0) ;
+            flow_connect_top_top (2,5,0) (1,3,0) ;
+            flow_connect_top_top (6,2,0) (4,6,0) ;
+        elseif (m=3) :
+            flow_connect_bottom_bottom (2,2,0) (4,5,0) ;
+            flow_connect_bottom_bottom (3,3,0) (5,1,0) ;
+            flow_connect_bottom_bottom (2,5,0) (1,3,0) ;
+            flow_connect_bottom_bottom (6,2,0) (4,6,0) ;
+        elseif (m=4) :
+            flow_connect_left_right (2,2,0) (4,5,0) ;
+            flow_connect_left_right (3,3,0) (5,1,0) ;
+            flow_connect_left_right (2,5,0) (1,3,0) ;
+            flow_connect_left_right (6,2,0) (4,6,0) ;
+        elseif (m=5) :
+            flow_connect_left_left (2,2,0) (4,5,0) ;
+            flow_connect_left_left (3,3,0) (5,1,0) ;
+            flow_connect_left_left (2,5,0) (1,3,0) ;
+            flow_connect_left_left (6,2,0) (4,6,0) ;
+        elseif (m=6) :
+            flow_connect_right_right (2,2,0) (4,5,0) ;
+            flow_connect_right_right (3,3,0) (5,1,0) ;
+            flow_connect_right_right (2,5,0) (1,3,0) ;
+            flow_connect_right_right (6,2,0) (4,6,0) ;
+        elseif (m=7) :
+            flow_connect_left_top (2,2,0) (4,5,0) ;
+            flow_connect_left_top (3,3,0) (5,1,0) ;
+            flow_connect_left_top (2,5,0) (1,3,0) ;
+            flow_connect_left_top (6,2,0) (4,6,0) ;
+        elseif (m=8) :
+            flow_connect_left_bottom (2,2,0) (4,5,0) ;
+            flow_connect_left_bottom (3,3,0) (5,1,0) ;
+            flow_connect_left_bottom (2,5,0) (1,3,0) ;
+            flow_connect_left_bottom (6,2,0) (4,6,0) ;
+        elseif (m=9) :
+            flow_connect_right_top (2,2,0) (4,5,0) ;
+            flow_connect_right_top (3,3,0) (5,1,0) ;
+            flow_connect_right_top (2,5,0) (1,3,0) ;
+            flow_connect_right_top (6,2,0) (4,6,0) ;
+        else :
+            flow_connect_right_bottom (2,2,0) (4,5,0) ;
+            flow_connect_right_bottom (3,3,0) (5,1,0) ;
+            flow_connect_right_bottom (2,5,0) (1,3,0) ;
+            flow_connect_right_bottom (6,2,0) (4,6,0) ;
+        fi ;
+
+    flow_end_chart ;
+
+enddef ;
+
+def flow_show_connections =
+    for f=1 upto 10 :
+        flow_show_connection(f,f) ;
+    endfor ;
+enddef ;
+
+%D charts
+
+def flow_clip_chart(expr minx, miny, maxx, maxy) =
+    flow_cmin_x := minx ;
+    flow_cmax_x := maxx ;
+    flow_cmin_y := miny ;
+    flow_cmax_y := maxy ;
+enddef ;
+
+def flow_begin_chart(expr n, maxx, maxy) =
+    flow_new_chart ;
+    flow_chart_figure := n ;
+    flow_chart_scale := 1 ;
+    if flow_chart_figure>0:
+        beginfig(flow_chart_figure) ;
+    fi ;
+    flow_initialize_grid (maxx, maxy) ;
+    bboxmargin := 0 ;
+    flow_cmin_x := 1 ;
+    flow_cmax_x := maxx ;
+    flow_cmin_y := 1 ;
+    flow_cmax_y := maxy ;
+enddef ;
+
+def flow_end_chart =
+    begingroup ;
+    save p ; path p ;
+    flow_flush_shapes ;
+    flow_flush_connections ;
+    flow_flush_pictures ;
+    flow_cmin_x := flow_cmin_x ;
+    flow_cmax_x := flow_cmin_x+flow_cmax_x ;
+    flow_cmin_y := flow_cmin_y-1 ;
+    flow_cmax_y := flow_cmin_y+flow_cmax_y ;
+    if flow_reverse_y :
+        flow_cmin_y := flow_y_pos(flow_cmin_y) ;
+        flow_cmax_y := flow_y_pos(flow_cmax_y) ;
+    fi ;
+    p := (((flow_cmin_x,flow_cmin_y)--(flow_cmax_x,flow_cmin_y)--
+         (flow_cmax_x,flow_cmax_y)--(flow_cmin_x,flow_cmax_y)--cycle))
+       flow_scaled_to_grid ;
+    %draw p withcolor red ;
+    p := p enlarged flow_chart_offset ;
+    clip currentpicture to p ;
+    setbounds currentpicture to p ;
+    endgroup ;
+    currentpicture := currentpicture scaled flow_chart_scale ;
+    if flow_chart_figure>0:
+        endfig ;
+    fi ;
+enddef ;
+
+def flow_new_shape(expr x, y, n) =
+    if known n :
+        if (x>0) and (x<=flow_max_x) and (y>0) and (y<=flow_max_y) :
+            flow_draw_shape(x,y,some_shape_path(n), flow_shape_width/flow_grid_width, flow_shape_height/flow_grid_height) ;
+        else :
+            message ("shape outside grid ignored") ;
+        fi ;
+    else :
+        message ("shape not known" ) ;
+    fi ;
+enddef ;
+
+def flow_begin_sub_chart =
+    begingroup ;
+    save    flow_shape_line_width, flow_connection_line_width ;
+    save    flow_shape_line_color, flow_shape_fill_color, flow_connection_line_color ;
+    color   flow_shape_line_color, flow_shape_fill_color, flow_connection_line_color ;
+    save    flow_smooth, flow_arrowtip, flow_dashline, flow_peepshape ;
+    boolean flow_smooth, flow_arrowtip, flow_dashline, flow_peepshape ;
+enddef ;
+
+def flow_end_sub_chart =
+    endgroup ;
+enddef ;
+
diff --git a/metapost/context/base/mp-shap.mp b/metapost/context/base/mp-shap.mp
index 0f5fe431d..785231278 100644
--- a/metapost/context/base/mp-shap.mp
+++ b/metapost/context/base/mp-shap.mp
@@ -1,6 +1,6 @@
 %D \module
 %D   [       file=mp-shap.mp,
-%D        version=2000.05.31, 
+%D        version=2000.05.31,
 %D          title=\CONTEXT\ \METAPOST\ graphics,
 %D       subtitle=shapes,
 %D         author=Hans Hagen,
@@ -8,300 +8,199 @@
 %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_shap : endinput         ; fi ; 
-
-boolean context_shap ; context_shap := true ; 
+%C therefore copyrighted by \PRAGMA. See licen-en.pdf for
+%C details.
+
+if unknown context_tool :    input mp-tool ; fi ;
+if   known context_shap : endinput         ; fi ;
+
+boolean context_shap ; context_shap := true ;
+
+path predefined_shapes[] ;
+
+begingroup ;
+
+save xradius, yradius, xxradius, yyradius ;
+save ll, lr, ur, ul, llx, lly, lrx, lry, urx, ury, ulx, uly, llxx, llyy, lrxx, lryy, urxx, uryy, ulxx, ulyy, lc, rc, tc, bc ;
+
+numeric xradius, yradius, xxradius, yyradius ;
+pair ll, lr, ur, ul, llx, lly, lrx, lry, urx, ury, ulx, uly, llxx, llyy, lrxx, lryy, urxx, uryy, ulxx, ulyy, lc, rc, tc, bc ;
+
+xradius  := .15 ;
+yradius  := .15 ;
+xxradius := .10 ;
+yyradius := .10 ;
+
+ll       := llcorner (unitsquare shifted (-.5,-.5)) ;
+lr       := lrcorner (unitsquare shifted (-.5,-.5)) ;
+ur       := urcorner (unitsquare shifted (-.5,-.5)) ;
+ul       := ulcorner (unitsquare shifted (-.5,-.5)) ;
+
+llx      := ll shifted (xradius,0)  ;
+lly      := ll shifted (0,yradius)  ;
+
+lrx      := lr shifted (-xradius,0) ;
+lry      := lr shifted (0,yradius)  ;
+
+urx      := ur shifted (-xradius,0) ;
+ury      := ur shifted (0,-yradius) ;
+
+ulx      := ul shifted (xradius,0)  ;
+uly      := ul shifted (0,-yradius) ;
+
+llxx     := ll shifted (xxradius,0)  ;
+llyy     := ll shifted (0,yyradius)  ;
+
+lrxx     := lr shifted (-xxradius,0) ;
+lryy     := lr shifted (0,yyradius)  ;
+
+urxx     := ur shifted (-xxradius,0) ;
+uryy     := ur shifted (0,-yyradius) ;
+
+ulxx     := ul shifted (xxradius,0)  ;
+ulyy     := ul shifted (0,-yyradius) ;
+
+lc       := ll shifted (0,.5) ;
+rc       := lr shifted (0,.5) ;
+tc       := ul shifted (.5,0) ;
+bc       := ll shifted (.5,0) ;
+
+predefined_shapes[ 0] := (origin--cycle) ;
+predefined_shapes[ 5] := (llx--lrx{right}...rc...{left}urx--ulx{left}...lc...{right}cycle) ;
+predefined_shapes[ 6] := (ll--lrx{right}...rc...{left}urx--ul--cycle) ;
+predefined_shapes[ 7] := (ll--lrx{right}...rc...{left}urx--ul--cycle) rotatedaround(origin,180) ;
+predefined_shapes[ 8] := (lr--ury{up}...tc...{down}uly--ll--cycle) ;
+predefined_shapes[ 9] := (lr--ury{up}...tc...{down}uly--ll--cycle) rotatedaround(origin,180) ;
+predefined_shapes[10] := (ll--lr--ur--ul--ll--ur--ul--ll--cycle) ;
+predefined_shapes[11] := (ll--lr--ur--ul--ll--lr--ul--ll--cycle) ;
+predefined_shapes[12] := (ll--lrx--ur--ulx--cycle) ;
+predefined_shapes[13] := (llx--lr--urx--ul--cycle) ;
+predefined_shapes[14] := (lly--bc--lry--ury--tc--uly--cycle) ;
+predefined_shapes[15] := (llx--lrx--rc--urx--ulx--lc--cycle) ;
+predefined_shapes[16] := (ll--lrx--rc--urx--ul--cycle) ;
+predefined_shapes[17] := (ll--lrx--rc--urx--ul--cycle) rotatedaround(origin,180) ;
+predefined_shapes[18] := (lr--ury--tc--uly--ll--cycle) ;
+predefined_shapes[19] := (lr--ury--tc--uly--ll--cycle) rotatedaround(origin,180) ;
+predefined_shapes[20] := (ll--lr--ur--ul--ll--llxx--ulxx--ul--ll--lr--ur--urxx--lrxx--cycle) ;
+predefined_shapes[21] := (ul--ll--lr--ur--ul--ulyy--uryy--ur--ul--ll--lr--lryy--llyy--cycle) ;
+predefined_shapes[22] := (ll--lrx--lry--ur--ulx--uly--cycle) ;
+predefined_shapes[23] := (llx--lr--ury--urx--ul--lly--cycle) ;
+predefined_shapes[24] := (ll--lr--ur--ul--cycle) ;
+predefined_shapes[25] := (llx--lrx--lry--ury--urx--ulx--uly--lly--cycle) ;
+predefined_shapes[26] := (ll--lrx--lry--ur--ul--cycle) ;
+predefined_shapes[27] := (ll--lr--ury--urx--ul--cycle) rotatedaround(origin,180) ;
+predefined_shapes[28] := (ll--lr--ury--urx--ul--cycle) ;
+predefined_shapes[29] := (ll--lrx--lry--ur--ul--cycle) rotatedaround(origin,180) ;
+predefined_shapes[30] := (bc{right}...{up}rc...tc{left}...{down}lc...{right}bc & bc--tc & tc{left}..{down}lc & lc--rc & rc{up}..tc{left}...{down}lc...{right}bc & cycle) rotated 45;
+predefined_shapes[31] := (bc{right}...{up}rc...tc{left}...{down}lc...{right}bc & bc--tc & tc{left}..{down}lc & lc--rc & rc{up}..tc{left}...{down}lc...{right}bc & cycle) ;
+predefined_shapes[32] := (ll{right}...{right}lry--ur--ul--ll--cycle) ;
+predefined_shapes[33] := (ll{right}...{right}lry--ur--ul--ll--cycle--ul--ulx--ulx shifted(0,yyradius)--ur shifted(yyradius,yyradius)--lry shifted(yyradius,yyradius)--lry shifted(0,yyradius)--ur--ul--cycle ) ;
+predefined_shapes[34] := (uly..tc..ury & ury..tc shifted (0,-2yradius)..uly & uly--lly & lly..bc..lry & lry--ury & ury..tc shifted (0,-2yradius)..uly & cycle ) ;
+predefined_shapes[35] := (bc{right}...rc{up}...tc{left}...lc{down}...cycle) ;
+predefined_shapes[36] := (ul--tc{right}..rc{down}..{left}bc--ll & ll..(xpart llx, ypart lc)..ul & cycle) ;
+predefined_shapes[37] := (ul--tc{right}..rc{down}..{left}bc--ll & ll..(xpart llx, ypart lc)..ul & cycle) rotatedaround(origin,180) ;
+predefined_shapes[38] := (ll--lc{up}..tc{right}..{down}rc--lr & lr..(xpart bc, ypart lly)..ll & cycle) ;
+predefined_shapes[39] := (ll--lc{up}..tc{right}..{down}rc--lr & lr..(xpart bc, ypart lly)..ll & cycle) rotatedaround(origin,180) ;
+predefined_shapes[40] := (ll--lr--ur--ul--ll--ur--ul--ll--lr--ul--ll--cycle) ;
+predefined_shapes[41] := (ll--lr--ur--ul--ll--lr--rc--lc--ll--bc--tc--ul--ll & cycle) ;
+predefined_shapes[42] := (ll--lr--origin shifted (+epsilon,0)--ur--ul--origin shifted (-epsilon,0)--cycle) ;
+predefined_shapes[43] := (ll--ul--origin shifted (0,+epsilon)--ur--lr--origin shifted (0,-epsilon)--cycle) ;
+predefined_shapes[45] := (bc--rc--tc--lc--cycle) ;
+predefined_shapes[46] := (ll--ul--rc--cycle) ;
+predefined_shapes[47] := (ll--ul--rc--cycle) rotatedaround(origin,180) ;
+predefined_shapes[48] := (ul--ur--bc--cycle) rotatedaround(origin,180) ;
+predefined_shapes[49] := (ul--ur--bc--cycle) ;
+predefined_shapes[56] := (ll--lry--ury--ul--cycle) ;
+predefined_shapes[57] := (ll--lry--ury--ul--cycle) rotatedaround(origin,180) ;
+predefined_shapes[58] := (ll--ulx--urx--lr--cycle) ;
+predefined_shapes[59] := (ll--ulx--urx--lr--cycle) rotatedaround(origin,180);
+predefined_shapes[66] := (rc--origin shifted ( epsilon,0) --cycle & rc--origin--cycle ) ;
+predefined_shapes[67] := (lc--origin shifted (-epsilon,0) --cycle & lc--origin--cycle ) ;
+predefined_shapes[68] := (tc--origin shifted (0, epsilon) --cycle & tc--origin--cycle ) ;
+predefined_shapes[69] := (bc--origin shifted (0,-epsilon) --cycle & bc--origin--cycle ) ;
+predefined_shapes[75] := (lly--lry--ury--uly--cycle) rotatedaround(origin,180) ;
+predefined_shapes[76] := (ll--lr--ur--uly--cycle) rotatedaround(origin,180) ;
+predefined_shapes[77] := (ll--lr--ury--ul--cycle) rotatedaround(origin,180) ;
+predefined_shapes[78] := (lly--lr--ur--ul--cycle) rotatedaround(origin,180) ;
+predefined_shapes[79] := (ll--lry--ur--ul--cycle) rotatedaround(origin,180) ;
+
+numeric predefined_shapes_xradius  ; predefined_shapes_xradius  := xradius  ;
+numeric predefined_shapes_yradius  ; predefined_shapes_yradius  := yradius  ;
+numeric predefined_shapes_xxradius ; predefined_shapes_xxradius := xxradius ;
+numeric predefined_shapes_yyradius ; predefined_shapes_yyradius := yyradius ;
+
+endgroup ;
 
 vardef some_shape_path (expr type) =
+    if known predefined_shapes[type] : predefined_shapes[type] else : predefined_shapes[0] fi
+enddef ;
 
+def some_shape (expr shape_type, shape_width, shape_height, shape_linewidth, shape_linecolor, shape_fillcolor) =
     begingroup ;
-
-    save border, xradius, yradius, 
-         normal, mirror, rotate, 
-         lc, rc, tc, bc, ll, lr, ur, ul, 
-         llx, lrx, urx, ulx, lly, lry, ury, uly ;
-
-    path border ;
-
-    xradius := .15 ; xxradius := .10 ; 
-    yradius := .15 ; yyradius := .10 ; 
-
-    pair ll ; ll := llcorner (unitsquare shifted (-.5,-.5)) ;
-    pair lr ; lr := lrcorner (unitsquare shifted (-.5,-.5)) ;
-    pair ur ; ur := urcorner (unitsquare shifted (-.5,-.5)) ;
-    pair ul ; ul := ulcorner (unitsquare shifted (-.5,-.5)) ;
-
-    pair llx ; llx := ll shifted (xradius,0)  ;
-    pair lly ; lly := ll shifted (0,yradius)  ;
-
-    pair lrx ; lrx := lr shifted (-xradius,0) ;
-    pair lry ; lry := lr shifted (0,yradius)  ;
-
-    pair urx ; urx := ur shifted (-xradius,0) ;
-    pair ury ; ury := ur shifted (0,-yradius) ;
-
-    pair ulx ; ulx := ul shifted (xradius,0)  ;
-    pair uly ; uly := ul shifted (0,-yradius) ;
-
-    pair llxx ; llxx := ll shifted (xxradius,0)  ;
-    pair llyy ; llyy := ll shifted (0,yyradius)  ;
-
-    pair lrxx ; lrxx := lr shifted (-xxradius,0) ;
-    pair lryy ; lryy := lr shifted (0,yyradius)  ;
-
-    pair urxx ; urxx := ur shifted (-xxradius,0) ;
-    pair uryy ; uryy := ur shifted (0,-yyradius) ;
-
-    pair ulxx ; ulxx := ul shifted (xxradius,0)  ;
-    pair ulyy ; ulyy := ul shifted (0,-yyradius) ;
-
-    pair lc  ; lc  := ll shifted (0,.5) ;
-    pair rc  ; rc  := lr shifted (0,.5) ;
-    pair tc  ; tc  := ul shifted (.5,0) ;
-    pair bc  ; bc  := ll shifted (.5,0) ;
-
-    def mirror (expr p) =
-      p rotatedaround(origin,180)
-    enddef ;
-
-    def normal (expr p ) =
-      p
-    enddef ;
-
-    def rotate (expr p) = 
-      p rotated 45 
-    enddef ; 
-
-    if     type= 0 :
-      border := normal (origin--cycle) ;
-
-    elseif type= 5 :
-      border := normal (llx--lrx{right}...rc...{left}urx--ulx{left}...lc...{right}cycle) ;
-    elseif type= 6 :
-      border := normal (ll--lrx{right}...rc...{left}urx--ul--cycle) ;
-    elseif type= 7 :
-      border := mirror (ll--lrx{right}...rc...{left}urx--ul--cycle) ;
-    elseif type= 8 :
-      border := normal (lr--ury{up}...tc...{down}uly--ll--cycle) ;
-    elseif type= 9 :
-      border := mirror (lr--ury{up}...tc...{down}uly--ll--cycle) ;
-    elseif type=10 :
-      border := normal (ll--lr--ur--ul--ll--ur--ul--ll--cycle) ; 
-    elseif type=11 :
-      border := normal (ll--lr--ur--ul--ll--lr--ul--ll--cycle) ; 
-    elseif type=12 :
-      border := normal (ll--lrx--ur--ulx--cycle) ;
-    elseif type=13 :
-      border := normal (llx--lr--urx--ul--cycle) ;
-    elseif type=14 :
-      border := normal (lly--bc--lry--ury--tc--uly--cycle) ;
-    elseif type=15 :
-      border := normal (llx--lrx--rc--urx--ulx--lc--cycle) ;
-    elseif type=16 :
-      border := normal (ll--lrx--rc--urx--ul--cycle) ;
-    elseif type=17 :
-      border := mirror (ll--lrx--rc--urx--ul--cycle) ;
-    elseif type=18 :
-      border := normal (lr--ury--tc--uly--ll--cycle) ;
-    elseif type=19 :
-      border := mirror (lr--ury--tc--uly--ll--cycle) ;
-    elseif type=20 :
-      border := normal (ll--lr--ur--ul--ll--llxx--ulxx--ul--ll--
-                        lr--ur--urxx--lrxx--cycle) ;
-    elseif type=21 :
-      border := normal (ul--ll--lr--ur--ul--ulyy--uryy--ur--ul--
-                        ll--lr--lryy--llyy--cycle) ;
-    elseif type=22 :
-      border := normal (ll--lrx--lry--ur--ulx--uly--cycle) ;
-    elseif type=23 :
-      border := normal (llx--lr--ury--urx--ul--lly--cycle) ;
-    elseif type=24 :
-      border := normal (ll--lr--ur--ul--cycle) ;
-    elseif type=25 :
-      border := normal (llx--lrx--lry--ury--urx--ulx--uly--lly--cycle) ;
-    elseif type=26 :
-      border := normal (ll--lrx--lry--ur--ul--cycle) ;
-    elseif type=27 :
-      border := mirror (ll--lr--ury--urx--ul--cycle) ;
-    elseif type=28 :
-      border := normal (ll--lr--ury--urx--ul--cycle) ;
-    elseif type=29 :
-      border := mirror (ll--lrx--lry--ur--ul--cycle) ;
-    elseif type=30 :
-      border := rotate (bc{right}...{up}rc...tc{left}...{down}lc...{right}bc &
-                        bc--tc & tc{left}..{down}lc & lc--rc & 
-                        rc{up}..tc{left}...{down}lc...{right}bc & cycle) ;
-    elseif type=31 :
-      border := normal (bc{right}...{up}rc...tc{left}...{down}lc...{right}bc &
-                        bc--tc & tc{left}..{down}lc & lc--rc & 
-                        rc{up}..tc{left}...{down}lc...{right}bc & cycle) ;
-    elseif type=32 :
-      border := normal (ll{right}...{right}lry--ur--ul--ll--cycle) ;
-    elseif type=33 :
-      border := normal (ll{right}...{right}lry--ur--ul--ll--cycle
-                        --ul--ulx--ulx shifted(0,yyradius)
-                        --ur shifted(yyradius,yyradius)
-                        --lry shifted(yyradius,yyradius)
-                        --lry shifted(0,yyradius)
-                        --ur--ul--cycle ) ;
-    elseif type=34 :
-      border := normal (uly..tc..ury & 
-                        ury..tc shifted (0,-2yradius)..uly & 
-                        uly--lly &
-                        lly..bc..lry &
-                        lry--ury & 
-                        ury..tc shifted (0,-2yradius)..uly & cycle ) ;  
-    elseif type=35 :
-      border := normal (bc{right}...rc{up}...tc{left}...lc{down}...cycle) ;
-    elseif type=36 :
-      border := normal (ul--tc{right}..rc{down}..{left}bc--ll & 
-                        ll..(xpart llx, ypart lc)..ul & cycle) ;
-    elseif type=37 :
-      border := mirror (ul--tc{right}..rc{down}..{left}bc--ll & 
-                        ll..(xpart llx, ypart lc)..ul & cycle) ;
-    elseif type=38 :
-      border := normal (ll--lc{up}..tc{right}..{down}rc--lr & 
-                        lr..(xpart bc, ypart lly)..ll & cycle) ;
-    elseif type=39 :
-      border := mirror (ll--lc{up}..tc{right}..{down}rc--lr & 
-                        lr..(xpart bc, ypart lly)..ll & cycle) ;
-    elseif type=40 :
-      border := normal (ll--lr--ur--ul--ll--ur--ul--ll--lr--ul--ll--cycle) ; 
-    elseif type=41 :
-      border := normal (ll--lr--ur--ul--ll--lr--rc--lc--ll--bc--tc--ul--ll & cycle) ; 
-    elseif type=42 :
-      border := normal (ll--lr--origin shifted (+epsilon,0)--
-                        ur--ul--origin shifted (-epsilon,0)--cycle) ; 
-    elseif type=43 :
-      border := normal (ll--ul--origin shifted (0,+epsilon)--
-                        ur--lr--origin shifted (0,-epsilon)--cycle) ; 
-    elseif type=45 :
-      border := normal (bc--rc--tc--lc--cycle) ;
-    elseif type=46 :
-      border := normal (ll--ul--rc--cycle) ;
-    elseif type=47 :
-      border := mirror (ll--ul--rc--cycle) ;
-    elseif type=48 :
-      border := mirror (ul--ur--bc--cycle) ;
-    elseif type=49 :
-      border := normal (ul--ur--bc--cycle) ;
-
-    elseif type=56 :
-      border := normal (ll--lry--ury--ul--cycle) ;
-    elseif type=57 :
-      border := mirror (ll--lry--ury--ul--cycle) ;
-    elseif type=58 :
-      border := normal (ll--ulx--urx--lr--cycle) ;
-    elseif type=59 :
-      border := mirror (ll--ulx--urx--lr--cycle) ;
-
-    elseif type=61 : 
-      border := normal (fullcircle scaled (1.5*yradius) xscaled (grid_height/grid_width)) ;
-    elseif type=62 : 
-      border := normal (fullcircle scaled (2.0*yradius) xscaled (grid_height/grid_width)) ;
-
-    elseif type=66 :
-      border := normal (rc--origin shifted ( epsilon,0) --cycle & 
-                        rc--origin                      --cycle ) ;
-    elseif type=67 :
-      border := normal (lc--origin shifted (-epsilon,0) --cycle & 
-                        lc--origin                      --cycle ) ;
-    elseif type=68 :
-      border := normal (tc--origin shifted (0, epsilon) --cycle & 
-                        tc--origin                      --cycle ) ;
-    elseif type=69 :
-      border := normal (bc--origin shifted (0,-epsilon) --cycle & 
-                        bc--origin                      --cycle ) ;
-
-    elseif type=75 : 
-      border := mirror (lly--lry--ury--uly--cycle) ;
-    elseif type=76 : 
-      border := mirror (ll--lr--ur--uly--cycle) ;
-    elseif type=77 : 
-      border := mirror (ll--lr--ury--ul--cycle) ;
-    elseif type=78 : 
-      border := mirror (lly--lr--ur--ul--cycle) ;
-    elseif type=79 : 
-      border := mirror (ll--lry--ur--ul--cycle) ;
-
-    else :
-      border := normal (origin--cycle) ;
-     %border := normal (ll--lr--ur--ul--cycle) ;
-    fi ;
-
-    border
-
-    endgroup
-
-enddef;
-
-def some_shape ( expr shape_type      , 
-                      shape_width     , 
-                      shape_height    , 
-                      shape_linewidth , 
-                      shape_linecolor ,     
-                      shape_fillcolor ) = 
-
-  path p ; p := 
-    some_shape_path (shape_type) 
-      xscaled shape_width 
-      yscaled shape_height ; 
-
-  pickup pencircle scaled shape_linewidth ;
-
-  fill p withcolor shape_fillcolor ; 
-  draw p withcolor shape_linecolor ; 
- 
-enddef ; 
+        save p ; path p ;
+        p := some_shape_path (shape_type) xscaled shape_width yscaled shape_height ;
+        pickup pencircle scaled shape_linewidth ;
+        fill p withcolor shape_fillcolor ;
+        draw p withcolor shape_linecolor ;
+    endgroup ;
+enddef ;
 
 vardef drawshape (expr t, p, lw, lc, fc) =
-  save pp ; 
-  if t>1 : % normal shape
-    path pp ;
-    pp := some_shape_path(t) xyscaled(bbwidth(p), bbheight(p)) shifted center p ;
-    fill pp withcolor fc ;
-    draw pp withpen pencircle scaled lw withcolor lc ;
-  elseif t=1 : % background only 
-    path pp ; 
-    pp := fullsquare xyscaled(bbwidth(p), bbheight(p)) shifted center p ;
-    fill pp withcolor fc ;
-  else : % dimensions only 
-    picture pp ; pp := nullpicture ; 
-    setbounds pp to fullsquare xyscaled(bbwidth(p), bbheight(p)) shifted center p ;
-    draw pp ; 
-  fi ; 
+    save pp ;
+    if t>1 : % normal shape
+        path pp ;
+        pp := some_shape_path(t) xyscaled(bbwidth(p), bbheight(p)) shifted center p ;
+        fill pp withcolor fc ;
+        draw pp withpen pencircle scaled lw withcolor lc ;
+    elseif t=1 : % background only
+        path pp ;
+        pp := fullsquare xyscaled(bbwidth(p), bbheight(p)) shifted center p ;
+        fill pp withcolor fc ;
+    else : % dimensions only
+        picture pp ; pp := nullpicture ;
+        setbounds pp to fullsquare xyscaled(bbwidth(p), bbheight(p)) shifted center p ;
+        draw pp ;
+    fi ;
 enddef ;
 
 vardef drawline (expr t, p, lw, lc) =
-  if (t>0) and (length(p)>1) :
-    saveoptions ;
-    drawoptions(withpen pencircle scaled lw withcolor lc) ;
-    draw p ;
-    if     t =  1 : 
-      draw arrowheadonpath(p,1) ;
-    elseif t =  2 :
-      draw arrowheadonpath(reverse p,1) ;
-    elseif t =  3 :
-      for $ = p,reverse p : draw arrowheadonpath($,1) ; endfor ; 
-    elseif t = 11 :
-      draw arrowheadonpath(p,1/2) ;
-    elseif t = 12 :
-      draw arrowheadonpath(reverse p,1/2) ;
-    elseif t = 13 :
-      for $=p,reverse p : draw arrowheadonpath($,1) ; endfor ;
-      for $=p,reverse p : draw arrowheadonpath($,3/4) ; endfor ;
-    elseif t = 21 :
-      for $=1/5,1/2,4/5 : draw arrowheadonpath(p,$) ; endfor ;
-    elseif t = 22 :
-      for $=1/5,1/2,4/5 : draw arrowheadonpath(reverse p,$) ; endfor ;
-    elseif t = 23 :
-      for $=p,reverse p : draw arrowheadonpath($,1/4) ; endfor ;
+    if (t>0) and (length(p)>1) :
+        saveoptions ;
+        drawoptions(withpen pencircle scaled lw withcolor lc) ;
+        draw p ;
+        if     t =  1 :
+            draw arrowheadonpath(p,1) ;
+        elseif t =  2 :
+            draw arrowheadonpath(reverse p,1) ;
+        elseif t =  3 :
+            for $ = p,reverse p :
+                draw arrowheadonpath($,1) ;
+            endfor ;
+        elseif t = 11 :
+            draw arrowheadonpath(p,1/2) ;
+        elseif t = 12 :
+            draw arrowheadonpath(reverse p,1/2) ;
+        elseif t = 13 :
+            for $=p,reverse p :
+                draw arrowheadonpath($,1) ;
+            endfor ;
+            for $=p,reverse p :
+                draw arrowheadonpath($,3/4) ;
+            endfor ;
+        elseif t = 21 :
+            for $=1/5,1/2,4/5 :
+                draw arrowheadonpath(p,$) ;
+            endfor ;
+        elseif t = 22 :
+            for $=1/5,1/2,4/5 :
+                draw arrowheadonpath(reverse p,$) ;
+            endfor ;
+        elseif t = 23 :
+            for $=p,reverse p :
+                draw arrowheadonpath($,1/4) ;
+            endfor ;
+        fi ;
     fi ;
-  fi ; 
 enddef ;
 
-endinput ;  
+endinput ;