2017-05-14 19:15:00

20 files changed, 2338 insertions, 558 deletions

diff --git a/metapost/context/base/mpii/mp-core.mpii b/metapost/context/base/mpii/mp-core.mpii
index 33e9b386e..79b5d2ab7 100644
--- a/metapost/context/base/mpii/mp-core.mpii
+++ b/metapost/context/base/mpii/mp-core.mpii
@@ -897,7 +897,7 @@ enddef ;
 
       save_multipar (i,3,multipar) ;
 
-    elseif multi_column_first_page_hack and ((nxy[fpos]=RealPageNumber) and (nxy[tpos]>=RealPageNumber) : % and (NOfTextColumns>1)) :
+    elseif multi_column_first_page_hack and ((nxy[fpos]=RealPageNumber) and (nxy[tpos]>=RealPageNumber)) : % and (NOfTextColumns>1)) :
 
       save_multipar (i,2,multipar) ;
 
diff --git a/metapost/context/base/mpii/mp-symb.mpii b/metapost/context/base/mpii/mp-symb.mpii
new file mode 100644
index 000000000..40681adf1
--- /dev/null
+++ b/metapost/context/base/mpii/mp-symb.mpii
@@ -0,0 +1,351 @@
+%D \module
+%D   [       file=mp-symb.mp,
+%D        version=very old,
+%D          title=\CONTEXT\ \METAPOST\ graphics,
+%D       subtitle=navigation symbol macros,
+%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 mreadme.pdf for
+%C details.
+
+%D Instead of these symbols, you can use the \type {contnav}
+%D font by Taco Hoekwater that is derived form this file.
+
+u  := 3;
+h  := 5u;
+wt := 5u;
+wb := .25wt;
+o  := .1u;
+pw := .5u;
+
+drawoptions (withpen pencircle scaled pw);
+
+path lefttriangle, righttriangle, sublefttriangle, subrighttriangle;
+
+pair s ; s = (2wb,0) ;
+
+x1t = x2t = 0;
+x3t = wt;
+y3t = .5h;
+z1t-z2t = (z3t-z2t) rotated 60;
+
+z4t = (z2t--z3t) intersectionpoint ((z1t--z2t) shifted s) ;
+z5t = (z3t--z1t) intersectionpoint ((z1t--z2t) shifted s) ;
+
+righttriangle = z1t--z2t--z3t--cycle;
+lefttriangle = righttriangle rotatedaround((0,.5h), 180) shifted (wt,0);
+
+subrighttriangle = z4t--((z2t--z3t--z1t) shifted s)--z5t ;
+sublefttriangle  = subrighttriangle rotatedaround((0,.5h), 180) shifted (wt,0);
+
+path sidebar;
+
+x1b = x4b = 0;
+x2b = x3b = wb;
+y1b = y2b = y1t;
+y3b = y4b = y2t;
+
+sidebar = z1b--z2b--z3b--z4b--cycle;
+
+path midbar, onebar, twobar;
+
+hh = abs(y1t-y2t);
+
+%midbar := unitsquare scaled 2hh/3;
+midbar := unitsquare scaled hh;
+onebar := unitsquare xscaled (hh/3) yscaled hh;
+twobar := onebar;
+
+def prepareglyph =
+  drawoptions (withpen pencircle scaled .5u);
+enddef;
+
+def finishglyph =
+  set_outer_boundingbox currentpicture;
+  bboxmargin := o;
+  setbounds currentpicture to bbox currentpicture;
+%  draw boundingbox currentpicture withcolor red withpen pencircle scaled 1;
+enddef;
+
+beginfig  (1);
+  prepareglyph;
+  fill lefttriangle;
+  draw lefttriangle;  % draw gets the bbox right, filldraw doesn't
+  finishglyph;
+endfig;
+
+beginfig  (2);
+  prepareglyph;
+  fill righttriangle;
+  draw righttriangle;
+  finishglyph;
+endfig;
+
+beginfig  (3);
+  prepareglyph;
+  fill sidebar;
+  draw sidebar;
+  fill lefttriangle shifted (.5s);
+  draw lefttriangle shifted (.5s);
+  finishglyph;
+endfig;
+
+beginfig  (4);
+  prepareglyph;
+  fill righttriangle;
+  draw righttriangle;
+  fill sidebar shifted (wt,0);
+  draw sidebar shifted (wt,0);
+  finishglyph;
+endfig;
+
+beginfig  (5);
+  prepareglyph;
+  fill lefttriangle;
+  draw lefttriangle;
+  fill lefttriangle shifted s;
+  draw lefttriangle shifted s;
+  finishglyph;
+endfig;
+
+beginfig  (6);
+  prepareglyph;
+  fill righttriangle;
+  draw righttriangle;
+  fill righttriangle shifted s;
+  draw righttriangle shifted s;
+  finishglyph;
+endfig;
+
+beginfig  (7);
+  prepareglyph;
+  fill midbar;
+  draw midbar;
+  finishglyph;
+endfig;
+
+beginfig  (8);
+  prepareglyph;
+  fill onebar;
+  draw onebar;
+  finishglyph;
+endfig;
+
+beginfig  (9);
+  prepareglyph;
+  fill twobar;
+  draw twobar;
+  fill twobar shifted (pw+hh/2,0);
+  draw twobar shifted (pw+hh/2,0);
+  finishglyph;
+endfig;
+
+beginfig(101);
+  prepareglyph;
+  draw lefttriangle;
+  finishglyph;
+endfig;
+
+beginfig(102);
+  prepareglyph;
+  draw righttriangle;
+  finishglyph;
+endfig;
+
+beginfig(103);
+  prepareglyph;
+  draw sidebar;
+  draw lefttriangle shifted (.5s);
+  finishglyph;
+endfig;
+
+beginfig(104);
+  prepareglyph;
+  draw righttriangle;
+  draw sidebar shifted (wt,0);
+  finishglyph;
+endfig;
+
+beginfig(105);
+  prepareglyph;
+  draw lefttriangle;
+  draw lefttriangle shifted s;
+  finishglyph;
+endfig;
+
+beginfig(106);
+  prepareglyph;
+  draw righttriangle;
+  draw righttriangle shifted s;
+  finishglyph;
+endfig;
+
+beginfig(107);
+  prepareglyph;
+  draw midbar;
+  finishglyph;
+endfig;
+
+beginfig(108);
+  prepareglyph;
+  draw onebar;
+  finishglyph;
+endfig;
+
+beginfig(109);
+  prepareglyph;
+  draw twobar;
+  draw twobar shifted (pw+hh/2,0);
+  finishglyph;
+endfig;
+
+beginfig(201);
+  prepareglyph;
+  draw lefttriangle;
+  finishglyph;
+endfig;
+
+beginfig(202);
+  prepareglyph;
+  draw righttriangle;
+  finishglyph;
+endfig;
+
+beginfig(203);
+  prepareglyph;
+  draw sidebar;
+  draw lefttriangle shifted (.5s);
+  finishglyph;
+endfig;
+
+beginfig(204);
+  prepareglyph;
+  draw righttriangle;
+  draw sidebar shifted (wt,0);
+  finishglyph;
+endfig;
+
+beginfig(205);
+  prepareglyph;
+  draw sublefttriangle shifted s;
+  draw lefttriangle shifted s;
+  finishglyph;
+endfig;
+
+beginfig(206);
+  prepareglyph;
+  draw subrighttriangle;
+  draw righttriangle;
+  finishglyph;
+endfig;
+
+beginfig(207);
+  prepareglyph;
+  draw midbar;
+  finishglyph;
+endfig;
+
+beginfig(208);
+  prepareglyph;
+  draw onebar;
+  finishglyph;
+endfig;
+
+beginfig(209);
+  prepareglyph;
+  draw twobar;
+  draw twobar shifted (pw+hh/2,0);
+  finishglyph;
+endfig;
+
+
+beginfig(999);
+
+picture collection []  ;
+
+prepareglyph ;
+draw lefttriangle ;
+finishglyph ;
+collection[201] := currentpicture ;
+currentpicture := nullpicture ;
+
+prepareglyph ;
+draw righttriangle ;
+finishglyph ;
+collection[202] := currentpicture ;
+currentpicture := nullpicture ;
+
+prepareglyph ;
+draw sidebar ;
+draw lefttriangle shifted (.5s) ;
+finishglyph ;
+collection[203] := currentpicture ;
+currentpicture := nullpicture ;
+
+prepareglyph ;
+draw righttriangle ;
+draw sidebar shifted (wt,0) ;
+finishglyph ;
+collection[204] := currentpicture ;
+currentpicture := nullpicture ;
+
+prepareglyph ;
+draw sublefttriangle shifted s ;
+draw lefttriangle shifted s ;
+finishglyph ;
+collection[205] := currentpicture ;
+currentpicture := nullpicture ;
+
+prepareglyph ;
+draw subrighttriangle ;
+draw righttriangle ;
+finishglyph ;
+collection[206] := currentpicture ;
+currentpicture := nullpicture ;
+
+prepareglyph ;
+draw midbar ;
+finishglyph ;
+collection[207] := currentpicture ;
+currentpicture := nullpicture ;
+
+prepareglyph ;
+draw onebar ;
+finishglyph ;
+collection[208] := currentpicture ;
+currentpicture := nullpicture ;
+
+prepareglyph ;
+draw twobar ;
+draw twobar shifted (pw+hh/2,0) ;
+finishglyph ;
+collection[209] := currentpicture ;
+currentpicture := nullpicture ;
+
+for i=201 upto 209 :
+  collection[i] := collection[i] shifted - center collection[i] ;
+endfor ;
+
+addto currentpicture also collection[205] shifted (   0,   0)
+  withcolor (.3,.4,.5) ;
+addto currentpicture also collection[202] shifted (   0,1.5h)
+  withcolor (.5,.6,.7) ;
+addto currentpicture also collection[201] shifted (1.5h,   0)
+  withcolor (.6,.7,.8) ;
+addto currentpicture also collection[206] shifted (1.5h,1.5h)
+  withcolor (.4,.5,.6) ;
+
+collection[210] := currentpicture ;
+currentpicture := nullpicture ;
+
+bboxmargin := .25u;
+
+fill bbox collection[210] withcolor .95(1,1,0);
+addto currentpicture also collection[210] ;
+
+endfig ;
+
+end
diff --git a/metapost/context/base/mpii/mp-tool.mpii b/metapost/context/base/mpii/mp-tool.mpii
index f476361c7..a3300f5bb 100644
--- a/metapost/context/base/mpii/mp-tool.mpii
+++ b/metapost/context/base/mpii/mp-tool.mpii
@@ -28,7 +28,9 @@ let @## = @# ;
 
 if not known mpversion : string mpversion ; mpversion := "0.641" ; fi ;
 
-newinternal metapostversion ; metapostversion := scantokens(mpversion) ;
+% newinternal metapostversion ; metapostversion := scantokens(mpversion) ;
+
+newinternal metapostversion ; metapostversion := 2.0 ;
 
 % vardef mpversiongt(expr s) =
 %     scantokens (mpversion & " > " & if numeric s : decimal s else : s fi)
@@ -2661,41 +2663,41 @@ vardef undecorated (text imagedata) text decoration =
 enddef ;
 
 
-if metapostversion < 1.770  :
-
-    vardef decorated (text imagedata) text decoration =
-        save mfun_decorated_path, currentpicture ;
-        picture mfun_decorated_path, currentpicture ;
-        currentpicture := nullpicture ;
-        imagedata ;
-        mfun_decorated_path := currentpicture ;
-        currentpicture := nullpicture ;
-        for i within mfun_decorated_path :
-            addto currentpicture
-                if stroked i :
-                    doublepath pathpart i
-                    dashed dashpart i
-                    withpen penpart i
-                    withcolor colorpart i
-                    decoration
-                elseif filled i :
-                    contour pathpart i
-                    withpen penpart i
-                    withcolor colorpart i
-                    decoration
-                elseif textual i :
-                    also i
-                    withcolor colorpart i
-                    decoration
-                else :
-                    also i
-                fi
-            ;
-        endfor ;
-        currentpicture
-    enddef ;
-
-else:
+% if metapostversion < 1.770  :
+%
+%     vardef decorated (text imagedata) text decoration =
+%         save mfun_decorated_path, currentpicture ;
+%         picture mfun_decorated_path, currentpicture ;
+%         currentpicture := nullpicture ;
+%         imagedata ;
+%         mfun_decorated_path := currentpicture ;
+%         currentpicture := nullpicture ;
+%         for i within mfun_decorated_path :
+%             addto currentpicture
+%                 if stroked i :
+%                     doublepath pathpart i
+%                     dashed dashpart i
+%                     withpen penpart i
+%                     withcolor colorpart i
+%                     decoration
+%                 elseif filled i :
+%                     contour pathpart i
+%                     withpen penpart i
+%                     withcolor colorpart i
+%                     decoration
+%                 elseif textual i :
+%                     also i
+%                     withcolor colorpart i
+%                     decoration
+%                 else :
+%                     also i
+%                 fi
+%             ;
+%         endfor ;
+%         currentpicture
+%     enddef ;
+%
+% else:
 
     vardef decorated (text imagedata) text decoration =
         save mfun_decorated_path, currentpicture ;
@@ -2735,7 +2737,7 @@ else:
         currentpicture
     enddef ;
 
-fi ;
+% fi ;
 
 vardef redecorated (text imagedata) text decoration =
     save mfun_decorated_path, currentpicture ;
diff --git a/metapost/context/base/mpiv/metafun.mpiv b/metapost/context/base/mpiv/metafun.mpiv
index b1d4f32e7..ab3fa8638 100644
--- a/metapost/context/base/mpiv/metafun.mpiv
+++ b/metapost/context/base/mpiv/metafun.mpiv
@@ -35,6 +35,8 @@ input "mp-func.mpiv" ; % under construction
 %     "mp-char.mpiv" ; % loaded on demand
 %     "mp-step.mpiv" ; % loaded on demand
 %     "mp-chem.mpiv" ; % loaded on demand
+input "mp-apos.mpiv" ;
+input "mp-abck.mpiv" ;
 
 string metafunversion ; metafunversion =
     "metafun iv"                        & " " &
diff --git a/metapost/context/base/mpiv/mp-abck.mpiv b/metapost/context/base/mpiv/mp-abck.mpiv
index abd7d8848..57c8f226b 100644
--- a/metapost/context/base/mpiv/mp-abck.mpiv
+++ b/metapost/context/base/mpiv/mp-abck.mpiv
@@ -50,17 +50,6 @@ numeric boxfilloffset    ; boxfilloffset    := 0 ;
 numeric boxgriddistance  ; boxgriddistance  := .5cm ;
 numeric boxgridshift     ; boxgridshift     := 0 ;
 
-def abck_show_path(expr p, r, c) =
-    draw p withpen pencircle scaled .5pt withcolor c ;
-    if length(p) > 2 :
-        begingroup ; save _c_ ; path _c_ ; _c_ := fullcircle scaled r ;
-        for i=0 upto length(p) if cycle p : -1 fi :
-            fill _c_ shifted point i of p withcolor white ;
-            draw _c_ shifted point i of p withpen pencircle scaled .5pt withcolor c ;
-        endfor ;
-    fi ;
-enddef ;
-
 vardef abck_draw_path(expr p) =
     if (length p > 2) and (bbwidth(p) > 1) and (bbheight(p) > 1) :
         save pp ; path pp ;
@@ -160,7 +149,7 @@ enddef ;
 
 def show_multi_pars =
     for i=1 upto nofmultipars :
-        abck_show_path(multipars[i], 6pt, .5blue) ;
+        drawpathwithpoints multipars[i] withcolor .5blue ;
     endfor ;
 enddef ;
 
@@ -267,3 +256,43 @@ enddef ;
 def anchor_box (expr n,x,y,w,h,d) =
     currentpicture := currentpicture shifted (-x,-y) ;
 enddef ;
+
+def draw_box = % for old times sake
+    draw pxy        boxlineoptions withpen pencircle scaled boxlinewidth ;
+    draw lxy -- rxy boxlineoptions withpen pencircle scaled boxgridwidth ;
+enddef ;
+
+def draw_free_region(expr width, height, depth, loffset, roffset, toffset, boffset) =
+
+    begingroup ; save b, o, l ; path b, o, l[] ; save d ;
+
+    b := fullsquare
+        xysized(width,height+depth) ;
+    o := b
+        topenlarged    toffset
+        bottomenlarged boffset
+        leftenlarged   loffset
+        rightenlarged  roffset ;
+    d := max(PaperWidth,PaperHeight) ;
+
+    fill o withcolor .5white ;
+    fill b withcolor .7white ;
+
+    interim linecap := butt ;
+
+    l[1] := topboundary    (topboundary    o leftenlarged d rightenlarged  d) ;
+    l[2] := bottomboundary (bottomboundary o leftenlarged d rightenlarged  d) ;
+    l[3] := leftboundary   (leftboundary   o topenlarged  d bottomenlarged d) ;
+    l[4] := rightboundary  (rightboundary  o topenlarged  d bottomenlarged d) ;
+
+    for i=1 upto 4 :
+        draw l[i] withpen pencircle scaled 1bp withcolor white ;
+        draw l[i] withpen pencircle scaled 1bp dashed (evenly scaled 1bp) withcolor black ;
+    endfor ;
+
+    setbounds currentpicture to b ;
+
+    endgroup ;
+
+enddef ;
+
diff --git a/metapost/context/base/mpiv/mp-asnc.mpiv b/metapost/context/base/mpiv/mp-asnc.mpiv
index 2626e4d58..fba182a64 100644
--- a/metapost/context/base/mpiv/mp-asnc.mpiv
+++ b/metapost/context/base/mpiv/mp-asnc.mpiv
@@ -13,7 +13,7 @@
 
 if known context_asnc : endinput ; fi ;
 
-boolean context_av ; context_asnc := true ;
+boolean context_asnc ; context_asnc := true ;
 
 % will be replaced
 
diff --git a/metapost/context/base/mpiv/mp-base.mpiv b/metapost/context/base/mpiv/mp-base.mpiv
index 28eb57fb8..0cc209302 100644
--- a/metapost/context/base/mpiv/mp-base.mpiv
+++ b/metapost/context/base/mpiv/mp-base.mpiv
@@ -66,8 +66,8 @@ def stop expr s =
     gobble readstring
 enddef ;
 
-warningcheck     :=1 ;
-tracinglostchars :=1 ;
+warningcheck     := 1 ;
+tracinglostchars := 1 ;
 
 def interact = % sets up to make "show" commands stop
     hide (
@@ -458,8 +458,8 @@ enddef ;
 
 % special operators
 
-vardef incr suffix $ = $:=$+1; $ enddef ;
-vardef decr suffix $ = $:=$-1; $ enddef ;
+vardef incr suffix $ = $ := $ + 1 ; $ enddef ;
+vardef decr suffix $ = $ := $ - 1 ; $ enddef ;
 
 def reflectedabout(expr w,z) = % reflects about the line w..z
     transformed
diff --git a/metapost/context/base/mpiv/mp-char.mpiv b/metapost/context/base/mpiv/mp-char.mpiv
index f604accd8..e878c2d16 100644
--- a/metapost/context/base/mpiv/mp-char.mpiv
+++ b/metapost/context/base/mpiv/mp-char.mpiv
@@ -678,14 +678,14 @@ vardef flow_valid_connection (expr xfrom, yfrom, xto, yto) =
             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 ( ( (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 ;
+%                     fi ;
                 endfor ;
             endfor ;
             % if not ok: message("crossing") ; fi ;
@@ -944,20 +944,27 @@ def flow_connect_bottom_right (expr n) (expr xfrom,yfrom,zfrom) (expr xto,yto,zt
 enddef ;
 
 def flow_draw_test_shape(expr x, y) =
-    flow_draw_shape(x,y,fullcircle, .7, .7) ;
+    flow_draw_shape(x,y,fullcircle,flow_shape_width/flow_grid_width,flow_shape_height/flow_grid_height) ;
 enddef ;
 
 def flow_draw_test_shapes =
+    flow_draw_test_area ;
     for i=1 upto flow_max_x :
         for j=1 upto flow_max_y :
             flow_draw_test_shape(i,j) ;
+            flow_chart_draw_label(i,j,"",textext("\ttx(" & decimal i & "," & decimal 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 ;
+    for i=1 upto flow_max_x + 1 :
+        draw ((i,1) -- (i,flow_max_y+1)) flow_scaled_to_grid withcolor white/2 ;
+    endfor ;
+    for i=1 upto flow_max_y + 1 :
+        draw ((1,i) -- (flow_max_x+1,i)) flow_scaled_to_grid withcolor white/2 ;
+    endfor ;
 enddef ;
 
 def flow_show_connection(expr n, m) =
diff --git a/metapost/context/base/mpiv/mp-chem.mpiv b/metapost/context/base/mpiv/mp-chem.mpiv
index b861d3f12..4ed9eaa8f 100644
--- a/metapost/context/base/mpiv/mp-chem.mpiv
+++ b/metapost/context/base/mpiv/mp-chem.mpiv
@@ -48,26 +48,34 @@ path
 pair
     chem_origin, chem_mirror,
     chem_pair[], % scratch
-    chem_sb_pair, chem_sb_pair.m, chem_sb_pair.p, chem_sb_pair.b ;
+    chem_sb_pair, chem_sb_pair.m, chem_sb_pair.mm, chem_sb_pair.p, chem_sb_pair.pp, chem_sb_pair.b ;
 
 picture
-    chem_pic, % scratch
+    chem_pic; % scratch
     % The use of dashpattern is found to dot the starting point with chem_sb_dash.m...
     %chem_sb_dash, chem_sb_dash.m, chem_sb_dash.p, chem_sb_dash.b,
+
+% nice hack but now redone
+%
+% picture chem_axis_color ;
+%
+% chem_axis_color := image(draw origin withcolor axiscolor) ; % so we handle all color models
+%
+% withpen pencircle scaled chem_axis_rulethickness withcolor colorpart(chem_axis_color) ;
+
+string
     chem_axis_color ;
 
 transform
     chem_t ; % scratch
 
-color lightblue ; lightblue := (173/255,216/255,230/255) ;
-
 % debugging
 
 boolean chem_trace_nesting     ; chem_trace_nesting     := false ;
 boolean chem_trace_text        ; chem_trace_text        := false ;
 boolean chem_trace_boundingbox ; chem_trace_boundingbox := false ;
 
-chem_axis_color         := image(draw origin withcolor lightblue) ;
+chem_axis_color         := "lightblue" ;
 chem_setting_axis       := false ;
 chem_axis_rulethickness := 1pt ;
 chem_emwidth            := 10pt ; % EmWidth or \the\emwidth does not work...
@@ -81,7 +89,9 @@ chem_text_max           := 1.25 ;
 chem_dot_factor         := 2 ; % *linewidth
 chem_sb_pair            := (0.25,0.75) ; %chem_sb_dash   := dashpattern(off 0.25 on 0.5 off 0.25) ;
 chem_sb_pair.m          := (0.25,1   ) ; %chem_sb_dash.m := dashpattern(off 0.25 on 0.75) ;
+chem_sb_pair.mm         := (0.50,1   ) ; %chem_sb_dash.m := dashpattern(off 0.25 on 0.75) ;
 chem_sb_pair.p          := (0   ,0.75) ; %chem_sb_dash.p := dashpattern(on  0.75 off 0.25) ;
+chem_sb_pair.pp         := (0   ,0.50) ; %chem_sb_dash.p := dashpattern(on  0.75 off 0.25) ;
 chem_sb_pair.b          := (0   ,1   ) ; %chem_sb_dash.b := dashpattern(on  1) ;
 
 chem_bd_wedge           := true ; % according to IUPAC 2005
@@ -333,7 +343,7 @@ def chem_start_structure(expr i, l, r, t, b, rotation, unit, bond, scale, offset
     chem_setting_offset     := offset ;
     chem_setting_axis       := if boolean axis : axis else : (axis<>0) fi ;
     chem_axis_rulethickness := .75*(rulethickness) ; % axis 50% thinner than frame and bonds.
-    chem_axis_color         := image(draw origin withcolor axiscolor) ; % so we handle all color models
+    chem_axis_color         := axiscolor ;
 
     chem_reset ;
 enddef ;
@@ -367,24 +377,24 @@ vardef chem_stop_structure =
         % draw the axes to the bounding box of the entire structure,
         % not necessarily the bounding box of the final figure
         draw (l,0) -- (r,0)
-            withpen pencircle scaled chem_axis_rulethickness withcolor colorpart(chem_axis_color) ;
+            withpen pencircle scaled chem_axis_rulethickness withcolor chem_axis_color ;
         draw (0,b) -- (0,t)
-            withpen pencircle scaled chem_axis_rulethickness withcolor colorpart(chem_axis_color) ;
+            withpen pencircle scaled chem_axis_rulethickness withcolor chem_axis_color ;
         for i = 0 step  chem_num0 until r :
             draw (i,-chem_num1) -- (i,chem_num1)
-            withpen pencircle scaled chem_axis_rulethickness withcolor colorpart(chem_axis_color) ;
+            withpen pencircle scaled chem_axis_rulethickness withcolor chem_axis_color ;
         endfor
         for i = 0 step -chem_num0 until l :
             draw (i,-chem_num1) -- (i,chem_num1)
-            withpen pencircle scaled chem_axis_rulethickness withcolor colorpart(chem_axis_color) ;
+            withpen pencircle scaled chem_axis_rulethickness withcolor chem_axis_color ;
         endfor
         for i = 0 step  chem_num0 until t :
             draw (-chem_num1,i) -- (chem_num1,i)
-            withpen pencircle scaled chem_axis_rulethickness withcolor colorpart(chem_axis_color) ;
+            withpen pencircle scaled chem_axis_rulethickness withcolor chem_axis_color ;
         endfor
         for i = 0 step -chem_num0 until b :
             draw (-chem_num1,i) -- (chem_num1,i)
-            withpen pencircle scaled chem_axis_rulethickness withcolor colorpart(chem_axis_color) ;
+            withpen pencircle scaled chem_axis_rulethickness withcolor chem_axis_color ;
         endfor
         addto currentpicture also chem_pic ;
     fi ;
@@ -406,9 +416,8 @@ vardef chem_stop_component  = enddef ;
 
 vardef chem_pb = % PB :
     if chem_trace_nesting :
-        draw boundingbox currentpicture
-                    withpen pencircle scaled 1mm withcolor colorpart(chem_axis_color) ;
-        draw origin withpen pencircle scaled 2mm withcolor colorpart(chem_axis_color) ;
+        draw boundingbox currentpicture withpen pencircle scaled 1mm withcolor chem_axis_color ;
+        draw origin withpen pencircle scaled 2mm withcolor chem_axis_color ;
     fi ;
     chem_doing_pb := true ;
 enddef ;
@@ -507,21 +516,21 @@ enddef ;
 vardef chem_draw (expr what, r, c) (text extra) =
     draw what
         withpen pencircle scaled r
-        withcolor c %\MPcolor{c}
+        withcolor c
         extra ;
 enddef ;
 
 vardef chem_fill (expr what, r, c) (text extra) =
     fill what
         withpen pencircle scaled r
-        withcolor c %\MPcolor{c}
+        withcolor c
         extra ;
 enddef ;
 
 vardef chem_drawarrow (expr what, r, c) (text extra) =
     drawarrow what
         withpen pencircle scaled r
-        withcolor c %\MPcolor{c}
+        withcolor c
         extra ;
 enddef ;
 
@@ -1372,7 +1381,7 @@ vardef chem_bw@# (suffix $) (expr f, t, r, c) = % BW
 enddef ;
 
 vardef chem_bd@# (suffix $) (expr f, t, r, c) = % BD
-    if chem_star[$] : chem_rbd#@($,f,t,r,c) ; fi
+    if chem_star[$] : chem_rbd@#($,f,t,r,c) ; fi
 enddef ;
 
 vardef chem_rbd@# (suffix $) (expr f, t, r, c) = % RBD
@@ -1691,14 +1700,14 @@ vardef chem_line (suffix $) (expr f, t, r, c) = % LINE
     draw if f=t : origin else : chem_marked(f) fi -- chem_marked(t)
         % no chem_transformed
         withpen pencircle scaled r
-        withcolor c %\MPcolor{c}
+        withcolor c
 enddef ;
 
 vardef chem_dash (suffix $) (expr f, t, r, c) = % DASH
     draw if f=t : origin else : chem_marked(f) fi -- chem_marked(t)
         % no chem_transformed
         withpen pencircle scaled r
-        withcolor c %\MPcolor{c}
+        withcolor c
         dashed evenly ;
 enddef ;
 
@@ -1706,7 +1715,7 @@ vardef chem_arrow (suffix $) (expr f, t, r, c) = % ARROW
     drawarrow if f=t : origin else : chem_marked(f) fi -- chem_marked(t)
         % no chem_transformed
         withpen pencircle scaled r
-        withcolor c %\MPcolor{c}
+        withcolor c
 enddef ;
 
 
diff --git a/metapost/context/base/mpiv/mp-core.mpiv b/metapost/context/base/mpiv/mp-core.mpiv
index 9b7182908..0ef24e57e 100644
--- a/metapost/context/base/mpiv/mp-core.mpiv
+++ b/metapost/context/base/mpiv/mp-core.mpiv
@@ -513,9 +513,6 @@ def do_initialize_par (expr fpos, tpos, mpos, ppos, rw,rl,rr,rh,ra,ri) =
 
 enddef ;
 
-TopSkip     := 0 ; % will move
-StrutHeight := 0 ; % will move
-
 pair last_multi_par_shift ; last_multi_par_shift := origin ;
 
 def relocate_multipars (expr xy) =
@@ -1187,10 +1184,10 @@ numeric boxfilloffset    ; boxfilloffset    := 0pt ;
 numeric boxgriddistance  ; boxgriddistance  := .5cm ;
 numeric boxgridshift     ; boxgridshift     := 0pt ;
 
-def draw_box =
-    draw pxy        boxlineoptions withpen pencircle scaled boxlinewidth ;
-    draw lxy -- rxy boxlineoptions withpen pencircle scaled boxgridwidth ;
-enddef ;
+% def draw_box =
+%     draw pxy        boxlineoptions withpen pencircle scaled boxlinewidth ;
+%     draw lxy -- rxy boxlineoptions withpen pencircle scaled boxgridwidth ;
+% enddef ;
 
 def draw_par  = % 1 2 3 11 12
     do_draw_par(pxy) ; do_draw_par(txy) ; do_draw_par(bxy) ;
diff --git a/metapost/context/base/mpiv/mp-grap.mpiv b/metapost/context/base/mpiv/mp-grap.mpiv
index 4fd8ee5bd..3a1d7742a 100644
--- a/metapost/context/base/mpiv/mp-grap.mpiv
+++ b/metapost/context/base/mpiv/mp-grap.mpiv
@@ -17,9 +17,8 @@ boolean context_grap ; context_grap := true ;
 
 % Below is a modified graph.mp
 
-show numbersystem, numberprecision ;
+message ("using number system " & numbersystem & " with precision " & decimal numberprecision) ;
 
-%if epsilon/4 = 0 :
 if numbersystem <> "double" :
     errmessage "The graph macros require the double precision number system." ;
     endinput ;
@@ -161,7 +160,6 @@ enddef ;
 % New :
 
 save graph_background ; color graph_background ; % if defined, fill the frame.
-save graph_close_file ; boolean graph_close_file ; graph_close_file = false ;
 
 def begingraph(expr w, h) =
   begingroup
@@ -475,9 +473,9 @@ enddef ;
 % String manipulation routines for MetaPost
 % It is harmless to input this file more than once.
 
-vardef isdigit primary d =
-    ("0"<=d)and(d<="9")
-enddef ;
+% vardef isdigit primary d =
+%     ("0"<=d)and(d<="9")
+% enddef ;
 
 % Number of initial characters of string s where `c <character>' is true
 
@@ -527,15 +525,18 @@ enddef ;
 % line with no data.  Commands c can use line number i and tokens $1, $2, ...
 % and j is the number of fields.
 
+% def gdata(expr f)(suffix $)(text c) =
+%   for i=1 upto largestmantissa :
+%     exitunless graph_read_line$(f) ;
+%     c
+%   endfor ;
+% enddef ;
+
 def gdata(expr f)(suffix $)(text c) =
-  %boolean flag ; % not used?
   for i=1 upto largestmantissa :
     exitunless graph_read_line$(f) ;
     c
   endfor
-  if graph_close_file :
-    closefrom f ;
-  fi
 enddef ;
 
 % Read a path from file f. The path is terminated by blank line or EOF.
@@ -1259,7 +1260,6 @@ def plotsymbol(expr n, f) text t =
             fg := if known graph_foreground : graph_foreground else : black fi ;
             save p ; path p ; p = graph_shape[n] scaled graph_shapesize ;
             draw p withcolor bg withpen currentpen scaled 2 ; % halo
-            currentpen := currentpen scaled .5 ;
             if cycle p :
                 fill p withcolor
                     if known f :
diff --git a/metapost/context/base/mpiv/mp-idea.mpiv b/metapost/context/base/mpiv/mp-idea.mpiv
index 462d97553..d417ab51f 100644
--- a/metapost/context/base/mpiv/mp-idea.mpiv
+++ b/metapost/context/base/mpiv/mp-idea.mpiv
@@ -28,3 +28,17 @@ vardef somecolor = (1,1,0,0) enddef ;
 
 fill OverlayBox withcolor (rcomponent somecolor,gcomponent somecolor,bcomponent somecolor) ;
 fill OverlayBox withcolor (ccomponent somecolor,mcomponent somecolor,ycomponent somecolor,bcomponent somecolor) ;
+
+% def newcolor     text v = forsuffixes i=v : save i ; color     i ; endfor ; enddef ;
+% def newnumeric   text v = forsuffixes i=v : save i ; numeric   i ; endfor ; enddef ;
+% def newboolean   text v = forsuffixes i=v : save i ; boolean   i ; endfor ; enddef ;
+% def newtransform text v = forsuffixes i=v : save i ; transform i ; endfor ; enddef ;
+% def newpath      text v = forsuffixes i=v : save i ; path      i ; endfor ; enddef ;
+% def newpicture   text v = forsuffixes i=v : save i ; picture   i ; endfor ; enddef ;
+% def newstring    text v = forsuffixes i=v : save i ; string    i ; endfor ; enddef ;
+
+% width := 10 ;
+% beginfig(1) ;
+%   newpath width, height ; width := origin -- cycle ;
+% endfig ;
+% width := 10 ;
diff --git a/metapost/context/base/mpiv/mp-luas.mpiv b/metapost/context/base/mpiv/mp-luas.mpiv
index c30798247..76d28f7f9 100644
--- a/metapost/context/base/mpiv/mp-luas.mpiv
+++ b/metapost/context/base/mpiv/mp-luas.mpiv
@@ -57,6 +57,8 @@ vardef mlib_luas_luacall(text t) =
             & decimal s
         elseif boolean s :
             & if s : "true" else : "false" fi
+        else :
+            & ditto & tostring(s) & ditto
         fi endfor
     )
 enddef ;
@@ -75,6 +77,8 @@ vardef mlib_luas_lualist(expr c)(text t) =
             & decimal s
         elseif boolean s :
             & if s : "true" else : "false" fi
+        else :
+            & ditto & tostring(s) & ditto
         fi endfor & ")"
     )
 enddef ;
@@ -97,3 +101,65 @@ enddef ;
 vardef MP@#(text t) =
     mlib_luas_lualist("MP." & str @#,t)
 enddef ;
+
+def message expr t =
+    if t <> "" : lua.mp.report(t) fi ;
+enddef ;
+
+% a few helpers
+
+% A few helpers:
+
+vardef isarray suffix a =
+    lua.mp.isarray(str a)
+enddef ;
+
+vardef prefix suffix a =
+    lua.mp.prefix(str a)
+enddef ;
+
+vardef dimensions suffix a =
+    lua.mp.dimensions(str a)
+enddef ;
+
+% More access
+
+def getdimen(expr k)    = lua.mp._get_dimen_(k)   enddef ;
+def getcount(expr k)    = lua.mp._get_count_(k)   enddef ;
+def gettoks (expr k)    = lua.mp._get_toks_ (k)   enddef ;
+def setdimen(expr k, v) = lua.mp._set_dimen_(k,v) enddef ;
+def setcount(expr k, v) = lua.mp._set_count_(k,v) enddef ;
+def settoks (expr k, v) = lua.mp._set_toks_ (k,v) enddef ;
+
+% vardef getdimen(expr k)   = save getdimen ; lua.mp.getdimen(k) enddef ;
+% vardef getcount(expr k)   = save getcount ; lua.mp.getcount(k) enddef ;
+% vardef gettoks (expr k)   = save gettoks  ; lua.mp.gettoks (k) enddef ;
+% vardef setdimen(expr k,v) = save setdimen ; lua.mp.setdimen(k,v) enddef ;
+% vardef setcount(expr k,v) = save setcount ; lua.mp.setcount(k,v) enddef ;
+% vardef settoks (expr k,v) = save settoks  ; lua.mp.settoks (k,v) enddef ;
+
+vardef positionpath  (expr name) = lua.mp.positionpath  (name) enddef ;
+vardef positioncurve (expr name) = lua.mp.positioncurve (name) enddef ;
+vardef positionxy    (expr name) = lua.mp.positionxy    (name) enddef ;
+vardef positionpxy   (expr name) = lua.mp.positionpxy   (name) enddef ;
+vardef positionwhd   (expr name) = lua.mp.positionwhd   (name) enddef ;
+vardef positionpage  (expr name) = lua.mp.positionpage  (name) enddef ;
+vardef positionregion(expr name) = lua.mp.positionregion(name) enddef ;
+vardef positionbox   (expr name) = lua.mp.positionbox   (name) enddef ;
+vardef positionanchor            = lua.mp.positionanchor()     enddef ;
+
+let wdpart = redpart ;
+let htpart = greenpart ;
+let dppart = bluepart ;
+
+vardef positioninregion =
+    currentpicture := currentpicture shifted - positionxy(positionanchor) ;
+enddef ;
+
+vardef positionatanchor(expr name) =
+    currentpicture := currentpicture shifted - positionxy(name) ;
+enddef ;
+
+
+vardef texvar(expr name) = lua.mp.texvar(name) enddef ;
+vardef texstr(expr name) = lua.mp.texstr(name) enddef ;
diff --git a/metapost/context/base/mpiv/mp-mlib.mpiv b/metapost/context/base/mpiv/mp-mlib.mpiv
index 326342b70..0638ee3e1 100644
--- a/metapost/context/base/mpiv/mp-mlib.mpiv
+++ b/metapost/context/base/mpiv/mp-mlib.mpiv
@@ -54,8 +54,8 @@ vardef transparency_alternative_to_number(expr name) =
     fi
 enddef ;
 
-def namedcolor (expr n) =
-    1
+def namedcolor expr n =
+    (1)
     withprescript "sp_type=named"
     withprescript "sp_name=" & n
 enddef ;
@@ -76,22 +76,22 @@ enddef ;
 %     withprescript "sp_value="      & value
 % enddef ;
 
-def spotcolor(expr n, v) =
-    1
+def spotcolor(expr name, v) =
+    (1)
     withprescript "sp_type=spot"
-    withprescript "sp_name="  & n
+    withprescript "sp_name="  & name
     withprescript "sp_value=" & colordecimals v
 enddef ;
 
 def multitonecolor(expr name)(text t) =
-    1
+    (1)
     withprescript "sp_type=multitone"
     withprescript "sp_name=" & name
     withprescript "sp_value=" & colordecimalslist(t)
 enddef ;
 
 def transparent(expr a, t)(text c) = % use withtransparency instead
-    1 % this permits withcolor x intoshade y
+    (1) % this permits withcolor x intoshade y
     withprescript "tr_alternative="  & decimal transparency_alternative_to_number(a)
     withprescript "tr_transparency=" & decimal t
     withcolor c
@@ -240,6 +240,32 @@ vardef rawtextext(expr s) = % todo: avoid currentpicture
     fi
 enddef ;
 
+vardef validtexbox(expr category, name) =
+    if category == "" :
+        false
+    elseif string name :
+        name <> ""
+    elseif numeric name :
+        name > 0
+    else :
+        true
+    fi
+enddef ;
+
+vardef rawtexbox(expr category, name) =
+    mfun_tt_c := nullpicture ;
+    if validtexbox(category,name) :
+        mfun_tt_b := lua.mp.tb_dimensions(category, name) ;
+        addto mfun_tt_c doublepath unitsquare
+            xscaled redpart mfun_tt_b
+            yscaled (greenpart mfun_tt_b + bluepart mfun_tt_b)
+            shifted (0,- bluepart mfun_tt_b)
+            withprescript "bx_category=" & if numeric category : decimal fi category
+            withprescript "bx_name=" & if numeric name : decimal fi name ;
+    fi
+    mfun_tt_c
+enddef ;
+
 % More text
 
 defaultfont  := "Mono" ;
@@ -403,6 +429,88 @@ vardef onetimetextext@#(expr p) = % no draw here
     thetextext@#(p,origin)
 enddef ;
 
+% formatted text
+
+pair mfun_tt_z ;
+
+vardef rawfmttext(text t) = % todo: avoid currentpicture
+    mfun_tt_n := mfun_tt_n + 1 ;
+    mfun_tt_c := nullpicture ;
+    if mfun_trial_run :
+        mfun_tt_o := nullpicture ;
+        addto mfun_tt_o doublepath origin _op_ ; % save drawoptions
+        addto mfun_tt_c doublepath unitsquare
+            withprescript "tx_number=" & decimal mfun_tt_n
+            withprescript "tx_stage=trial"
+            withprescript "tx_color=" & colordecimals colorpart mfun_tt_o
+            % begin of fmt specific
+            withprescript "tx_type=format"
+            for s = t :
+                        if string  s : withpostscript "s:" & s
+                    elseif numeric s : withpostscript "n:" & decimal s
+                    elseif boolean s : withpostscript "b:" & if s : "true" else : "false" fi
+                    elseif pair    s : hide(mfun_tt_z := s ; )
+                    fi
+            endfor ;
+            % end of fmt specific
+        if not mfun_onetime_textext :
+            addto mfun_tt_p also mfun_tt_c
+                withprescript "tx_global=yes" ;
+        fi ;
+    else :
+        mfun_tt_b := lua.mp.tt_dimensions(mfun_tt_n) ;
+        addto mfun_tt_c doublepath unitsquare
+            xscaled redpart mfun_tt_b
+            yscaled (greenpart mfun_tt_b + bluepart mfun_tt_b)
+            shifted (0,- bluepart mfun_tt_b)
+            withprescript "tx_number=" & decimal mfun_tt_n
+            withprescript "tx_stage=final" ;
+        % begin of fmt specific
+        for s = t :
+            if pair s : mfun_tt_z := s ; fi
+        endfor ;
+        % end of fmt specific
+    fi ;
+    mfun_onetime_textext := false ;
+    mfun_tt_c
+enddef ;
+
+vardef thefmttext@#(text t) =
+    mfun_tt_z := origin ;
+    save p ; picture p ; p := rawfmttext(t) ;
+    p
+        if (mfun_labtype@# >= 10) :
+            shifted (0,ypart center p)
+        fi
+        shifted (mfun_tt_z + textextoffset*mfun_laboff@# - (mfun_labxf@#*lrcorner p + mfun_labyf@#*ulcorner p + (1-mfun_labxf@#-mfun_labyf@#)*llcorner p))
+enddef ;
+
+vardef fmttext@#(text t) = % no draw here
+    thefmttext@#(t,origin)
+enddef ;
+
+% or just: def fmttext = thefmttext enddef ;
+
+vardef onetimefmttext@#(text t) = % no draw here
+    mfun_onetime_textext := true ;
+    thefmttext@#(t,origin)
+enddef ;
+
+% so much for formatted text
+
+vardef thetexbox@#(expr category, name, z) =
+    save p ; picture p ; p := rawtexbox(category,name) ;
+    p
+        if (mfun_labtype@# >= 10) :
+            shifted (0,ypart center p)
+        fi
+        shifted (z + textextoffset*mfun_laboff@# - (mfun_labxf@#*lrcorner p + mfun_labyf@#*ulcorner p + (1-mfun_labxf@#-mfun_labyf@#)*llcorner p))
+enddef ;
+
+vardef texbox@#(expr category, name) = % no draw here
+    thetexbox@#(category,name,origin)
+enddef ;
+
 vardef thelabel@#(expr p,z) =
     if string p :
         thelabel@#(rawtextext("\definedfont[" & defaultfont & "]" & p) scaled defaultscale,z)
@@ -507,16 +615,52 @@ def mfun_withshadestep (text t) =
     t
 enddef ;
 
+numeric mfun_shade_fx, mfun_shade_fy ;
+numeric mfun_shade_lx, mfun_shade_ly ;
+numeric mfun_shade_nx, mfun_shade_ny ;
+numeric mfun_shade_dx, mfun_shade_dy ;
+numeric mfun_shade_tx, mfun_shade_ty ;
+
+% first
+
+def mfun_with_shade_method_analyze(expr p) =
+    mfun_shade_path := p ;
+    mfun_shade_step := 1 ;
+    mfun_shade_fx   := xpart point 0 of p ;
+    mfun_shade_fy   := ypart point 0 of p ;
+    mfun_shade_lx   := mfun_shade_fx ;
+    mfun_shade_ly   := mfun_shade_fy ;
+    mfun_shade_nx   := 0 ;
+    mfun_shade_ny   := 0 ;
+    mfun_shade_dx   := abs(mfun_shade_fx - mfun_shade_lx) ;
+    mfun_shade_dy   := abs(mfun_shade_fy - mfun_shade_ly) ;
+    for i=1 upto length(p) :
+        mfun_shade_tx := abs(mfun_shade_fx - xpart point i of p) ;
+        mfun_shade_ty := abs(mfun_shade_fy - ypart point i of p) ;
+        if mfun_shade_tx > mfun_shade_dx :
+            mfun_shade_nx := i + 1 ;
+            mfun_shade_lx := xpart point i of p ;
+            mfun_shade_dx := mfun_shade_tx ;
+        fi ;
+        if mfun_shade_ty > mfun_shade_dy :
+            mfun_shade_ny := i + 1 ;
+            mfun_shade_ly := ypart point i of p ;
+            mfun_shade_dy := mfun_shade_ty ;
+        fi ;
+    endfor ;
+enddef ;
+
 primarydef p withshademethod m =
-    hide(
-        mfun_shade_path := p ;
-        mfun_shade_step := 1 ;
-    )
+    hide(mfun_with_shade_method_analyze(p))
     p
     withprescript "sh_domain=0 1"
+    withprescript "sh_transform=yes"
     withprescript "sh_color=into"
     withprescript "sh_color_a=" & colordecimals white
     withprescript "sh_color_b=" & colordecimals black
+    withprescript "sh_first=" & ddecimal point 0 of p % used for support scaling
+    withprescript "sh_set_x=" & ddecimal (mfun_shade_nx,mfun_shade_lx) %
+    withprescript "sh_set_y=" & ddecimal (mfun_shade_ny,mfun_shade_ly) %
     if m = "linear" :
         withprescript "sh_type=linear"
         withprescript "sh_factor=1"
@@ -537,6 +681,16 @@ primarydef p withshademethod m =
     fi
 enddef ;
 
+def withshaderadius expr a =
+    withprescript "sh_radius_a=" & decimal (xpart a)
+    withprescript "sh_radius_b=" & decimal (ypart a)
+enddef ;
+
+def withshadeorigin expr a =
+    withprescript "sh_center_a=" & ddecimal a
+    withprescript "sh_center_b=" & ddecimal a
+enddef ;
+
 def withshadevector expr a =
     withprescript "sh_center_a=" & ddecimal (point xpart a of mfun_shade_path)
     withprescript "sh_center_b=" & ddecimal (point ypart a of mfun_shade_path)
@@ -547,6 +701,10 @@ def withshadedirection expr a =
     withprescript "sh_center_b=" & ddecimal (point ypart a of boundingbox(mfun_shade_path))
 enddef ;
 
+def withshadetransform expr a = % yes | no
+    withprescript "sh_transform=" & a
+enddef ;
+
 pair shadedup    ; shadedup    := (0.5,2.5) ;
 pair shadeddown  ; shadeddown  := (2.5,0.5) ;
 pair shadedleft  ; shadedleft  := (1.5,3.5) ;
@@ -616,10 +774,47 @@ def shaded text s =
     s
 enddef ;
 
+% For me.
+
+primarydef p shownshadevector v =
+    image (
+        drawarrow (point xpart v of p) -- (point ypart v of p) ;
+        fill fullcircle scaled 2 shifted point xpart v of p ;
+        setbounds currentpicture to center currentpicture -- cycle ;
+    )
+enddef ;
+
+primarydef p shownshadedirection v =
+    image (
+        drawarrow (point xpart v of boundingbox p) -- (point ypart v of boundingbox p) ;
+        fill fullcircle scaled 2 shifted (point xpart v of boundingbox p) ;
+        setbounds currentpicture to center currentpicture -- cycle ;
+    )
+enddef ;
+
+primarydef p shownshadecenter v =
+    image (
+        fill fullcircle scaled 2
+            shifted center p shifted (
+            xpart v * bbwidth (p)/2,
+            ypart v * bbheight(p)/2
+        ) ;
+        setbounds currentpicture to center currentpicture -- cycle ;
+    )
+enddef ;
+
+primarydef p shownshadeorigin v =
+    image (
+        fill fullcircle scaled 2 shifted v ;
+        setbounds currentpicture to center currentpicture -- cycle ;
+    )
+enddef ;
+
 % Old macros:
 
 def withcircularshade (expr a, b, ra, rb, ca, cb) =
     withprescript "sh_type=circular"
+    withprescript "sh_transform=yes"
     withprescript "sh_domain=0 1"
     withprescript "sh_factor=1"
     withprescript "sh_color_a="  & colordecimals ca
@@ -632,6 +827,7 @@ enddef ;
 
 def withlinearshade (expr a, b, ca, cb) =
     withprescript "sh_type=linear"
+    withprescript "sh_transform=yes"
     withprescript "sh_domain=0 1"
     withprescript "sh_factor=1"
     withprescript "sh_color_a="  & colordecimals ca
@@ -830,11 +1026,17 @@ vardef mfun_do_outline_text_flush (expr kind, n, x, y) (text t) =
         mfun_do_outline_text_r (n, x, y) (t)
     elseif kind = "p" :
         mfun_do_outline_text_p (n, x, y) (t)
+    elseif kind = "u" :
+        mfun_do_outline_text_u (n, x, y) (t)
     else :
         mfun_do_outline_text_n (n, x, y) (t)
     fi ;
 enddef ;
 
+vardef mfun_do_outline_rule_flush (expr kind, x, y, w, h) =
+    mfun_do_outline_text_flush (kind, 1, x, y) (fullsquare xyscaled(w,h))
+enddef ;
+
 numeric mfun_do_outline_n ; mfun_do_outline_n := 0 ;
 
 vardef mfun_do_outline_text_f (expr n, x, y) (text t) =
@@ -842,7 +1044,19 @@ vardef mfun_do_outline_text_f (expr n, x, y) (text t) =
     for i=t :
         mfun_do_outline_n := mfun_do_outline_n + 1 ;
         if mfun_do_outline_n = n :
-            fill   i shifted(x,y) mfun_do_outline_options_f
+            fill   i shifted(x,y) mfun_do_outline_options_f withpen pencircle scaled 0
+        else :
+            nofill i shifted(x,y)
+        fi ;
+    endfor ;
+enddef ;
+
+vardef mfun_do_outline_text_u (expr n, x, y) (text t) =
+    mfun_do_outline_n := 0 ;
+    for i=t :
+        mfun_do_outline_n := mfun_do_outline_n + 1 ;
+        if mfun_do_outline_n = n :
+            fillup i shifted(x,y) mfun_do_outline_options_f
         else :
             nofill i shifted(x,y)
         fi ;
@@ -935,6 +1149,9 @@ def mfun_do_outline_options_r = enddef ;
 vardef outlinetext@# (expr t) text rest =
     save kind ; string kind ; kind := str @# ;
     currentoutlinetext := currentoutlinetext + 1 ;
+    def mfun_do_outline_options_d = enddef ;
+    def mfun_do_outline_options_f = enddef ;
+    def mfun_do_outline_options_r = enddef ;
     image ( normaldraw image (
         if mfun_trial_run :
           % lua.mp.report("set outline text",currentoutlinetext);
@@ -951,6 +1168,8 @@ vardef outlinetext@# (expr t) text rest =
                 mfun_do_outline_text_set_d rest ;
             elseif kind = "b" :
                 mfun_do_outline_text_set_b rest ;
+            elseif kind = "u" :
+                mfun_do_outline_text_set_f rest ;
             elseif kind = "r" :
                 mfun_do_outline_text_set_r rest ;
             elseif kind = "p" :
@@ -1026,19 +1245,19 @@ vardef properties(text t) =
     image(draw unitcircle t)
 enddef ;
 
-if metapostversion < 1.770  :
-
-    def withproperties expr p =
-        if colormodel p = 3 :
-            withcolor greypart p
-        elseif colormodel p = 5 :
-            withcolor (redpart p,greenpart p,bluepart p)
-        elseif colormodel p = 7 :
-            withcolor (cyanpart p,magentapart p,yellowpart p,blackpart p)
-        fi
-    enddef ;
-
-else :
+% if metapostversion < 1.770  :
+%
+%     def withproperties expr p =
+%         if colormodel p = 3 :
+%             withcolor greypart p
+%         elseif colormodel p = 5 :
+%             withcolor (redpart p,greenpart p,bluepart p)
+%         elseif colormodel p = 7 :
+%             withcolor (cyanpart p,magentapart p,yellowpart p,blackpart p)
+%         fi
+%     enddef ;
+%
+% else :
 
     def withproperties expr p =
         if colormodel p = 3 :
@@ -1052,7 +1271,7 @@ else :
         withpostscript postscriptpart p
     enddef ;
 
-fi ;
+% fi ;
 
 % Experimental:
 
@@ -1065,11 +1284,7 @@ primarydef t asgroup s = % s = isolated|knockout
     wrappedpicture:= nullpicture ;
     addto wrappedpicture contour groupbounds
         withprescript "gr_state=start"
-        withprescript "gr_type=" & s
-        withprescript "gr_llx=" & decimal xpart llcorner groupbounds
-        withprescript "gr_lly=" & decimal ypart llcorner groupbounds
-        withprescript "gr_urx=" & decimal xpart urcorner groupbounds
-        withprescript "gr_ury=" & decimal ypart urcorner groupbounds ;
+        withprescript "gr_type=" & s ;
     addto wrappedpicture also grouppicture ;
     addto wrappedpicture contour groupbounds
         withprescript "gr_state=stop" ;
@@ -1166,32 +1381,31 @@ vardef mfun_boolean_to_string(expr b) =
     if b : "true" else : "false" fi
 enddef ;
 
-% def passvariable(expr key, value) =
-%     special
-%         if     numeric   value : "1:" & key & "=" & mfun_numeric_to_string(value)
-%         elseif pair      value : "4:" & key & "=" & mfun_pair_to_string(value)
-%         elseif rgbcolor  value : "5:" & key & "=" & mfun_rgbcolor_to_string(value)
-%         elseif cmykcolor value : "6:" & key & "=" & mfun_cmykcolor_to_string(value)
-%         elseif boolean   value : "3:" & key & "=" & mfun_boolean_to_string(value)
-%         elseif path      value : "7:" & key & "=" & mfun_path_to_string(value)
-%         elseif transform value : "8:" & key & "=" & mfun_transform_to_string(value)
-%         else                   : "2:" & key & "=" & value
-%         fi ;
-% enddef ;
-
-vardef tostring(expr value) =
-    if     numeric   value : mfun_numeric_to_string(value)
-    elseif pair      value : mfun_pair_to_string(value)
-    elseif rgbcolor  value : mfun_rgbcolor_to_string(value)
-    elseif cmykcolor value : mfun_cmykcolor_to_string(value)
-    elseif greycolor value : mfun_greycolor_to_string(value)
-    elseif boolean   value : mfun_boolean_to_string(value)
-    elseif path      value : mfun_path_to_string(value)
-    elseif transform value : mfun_transform_to_string(value)
-    else                   : value
+vardef tostring primary v =
+    if     numeric   v : mfun_numeric_to_string(v)
+    elseif pair      v : mfun_pair_to_string(v)
+    elseif rgbcolor  v : mfun_rgbcolor_to_string(v)
+    elseif cmykcolor v : mfun_cmykcolor_to_string(v)
+    elseif greycolor v : mfun_greycolor_to_string(v)
+    elseif boolean   v : mfun_boolean_to_string(v)
+    elseif path      v : mfun_path_to_string(v)
+    elseif transform v : mfun_transform_to_string(v)
+    else               : v
     fi
 enddef ;
 
+vardef topair primary p =
+    if     pair    p : "(" & decimal xpart p & "," & decimal ypart p & ")"
+    elseif numeric p : "(" & decimal       p & "," & decimal       p & ")"
+    else             : "" fi
+enddef ;
+
+string dq ; dq := char 92 & char 34 ;
+string sq ; sq := char 92 & char 39 ;
+
+vardef quote     primary s = sq & tostring(s) & sq enddef;
+vardef quotation primary s = dq & tostring(s) & dq enddef;
+
 vardef mfun_tagged_string(expr value) =
     if     numeric   value : "1:" & mfun_numeric_to_string(value)
     elseif pair      value : "4:" & mfun_pair_to_string(value)
@@ -1204,178 +1418,106 @@ vardef mfun_tagged_string(expr value) =
     fi
 enddef ;
 
-% amore flexible variant for passing data to context
+% A more flexible variant for passing data to context. We used to construct strings
+% but running lua is fast enough so we can gain on string construction in metapost
+% which is also not that efficient.
 
-vardef mfun_point_to_lua(expr p,i) =
-    "{" &
-    decimal xpart (point       i of p) & "," &
-    decimal ypart (point       i of p) & "," &
-    decimal xpart (precontrol  i of p) & "," &
-    decimal ypart (precontrol  i of p) & "," &
-    decimal xpart (postcontrol i of p) & "," &
-    decimal ypart (postcontrol i of p)
-    & "}"
+vardef mfun_key_to_lua(expr k) =
+    if numeric k : decimal k else : "'" & k & "'" fi
 enddef ;
 
-vardef mfun_transform_to_lua(expr t) =
-    "{" &
-    decimal xxpart t & "," &   % rx
-    decimal xypart t & "," &   % sx
-    decimal yxpart t & "," &   % sy
-    decimal yypart t & "," &   % ry
-    decimal xpart  t & "," &   % tx
-    decimal ypart  t           % ty
-    & "}"
+vardef mfun_point_to_lua(expr k,p,i) =
+    runscript( "metapost.setvariable(" & mfun_key_to_lua(k) & ",{" &
+        decimal xpart (point       i of p) & "," &
+        decimal ypart (point       i of p) & "," &
+        decimal xpart (precontrol  i of p) & "," &
+        decimal ypart (precontrol  i of p) & "," &
+        decimal xpart (postcontrol i of p) & "," &
+        decimal ypart (postcontrol i of p)
+    & "})" ) ;
 enddef ;
 
-vardef mfun_numeric_to_lua(expr n) =
-    decimal n
+vardef mfun_transform_to_lua(expr k,t) =
+    runscript( "metapost.setvariable(" & mfun_key_to_lua(k) & ",{" &
+        decimal xxpart t & "," &   % rx
+        decimal xypart t & "," &   % sx
+        decimal yxpart t & "," &   % sy
+        decimal yypart t & "," &   % ry
+        decimal xpart  t & "," &   % tx
+        decimal ypart  t           % ty
+    & "})" ) ;
 enddef ;
 
-vardef mfun_pair_to_lua(expr p) =
-    "{" &
-    decimal xpart p & "," &
-    decimal ypart p
-    & "}"
+vardef mfun_numeric_to_lua(expr k,n) =
+    runscript( "metapost.setvariable(" & mfun_key_to_lua(k) & "," & decimal n & ")" ) ;
 enddef ;
 
-vardef mfun_rgbcolor_to_lua(expr c) =
-    "{" &
-    decimal redpart   c & "," &
-    decimal greenpart c & "," &
-    decimal bluepart  c
-    & "}"
+vardef mfun_pair_to_lua(expr k,p) =
+    runscript( "metapost.setvariable(" & mfun_key_to_lua(k) & ",{" &
+        decimal xpart p & "," &
+        decimal ypart p
+    & "})" ) ;
 enddef ;
 
-vardef mfun_cmykcolor_to_lua(expr c) =
-    "{" &
-    decimal cyanpart    c & "," &
-    decimal magentapart c & "," &
-    decimal yellowpart  c & "," &
-    decimal blackpart   c
-    & "}"
+vardef mfun_rgbcolor_to_lua(expr k,c) =
+    runscript( "metapost.setvariable(" & mfun_key_to_lua(k) & ",{" &
+        decimal redpart   c & "," &
+        decimal greenpart c & "," &
+        decimal bluepart  c
+    & "})" ) ;
 enddef ;
 
-vardef mfun_path_to_lua(expr p) =
-    "{" &
-    mfun_point_to_lua(p,0) for i=1 upto length(p) : & "," & mfun_point_to_lua(p,i) endfor
-    & "}"
+vardef mfun_cmykcolor_to_lua(expr k,c) =
+    runscript( "metapost.setvariable(" & mfun_key_to_lua(k) & ",{" &
+        decimal cyanpart    c & "," &
+        decimal magentapart c & "," &
+        decimal yellowpart  c & "," &
+        decimal blackpart   c
+    & "})" ) ;
 enddef ;
 
-vardef mfun_boolean_to_lua(expr b) =
-    if b : "true" else : "false" fi
-enddef ;
-
-vardef mfun_string_to_lua(expr s) =
-   "[==[" & s & "]==]"
+vardef mfun_path_to_lua(expr k,p) =
+    runscript("metapost.pushvariable(" & mfun_key_to_lua(k) & ")") ;
+    for i=0 upto length(p) :
+        mfun_point_to_lua(i+1,p,i) ;
+    endfor ;
+    runscript("metapost.popvariable()") ;
 enddef ;
 
-def mfun_to_lua(expr key)(expr value)(text t) =
-    special "metapost.variables['" & key & "']=" & t(value) ;
+vardef mfun_boolean_to_lua(expr k,b) =
+    runscript( "metapost.setvariable(" & mfun_key_to_lua(k) & if b : ",true)" else : ",false)" fi ) ;
 enddef ;
 
-def mfun_array_to_lua(expr key)(suffix value)(expr first, last, stp)(text t) =
-    special
-        "metapost.variables['" & key & "']={"
-            for i=first step stp until last :
-                & "[" & decimal i & "]=" & t(value[i]) & ","
-            endfor
-        & "}" ;
+vardef mfun_string_to_lua(expr k,s) =
+    runscript( "metapost.setvariable(" & mfun_key_to_lua(k) & ",[==[" & s & "]==])" ) ;
 enddef ;
 
 def passvariable(expr key, value) =
-    if     numeric   value : mfun_to_lua(key,value,mfun_numeric_to_lua)
-    elseif pair      value : mfun_to_lua(key,value,mfun_pair_to_lua)
-    elseif string    value : mfun_to_lua(key,value,mfun_string_to_lua)
-    elseif boolean   value : mfun_to_lua(key,value,mfun_boolean_to_lua)
-    elseif path      value : mfun_to_lua(key,value,mfun_path_to_lua)
-    elseif rgbcolor  value : mfun_to_lua(key,value,mfun_rgbcolor_to_lua)
-    elseif cmykcolor value : mfun_to_lua(key,value,mfun_cmykcolor_to_lua)
-    elseif transform value : mfun_to_lua(key,value,mfun_transform_to_lua)
+    if     numeric   value : mfun_numeric_to_lua  (key,value) ;
+    elseif pair      value : mfun_pair_to_lua     (key,value) ;
+    elseif string    value : mfun_string_to_lua   (key,value) ;
+    elseif boolean   value : mfun_boolean_to_lua  (key,value) ;
+    elseif path      value : mfun_path_to_lua     (key,value) ;
+    elseif rgbcolor  value : mfun_rgbcolor_to_lua (key,value) ;
+    elseif cmykcolor value : mfun_cmykcolor_to_lua(key,value) ;
+    elseif transform value : mfun_transform_to_lua(key,value) ;
     fi ;
 enddef ;
 
 def passarrayvariable(expr key)(suffix values)(expr first, last, stp) =
-    if     numeric   values[first] : mfun_array_to_lua(key,values,first,last,stp,mfun_numeric_to_lua)
-    elseif pair      values[first] : mfun_array_to_lua(key,values,first,last,stp,mfun_pair_to_lua)
-    elseif string    values[first] : mfun_array_to_lua(key,values,first,last,stp,mfun_string_to_lua)
-    elseif boolean   values[first] : mfun_array_to_lua(key,values,first,last,stp,mfun_boolean_to_lua)
-    elseif path      values[first] : mfun_array_to_lua(key,values,first,last,stp,mfun_path_to_lua)
-    elseif rgbcolor  values[first] : mfun_array_to_lua(key,values,first,last,stp,mfun_rgbcolor_to_lua)
-    elseif cmykcolor values[first] : mfun_array_to_lua(key,values,first,last,stp,mfun_cmykcolor_to_lua)
-    elseif transform values[first] : mfun_array_to_lua(key,values,first,last,stp,mfun_transform_to_lua)
-    fi ;
+    runscript("metapost.pushvariable(" & mfun_key_to_lua(key) & ")") ;
+    for i=first step stp until last :
+        passvariable(i, values[i]) ;
+    endfor
+    runscript("metapost.popvariable()") ;
 enddef ;
 
 def startpassingvariable(expr k) =
-    begingroup ;
-    save stoppassingvariable, startarray, stoparray, starthash, stophash, index, key, value, slot, entry ;
-    let stoppassingvariable = mfun_stop_lua_variable ;
-    let startarray = mfun_start_lua_array ;
-    let stoparray = mfun_stop_lua_array ;
-    let starthash = mfun_start_lua_hash ;
-    let stophash = mfun_stop_lua_hash ;
-    let index = mfun_lua_index ;
-    let key = mfun_lua_key ;
-    let value = mfun_lua_value ;
-    let slot = mfun_lua_slot ;
-    let entry = mfun_lua_entry ;
-    save s ; string s ;
-    s := "metapost.variables['" & k & "']="
-enddef ;
-
-def mfun_stop_lua_variable =
-    ;
-    special substring(0,length(s)-1) of s ;
-    endgroup ;
+    runscript("metapost.pushvariable(" & mfun_key_to_lua(k) & ")") ;
 enddef ;
 
-% currently there is no difference between array and hash
-
-def mfun_start_lua_array =
-    & "{"
-enddef ;
-
-def mfun_stop_lua_array =
-    & "},"
-enddef ;
-
-def mfun_start_lua_hash =
-    & "{"
-enddef ;
-
-def mfun_stop_lua_hash =
-    & "},"
-enddef ;
-
-def mfun_lua_key(expr k) =
-    & "['" & k & "']="
-enddef ;
-
-def mfun_lua_index(expr k) =
-    & "[" & decimal k & "]="
-enddef ;
-
-def mfun_lua_value(expr v) =
-    if     numeric   v : & mfun_numeric_to_lua(v) & ","
-    elseif pair      v : & mfun_pair_to_lua(v) & ","
-    elseif string    v : & mfun_string_to_lua(v) & ","
-    elseif boolean   v : & mfun_boolean_to_lua(v) & ","
-    elseif path      v : & mfun_path_to_lua(v) & ","
-    elseif rgbcolor  v : & mfun_rgbcolor_to_lua(v) & ","
-    elseif cmykcolor v : & mfun_cmykcolor_to_lua(v) & ","
-    elseif transform v : & mfun_transform_to_lua(v) & ","
-    fi
-enddef ;
-
-def mfun_lua_entry(expr k, v) =
-    mfun_lua_key(k)
-    mfun_lua_value(v)
-enddef ;
-
-def mfun_lua_slot(expr k, v) =
-    mfun_lua_index(k)
-    mfun_lua_value(v)
+def stoppassingvariable =
+    runscript("metapost.popvariable()") ;
 enddef ;
 
 % moved here from mp-grap.mpiv
@@ -1449,6 +1591,9 @@ vardef formatted(expr f, x) = textext(varfmt(f, x)) enddef ;
 % def strfmt = format    enddef ; % old
 % def varfmt = formatted enddef ; % old
 
+
+% def fmttext = lua.mp.formatted enddef ;
+
 % new
 
 def fillup   text t = draw t withpostscript "both"    enddef ; % we use draw because we need the proper boundingbox
@@ -1460,3 +1605,52 @@ def nofill   text t = fill t withpostscript "collect" enddef ;
 % def withrule expr r =
 %     if (t = "even-odd") or (t = "evenodd") : withpostscript "evenodd" fi
 % enddef ;
+
+% so we can do: withcolor "red"
+
+vardef resolvedcolor primary s =
+  % lua.mp.namedcolor(s)   % conflicts with macro namedcolor
+  % lua.mp.NamedColor(s)   % okay but, can also be
+  % lua.mp("NamedColor",s) % which gives expansion mess
+    if string s :
+        runscript("mp.NamedColor('" & s & "')") % faster anyway
+    else :
+        s
+    fi
+enddef ;
+
+% A comment will end up on top of the graphic in the output. This can be handy for
+% locating a graphic: comment("test graphic").
+
+def comment expr str =
+    special "metapost.comment[[" & str & "]]" ;
+enddef ;
+
+% This overloads a dummy:
+
+vardef uniquelist(suffix list) =
+    % this can be optimized by passing all values at once and returning
+    % a result but for now this is ok .. we need an undef foo
+    save i, j, h ;
+    if known lis[0] :
+        i := 0 ;
+        j := -1 ;
+    else :
+        i := 1 ;
+        j := 0 ;
+    fi ;
+    h := lua.mp.newhash() ;
+    forever :
+        exitif unknown list[i] ;
+        if not lua.mp.inhash(h,list[i]) :
+            j := j + 1 ;
+            list[j] := list[i] ;
+            lua.mp.tohash(h,list[i]) ;
+        fi ;
+        i := i + 1 ;
+    endfor ;
+    for n = j+1 step 1 until i-1 :
+        dispose(list[n])
+    endfor ;
+    lua.mp.disposehash(h) ;
+enddef ;
diff --git a/metapost/context/base/mpiv/mp-node.mpiv b/metapost/context/base/mpiv/mp-node.mpiv
new file mode 100644
index 000000000..fdd308ad1
--- /dev/null
+++ b/metapost/context/base/mpiv/mp-node.mpiv
@@ -0,0 +1,182 @@
+%D \module
+%D   [       file=mp-node.mpiv,
+%D        version=1998.02.15,
+%D          title=\CONTEXT\ \METAPOST\ graphics,
+%D       subtitle=Node Based Graphics,
+%D         author=Alan Braslau,
+%D           date=\currentdate,
+%D      copyright={Alan Braslau & \CONTEXT\ Development Team}]
+%C
+%C This module is part of the \CONTEXT\ macro||package and is
+%C therefore copyrighted by \PRAGMA. See mreadme.pdf for
+%C details.
+
+%D Ths crossing macros were written as part of this module but as they
+%D can be of use elsewhere they are defined in mp-tool.
+
+if known context_node : endinput ; fi ;
+
+boolean context_node ; context_node := true ;
+
+% returns a pair suffix if the path is unknown
+
+vardef makenode@#(suffix p)(text t) =
+    save i, b ; numeric i ; string b ;
+    for a = t :
+        if unknown i : % first argument is the index
+            i = a ;
+            if isarray p :
+                %
+                % note that one needs to declare "path p[] ; picture p[]pic[] ;"
+                % before calling node() if one is to use a pseudo-array for p
+                % because "picture p1.pic[] ;" is not a valid syntax!
+                %
+                % The following works, but is a bit awkward...
+                %
+                b := prefix p ;
+                if not picture p.pic[i] : scantokens("picture " & b & "[]pic[] ;") ; fi
+                if not pair    p.pos[i] : scantokens("pair    " & b & "[]pos[] ;") ; fi
+            else :
+                if not picture p.pic[i] : picture p.pic[] ; fi
+                if not pair    p.pos[i] : pair    p.pos[] ; fi
+            fi
+        else :
+            if known p.pic[i] :
+                addto p.pic[i] also
+            else :
+                p.pic[i] :=
+            fi
+            if     picture a           : a
+            elseif string  a           : textext@#(a)
+            elseif numeric a           : textext@#(decimal a)
+            elseif ((boolean a) and a) : image(draw origin)
+            else                       : nullpicture
+            fi ;
+        fi
+    endfor
+    p.pos[i] if known p : := point i of p ; fi
+enddef ;
+
+% returns a picture
+
+vardef node@#(suffix p)(text t) =
+    if pair makenode@#(p)(t) :
+        % nop: gobble the function return.
+    fi
+    for a = t :
+        if (unknown p) and (known p.pos[a]) :
+            makenodepath(p) ;
+        fi
+        if known p.pic[a] :
+            p.pic[a] if known p : shifted point a of p fi
+        else :
+            nullpicture
+        fi
+        exitif true ;
+    endfor
+enddef ;
+
+% returns a path
+
+vardef fromto@#(expr d)(suffix p)(expr f)(suffix q)(text s) =
+    save r, t, l ;
+    path r[] ; numeric t ; picture l ;
+    for a = s :
+        if unknown t :
+            t = a ;
+            if (unknown p) and (known p.pos[f]) :
+                makenodepath(p) ;
+            fi
+            if (unknown q) and (known q.pos[t]) :
+                makenodepath(q) ;
+            fi
+            r0 = if ((not numeric d) and
+                     (point f of p = point f of q) and
+                     (point t of p = point t of q)) :
+                     subpath (f,t) of p
+                 else :
+                     point f of p -- point t of q
+                 fi ;
+            save deviation ; numeric deviation ;
+            deviation := if numeric d: d else: 0 fi ;
+            r1 = if deviation=0 : r0
+                else :
+                    point 0 of r0 ..
+                    unitvector direction .5length r0 of r0 rotated 90
+                        scaled deviation * arclength r0
+                        shifted point .5length r0 of r0 ..
+                    point length r0 of r0
+                fi ;
+        else :
+            if known l :
+                addto l also
+            else :
+                l :=
+            fi
+                 if     picture a           : a
+                 elseif string a            : textext@#(a)
+                 elseif numeric a           : textext@#(decimal a)
+                 elseif ((boolean a) and a) : image(draw origin withpen currentpen scaled 4)
+                 else                       : nullpicture
+                 fi ;
+        fi
+    endfor
+    r2 = r1
+        if known p.pic[f if cycle p: mod length p fi] :
+            cutbefore boundingbox (p.pic[f if cycle p: mod length p fi] shifted point f of p)
+        fi
+        if known q.pic[t if cycle q: mod length q fi] :
+            cutafter  boundingbox (q.pic[t if cycle q: mod length q fi] shifted point t of q)
+        fi
+        ;
+    if known l :
+        l := l shifted point .5length r2 of r2 ;
+        draw l ;
+        (r2 if str @# = "" : crossingunder l fi)
+    else :
+        r2
+    fi
+enddef ;
+
+% returns pair: bounding point of the node picture
+
+vardef nodeboundingpoint@#(suffix p)(expr i) =
+    if known p.pic[i] :
+        boundingpoint@#(p.pic[i])
+    else :
+        origin
+    fi
+enddef ;
+
+% returns pair: scaled laboff direction
+
+vardef relative@#(expr s) =
+    (mfun_laboff@# scaled s)
+enddef ;
+
+% returns pair: vector between nodes (+ optional scale)
+
+vardef betweennodes@#(suffix p)(expr f)(suffix q)(text s) =
+    save t ; numeric t ;
+    for a = s :
+        if unknown t :
+            t = a ;
+            nodeboundingpoint@#(q,t) + nodeboundingpoint@#(p,f)
+        else :
+            + relative@#(a)
+        fi
+    endfor
+enddef ;
+
+% build a path from the node positions.
+% Must be continuous in index starting at 0.
+
+vardef makenodepath(suffix p) =
+    if unknown p :
+        save i ; i = -1 ;
+        p = forever : exitif unknown p.pos[incr i] ;
+                 p.pos[i] --
+             endfor cycle ;
+    fi
+enddef ;
+
diff --git a/metapost/context/base/mpiv/mp-page.mpiv b/metapost/context/base/mpiv/mp-page.mpiv
index 2e4a2b437..f32990677 100644
--- a/metapost/context/base/mpiv/mp-page.mpiv
+++ b/metapost/context/base/mpiv/mp-page.mpiv
@@ -290,16 +290,24 @@ vardef CutSpace            = if mfun_swapped and not OnRightPage : PaperWidth -
 vardef OuterMarginWidth    = if not OnRightPage : lua.mp.LeftMarginWidth    () else : lua.mp.RightMarginWidth   () fi enddef ;
 vardef InnerMarginWidth    = if not OnRightPage : lua.mp.RightMarginWidth   () else : lua.mp.LeftMarginWidth    () fi enddef ;
 vardef OuterMarginDistance = if not OnRightPage : lua.mp.LeftMarginDistance () else : lua.mp.RightMarginDistance() fi enddef ;
-vardef InnerMarginDistance = if not OnRightPage : lua.mp.RightMarginDistance() else : lua.mp.leftMarginDistance () fi enddef ;
+vardef InnerMarginDistance = if not OnRightPage : lua.mp.RightMarginDistance() else : lua.mp.LeftMarginDistance () fi enddef ;
 
 vardef OuterEdgeWidth      = if not OnRightPage : lua.mp.LeftEdgeWidth      () else : lua.mp.RightEdgeWidth     () fi enddef ;
 vardef InnerEdgeWidth      = if not OnRightPage : lua.mp.RightEdgeWidth     () else : lua.mp.LeftEdgeWidth      () fi enddef ;
 vardef OuterEdgeDistance   = if not OnRightPage : lua.mp.LeftEdgeDistance   () else : lua.mp.RightEdgeDistance  () fi enddef ;
-vardef InnerEdgeDistance   = if not OnRightPage : lua.mp.RightEdgeDistance  () else : lua.mp.leftEdgeDistance   () fi enddef ;
+vardef InnerEdgeDistance   = if not OnRightPage : lua.mp.RightEdgeDistance  () else : lua.mp.LeftEdgeDistance   () fi enddef ;
 
 vardef OuterSpaceWidth     = if not OnRightPage : lua.mp.BackSpace          () else : lua.mp.CutSpace           () fi enddef ;
 vardef InnerSpaceWidth     = if not OnRightPage : lua.mp.CutSpace           () else : lua.mp.BackSpace          () fi enddef ;
 
+% indices
+
+vardef OuterMargin = if not OnRightPage : LeftMargin  else : RightMargin fi enddef ;
+vardef InnerMargin = if not OnRightPage : RightMargin else : LeftMargin  fi enddef ;
+
+vardef OuterEdge   = if not OnRightPage : LeftEdge    else : RightEdge   fi enddef ;
+vardef InnerEdge   = if not OnRightPage : Rightedge   else : LeftEdge    fi enddef ;
+
 % vardef CurrentLayout = lua.mp.CurrentLayout () enddef ;
 
 vardef OverlayWidth      = lua.mp.OverlayWidth    ()  enddef ;
@@ -670,6 +678,8 @@ string  RuleOption    ; RuleOption    := "" ;
 numeric RuleWidth     ; RuleWidth     := 0 ;
 numeric RuleHeight    ; RuleHeight    := 0 ;
 numeric RuleDepth     ; RuleDepth     := 0 ;
+numeric RuleH         ; RuleH         := 0 ;
+numeric RuleV         ; RuleV         := 0 ;
 numeric RuleThickness ; RuleThickness := 0 ;
 numeric RuleFactor    ; RuleFactor    := 0 ;
 numeric RuleOffset    ; RuleOffset    := 0 ;
diff --git a/metapost/context/base/mpiv/mp-shap.mpiv b/metapost/context/base/mpiv/mp-shap.mpiv
index 713656510..a511ef375 100644
--- a/metapost/context/base/mpiv/mp-shap.mpiv
+++ b/metapost/context/base/mpiv/mp-shap.mpiv
@@ -74,6 +74,8 @@ def stop_predefined_shape_definition =
 
 enddef ;
 
+% this can be delayed
+
 start_predefined_shape_definition ;
 
     predefined_shapes[ 0] := (origin--cycle) ;
@@ -143,7 +145,7 @@ start_predefined_shape_definition ;
 stop_predefined_shape_definition ;
 
 vardef some_shape_path (expr type) =
-    if known predefined_shapes[type] : predefined_shapes[type] else : predefined_shapes[0] fi
+    if known predefined_shapes[type] : predefined_shapes[type] else : predefined_shapes[24] fi
 enddef ;
 
 def some_shape (expr shape_type, shape_width, shape_height, shape_linewidth, shape_linecolor, shape_fillcolor) =
@@ -156,14 +158,22 @@ def some_shape (expr shape_type, shape_width, shape_height, shape_linewidth, sha
     endgroup ;
 enddef ;
 
+% maybe:
+%
+%     if t>1 : % normal shape
+%         path pp ; pp := some_shape_path(t) xyscaled(bbwidth(p), bbheight(p)) ;
+%         pp := pp shifted - center pp shifted center p ;
+%         fill pp withcolor fc ;
+%         draw pp withpen pencircle scaled lw withcolor lc ;
+
 vardef drawpredefinedshape (expr t, p, lw, lc, fc) =
     save pp ;
-    if t>1 : % normal shape
+    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
+    elseif t = 1 : % background only
         path pp ;
         pp := fullsquare xyscaled(bbwidth(p), bbheight(p)) shifted center p ;
         fill pp withcolor fc ;
diff --git a/metapost/context/base/mpiv/mp-step.mpiv b/metapost/context/base/mpiv/mp-step.mpiv
index f7a7ba5de..16d6be3a7 100644
--- a/metapost/context/base/mpiv/mp-step.mpiv
+++ b/metapost/context/base/mpiv/mp-step.mpiv
@@ -11,11 +11,12 @@
 %C therefore copyrighted by \PRAGMA. See licen-en.pdf for
 %C details.
 
-% step prefixes .. no save needed
+% maybe todo: step prefixes .. no save needed
+% not todo  : make it unreadable by lots of suffix compaction
 
-if known context_cell : endinput ; fi ;
+if known context_step : endinput ; fi ;
 
-boolean context_cell ; context_cell := true ;
+boolean context_step ; context_step := true ;
 
 def initialize_step_variables =
     save
@@ -23,14 +24,16 @@ def initialize_step_variables =
         cell_fill_color, cell_line_color, cell_line_width, cell_offset,
         line_line_color, line_line_width, line_alternative,
         line_distance, cell_distance_y, cell_distance_x,
-        nofcells, chart_vertical ;
+        nofcells, chart_vertical, chart_align, chart_category ;
 
-    color   text_line_color     ; text_line_color     := red ;
-    color   cell_line_color     ; cell_line_color     := blue ;
-    color   line_line_color     ; line_line_color     := green ;
+    string  chart_category      ; chart_category      := "" ;
 
-    color   text_fill_color     ; text_fill_color     := white ;
-    color   cell_fill_color     ; cell_fill_color     := white ;
+    string  text_line_color     ; text_line_color     := "red" ;
+    string  cell_line_color     ; cell_line_color     := "blue" ;
+    string  line_line_color     ; line_line_color     := "green" ;
+
+    string  text_fill_color     ; text_fill_color     := "white" ;
+    string  cell_fill_color     ; cell_fill_color     := "white" ;
 
     numeric text_line_width     ; text_line_width     := 2pt ;
     numeric cell_line_width     ; cell_line_width     := 2pt ;
@@ -49,6 +52,7 @@ def initialize_step_variables =
     numeric text_distance_set   ; text_distance_set   :=  4pt ;
 
     boolean chart_vertical      ; chart_vertical      := false ;
+    boolean chart_align         ; chart_align         := false ;
 
     numeric nofcells            ; nofcells            := 0 ;
 
@@ -56,17 +60,17 @@ enddef ;
 
 def step_cells (expr t, b) =
     nofcells := nofcells + 1 ;
-    cells_t[nofcells] := textext.d(t) ;
-    cells_b[nofcells] := textext.d(b) ;
+    cells_t[nofcells] := texbox.d(chart_category,t) ;
+    cells_b[nofcells] := texbox.d(chart_category,b) ;
     texts_t[nofcells] := nullpicture ;
     texts_m[nofcells] := nullpicture ;
     texts_b[nofcells] := nullpicture ;
 enddef ;
 
-def step_texts (expr t, b) =
-    texts_t[nofcells] := textext.d(t) ;
-    texts_m[nofcells] := textext.d(m) ;
-    texts_b[nofcells] := textext.d(b) ;
+def step_texts (expr t, m, b) =
+    texts_t[nofcells] := texbox.d(chart_category,t) ;
+    texts_m[nofcells] := texbox.d(chart_category,m) ;
+    texts_b[nofcells] := texbox.d(chart_category,b) ;
 enddef ;
 
 def step_begin_cell =
@@ -81,11 +85,66 @@ enddef ;
 def step_end_cell =
 enddef ;
 
-def step_cell_top (expr t) = cells_t[nofcells] := textext.d(t) ; enddef ;
-def step_cell_bot (expr b) = cells_b[nofcells] := textext.d(b) ; enddef ;
-def step_text_top (expr t) = texts_t[nofcells] := textext.d(t) ; enddef ;
-def step_text_mid (expr m) = texts_m[nofcells] := textext.d(m) ; enddef ;
-def step_text_bot (expr b) = texts_b[nofcells] := textext.d(b) ; enddef ;
+% maybe: texbox.d
+
+def step_cell_top (expr t, c, f, l, s) =
+    cells_t[nofcells] := texbox.d(chart_category,t) ;
+    cell_top_colors[nofcells] := c ;
+    cell_top_fills [nofcells] := f ;
+    cell_top_lines [nofcells] := l ;
+    cell_top_shapes[nofcells] := s ;
+enddef ;
+
+def step_cell_bot (expr b, c, f, l, s) =
+    cells_b[nofcells] := texbox.d(chart_category,b) ;
+    cell_bot_colors[nofcells] := c ;
+    cell_bot_fills [nofcells] := f ;
+    cell_bot_lines [nofcells] := l ;
+    cell_bot_shapes[nofcells] := s ;
+enddef ;
+
+def step_cell_ali (expr ca, cb, cc, c, f, l, s) =
+    cells_a[nofcells][1] := texbox.d(chart_category,ca) ;
+    cells_a[nofcells][2] := texbox.d(chart_category,cb) ;
+    cells_a[nofcells][3] := texbox.d(chart_category,cc) ;
+    cell_top_colors[nofcells] := c ;
+    cell_top_fills [nofcells] := f ;
+    cell_top_lines [nofcells] := l ;
+    cell_top_shapes[nofcells] := s ;
+enddef ;
+
+def step_text_top (expr t, tc, tf, tl, ts, lc, ll, ls) =
+    texts_t[nofcells] := texbox.d(chart_category,t) ;
+    text_top_colors[nofcells] := tc ;
+    text_top_fills [nofcells] := tf ;
+    text_top_lines [nofcells] := tl ;
+    text_top_shapes[nofcells] := ts ;
+    line_top_colors[nofcells] := lc ;
+    line_top_lines [nofcells] := ll ;
+    line_top_shapes[nofcells] := ls ;
+enddef ;
+
+def step_text_mid (expr m, tc, tf, tl, ts, lc, ll, ls) =
+    texts_m[nofcells] := texbox.d(chart_category,m) ;
+    text_mid_colors[nofcells] := tc ;
+    text_mid_fills [nofcells] := tf ;
+    text_mid_lines [nofcells] := tl ;
+    text_mid_shapes[nofcells] := ts ;
+    line_mid_colors[nofcells] := lc ;
+    line_mid_lines [nofcells] := ll ;
+    line_mid_shapes[nofcells] := ls ;
+enddef ;
+
+def step_text_bot (expr b, tc, tf, tl, ts, lc, ll, ls) =
+    texts_b[nofcells] := texbox.d(chart_category,b) ;
+    text_bot_colors[nofcells] := tc ;
+    text_bot_fills [nofcells] := tf ;
+    text_bot_lines [nofcells] := tl ;
+    text_bot_shapes[nofcells] := ts ;
+    line_bot_colors[nofcells] := lc ;
+    line_bot_lines [nofcells] := ll ;
+    line_bot_shapes[nofcells] := ls ;
+enddef ;
 
 def step_begin_chart =
     begingroup ;
@@ -93,6 +152,44 @@ def step_begin_chart =
         save nofcells ; numeric nofcells ; nofcells := 0 ;
         save cells_t, cells_m, cells_b ; picture cells_t[], cells_m[], cells_b[] ;
         save texts_t, texts_m, texts_b ; picture texts_t[], texts_m[], texts_b[] ;
+        save start_t, start_m, start_b ; numeric start_t[], start_m[], start_b[] ;
+        save cells_a ; picture cells_a[][] ;
+
+        save cell_top_colors ; string cell_top_colors[] ;
+        save cell_bot_colors ; string cell_bot_colors[] ;
+        save text_top_colors ; string text_top_colors[] ;
+        save text_mid_colors ; string text_mid_colors[] ;
+        save text_bot_colors ; string text_bot_colors[] ;
+
+        save cell_top_fills  ; string cell_top_fills[] ;
+        save cell_bot_fills  ; string cell_bot_fills[] ;
+        save text_top_fills  ; string text_top_fills[] ;
+        save text_mid_fills  ; string text_mid_fills[] ;
+        save text_bot_fills  ; string text_bot_fills[] ;
+
+        save cell_top_lines  ; numeric cell_top_lines[] ;
+        save cell_bot_lines  ; numeric cell_bot_lines[] ;
+        save text_top_lines  ; numeric text_top_lines[] ;
+        save text_mid_lines  ; numeric text_mid_lines[] ;
+        save text_bot_lines  ; numeric text_bot_lines[] ;
+
+        save cell_top_shapes ; numeric cell_top_shapes[] ;
+        save cell_bot_shapes ; numeric cell_bot_shapes[] ;
+        save text_top_shapes ; numeric text_top_shapes[] ;
+        save text_mid_shapes ; numeric text_mid_shapes[] ;
+        save text_bot_shapes ; numeric text_bot_shapes[] ;
+
+        save line_top_lines  ; numeric line_top_lines[] ;
+        save line_mid_lines  ; numeric line_mid_lines[] ;
+        save line_bot_lines  ; numeric line_bot_lines[] ;
+
+        save line_top_colors ; string line_top_colors[] ;
+        save line_mid_colors ; string line_mid_colors[] ;
+        save line_bot_colors ; string line_bot_colors[] ;
+
+        save line_top_shapes ; numeric line_top_shapes[] ;
+        save line_mid_shapes ; numeric line_mid_shapes[] ;
+        save line_bot_shapes ; numeric line_bot_shapes[] ;
 enddef ;
 
 def step_end_chart =
@@ -106,6 +203,7 @@ def step_end_chart =
     save height_t, width_t, max_height_t, max_width_t ; numeric height_t, width_t, max_height_t, max_width_t ;
     save height_m, width_m, max_height_m, max_width_m ; numeric height_m, width_m, max_height_m, max_width_m ;
     save height_b, width_b, max_height_b, max_width_b ; numeric height_b, width_b, max_height_b, max_width_b ;
+    save alternative ; numeric alternative ;
     % check rows
     one_row_only := true ;
     for i=1 upto nofcells :
@@ -113,18 +211,43 @@ def step_end_chart =
             one_row_only := false ;
         fi ;
     endfor ;
+    %
+    if chart_align :
+        save size, delta, width ; numeric size[], delta[], width[] ;
+        for i=1 upto 3:
+            size[i] = 0 ;
+            for c=1 upto nofcells :
+                size[i] := max(size[i],bbwidth(cells_a[c][i])) ;
+            endfor ;
+        endfor ;
+        for c=1 upto nofcells :
+            cells_t[c] := image (
+                for i=1 upto 3:
+                    width[i] := bbwidth(cells_a[c][i]);
+                    delta[i] := size[i] - width[i] ;
+                endfor;
+                setbounds cells_a[c][1] to boundingbox(cells_a[c][1]) leftenlarged (delta[1]) ;
+                setbounds cells_a[c][2] to boundingbox(cells_a[c][2]) leftenlarged (delta[2]/2)
+                                                                      rightenlarged(delta[2]/2) ;
+                setbounds cells_a[c][3] to boundingbox(cells_a[c][3]) rightenlarged(delta[3]) ;
+                cells_a[c][1] := cells_a[c][1] shifted (- width[1]/2 - size[2]/2 - text_distance_set,0) ;
+                cells_a[c][3] := cells_a[c][3] shifted (  width[3]/2 + size[2]/2 + text_distance_set,0) ;
+                for i=1 upto 3:
+                    draw cells_a[c][i] ;
+                  % draw boundingbox cells_a[c][i] ;
+                endfor ;
+            ) ;
+        endfor ;
+    fi ;
     % swap and rotate
     if chart_vertical :
         if one_row_only :
             % deal with mid_texts
             max_width_t := max_width_m := max_width_b := 0 ;
             for i=1 upto nofcells :
-                width_t := bbwidth(texts_t[i]) ;
-                width_m := bbwidth(texts_m[i]) ;
-                width_b := bbwidth(texts_b[i]) ;
-                if width_t > max_width_t : max_width_t := width_t fi ;
-                if width_m > max_width_m : max_width_m := width_m fi ;
-                if width_b > max_width_b : max_width_b := width_b fi ;
+                max_width_t := max(max_width_t,bbwidth(texts_t[i]));
+                max_width_m := max(max_width_m,bbwidth(texts_m[i]));
+                max_width_b := max(max_width_b,bbwidth(texts_b[i]));
             endfor ;
             if max_width_m > 0 :
                 for i=1 upto nofcells :
@@ -132,14 +255,17 @@ def step_end_chart =
                     text_m := texts_m[i] ; width_m := bbwidth(text_m) ;
                     text_b := texts_b[i] ; width_b := bbwidth(text_b) ;
                     if width_t < max_width_t :
-                        setbounds text_t to boundingbox text_t leftenlarged (max_width_t - width_t) ;
+                        setbounds text_t to boundingbox text_t
+                            leftenlarged (max_width_t - width_t) ;
                     fi ;
                     if width_m < max_width_m :
-                        setbounds text_m to boundingbox text_m leftenlarged  ((max_width_m - width_m)/2) ;
-                        setbounds text_m to boundingbox text_m rightenlarged ((max_width_m - width_m)/2) ;
+                        setbounds text_m to boundingbox text_m
+                            leftenlarged  ((max_width_m - width_m)/2)
+                            rightenlarged ((max_width_m - width_m)/2) ;
                     fi ;
                     if width_b < max_width_b :
-                        setbounds text_b to boundingbox text_b rightenlarged (max_width_b - width_b) ;
+                        setbounds text_b to boundingbox text_b
+                            rightenlarged (max_width_b - width_b) ;
                     fi ;
                     text_t := text_t shifted (- xpart llcorner text_t, 0) ;
                     text_m := text_m shifted (- xpart llcorner text_m, 0) ;
@@ -161,6 +287,7 @@ def step_end_chart =
             fi ;
         else :
             for i=1 upto nofcells :
+                % swaps so we need a scratch variable
                 cell_t := cells_t[i] ;
                 cell_b := cells_b[i] ;
                 cells_t[i] := cell_b rotated 90 ;
@@ -174,39 +301,31 @@ def step_end_chart =
     fi ;
     % align horizontal
     for i=1 upto nofcells :
-        cell_t := cells_t[i] ;
-        cell_b := cells_b[i] ;
-        width_t := bbwidth(cell_t) ;
-        width_b := bbwidth(cell_b) ;
+        width_t := bbwidth(cells_t[i]) ;
+        width_b := bbwidth(cells_b[i]) ;
         if (width_t = 0) and (width_b = 0) :
             % skip
         elseif (width_t > 0) and (width_t < width_b) :
             delta := (width_b-width_t)/2 ;
-            setbounds cell_t to boundingbox cell_t leftenlarged delta rightenlarged delta ;
-            cells_t[i] := cell_t ;
+            setbounds cells_t[i] to boundingbox cells_t[i] leftenlarged delta rightenlarged delta ;
         elseif (width_b > 0) and (width_t > width_b) :
             delta := (width_t-width_b)/2 ;
-            setbounds cell_b to boundingbox cell_b leftenlarged delta rightenlarged delta ;
-            cells_b[i] := cell_b ;
+            setbounds cells_b[i] to boundingbox cells_b[i] leftenlarged delta rightenlarged delta ;
         fi ;
     endfor ;
     % analyze vertical
     max_height_t := 0 ;
     max_height_b := 0 ;
     for i=1 upto nofcells :
-        cell_t := cells_t[i] ;
-        cell_b := cells_b[i] ;
-        height_t := bbheight(cell_t) ;
-        height_b := bbheight(cell_b) ;
+        height_t := bbheight(cells_t[i]) ;
+        height_b := bbheight(cells_b[i]) ;
         if height_t > 0 :
-            setbounds cell_t to boundingbox cell_t enlarged cell_offset ;
+            setbounds cells_t[i] to boundingbox cells_t[i] enlarged cell_offset ;
             height_t := height_t + 2 * cell_offset ;
-            cells_t[i] := cell_t ;
         fi ;
         if height_b > 0 :
-            setbounds cell_b to boundingbox cell_b enlarged cell_offset ;
+            setbounds cells_b[i] to boundingbox cells_b[i] enlarged cell_offset ;
             height_b := height_b + 2 * cell_offset ;
-            cells_b[i] := cell_b ;
         fi ;
         if height_t > max_height_t :
             max_height_t := height_t ;
@@ -217,34 +336,24 @@ def step_end_chart =
     endfor ;
     % align vertical
     for i=1 upto nofcells :
-        cell_t := cells_t[i] ;
-        cell_b := cells_b[i] ;
-        height_t := bbheight(cell_t) ;
-        height_b := bbheight(cell_b) ;
+        height_t := bbheight(cells_t[i]) ;
+        height_b := bbheight(cells_b[i]) ;
         if height_t > 0 :
             delta := (max_height_t-height_t)/2 ;
-            setbounds cell_t to boundingbox cell_t topenlarged delta bottomenlarged delta ;
+            setbounds cells_t[i] to boundingbox cells_t[i] topenlarged delta bottomenlarged delta ;
         fi ;
         if height_b > 0 :
             delta := (max_height_b-height_b)/2 ;
-            setbounds cell_b to boundingbox cell_b topenlarged delta bottomenlarged delta ;
+            setbounds cells_b[i] to boundingbox cells_b[i] topenlarged delta bottomenlarged delta ;
         fi ;
-        cells_t[i] := cell_t ;
-        cells_b[i] := cell_b ;
     endfor ;
     % position
     dx := 0 ;
     for i=1 upto nofcells :
-        cell_t := cells_t[i] ;
-        cell_b := cells_b[i] ;
-        cell_t := cell_t shifted -llcorner cell_t ;
-        cell_b := cell_b shifted -llcorner cell_b ;
-        cell_t := cell_t shifted (dx, 0) ;
-        cell_b := cell_b shifted (dx,-cell_distance_y-max_height_b) ;
-        cells_t[i] := cell_t ;
-        cells_b[i] := cell_b ;
-        width_t := bbwidth(cell_t) ;
-        width_b := bbwidth(cell_b) ;
+        cells_t[i] := cells_t[i] shifted -llcorner cells_t[i] shifted (dx, 0) ;
+        cells_b[i] := cells_b[i] shifted -llcorner cells_b[i] shifted (dx,-cell_distance_y-max_height_b) ;
+        width_t := bbwidth(cells_t[i]) ;
+        width_b := bbwidth(cells_b[i]) ;
         if width_t > 0 :
             dx := dx + cell_distance_x + width_t ;
         elseif width_b > 0 :
@@ -253,19 +362,27 @@ def step_end_chart =
     endfor ;
     % flush
     for i=1 upto nofcells :
-        cell_t := cells_t[i] ;
-        cell_b := cells_b[i] ;
-        width_t := bbwidth(cell_t) ;
-        width_b := bbwidth(cell_b) ;
+        width_t := bbwidth(cells_t[i]) ;
+        width_b := bbwidth(cells_b[i]) ;
         if width_t > 0 :
-            fill boundingbox cell_t withcolor cell_fill_color ;
-            draw boundingbox cell_t withpen pencircle scaled cell_line_width withcolor cell_line_color ;
-            draw cell_t ;
+            drawpredefinedshape (
+                if known cell_top_shapes[i] : cell_top_shapes[i] else : 24 fi,
+                cells_t[i],
+                if known cell_top_lines [i] : cell_top_lines [i] else : cell_line_width fi,
+                if known cell_top_colors[i] : cell_top_colors[i] else : cell_line_color fi,
+                if known cell_top_fills [i] : cell_top_fills [i] else : cell_fill_color fi
+            ) ;
+            draw cells_t[i] ;
         fi ;
         if width_b > 0 :
-            fill boundingbox cell_b withcolor cell_fill_color ;
-            draw boundingbox cell_b withpen pencircle scaled cell_line_width withcolor cell_line_color ;
-            draw cell_b ;
+            drawpredefinedshape (
+                if known cell_bot_shapes[i] : cell_bot_shapes[i] else : 24 fi,
+                cells_b[i],
+                if known cell_bot_lines [i] : cell_bot_lines [i] else : cell_line_width fi,
+                if known cell_bot_colors[i] : cell_bot_colors[i] else : cell_line_color fi,
+                if known cell_bot_fills [i] : cell_bot_fills [i] else : cell_fill_color fi
+            ) ;
+            draw cells_b[i] ;
         fi ;
     endfor ;
     %
@@ -273,55 +390,71 @@ def step_end_chart =
     def midbottomboundary expr p = 0.5[llcorner boundingbox p, lrcorner boundingbox p] enddef ;
     % draw top and bottom text boxes
     for i=1 upto nofcells-1 :
-        text_t := texts_t[i] ;
-        text_b := texts_b[i] ;
-        if bbwidth(text_t) > 0 :
-            setbounds text_t to boundingbox text_t enlarged text_offset ;
-            texts_t[i] := text_t ;
+        if bbwidth(texts_t[i]) > 0 :
+            setbounds texts_t[i] to boundingbox texts_t[i] enlarged text_offset ;
         fi ;
-        if bbwidth(text_b) > 0 :
-            setbounds text_b to boundingbox text_b enlarged text_offset ;
-            texts_b[i] := text_b ;
+        if bbwidth(texts_b[i]) > 0 :
+            setbounds texts_b[i] to boundingbox texts_b[i] enlarged text_offset ;
         fi ;
     endfor ;
     % arrows
     for i=1 upto nofcells-1 :
-        cell_t := cells_t[i] ;
-        cell_b := cells_b[i] ;
-        next_t := cells_t[i+1] ;
-        next_b := cells_b[i+1] ;
         pair t_a, t_b, t_c, b_a, b_b, b_c ;
-        t_a := midtopboundary cell_t ;
-        t_b := midtopboundary next_t ;
-        t_c := (xpart 0.5[t_a,t_b], ypart t_a+line_height+line_distance) ;
+        t_a := midtopboundary cells_t[i] ;
+        t_b := midtopboundary cells_t[i+1] ;
         if one_row_only :
-            b_a := midbottomboundary cell_t ;
-            b_b := midbottomboundary next_t ;
+            b_a := midbottomboundary cells_t[i] ;
+            b_b := midbottomboundary cells_t[i+1] ;
         else :
-            b_a := midbottomboundary cell_b ;
-            b_b := midbottomboundary next_b ;
+            b_a := midbottomboundary cells_b[i] ;
+            b_b := midbottomboundary cells_b[i+1] ;
         fi ;
+        t_c := (xpart 0.5[t_a,t_b], ypart t_a+line_height+line_distance) ;
         b_c := (xpart 0.5[b_a,b_b], ypart b_a-line_height-line_distance) ;
         texts_t[i] := thelabel.top(texts_t[i],t_c) ;
         texts_b[i] := thelabel.bot(texts_b[i],b_c) ;
     endfor ;
     %
     for i=1 upto nofcells-1 : % todo arrows when empty text
-        cell_t := cells_t[i] ;
-        cell_b := cells_b[i] ;
-        next_t := cells_t[i+1] ;
-        next_b := cells_b[i+1] ;
         text_t := texts_t[i] ;
         text_b := texts_b[i] ;
+        cell_t := cells_t[start_t[i]] ;
+        cell_b := cells_b[start_b[i]] ;
+        next_t := cells_t[i+1] ;
+        next_b := cells_b[i+1] ;
         if bbwidth(text_t) > 0 :
             if bbwidth(cell_t) > 0 :
-                drawarrow midtopboundary cell_t
-                    shifted (if i > 1 : line_offset else : 0 fi, cell_line_width) {up}  ..
-                    midbottomboundary text_t shifted (0,-line_distance) ..
-                    {down} midtopboundary next_t shifted(if i < nofcells - 1 : -line_offset else : 0 fi,cell_line_width)
-                    withpen pencircle scaled line_line_width
-                    withcolor line_line_color ;
-            else :
+                alternative := if known line_top_shapes[i] : line_top_shapes[i] else : 1 fi ;
+                if alternative <> 0 :
+                    if (alternative = 1) or (alternative = 2) or (alternative = 5) or (alternative = 6) :
+                        drawarrow
+                    elseif (alternative = 3) or (alternative = 7):
+                        drawdblarrow
+                    else :
+                        draw
+                    fi
+                        if (alternative = 2) or (alternative = 6) :
+                            reverse
+                        fi
+                            (
+                                midtopboundary cell_t
+                                    shifted (if i > 1 : line_offset else : 0 fi, cell_line_width) {up}  ..
+                                midbottomboundary text_t
+                                    shifted (0,-line_distance) ..
+                                {down} midtopboundary next_t
+                                    shifted (if i < nofcells - 1 : -line_offset else : 0 fi,cell_line_width)
+                            )
+                        withpen pencircle scaled
+                            if known line_top_lines [i] : line_top_lines [i] else : line_line_width fi
+                        withcolor
+                            if known line_top_colors[i] : line_top_colors[i] else : line_line_color fi
+                    if (alternative >= 5) and (alternative <= 8) :
+                        dashed evenly scaled (
+                            if known line_top_lines [i] : line_top_lines [i] else : line_line_width fi
+                        )
+                    fi
+                    ;
+                fi ;
             fi ;
         fi ;
         if bbwidth(text_b) > 0 :
@@ -330,29 +463,61 @@ def step_end_chart =
                 next_b := next_t ;
             fi ;
             if bbwidth(cell_b) > 0 :
-                drawarrow midbottomboundary cell_b
-                    shifted (if i > 1 : line_offset else : 0 fi, -cell_line_width) {down}  ..
-                    midtopboundary text_b shifted (0, line_distance) ..
-                    {up} midbottomboundary next_b shifted (if i < nofcells - 1 : -line_offset else : 0 fi,-cell_line_width)
-                    withpen pencircle scaled line_line_width
-                    withcolor line_line_color ;
-            else :
+                alternative := if known line_bot_shapes[i] : line_bot_shapes[i] else : 1 fi ;
+                if alternative <> 0 :
+                    if (alternative = 1) or (alternative = 2) or (alternative = 5) or (alternative = 6) :
+                        drawarrow
+                    elseif (alternative = 3) or (alternative = 7):
+                        drawdblarrow
+                    else :
+                        draw
+                    fi
+                        if (alternative = 2) or (alternative = 6) :
+                            reverse
+                        fi
+                            (
+                                midbottomboundary cell_b
+                                    shifted (if i > 1 : line_offset else : 0 fi, -cell_line_width) {down}  ..
+                                midtopboundary text_b
+                                    shifted (0, line_distance) ..
+                                {up} midbottomboundary next_b
+                                    shifted (if i < nofcells - 1 : -line_offset else : 0 fi,-cell_line_width)
+                            )
+                        withpen pencircle scaled
+                            if known line_bot_lines [i] : line_bot_lines [i] else : line_line_width fi
+                        withcolor
+                            if known line_bot_colors[i] : line_bot_colors[i] else : line_line_color fi
+                    if (alternative >= 5) and (alternative <= 8) :
+                        dashed evenly scaled (
+                            if known line_top_lines [i] : line_top_lines [i] else : line_line_width fi
+                        )
+                    fi
+                    ;
+                fi ;
             fi ;
         fi ;
     endfor ;
     % draw top and bottom text boxes
     for i=1 upto nofcells-1 :
-        text_t := texts_t[i] ;
-        text_b := texts_b[i] ;
-        if bbwidth(text_t) > 0 :
-            fill boundingbox text_t withcolor text_fill_color ;
-            draw boundingbox text_t withpen pencircle scaled text_line_width withcolor text_line_color ;
-            draw text_t ;
+        if bbwidth(texts_t[i]) > 0 :
+            drawpredefinedshape (
+                if known text_top_shapes[i] : text_top_shapes[i] else : 24 fi,
+                texts_t[i],
+                if known text_top_lines [i] : text_top_lines [i] else : text_line_width fi,
+                if known text_top_colors[i] : text_top_colors[i] else : text_line_color fi,
+                if known text_top_fills [i] : text_top_fills [i] else : text_fill_color fi
+            ) ;
+            draw texts_t[i] ;
         fi ;
-        if bbwidth(text_b) > 0 :
-            fill boundingbox text_b withcolor text_fill_color ;
-            draw boundingbox text_b withpen pencircle scaled text_line_width withcolor text_line_color ;
-            draw text_b ;
+        if bbwidth(texts_b[i]) > 0 :
+            drawpredefinedshape (
+                if known text_bot_shapes[i] : text_bot_shapes[i] else : 24 fi,
+                texts_b[i],
+                if known text_bot_lines [i] : text_bot_lines [i] else : text_line_width fi,
+                if known text_bot_colors[i] : text_bot_colors[i] else : text_line_color fi,
+                if known text_bot_fills [i] : text_bot_fills [i] else : text_fill_color fi
+            ) ;
+            draw texts_b[i] ;
         fi ;
     endfor ;
     if chart_vertical :
@@ -362,6 +527,8 @@ def step_end_chart =
     endgroup ;
 enddef ;
 
+% no longer working .. will do someday
+%
 % start_begin_step ;
 %     step_cells ("\strut test 0", "\strut test 0") ;
 %     step_cells ("\strut test 1", "\vbox{\hsize3cm \strut oeps 1\crlf oeps 1}") ;
diff --git a/metapost/context/base/mpiv/mp-symb.mpiv b/metapost/context/base/mpiv/mp-symb.mpiv
index a84c84e82..40681adf1 100644
--- a/metapost/context/base/mpiv/mp-symb.mpiv
+++ b/metapost/context/base/mpiv/mp-symb.mpiv
@@ -12,7 +12,7 @@
 %C details.
 
 %D Instead of these symbols, you can use the \type {contnav}
-%D font by Taco Hoekwater that is derived form this file. 
+%D font by Taco Hoekwater that is derived form this file.
 
 u  := 3;
 h  := 5u;
@@ -264,88 +264,88 @@ endfig;
 
 beginfig(999);
 
-picture collection []  ; 
+picture collection []  ;
 
-prepareglyph ; 
-draw lefttriangle ; 
+prepareglyph ;
+draw lefttriangle ;
 finishglyph ;
-collection[201] := currentpicture ; 
-currentpicture := nullpicture ; 
+collection[201] := currentpicture ;
+currentpicture := nullpicture ;
 
-prepareglyph ; 
-draw righttriangle ; 
+prepareglyph ;
+draw righttriangle ;
 finishglyph ;
-collection[202] := currentpicture ; 
-currentpicture := nullpicture ; 
+collection[202] := currentpicture ;
+currentpicture := nullpicture ;
 
-prepareglyph ; 
-draw sidebar ; 
+prepareglyph ;
+draw sidebar ;
 draw lefttriangle shifted (.5s) ;
 finishglyph ;
-collection[203] := currentpicture ; 
-currentpicture := nullpicture ; 
+collection[203] := currentpicture ;
+currentpicture := nullpicture ;
 
-prepareglyph ; 
-draw righttriangle ; 
-draw sidebar shifted (wt,0) ; 
+prepareglyph ;
+draw righttriangle ;
+draw sidebar shifted (wt,0) ;
 finishglyph ;
-collection[204] := currentpicture ; 
-currentpicture := nullpicture ; 
+collection[204] := currentpicture ;
+currentpicture := nullpicture ;
 
-prepareglyph ; 
-draw sublefttriangle shifted s ; 
+prepareglyph ;
+draw sublefttriangle shifted s ;
 draw lefttriangle shifted s ;
 finishglyph ;
-collection[205] := currentpicture ; 
-currentpicture := nullpicture ; 
+collection[205] := currentpicture ;
+currentpicture := nullpicture ;
 
 prepareglyph ;
 draw subrighttriangle ;
 draw righttriangle ;
 finishglyph ;
-collection[206] := currentpicture ; 
-currentpicture := nullpicture ; 
+collection[206] := currentpicture ;
+currentpicture := nullpicture ;
 
 prepareglyph ;
 draw midbar ;
 finishglyph ;
-collection[207] := currentpicture ; 
-currentpicture := nullpicture ; 
+collection[207] := currentpicture ;
+currentpicture := nullpicture ;
 
 prepareglyph ;
 draw onebar ;
 finishglyph ;
-collection[208] := currentpicture ; 
-currentpicture := nullpicture ; 
+collection[208] := currentpicture ;
+currentpicture := nullpicture ;
 
 prepareglyph ;
 draw twobar ;
 draw twobar shifted (pw+hh/2,0) ;
 finishglyph ;
-collection[209] := currentpicture ; 
-currentpicture := nullpicture ; 
+collection[209] := currentpicture ;
+currentpicture := nullpicture ;
 
-for i=201 upto 209 : 
+for i=201 upto 209 :
   collection[i] := collection[i] shifted - center collection[i] ;
-endfor ; 
+endfor ;
 
-addto currentpicture also collection[205] shifted (   0,   0) 
+addto currentpicture also collection[205] shifted (   0,   0)
   withcolor (.3,.4,.5) ;
-addto currentpicture also collection[202] shifted (   0,1.5h) 
+addto currentpicture also collection[202] shifted (   0,1.5h)
   withcolor (.5,.6,.7) ;
-addto currentpicture also collection[201] shifted (1.5h,   0) 
+addto currentpicture also collection[201] shifted (1.5h,   0)
   withcolor (.6,.7,.8) ;
-addto currentpicture also collection[206] shifted (1.5h,1.5h) 
+addto currentpicture also collection[206] shifted (1.5h,1.5h)
   withcolor (.4,.5,.6) ;
 
-collection[210] := currentpicture ; 
-currentpicture := nullpicture ; 
+collection[210] := currentpicture ;
+currentpicture := nullpicture ;
 
-bboxmargin := .25u; 
+bboxmargin := .25u;
 
 fill bbox collection[210] withcolor .95(1,1,0);
-addto currentpicture also collection[210] ; 
+addto currentpicture also collection[210] ;
 
-endfig ; 
+endfig ;
 
 end
diff --git a/metapost/context/base/mpiv/mp-tool.mpiv b/metapost/context/base/mpiv/mp-tool.mpiv
index 76459d25c..cd04b8dcb 100644
--- a/metapost/context/base/mpiv/mp-tool.mpiv
+++ b/metapost/context/base/mpiv/mp-tool.mpiv
@@ -11,8 +11,6 @@
 %C therefore copyrighted by \PRAGMA. See mreadme.pdf for
 %C details.
 
-% def loadfile(expr name) = scantokens("input " & name & ";") enddef ;
-
 if known context_tool : endinput ; fi ;
 
 boolean context_tool ; context_tool := true ;
@@ -28,7 +26,9 @@ let @## = @# ;
 
 if not known mpversion : string mpversion ; mpversion := "0.641" ; fi ;
 
-newinternal metapostversion ; metapostversion := scantokens(mpversion) ;
+% newinternal metapostversion ; metapostversion := scantokens(mpversion) ;
+
+newinternal metapostversion ; metapostversion := 2.0 ;
 
 %D We always want \EPS\ conforming output, so we say:
 
@@ -36,6 +36,10 @@ prologues    := 1 ;
 warningcheck := 0 ;
 mpprocset    := 1 ;
 
+%D Handy:
+
+def nothing = enddef ;
+
 %D Namespace handling:
 
 % let exclamationmark = ! ;
@@ -89,6 +93,47 @@ enddef ;
 let triplet    = rgbcolor ;
 let quadruplet = cmykcolor ;
 
+%D Image redefined, for Alan:
+
+vardef image@#(text t) =
+    save currentpicture ;
+    picture currentpicture ;
+    currentpicture := nullpicture ;
+    t ;
+    currentpicture
+    if str @# <> "" :
+        shifted (
+              mfun_labxf@#               * lrcorner p
+         +                 mfun_labyf@#  * ulcorner p
+         + (1-mfun_labxf@#-mfun_labyf@#) * llcorner p
+        )
+    fi
+enddef ;
+
+%D Variables
+
+def dispose suffix s =
+    if known s :
+        begingroup ;
+            save ss ;
+            if     numeric   s : numeric   ss
+            elseif boolean   s : boolean   ss
+            elseif pair      s : pair      ss
+            elseif path      s : path      ss
+            elseif picture   s : picture   ss
+            elseif string    s : string    ss
+            elseif transform s : transform ss
+            elseif color     s : color     ss
+            elseif rgbcolor  s : rgbcolor  ss
+            elseif cmykcolor s : cmykcolor ss
+            elseif pen       s : pen       ss
+            else             s : numeric   ss
+            fi ;
+            s := ss ;
+        endgroup ;
+    fi ;
+enddef ;
+
 %D Colors:
 
 newinternal nocolormodel   ; nocolormodel   := 1 ;
@@ -143,6 +188,8 @@ vardef colordecimals primary c =
         decimal cyanpart c & ":" & decimal magentapart c & ":" & decimal yellowpart c & ":" & decimal blackpart c
     elseif rgbcolor c :
         decimal redpart c & ":" & decimal greenpart c & ":" & decimal bluepart c
+    elseif string c:
+        colordecimals resolvedcolor(c)
     else :
         decimal c
     fi
@@ -335,6 +382,42 @@ enddef;
 %     mfun_a_b
 % enddef ;
 
+%D Here are some special ones, cooked up in the process of Alan's mp-node
+%D module:
+
+vardef boundingradius primary p =
+    if picture p :
+        max(
+            abs((llcorner p) shifted -center p),
+            abs((lrcorner p) shifted -center p),
+            abs((urcorner p) shifted -center p),
+            abs((ulcorner p) shifted -center p)
+        )
+    elseif pen p :
+        boundingradius image(draw makepath p ;)
+    elseif path p :
+        boundingradius image(draw p ;)
+    fi
+enddef ;
+
+vardef boundingcircle primary p =
+    fullcircle scaled 2boundingradius p shifted center p
+enddef ;
+
+vardef boundingpoint@#(expr p) =
+    if picture p : % pen?
+        (                 mfun_labxf@# *ulcorner p
+         +                mfun_labyf@# *lrcorner p
+         +(1-mfun_labxf@#-mfun_labyf@#)*urcorner p)
+    elseif path p :
+        boundingpoint@#(image(draw p ;))
+   %elseif pair p :
+   %    p
+   %else :
+   %    origin
+    fi
+enddef ;
+
 %D Some missing functions can be implemented rather straightforward (thanks to
 %D Taco and others):
 
@@ -373,6 +456,7 @@ vardef asinh  primary x = ln(x+(x++1))     enddef ;
 
 vardef sinh   primary x = save xx ; xx = exp x ; (xx-1/xx)/2 enddef ;
 vardef cosh   primary x = save xx ; xx = exp x ; (xx+1/xx)/2 enddef ;
+vardef tanh   primary x = save xx ; xx = exp x ; (xx-1/xx)/(xx+1/xx) enddef ;
 
 %D Like mod, but useful for anglesl it returns (-.5d,+.5d] and is used
 %D in for instance mp-chem.
@@ -715,7 +799,7 @@ primarydef p xyscaled q = % secundarydef does not work out well
     endgroup
 enddef ;
 
-%D Some personal code that might move to another module
+%D Some personal code that might move to another module (todo: save).
 
 def set_grid(expr w, h, nx, ny) =
     boolean grid[][] ; boolean grid_full ;
@@ -789,7 +873,7 @@ secondarydef p intersection_point q =
     begingroup
     save x_, y_ ;
     (x_,y_) = p intersectiontimes q ;
-    if x_<0 :
+    if x_< 0 :
         intersection_found := false ;
         center p % origin
     else :
@@ -817,36 +901,59 @@ enddef ;
 
 %D Some colors.
 
-def colortype(expr c) =
-    if cmykcolor c : cmykcolor elseif rgbcolor c : rgbcolor else : grayscale fi
+def resolvedcolor(expr s) =
+    .5white
+enddef ;
+
+let normalwithcolor = withcolor ;
+
+def withcolor expr c =
+    normalwithcolor if string c : resolvedcolor(c) else : c fi
 enddef ;
 
-vardef whitecolor(expr c) =
-    if cmykcolor c : (0,0,0,0) elseif rgbcolor c : (1,1,1)  else : 1 fi
+vardef colortype expr c =
+        if cmykcolor c : cmykcolor
+    elseif rgbcolor  c : rgbcolor
+    elseif numeric   c : grayscale
+        fi
+enddef ;
+
+vardef whitecolor expr c =
+        if cmykcolor c : (0,0,0,0)
+    elseif rgbcolor  c : (1,1,1)
+    elseif numeric   c : 1
+    elseif string    c : whitecolor resolvedcolor(c)
+        fi
 enddef ;
 
 vardef blackcolor expr c =
-    if cmykcolor c : (0,0,0,1) elseif rgbcolor c : (0,0,0)  else : 0 fi
+        if cmykcolor c : (0,0,0,1)
+    elseif rgbcolor  c : (0,0,0)
+    elseif numeric   c : 0
+    elseif string    c : blackcolor resolvedcolor(c)
+        fi
 enddef ;
 
-vardef complementary expr c = (
-        if cmykcolor c : (1,1,1,1) -
-    elseif rgbcolor  c : (1,1,1) -
-    elseif pair      c : (1,1) -
-    elseif numeric   c :  1 -
-        fi c
-) enddef ;
+vardef complementary expr c =
+        if cmykcolor c : (1,1,1,1) - c
+    elseif rgbcolor  c : (1,1,1) - c
+    elseif pair      c : (1,1) - c
+    elseif numeric   c :  1 - c
+    elseif string    c : complementary resolvedcolor(c)
+        fi
+enddef ;
 
 vardef complemented expr c =
     save m ;
         if cmykcolor c : m := max(cyanpart c, magentapart c, yellowpart c, blackpart c) ;
-                         ( (m,m,m,m) -
+                         (m,m,m,m) - c
     elseif rgbcolor  c : m := max(redpart c, greenpart c, bluepart c) ;
-                         ( (m,m,m) -
+                         (m,m,m) - c
     elseif pair      c : m := max(xpart c, ypart c) ;
-                         ( (m,m) -
-    elseif numeric   c : ( m -
-        fi c )
+                         (m,m) - c
+    elseif numeric   c : m - c
+    elseif string    c : complemented resolvedcolor(c)
+        fi
 enddef ;
 
 %D Well, this is the dangerous and naive version:
@@ -971,6 +1078,56 @@ primarydef p randomshifted s =
     endgroup
 enddef ;
 
+vardef mfun_randomized_path(expr p,s) =
+    for i=0 upto length(p)-1 :
+         (point       i    of p) .. controls
+        ((postcontrol i    of p) randomshifted s) and
+        ((precontrol (i+1) of p) randomshifted s) ..
+    endfor
+    if cycle p :
+        cycle
+    else :
+        (point length(p) of p)
+    fi
+enddef;
+
+vardef mfun_randomized_picture(expr p,s)(text rnd) =
+    save currentpicture ;
+    picture currentpicture ;
+    currentpicture := nullpicture ;
+    for i within p :
+        addto currentpicture
+            if stroked i :
+                doublepath pathpart i rnd s
+                dashed dashpart i
+                withpen penpart i
+                withcolor colorpart i
+                withprescript prescriptpart i
+                withpostscript postscriptpart i
+            elseif filled i :
+                contour pathpart i rnd s
+                withpen penpart i
+                withcolor colorpart i
+                withprescript prescriptpart i
+                withpostscript postscriptpart i
+            else :
+                also i
+            fi
+        ;
+    endfor ;
+    currentpicture
+enddef ;
+
+primarydef p randomizedcontrols s = (
+    if path p :
+        mfun_randomized_path(p,s)
+    elseif picture p :
+        mfun_randomized_picture(p,s)(randomizedcontrols)
+    else :
+        p randomized s
+    fi
+) enddef ;
+
 primarydef p randomized s = (
     if path p :
         for i=0 upto length(p)-1 :
@@ -1014,7 +1171,12 @@ primarydef p randomized s = (
         else :
             ((uniformdeviate s) * p)
         fi
+    elseif string p :
+        (resolvedcolor(p)) randomized s
+    elseif picture p :
+        mfun_randomized_picture(p,s)(randomized)
     else :
+      % p - s/2 + uniformdeviate s % would have been better but we want to be positive
         p + uniformdeviate s
     fi
 ) enddef ;
@@ -1165,6 +1327,15 @@ vardef arrowheadonpath (expr p, s) =
     arrowhead p if s < 1 : cutafter (point (s*arclength(p) + (ahlength/2)) on p) fi
 enddef ;
 
+def resetarrows =
+    hide (
+        ahlength  := 4 ;
+        ahangle   := 45 ;
+        ahvariant := 0 ;
+        ahdimple  := 1/5 ;
+    )
+enddef ;
+
 %D Points.
 
 def drawpoint expr c =
@@ -1384,13 +1555,12 @@ extra_beginfig := extra_beginfig & " miterlimit  := 10 ; "   ; % restores
 extra_beginfig := extra_beginfig & " linejoin := rounded ; " ; % restores
 extra_beginfig := extra_beginfig & " linecap  := rounded ; " ; % restores
 
-%D Normally, arrowheads don't scale well. So we provide a
-%D hack.
+%D Normally, arrowheads don't scale well. So we provide a hack.
 
 boolean autoarrows ; autoarrows := false ;
 numeric ahfactor   ; ahfactor   := 2.5 ;
 
-def set_ahlength (text t) =
+def set_ahlength (text t) = % called to often
   % ahlength := (ahfactor*pen_size(_op_ t)) ; % _op_ added
   % problem: _op_ can contain color so a no-go, we could apply the transform
   % but i need to figure out the best way (fakepicture and take components).
@@ -1413,31 +1583,158 @@ vardef arrowpath expr p = % patch by Peter Rolf: supports squared pen and shifti
     ))
 enddef;
 
-% def _finarr text t =
-%     if autoarrows : set_ahlength (t) fi ;
-%     draw     arrowpath _apth t ; % arrowpath added
-%     filldraw arrowhead _apth t ;
-% enddef;
+% New experimental extension: also handling pictures:
+%
+% drawarrow fullsquare scaled 2cm withcolor green ;
+% drawarrow fullcircle scaled 3cm withcolor green ;
+% drawarrow image (
+%     draw fullsquare scaled 4cm withcolor red ;
+%     draw fullcircle scaled 5cm withcolor blue ;
+% ) ;
+% currentpicture := currentpicture shifted (-bbwidth(currentpicture)-1cm,0) ;
+% drawdblarrow fullsquare scaled 2cm withcolor green ;
+% drawdblarrow fullcircle scaled 3cm withcolor green ;
+% drawdblarrow image (
+%     draw fullsquare scaled 4cm withcolor red ;
+%     draw fullcircle scaled 5cm withcolor blue ;
+% ) ;
+
+vardef stroked_paths(expr p) =
+    save n ; numeric n ; n := 0 ;
+    for i within p :
+        if stroked i :
+            n := n + 1 ;
+        fi
+    endfor ;
+    n
+enddef ;
 
-% def _finarr text t =
-%     if autoarrows : set_ahlength (t) fi ;
-%     draw arrowpath _apth t ; % arrowpath added
-%     fill arrowhead _apth t ;
-%     draw arrowhead _apth t ;
-% enddef;
+def mfun_decoration_i expr i =
+    withpen penpart i
+    withcolor colorpart i
+    withprescript prescriptpart i
+    withpostscript postscriptpart i
+enddef ;
 
-% def _finarr text t =
-%     if autoarrows : set_ahlength (t) fi ;
-%     draw arrowpath _apth t ; % arrowpath added
-%     fill arrowhead _apth t ;
-%     draw arrowhead _apth t undashed ;
-% enddef;
+% We could collapse all in one helper but in context we nowaways don't want
+% the added obscurity. Tokens come cheap.
 
-def _finarr text t =
-    if autoarrows : set_ahlength (t) fi ;
-    draw arrowpath _apth t ; % arrowpath added
-    fillup arrowhead _apth t ;
-enddef;
+numeric mfun_arrow_snippets ;
+numeric mfun_arrow_count ;
+
+def drawarrow expr p =
+    begingroup ;
+    save mfun_arrow_path ;
+    path mfun_arrow_path ;
+    if path p :
+        mfun_arrow_path := p ;
+        expandafter mfun_draw_arrow_path
+    elseif picture p :
+        save mfun_arrow_picture ;
+        picture mfun_arrow_picture ;
+        mfun_arrow_picture := p ;
+        expandafter mfun_draw_arrow_picture
+    else :
+        expandafter mfun_draw_arrow_nothing
+    fi
+enddef ;
+
+def drawdblarrow expr p =
+    begingroup ;
+    save mfun_arrow_path ;
+    path mfun_arrow_path ;
+    if path p :
+        mfun_arrow_path := p ;
+        expandafter mfun_draw_arrow_path_double
+    elseif picture p :
+        save mfun_arrow_picture ;
+        picture mfun_arrow_picture ;
+        mfun_arrow_picture := p ;
+        expandafter mfun_draw_arrow_picture_double
+    else :
+        expandafter mfun_draw_arrow_nothing
+    fi
+enddef ;
+
+def mfun_draw_arrow_nothing text t =
+enddef ;
+
+% The path is shortened so that the arrow head extends it to the original
+% length. In case of a double arrow the path gets shortened twice.
+
+def mfun_draw_arrow_path text t =
+    if autoarrows :
+        set_ahlength(t) ;
+    fi
+    draw arrowpath mfun_arrow_path t ;
+    fillup arrowhead mfun_arrow_path t ;
+    endgroup ;
+enddef ;
+
+def mfun_draw_arrow_path_double text t =
+    if autoarrows :
+        set_ahlength(t) ;
+    fi
+    draw arrowpath (reverse arrowpath mfun_arrow_path) t ;
+    fillup arrowhead mfun_arrow_path t ;
+    fillup arrowhead reverse mfun_arrow_path t ;
+    endgroup ;
+enddef ;
+
+% The picture variant is not treating each path but only the first and
+% last path. This can be somewhat counterintuitive but is needed for Alan's
+% macros. So here the last and in case of a double path first paths in a
+% picture get the shortening.
+
+def mfun_with_arrow_picture (text t) =
+    mfun_arrow_count := 0 ;
+    mfun_arrow_snippets := stroked_paths(mfun_arrow_picture) ;
+    for i within mfun_arrow_picture :
+        if stroked i :
+            mfun_arrow_count := mfun_arrow_count + 1 ;
+            mfun_arrow_path := pathpart i ;
+            t
+        fi ;
+    endfor ;
+enddef ;
+
+def mfun_draw_arrow_picture text t =
+    if autoarrows :
+        set_ahlength(t) ;
+    fi
+    mfun_with_arrow_picture (
+        if mfun_arrow_count = mfun_arrow_snippets :
+            draw arrowpath mfun_arrow_path mfun_decoration_i i t ;
+            fillup arrowhead mfun_arrow_path mfun_decoration_i i t ;
+        else :
+            draw mfun_arrow_path mfun_decoration_i i t ;
+        fi ;
+    )
+    endgroup ;
+enddef ;
+
+def mfun_draw_arrow_picture_double text t =
+    if autoarrows :
+        set_ahlength(t) ;
+    fi
+    mfun_with_arrow_picture (
+        draw
+            if mfun_arrow_count = 1 :
+                arrowpath reverse
+            fi
+            if mfun_arrow_count = mfun_arrow_snippets :
+                arrowpath
+            fi
+            mfun_arrow_path mfun_decoration_i i t ;
+        if mfun_arrow_count = 1 :
+            fillup arrowhead reverse mfun_arrow_path mfun_decoration_i i t ;
+        fi
+        if mfun_arrow_count = mfun_arrow_snippets :
+            fillup arrowhead mfun_arrow_path mfun_decoration_i i t ;
+        fi
+    )
+    endgroup ;
+enddef ;
 
 %D Handy too ......
 
@@ -1487,9 +1784,7 @@ enddef ;
 
 %D To be documented.
 
-path freesquare ;
-
-freesquare := (
+path freesquare ; freesquare := (
     (-1,0) -- (-1,-1) -- (0,-1) -- (+1,-1) --
     (+1,0) -- (+1,+1) -- (0,+1) -- (-1,+1) -- cycle
 ) scaled .5 ;
@@ -1637,7 +1932,7 @@ enddef ;
 
 % nice: currentpicture := inverted currentpicture ;
 
-primarydef p uncolored c =
+primarydef p uncolored c = % not complete ... needs text and scripts and ...
     if color p :
         c - p
     else :
@@ -1699,6 +1994,8 @@ vardef grayed primary p =
         tripled(.30*(1-cyanpart i)+.59*(1-magentapart i)+.11*(1-yellowpart i)+blackpart i)
     elseif greycolor p :
         p
+    elseif string p :
+        grayed resolvedcolor(p)
     elseif picture p :
         image (
             for i within p :
@@ -1854,14 +2151,16 @@ inner end ;
 
 % this will be redone (when needed) using scripts and backend handling
 
-let normalwithcolor = withcolor ;
+let mfun_remap_colors_normalwithcolor = normalwithcolor ;
 
 def remapcolors =
-    def withcolor primary c = normalwithcolor remappedcolor(c) enddef ;
+    def normalwithcolor primary c =
+        mfun_remap_colors_normalwithcolor remappedcolor(c)
+    enddef ;
 enddef ;
 
 def normalcolors =
-    let withcolor = normalwithcolor ;
+    let normalwithcolor = mfun_remap_colors_normalwithcolor ;
 enddef ;
 
 def resetcolormap =
@@ -1912,7 +2211,7 @@ def reprocess suffix p = p := repathed (22,p) enddef ; % no attributes
 vardef repathed (expr mode, p) text t =
     begingroup ;
     if mode = 0 :
-        save withcolor ;
+        save normalwithcolor ;
         remapcolors ;
     fi ;
     save _p_, _pp_, _ppp_, _f_, _b_, _t_ ;
@@ -2138,8 +2437,22 @@ vardef mfun_straightened(expr sign, p) =
     _q_
 enddef ;
 
+% vardef mfun_straightened(expr sign, p) =
+%     save lp, lq, q ; path q ; q := p ;
+%     lp := length(p) ;
+%     forever :
+%         q := mfun_do_straightened(sign,q) ;
+%         lq := length(q) ;
+%         exitif lp = lq ;
+%         lp := lq ;
+%     endfor ;
+%     q
+% enddef ;
+
+% can be optimized:
+
 vardef mfun_do_straightened(expr sign, p) =
-    if length(p)>2 : % was 1, but straight lines are ok
+    if length(p) > 2 : % was 1, but straight lines are ok
         save pp ; path pp ;
         pp := point 0 of p ;
         for i=1 upto length(p)-1 :
@@ -2149,10 +2462,10 @@ vardef mfun_do_straightened(expr sign, p) =
         endfor ;
         save n, ok ; numeric n ; boolean ok ;
         n := length(pp) ; ok := false ;
-        if n>2 :
-            for i=0 upto n : % evt hier ook round
+        if n > 2 :
+            for i=0 upto n :
                 if unitvector(round(point i of pp - point if i=0 : n else : i-1 fi of pp)) <>
-                        sign * unitvector(round(point if i=n : 0 else : i+1 fi of pp - point i of pp)) :
+            sign * unitvector(round(point if i=n : 0 else : i+1 fi of pp - point i of pp)) :
                     if ok :
                         --
                     else :
@@ -2198,7 +2511,7 @@ vardef unspiked expr p = (
 path originpath ; originpath := origin -- cycle ;
 
 vardef unitvector primary z =
-    if abs z = abs origin : z else : z/abs z fi
+    if abs z = abs origin : z else : z/abs z fi % hm, abs origin is just origin
 enddef;
 
 % also new
@@ -2523,41 +2836,41 @@ vardef undecorated (text imagedata) text decoration =
     currentpicture
 enddef ;
 
-if metapostversion < 1.770  :
-
-    vardef decorated (text imagedata) text decoration =
-        save mfun_decorated_path, currentpicture ;
-        picture mfun_decorated_path, currentpicture ;
-        currentpicture := nullpicture ;
-        imagedata ;
-        mfun_decorated_path := currentpicture ;
-        currentpicture := nullpicture ;
-        for i within mfun_decorated_path :
-            addto currentpicture
-                if stroked i :
-                    doublepath pathpart i
-                    dashed dashpart i
-                    withpen penpart i
-                    withcolor colorpart i
-                    decoration
-                elseif filled i :
-                    contour pathpart i
-                    withpen penpart i
-                    withcolor colorpart i
-                    decoration
-                elseif textual i :
-                    also i
-                    withcolor colorpart i
-                    decoration
-                else :
-                    also i
-                fi
-            ;
-        endfor ;
-        currentpicture
-    enddef ;
-
-else:
+% if metapostversion < 1.770  :
+%
+%     vardef decorated (text imagedata) text decoration =
+%         save mfun_decorated_path, currentpicture ;
+%         picture mfun_decorated_path, currentpicture ;
+%         currentpicture := nullpicture ;
+%         imagedata ;
+%         mfun_decorated_path := currentpicture ;
+%         currentpicture := nullpicture ;
+%         for i within mfun_decorated_path :
+%             addto currentpicture
+%                 if stroked i :
+%                     doublepath pathpart i
+%                     dashed dashpart i
+%                     withpen penpart i
+%                     withcolor colorpart i
+%                     decoration
+%                 elseif filled i :
+%                     contour pathpart i
+%                     withpen penpart i
+%                     withcolor colorpart i
+%                     decoration
+%                 elseif textual i :
+%                     also i
+%                     withcolor colorpart i
+%                     decoration
+%                 else :
+%                     also i
+%                 fi
+%             ;
+%         endfor ;
+%         currentpicture
+%     enddef ;
+%
+% else:
 
     vardef decorated (text imagedata) text decoration =
         save mfun_decorated_path, currentpicture ;
@@ -2597,7 +2910,7 @@ else:
         currentpicture
     enddef ;
 
-fi ;
+% fi ;
 
 vardef redecorated (text imagedata) text decoration =
     save mfun_decorated_path, currentpicture ;
@@ -2726,4 +3039,431 @@ enddef;
 
 extra_endfig := extra_endfig & "mfun_apply_max_dimensions ;" ;
 
+%D Bonus shapes (need along):
+
+path unittriangle, fulltriangle ; % not really units but circle based
+
+unittriangle := point 0   along unitcircle
+             -- point 1/3 along unitcircle
+             -- point 2/3 along unitcircle
+             -- cycle ;
+fulltriangle := point 0   along fullcircle
+             -- point 1/3 along fullcircle
+             -- point 2/3 along fullcircle
+             -- cycle ;
+
+%D Kind of special and undocumented. On Wikipedia one can find examples
+%D of quick sort routines. Here we have a variant that permits a
+%D method.
+
+% vardef listsize(suffix list) =
+%     numeric len ; len := 0 ;
+%     forever :
+%         exitif unknown list[len+1] ;
+%         len := len + 1 ;
+%     endfor ;
+%     len
+% enddef ;
+
+vardef listsize(suffix list) =
+    numeric len ; len := 1 ;
+    forever :
+        exitif unknown list[len] ;
+        len := len + 1 ;
+    endfor ;
+    len if unknown list[0] : - 1 fi
+enddef ;
+
+vardef listlast(suffix list) =
+    numeric len ; len := if known list[0] : 0 else : 1 fi  ;
+    forever :
+        len := len + 1 ;
+        exitif unknown list[len] ;
+    endfor ;
+    len - 1
+enddef ;
+
+vardef mfun_quick_sort(suffix list)(expr _min_, _max_)(text what) =
+    save l, r, m ;
+    numeric l ; l := _min_ ;
+    numeric r ; r := _max_ ;
+    numeric m ; m := floor(.5[_min_,_max_]) ;
+    _mid_ := what list[m] ;
+    forever :
+        exitif l >= r ;
+        forever :
+            exitif l > _max_ ;
+          % exitif (what list[l]) >= (what list[m]) ;
+            exitif (what list[l]) >= _mid_ ;
+            l := l + 1 ;
+        endfor ;
+        forever :
+            exitif r < _min_ ;
+          % exitif (what list[m]) >= (what list[r]) ;
+            exitif _mid_ >= (what list[r]) ;
+            r := r - 1 ;
+        endfor ;
+        if l <= r :
+          temp := list[l] ;
+          list[l] := list[r] ;
+          list[r] := temp ;
+          l := l + 1 ;
+          r := r - 1 ;
+        fi ;
+    endfor ;
+    if _min_ < r :
+        mfun_quick_sort(list)(_min_,r)(what) ;
+    fi ;
+    if l < _max_ :
+        mfun_quick_sort(list)(l,_max_)(what) ;
+    fi ;
+enddef ;
+
+vardef sortlist(suffix list)(text what) =
+    save _max_ ; numeric _max_ ;
+    save _mid_ ; numeric _mid_ ;
+    save temp ;
+  % _max_ := listsize(list) ;
+    _max_ := listlast(list) ;
+    if pair list[_max_] :
+        pair temp ;
+    else :
+        numeric temp ;
+    fi ;
+    if pair what list[_max_] :
+        pair _mid_ ;
+    else :
+        numeric _mid_ ;
+    fi ;
+    if _max_ > 1 :
+      % mfun_quick_sort(list)(1,_max_)(what) ;
+        mfun_quick_sort(list)(if known list[0] : 0 else : 1 fi,_max_)(what) ;
+    fi ;
+enddef ;
+
+vardef uniquelist(suffix list) =
+    % this one will be defined later
+enddef ;
+
+vardef copylist(suffix list, target) =
+    save i ; i := 1 ;
+    forever :
+        exitif unknown list[i] ;
+        target[i] := list[i] ;
+        i := i + 1 ;
+    endfor ;
+enddef ;
+
+vardef listtolines(suffix list) =
+    list[1] for i=2 upto listsize(list) : -- list[i] endfor
+enddef ;
+
+vardef listtocurves(suffix list) =
+    list[1] for i=2 upto listsize(list) : .. list[i] endfor
+enddef ;
+
+%D The sorter is used in:
+
+% not yet ok
+
+vardef shapedlist(suffix p) = % takes a list of paths
+    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-1] := (xpart r[i-1],ypart r[i]) ;
+        fi ;
+        if xpart l[i] < xpart l[i-1] :
+            l[i-1] := (xpart l[i-1],ypart l[i]) ;
+        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 ;
+
+%D Dumping is fake anyway but let's keep this:
+
 let dump = relax ;
+
+%D Loading modules can be done with:
+
+def loadmodule expr name = % no vardef
+    % input can't be used directly in a macro
+    if unknown scantokens("context_" & name) :
+        save s ; string s ;
+      % s := "mp-" & name & ".mpiv" ;
+      % message("loading module",s) ;
+      % s := "input " & s ;
+        s := "input " & "mp-" & name & ".mpiv" ;
+        expandafter scantokens expandafter s
+    fi ;
+enddef ;
+
+%D Handy for backgrounds:
+
+def drawpathwithpoints expr p =
+    do_drawpathwithpoints(p)
+enddef ;
+
+def do_drawpathwithpoints(expr p) text t =
+    draw p t ;
+    if length(p) > 2 :
+        begingroup ;
+        save _c_ ; path _c_ ;
+        save _p_; picture _p_ ;
+        _p_ := image (
+            _c_ := if cycle p : fullsquare else : fullcircle fi scaled 6pt ;
+            for i=0 upto length(p) if cycle p : -1 fi :
+                fill _c_ shifted point i of p withcolor white ;
+                draw _c_ shifted point i of p withcolor white/2 withpen pencircle scaled .5pt ;
+                if (i = 0) and cycle p :
+                    _c_ := fullcircle scaled 6pt ;
+                fi ;
+            endfor ;
+            for i=0 upto length(p) if cycle p : -1 fi :
+                draw textext("\infofont " & decimal i) ysized 2pt shifted point i of p ;
+            endfor ;
+        ) ;
+        setbounds _p_ to boundingbox p ;
+        draw _p_ ;
+    fi ;
+enddef ;
+
+%D These new helpers are by Alan and are used in for instance the mp-node
+%D module.
+
+newinternal crossingdebug     ; crossingdebug     := 0 ;
+newinternal crossingscale     ; crossingscale     := 10 ;
+newinternal crossingnumbermax ; crossingnumbermax := 1000 ;
+
+% primary, secondary or tertiary? always hard to decide but primary makes sense
+
+vardef infotext@#(expr txt, ysize) =
+    textext@#("\infofont " & if numeric txt : decimal fi txt) ysized ysize
+enddef ;
+
+primarydef p crossingunder q =
+    begingroup
+    save pic ; picture pic ; pic := nullpicture ;
+    if picture p :
+        for i within p :
+            if stroked i :
+                addto pic also image(draw pathpart i crossingunder q) ;
+            fi
+        endfor
+    elseif path p :
+        save n, t, a, b, c, r, bcuttings, hold ;
+        numeric n, t[], hold ;
+        path a, b, c, r, bcuttings, hold[] ;
+        c := makepath(currentpen scaled crossingscale) ;
+        r := if picture q : boundingbox fi q ;
+        t[0] := n := hold := 0 ;
+        a := p ;
+        % The cutbefore/cutafter using c below prevents endless loops!
+       %forever : % find all intersections
+        for i=1 upto crossingnumbermax : % safeguard
+            clearxy ; z = a intersectiontimes r ;
+            if x < 0 :
+                exitif hold < 1 ;
+                a := hold[hold] ; hold := hold - 1 ;
+                clearxy ; z = a intersectiontimes r ;
+            fi
+            (t[incr n], whatever) = p intersectiontimes point x of a ;
+            if x = 0 :
+                a := a cutbefore c shifted point x of a ;
+            elseif x = length a :
+                a := a cutafter  c shifted point x of a ;
+            else : % before or after?
+                b := subpath (0,x)        of a cutafter  c shifted point x of a ;
+                bcuttings := cuttings ;
+                a := subpath (x,length a) of a cutbefore c shifted point x of a ;
+                clearxy ; z = a intersectiontimes r ;
+                if x < 0 :
+                    a := b ;
+                    cuttings := bcuttings ;
+                else :
+                    if length bcuttings > 0 :
+                        clearxy ; z = b intersectiontimes r ;
+                        if x >= 0 :
+                            hold[incr hold] := b ;
+                        fi
+                    fi
+                fi
+            fi
+            if length cuttings = 0 : % a single point: nothing cut
+                exitif hold < 1 ;
+                a := hold[hold] ; hold := hold - 1 ;
+            fi
+            if i = crossingnumbermax :
+                message("crossingunder reached maximum " & decimal i &
+                        " intersections.");
+            fi
+        endfor
+
+        if n = 0 : % No crossings, we return the PATH
+            save pic ; path pic ; pic := p ;
+        else : % n>0
+            sortlist(t,) ;
+            % we add too much, maybe a test is needed
+            t[incr n] = length p if cycle p : + t[1] fi ;
+% save tt[] ; numeric tt[] ; uniquelist(t,tt) ; t := tt ;
+            % Now, n>1 !
+            % t[0] is the first point of the path and t[n] is the last point
+            % (or the first intersection beyond the length if cyclic)
+            save m ; m := 0 ;
+            for i=if cycle p: 2 else: 1 fi upto n :
+                % skip the first segment if cyclic
+                % as it gets repeated (fully) at the end.
+                if crossingdebug > 0 :
+                    if crossingdebug = 1 :
+                        addto pic doublepath c shifted point t[i] of p
+                        withpen currentpen withtransparency(1,.5) ;
+                    elseif crossingdebug = 2 :
+                        addto pic also
+                        infotext (incr m,crossingscale/5)
+                        shifted point t[i] of p ;
+                    fi
+                fi
+                a := subpath (t[i-1],t[i]) of p
+                    if i > 1 :
+                        cutbefore (c shifted point t[i-1] of p)
+                    fi
+                    if (i < n) or (cycle p) :
+                        cutafter  (c shifted point t[i]   of p)
+                    fi ;
+                if (not picture q) or (a outsideof q) :
+                    addto pic doublepath a withpen currentpen ;
+                fi
+            endfor
+        fi
+    fi
+    pic
+    endgroup
+enddef ;
+
+primarydef p insideof q =
+    begingroup
+        save pth, pic, t ;
+        path pth ; picture pic ;
+        pic := if path q : image(draw q;) else : q fi ;
+        pth := p -- center pic ;
+        (t, whatever) = pth intersectiontimes boundingbox pic ;
+        t < 0
+    endgroup
+enddef ;
+
+% primarydef p insideof q =
+%     if (path q or picture q) :
+%         if (path p or picture p) :
+%             (xpart llcorner p > xpart llcorner q) and
+%             (xpart urcorner p < xpart urcorner q) and
+%             (ypart llcorner p > ypart llcorner q) and
+%             (ypart urcorner p < ypart urcorner q)
+%         elseif pair p  :
+%             (xpart p > xpart llcorner q) and
+%             (xpart p < xpart urcorner q) and
+%             (ypart p > ypart llcorner q) and
+%             (ypart p < ypart urcorner q)
+%         fi
+%     elseif (numeric p and pair q) :
+%         % range check
+%         (p >= xpart q) and (p <= ypart q)
+%     else : % maybe triplets and such
+%         false
+%     fi
+% enddef ;
+
+primarydef p outsideof q =
+    not (p insideof q)
+enddef ;
+
+%D Also handy:
+
+vardef circularpath primary n =
+    reverse (for i=0 step 2/n until 8-2/n+2eps: point i of fullcircle .. endfor cycle) rotated 90
+enddef ;
+
+vardef squarepath primary n =
+    for i=0 step 1/n until 4-1/n + 2eps: point i of fullsquare -- endfor cycle
+enddef ;
+
+vardef linearpath primary n =
+    origin for i=1/n step 1/n until 1-1/n + 2eps: -- point i of (origin--(1,0)) endfor
+enddef ;
+
+%D  A nice tracing helper:
+
+color       pensilcolor ; pensilcolor := .5red ;
+newinternal pensilstep  ; pensilstep  := 1/25 ;
+
+vardef pensilled(expr p, q) =
+    image (
+        draw p withcolor pensilcolor withpen q ;
+        for i = 0 step pensilstep until length(p) + eps:
+            draw point i of p withcolor white withtransparency (1,.5) withpen q ;
+        endfor ;
+    )
+enddef ;
+
+%D Easy to forget but handy for manuals:
+
+vardef tolist(suffix l)(text t) =
+    save n ; n := 1 ;
+    for p = t :
+        if numeric p :
+            n := p ;
+            dispose(l[n])
+        elseif pair p :
+            l[n] := p ;
+            n := n + 1 ;
+        elseif path p :
+            for i=0 step 1 until length(p) :
+                l[n] := point i of p ;
+                n := n + 1 ;
+            endfor ;
+        else :
+            % ignore
+        fi ;
+    endfor ;
+    forever :
+        exitif unknown l[n] ;
+        dispose(l[n])
+        n := n + 1 ;
+    endfor ;
+enddef ;
+
+vardef topath(suffix p)(text t) =
+    save i ; i := if known p[1] : 2 ; p[1] elseif known p[0] : 1 ; p[0] else : 0 ; origin fi
+    forever :
+        exitif unknown p[i] ;
+        t p[i]
+        hide(i := i + 1)
+    endfor
+enddef ;
+
+vardef tocycle(suffix p)(text t) =
+    topath(p,t) t cycle
+enddef ;