2016-01-12 16:26:00

1 files changed, 664 insertions, 0 deletions

diff --git a/metapost/context/base/mpiv/mp-page.mpiv b/metapost/context/base/mpiv/mp-page.mpiv
new file mode 100644
index 000000000..a6fa3fba3
--- /dev/null
+++ b/metapost/context/base/mpiv/mp-page.mpiv
@@ -0,0 +1,664 @@
+%D \module
+%D   [       file=mp-page.mpiv,
+%D        version=1999.03.10,
+%D          title=\CONTEXT\ \METAPOST\ graphics,
+%D       subtitle=page enhancements,
+%D         author=Hans Hagen,
+%D           date=\currentdate,
+%D      copyright={PRAGMA ADE \& \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 This module is rather preliminary and subjected to changes.
+
+if known context_page : endinput ; fi ;
+
+boolean context_page ; context_page := true ;
+
+% def LoadPageState =
+%     % now always set
+% enddef ;
+%
+% if unknown PageStateAvailable :
+%     boolean PageStateAvailable ;
+%     PageStateAvailable := false ;
+% fi ;
+%
+% if unknown OnRightPage :
+%     boolean OnRightPage ;
+%     OnRightPage := true ;
+% fi ;
+%
+% if unknown OnOddPage :
+%     boolean OnOddPage ;
+%     OnOddPage := true ;
+% fi ;
+%
+% if unknown InPageBody :
+%     boolean InPageBody ;
+%     InPageBody := false ;
+% fi ;
+%
+% string CurrentLayout ;
+%
+% CurrentLayout       := "default" ;
+%
+% PageNumber          := 0 ;
+% PaperHeight         := 845.04684pt  ;
+% PaperWidth          := 597.50787pt  ;
+% PrintPaperHeight    := 845.04684pt  ;
+% PrintPaperWidth     := 597.50787pt  ;
+% TopSpace            :=  71.12546pt  ;
+% BottomSpace         :=   0.0pt      ;
+% BackSpace           :=  71.13275pt  ;
+% CutSpace            :=   0.0pt      ;
+% MakeupHeight        := 711.3191pt   ;
+% MakeupWidth         := 426.78743pt  ;
+% TopHeight           :=   0.0pt      ;
+% TopDistance         :=   0.0pt      ;
+% HeaderHeight        :=  56.90294pt  ;
+% HeaderDistance      :=   0.0pt      ;
+% TextHeight          := 597.51323pt  ;
+% FooterDistance      :=   0.0pt      ;
+% FooterHeight        :=  56.90294pt  ;
+% BottomDistance      :=   0.0pt      ;
+% BottomHeight        :=   0.0pt      ;
+% LeftEdgeWidth       :=   0.0pt      ;
+% LeftEdgeDistance    :=   0.0pt      ;
+% LeftMarginWidth     :=   75.58197pt ;
+% LeftMarginDistance  :=   11.99829pt ;
+% TextWidth           :=  426.78743pt ;
+% RightMarginDistance :=   11.99829pt ;
+% RightMarginWidth    :=   75.58197pt ;
+% RightEdgeDistance   :=    0.0pt     ;
+% RightEdgeWidth      :=    0.0pt     ;
+%
+% PageOffset          :=    0.0pt     ;
+% PageDepth           :=    0.0pt     ;
+%
+% LayoutColumns       :=    0         ;
+% LayoutColumnDistance:=    0.0pt     ;
+% LayoutColumnWidth   :=    0.0pt     ;
+%
+% LeftEdge             :=  -4 ; Top             := -40 ;
+% LeftEdgeSeparator    :=  -3 ; TopSeparator    := -30 ;
+% LeftMargin           :=  -2 ; Header          := -20 ;
+% LeftMarginSeparator  :=  -1 ; HeaderSeparator := -10 ;
+% Text                 :=   0 ; Text            :=   0 ;
+% RightMarginSeparator :=  +1 ; FooterSeparator := +10 ;
+% RightMargin          :=  +2 ; Footer          := +20 ;
+% RightEdgeSeparator   :=  +3 ; BottomSeparator := +30 ;
+% RightEdge            :=  +4 ; Bottom          := +40 ;
+%
+% Margin      := LeftMargin  ; % obsolete
+% Edge        := LeftEdge    ; % obsolete
+% InnerMargin := RightMargin ; % obsolete
+% InnerEdge   := RightEdge   ; % obsolete
+% OuterMargin := LeftMargin  ; % obsolete
+% OuterEdge   := LeftEdge    ; % obsolete
+%
+% InnerMarginWidth     := 0pt ;
+% OuterMarginWidth     := 0pt ;
+% InnerMarginDistance  := 0pt ;
+% OuterMarginDistance  := 0pt ;
+%
+% InnerEdgeWidth     := 0pt ;
+% OuterEdgeWidth     := 0pt ;
+% InnerEdgeDistance  := 0pt ;
+% OuterEdgeDistance  := 0pt ;
+%
+% % path Area[][] ;
+% % pair Location[][] ;
+% % path Field[][] ;
+%
+% % numeric Hstep[] ;
+% % numeric Hsize[] ;
+% % numeric Vstep[] ;
+% % numeric Vsize[] ;
+%
+% path Page ;
+%
+% numeric HorPos ;
+% numeric VerPos ;
+%
+% % for VerPos=Top step 10 until Bottom:
+% %     for HorPos=LeftEdge step 1 until RightEdge:
+% %         Area[HorPos][VerPos] := origin--cycle ;
+% %         Area[VerPos][HorPos] := Area[HorPos][VerPos] ;
+% %         Location[HorPos][VerPos] := origin ;
+% %         Location[VerPos][HorPos] := Location[HorPos][VerPos] ;
+% %         Field[HorPos][VerPos] := origin--cycle ;
+% %         Field[VerPos][HorPos] := Field[HorPos][VerPos] ;
+% %     endfor ;
+% % endfor ;
+%
+% % def LoadPageState =
+% %   scantokens "input mp-state.tmp" ;
+% % enddef ;
+%
+% numeric mfun_temp ;
+%
+% def SwapPageState =
+%     if not OnRightPage :
+%              BackSpace := PaperWidth-MakeupWidth-BackSpace ;
+%               CutSpace := PaperWidth-MakeupWidth-CutSpace ;
+%              mfun_temp := LeftMarginWidth ;
+%        LeftMarginWidth := RightMarginWidth ;
+%       RightMarginWidth := mfun_temp ;
+%              mfun_temp := LeftMarginDistance ;
+%     LeftMarginDistance := RightMarginDistance ;
+%    RightMarginDistance := mfun_temp ;
+%              mfun_temp := LeftEdgeWidth ;
+%          LeftEdgeWidth := RightEdgeWidth ;
+%         RightEdgeWidth := mfun_temp ;
+%              mfun_temp := LeftEdgeDistance ;
+%       LeftEdgeDistance := RightEdgeDistance ;
+%      RightEdgeDistance := mfun_temp ;
+%
+%   % these are now available as ..Width and ..Distance
+%
+%                 Margin := LeftMargin ;
+%                   Edge := LeftEdge ;
+%            InnerMargin := RightMargin ;
+%              InnerEdge := RightEdge ;
+%            OuterMargin := LeftMargin ;
+%              OuterEdge := LeftEdge ;
+%     else :
+%                 Margin := RightMargin ;
+%                   Edge := RightEdge ;
+%            InnerMargin := LeftMargin ;
+%              InnerEdge := LeftEdge ;
+%            OuterMargin := RightMargin ;
+%              OuterEdge := RightEdge ;
+%     fi ;
+% enddef ;
+
+% the new way:
+
+def LoadPageState =
+    % now always set
+enddef ;
+
+if unknown PageStateAvailable :
+    boolean PageStateAvailable ;
+    PageStateAvailable := false ;
+fi ;
+
+string CurrentLayout ; CurrentLayout := "default" ;
+
+vardef PaperHeight          = lua.mp.PaperHeight         () enddef ;
+vardef PaperWidth           = lua.mp.PaperWidth          () enddef ;
+vardef PrintPaperHeight     = lua.mp.PrintPaperHeight    () enddef ;
+vardef PrintPaperWidth      = lua.mp.PrintPaperWidth     () enddef ;
+vardef TopSpace             = lua.mp.TopSpace            () enddef ;
+vardef BottomSpace          = lua.mp.BottomSpace         () enddef ;
+vardef BackSpace            = lua.mp.BackSpace           () enddef ;
+vardef CutSpace             = lua.mp.CutSpace            () enddef ;
+vardef MakeupHeight         = lua.mp.MakeupHeight        () enddef ;
+vardef MakeupWidth          = lua.mp.MakeupWidth         () enddef ;
+vardef TopHeight            = lua.mp.TopHeight           () enddef ;
+vardef TopDistance          = lua.mp.TopDistance         () enddef ;
+vardef HeaderHeight         = lua.mp.HeaderHeight        () enddef ;
+vardef HeaderDistance       = lua.mp.HeaderDistance      () enddef ;
+vardef TextHeight           = lua.mp.TextHeight          () enddef ;
+vardef FooterDistance       = lua.mp.FooterDistance      () enddef ;
+vardef FooterHeight         = lua.mp.FooterHeight        () enddef ;
+vardef BottomDistance       = lua.mp.BottomDistance      () enddef ;
+vardef BottomHeight         = lua.mp.BottomHeight        () enddef ;
+vardef LeftEdgeWidth        = lua.mp.LeftEdgeWidth       () enddef ;
+vardef LeftEdgeDistance     = lua.mp.LeftEdgeDistance    () enddef ;
+vardef LeftMarginWidth      = lua.mp.LeftMarginWidth     () enddef ;
+vardef LeftMarginDistance   = lua.mp.LeftMarginDistance  () enddef ;
+vardef TextWidth            = lua.mp.TextWidth           () enddef ;
+vardef RightMarginDistance  = lua.mp.RightMarginDistance () enddef ;
+vardef RightMarginWidth     = lua.mp.RightMarginWidth    () enddef ;
+vardef RightEdgeDistance    = lua.mp.RightEdgeDistance   () enddef ;
+vardef RightEdgeWidth       = lua.mp.RightEdgeWidth      () enddef ;
+vardef InnerMarginDistance  = lua.mp.InnerMarginDistance () enddef ;
+vardef InnerMarginWidth     = lua.mp.InnerMarginWidth    () enddef ;
+vardef OuterMarginDistance  = lua.mp.OuterMarginDistance () enddef ;
+vardef OuterMarginWidth     = lua.mp.OuterMarginWidth    () enddef ;
+vardef InnerEdgeDistance    = lua.mp.InnerEdgeDistance   () enddef ;
+vardef InnerEdgeWidth       = lua.mp.InnerEdgeWidth      () enddef ;
+vardef OuterEdgeDistance    = lua.mp.OuterEdgeDistance   () enddef ;
+vardef OuterEdgeWidth       = lua.mp.OuterEdgeWidth      () enddef ;
+vardef PageOffset           = lua.mp.PageOffset          () enddef ;
+vardef PageDepth            = lua.mp.PageDepth           () enddef ;
+vardef LayoutColumns        = lua.mp.LayoutColumns       () enddef ;
+vardef LayoutColumnDistance = lua.mp.LayoutColumnDistance() enddef ;
+vardef LayoutColumnWidth    = lua.mp.LayoutColumnWidth   () enddef ;
+
+vardef OnRightPage          = lua.mp.OnRightPage         () enddef ;
+vardef OnOddPage            = lua.mp.OnOddPage           () enddef ;
+vardef InPageBody           = lua.mp.InPageBody          () enddef ;
+
+vardef RealPageNumber       = lua.mp.RealPageNumber      () enddef ;
+vardef PageNumber           = lua.mp.PageNumber          () enddef ;
+vardef NOfPages             = lua.mp.NOfPages            () enddef ;
+vardef LastPageNumber       = lua.mp.LastPageNumber      () enddef ; % duplicates
+
+vardef CurrentColumn        = lua.mp.CurrentColumn       () enddef ;
+vardef NOfColumns           = lua.mp.NOfColumns          () enddef ;
+
+vardef BaseLineSkip         = lua.mp.BaseLineSkip        () enddef ;
+vardef LineHeight           = lua.mp.LineHeight          () enddef ;
+vardef BodyFontSize         = lua.mp.BodyFontSize        () enddef ;
+
+vardef TopSkip              = lua.mp.TopSkip             () enddef ;
+vardef StrutHeight          = lua.mp.StrutHeight         () enddef ;
+vardef StrutDepth           = lua.mp.StrutDepth          () enddef ;
+
+vardef CurrentWidth         = lua.mp.CurrentWidth        () enddef ;
+vardef CurrentHeight        = lua.mp.CurrentHeight       () enddef ;
+
+vardef HSize                = lua.mp.HSize               () enddef ; % duplicates
+vardef VSize                = lua.mp.VSize               () enddef ; % duplicates
+
+vardef EmWidth              = lua.mp.EmWidth             () enddef ;
+vardef ExHeight             = lua.mp.ExHeight            () enddef ;
+
+vardef PageFraction         = lua.mp.PageFraction        () enddef ;
+
+vardef SpineWidth           = lua.mp.SpineWidth          () enddef ;
+vardef PaperBleed           = lua.mp.PaperBleed          () enddef ;
+
+boolean mfun_swapped ;
+
+def SwapPageState =
+    mfun_swapped := true ; % eventually this will go !
+enddef ;
+
+extra_beginfig := extra_beginfig & "mfun_swapped := false ;" ;
+
+vardef LeftMarginWidth     = if mfun_swapped and not OnRightPage : lua.mp.RightMarginWidth   () else : lua.mp.LeftMarginWidth    () fi enddef ;
+vardef RightMarginWidth    = if mfun_swapped and not OnRightPage : lua.mp.LeftMarginWidth    () else : lua.mp.RightMarginWidth   () fi enddef ;
+vardef LeftMarginDistance  = if mfun_swapped and not OnRightPage : lua.mp.RightMarginDistance() else : lua.mp.LeftMarginDistance () fi enddef ;
+vardef RightMarginDistance = if mfun_swapped and not OnRightPage : lua.mp.LeftMarginDistance () else : lua.mp.RightMarginDistance() fi enddef ;
+
+vardef LeftEdgeWidth       = if mfun_swapped and not OnRightPage : lua.mp.RightEdgeWidth     () else : lua.mp.LeftEdgeWidth      () fi enddef ;
+vardef RightEdgeWidth      = if mfun_swapped and not OnRightPage : lua.mp.LeftEdgeWidth      () else : lua.mp.RightEdgeWidth     () fi enddef ;
+vardef LeftEdgeDistance    = if mfun_swapped and not OnRightPage : lua.mp.RightEdgeDistance  () else : lua.mp.LeftEdgeDistance   () fi enddef ;
+vardef RightEdgeDistance   = if mfun_swapped and not OnRightPage : lua.mp.LeftEdgeDistance   () else : lua.mp.RightEdgeDistance  () fi enddef ;
+
+vardef BackSpace           = if mfun_swapped and not OnRightPage : PaperWidth - MakeupWidth - fi  lua.mp.BackSpace() enddef ;
+vardef CutSpace            = if mfun_swapped and not OnRightPage : PaperWidth - MakeupWidth - fi  lua.mp.CutSpace () enddef ;
+
+% better use:
+
+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 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 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 ;
+
+% vardef CurrentLayout = lua.mp.CurrentLayout () enddef ;
+
+vardef OverlayWidth      = lua.mp.OverlayWidth    ()  enddef ;
+vardef OverlayHeight     = lua.mp.OverlayHeight   ()  enddef ;
+vardef OverlayDepth      = lua.mp.OverlayDepth    ()  enddef ;
+vardef OverlayLineWidth  = lua.mp.OverlayLineWidth()  enddef ;
+vardef OverlayOffset     = lua.mp.OverlayOffset   ()  enddef ;
+
+vardef defaultcolormodel = lua.mp.defaultcolormodel() enddef ;
+
+%  def OverlayLineColor  = lua.mp.OverlayLineColor()  enddef ;
+%  def OverlayColor      = lua.mp.OverlayColor    ()  enddef ;
+
+% Next we implement the the page area model. First some constants.
+
+LeftEdge             :=  -4 ; Top             := -40 ;
+LeftEdgeSeparator    :=  -3 ; TopSeparator    := -30 ;
+LeftMargin           :=  -2 ; Header          := -20 ;
+LeftMarginSeparator  :=  -1 ; HeaderSeparator := -10 ;
+Text                 :=   0 ; Text            :=   0 ;
+RightMarginSeparator :=  +1 ; FooterSeparator := +10 ;
+RightMargin          :=  +2 ; Footer          := +20 ;
+RightEdgeSeparator   :=  +3 ; BottomSeparator := +30 ;
+RightEdge            :=  +4 ; Bottom          := +40 ;
+
+% Margin      := LeftMargin  ; % obsolete
+% Edge        := LeftEdge    ; % obsolete
+% InnerMargin := RightMargin ; % obsolete
+% InnerEdge   := RightEdge   ; % obsolete
+% OuterMargin := LeftMargin  ; % obsolete
+% OuterEdge   := LeftEdge    ; % obsolete
+
+numeric HorPos ; HorPos := 0 ;
+numeric VerPos ; VerPos := 0 ;
+
+% We used to initialize these variables each (sub)run but at some point MP
+% became too slow for this. See later.
+
+% path Area[][] ;
+% pair Location[][] ;
+% path Field[][] ;
+%
+% numeric Hstep[] ;
+% numeric Hsize[] ;
+% numeric Vstep[] ;
+% numeric Vsize[] ;
+%
+% for VerPos=Top step 10 until Bottom:
+%     for HorPos=LeftEdge step 1 until RightEdge:
+%         Area[HorPos][VerPos] := origin--cycle ;
+%         Area[VerPos][HorPos] := Area[HorPos][VerPos] ;
+%         Location[HorPos][VerPos] := origin ;
+%         Location[VerPos][HorPos] := Location[HorPos][VerPos] ;
+%         Field[HorPos][VerPos] := origin--cycle ;
+%         Field[VerPos][HorPos] := Field[HorPos][VerPos] ;
+%     endfor ;
+% endfor ;
+%
+%
+% def SetPageAreas =
+%
+%     numeric Vsize[], Hsize[], Vstep[], Hstep[] ;
+%
+%     Vsize[Top]             = TopHeight ;
+%     Vsize[TopSeparator]    = TopDistance ;
+%     Vsize[Header]          = HeaderHeight ;
+%     Vsize[HeaderSeparator] = HeaderDistance ;
+%     Vsize[Text]            = TextHeight ;
+%     Vsize[FooterSeparator] = FooterDistance ;
+%     Vsize[Footer]          = FooterHeight ;
+%     Vsize[BottomSeparator] = BottomDistance ;
+%     Vsize[Bottom]          = BottomHeight ;
+%
+%     Vstep[Top]             = Vstep[TopSeparator]   +Vsize[TopSeparator] ;
+%     Vstep[TopSeparator]    = PaperHeight-TopSpace ;
+%     Vstep[Header]          = Vstep[TopSeparator]   -Vsize[Header] ;
+%     Vstep[HeaderSeparator] = Vstep[Header]         -Vsize[HeaderSeparator] ;
+%     Vstep[Text]            = Vstep[HeaderSeparator]-Vsize[Text] ;
+%     Vstep[FooterSeparator] = Vstep[Text]           -Vsize[FooterSeparator] ;
+%     Vstep[Footer]          = Vstep[FooterSeparator]-Vsize[Footer] ;
+%     Vstep[BottomSeparator] = Vstep[Footer]         -Vsize[BottomSeparator] ;
+%     Vstep[Bottom]          = Vstep[BottomSeparator]-Vsize[Bottom] ;
+%
+%     Hsize[LeftEdge]             = LeftEdgeWidth ;
+%     Hsize[LeftEdgeSeparator]    = LeftEdgeDistance ;
+%     Hsize[LeftMargin]           = LeftMarginWidth ;
+%     Hsize[LeftMarginSeparator]  = LeftMarginDistance ;
+%     Hsize[Text]                 = MakeupWidth ;
+%     Hsize[RightMarginSeparator] = RightMarginDistance ;
+%     Hsize[RightMargin]          = RightMarginWidth ;
+%     Hsize[RightEdgeSeparator]   = RightEdgeDistance ;
+%     Hsize[RightEdge]            = RightEdgeWidth ;
+%
+%     Hstep[LeftEdge]             = Hstep[LeftEdgeSeparator]   -Hsize[LeftEdge] ;
+%     Hstep[LeftEdgeSeparator]    = Hstep[LeftMargin]          -Hsize[LeftEdgeSeparator] ;
+%     Hstep[LeftMargin]           = Hstep[LeftMarginSeparator] -Hsize[LeftMargin] ;
+%     Hstep[LeftMarginSeparator]  = Hstep[Text]                -Hsize[LeftMarginSeparator] ;
+%     Hstep[Text]                 = BackSpace ;
+%     Hstep[RightMarginSeparator] = Hstep[Text]                +Hsize[Text] ;
+%     Hstep[RightMargin]          = Hstep[RightMarginSeparator]+Hsize[RightMarginSeparator] ;
+%     Hstep[RightEdgeSeparator]   = Hstep[RightMargin]         +Hsize[RightMargin] ;
+%     Hstep[RightEdge]            = Hstep[RightEdgeSeparator]  +Hsize[RightEdgeSeparator] ;
+%
+%     for VerPos=Top step 10 until Bottom:
+%         for HorPos=LeftEdge step 1 until RightEdge:
+%             Area[HorPos][VerPos] := unitsquare xscaled Hsize[HorPos] yscaled Vsize[VerPos] ;
+%             Area[VerPos][HorPos] := Area[HorPos][VerPos] ;
+%             Location[HorPos][VerPos] := (Hstep[HorPos],Vstep[VerPos]) ;
+%             Location[VerPos][HorPos] := Location[HorPos][VerPos] ;
+%             Field[HorPos][VerPos] := Area[HorPos][VerPos] shifted Location[HorPos][VerPos] ;
+%             Field[VerPos][HorPos] := Field[HorPos][VerPos] ;
+%         endfor ;
+%     endfor ;
+%
+%     Page := unitsquare xscaled PaperWidth yscaled PaperHeight ;
+%
+% enddef ;
+%
+% def BoundPageAreas =
+%     % pickup pencircle scaled 0pt ;
+%     bboxmargin := 0 ; setbounds currentpicture to Page ;
+% enddef ;
+%
+% def StartPage =
+%     begingroup ;
+%     if PageStateAvailable :
+%         LoadPageState ;
+%         SwapPageState ;
+%     fi ;
+%     SetPageAreas ;
+%     BoundPageAreas ;
+% enddef ;
+%
+% def StopPage =
+%     BoundPageAreas ;
+%     endgroup ;
+% enddef ;
+
+% Because metapost > 1.50 has dynamic memory management and is less
+% efficient than before we now delay calculations ... (on a document
+% with 150 pages the time spent in mp was close to 5 seconds which was
+% only due to initialising the page related areas, something that was
+% hardly noticeable before. At least now we're back to half a second
+% for such a case.
+
+def SetPageVsize =
+    numeric Vsize[] ;
+    Vsize[Top]             = TopHeight ;
+    Vsize[TopSeparator]    = TopDistance ;
+    Vsize[Header]          = HeaderHeight ;
+    Vsize[HeaderSeparator] = HeaderDistance ;
+    Vsize[Text]            = TextHeight ;
+    Vsize[FooterSeparator] = FooterDistance ;
+    Vsize[Footer]          = FooterHeight ;
+    Vsize[BottomSeparator] = BottomDistance ;
+    Vsize[Bottom]          = BottomHeight ;
+enddef ;
+
+def SetPageHsize =
+    numeric Hsize[] ;
+    Hsize[LeftEdge]             = LeftEdgeWidth ;
+    Hsize[LeftEdgeSeparator]    = LeftEdgeDistance ;
+    Hsize[LeftMargin]           = LeftMarginWidth ;
+    Hsize[LeftMarginSeparator]  = LeftMarginDistance ;
+    Hsize[Text]                 = MakeupWidth ;
+    Hsize[RightMarginSeparator] = RightMarginDistance ;
+    Hsize[RightMargin]          = RightMarginWidth ;
+    Hsize[RightEdgeSeparator]   = RightEdgeDistance ;
+    Hsize[RightEdge]            = RightEdgeWidth ;
+enddef ;
+
+def SetPageVstep =
+    numeric Vstep[] ;
+    Vstep[Top]             = Vstep[TopSeparator]   +Vsize[TopSeparator] ;
+    Vstep[TopSeparator]    = PaperHeight-TopSpace ;
+    Vstep[Header]          = Vstep[TopSeparator]   -Vsize[Header] ;
+    Vstep[HeaderSeparator] = Vstep[Header]         -Vsize[HeaderSeparator] ;
+    Vstep[Text]            = Vstep[HeaderSeparator]-Vsize[Text] ;
+    Vstep[FooterSeparator] = Vstep[Text]           -Vsize[FooterSeparator] ;
+    Vstep[Footer]          = Vstep[FooterSeparator]-Vsize[Footer] ;
+    Vstep[BottomSeparator] = Vstep[Footer]         -Vsize[BottomSeparator] ;
+    Vstep[Bottom]          = Vstep[BottomSeparator]-Vsize[Bottom] ;
+enddef ;
+
+def SetPageHstep =
+    numeric Hstep[] ;
+    Hstep[LeftEdge]             = Hstep[LeftEdgeSeparator]   -Hsize[LeftEdge] ;
+    Hstep[LeftEdgeSeparator]    = Hstep[LeftMargin]          -Hsize[LeftEdgeSeparator] ;
+    Hstep[LeftMargin]           = Hstep[LeftMarginSeparator] -Hsize[LeftMargin] ;
+    Hstep[LeftMarginSeparator]  = Hstep[Text]                -Hsize[LeftMarginSeparator] ;
+    Hstep[Text]                 = BackSpace ;
+    Hstep[RightMarginSeparator] = Hstep[Text]                +Hsize[Text] ;
+    Hstep[RightMargin]          = Hstep[RightMarginSeparator]+Hsize[RightMarginSeparator] ;
+    Hstep[RightEdgeSeparator]   = Hstep[RightMargin]         +Hsize[RightMargin] ;
+    Hstep[RightEdge]            = Hstep[RightEdgeSeparator]  +Hsize[RightEdgeSeparator] ;
+enddef ;
+
+def SetPageArea =
+    path Area[][] ;
+    for VerPos=Top step 10 until Bottom:
+        for HorPos=LeftEdge step 1 until RightEdge:
+            Area[HorPos][VerPos] := unitsquare xscaled Hsize[HorPos] yscaled Vsize[VerPos] ;
+            Area[VerPos][HorPos] := Area[HorPos][VerPos] ;
+        endfor ;
+    endfor ;
+enddef ;
+
+def SetPageLocation =
+    pair Location[][] ;
+    for VerPos=Top step 10 until Bottom:
+        for HorPos=LeftEdge step 1 until RightEdge:
+            Location[HorPos][VerPos] := (Hstep[HorPos],Vstep[VerPos]) ;
+            Location[VerPos][HorPos] := Location[HorPos][VerPos] ;
+        endfor ;
+    endfor ;
+enddef ;
+
+def SetPageField =
+    path Field[][] ;
+    for VerPos=Top step 10 until Bottom:
+        for HorPos=LeftEdge step 1 until RightEdge:
+            Field[HorPos][VerPos] := unitsquare xscaled Hsize[HorPos] yscaled Vsize[VerPos] shifted (Hstep[HorPos],Vstep[VerPos]) ;
+            Field[VerPos][HorPos] := Field[HorPos][VerPos] ;
+        endfor ;
+    endfor ;
+enddef ;
+
+def mfun_page_Area      = hide(SetPageArea     ;) Area      enddef ;
+def mfun_page_Location  = hide(SetPageLocation ;) Location  enddef ;
+def mfun_page_Field     = hide(SetPageField    ;) Field     enddef ;
+def mfun_page_Vsize     = hide(SetPageVsize    ;) Vsize     enddef ;
+def mfun_page_Hsize     = hide(SetPageHsize    ;) Hsize     enddef ;
+def mfun_page_Vstep     = hide(SetPageVstep    ;) Vstep     enddef ;
+def mfun_page_Hstep     = hide(SetPageHstep    ;) Hstep     enddef ;
+
+def SetAreaVariables =
+    let Area      = mfun_page_Area ;
+    let Location  = mfun_page_Location ;
+    let Field     = mfun_page_Field ;
+    let Vsize     = mfun_page_Vsize ;
+    let Hsize     = mfun_page_Hsize ;
+    let Vstep     = mfun_page_Vstep ;
+    let Hstep     = mfun_page_Hstep ;
+enddef ;
+
+% we should make Page no path .. from now on don't assume this .. for a while we keek it
+
+vardef FrontPageWidth  = PaperWidth enddef ;
+vardef BackPageWidth   = PaperWidth enddef ;
+vardef CoverWidth      = 2 * PaperWidth + SpineWidth enddef ;
+vardef CoverHeight     = PaperHeight enddef ;
+
+vardef FrontPageHeight = PaperHeight enddef ;
+vardef BackPageHeight  = PaperHeight enddef ;
+vardef SpineHeight     = PaperHeight enddef ;
+
+def SetPagePage      = path Page      ; Page      := unitsquare xscaled PaperWidth      yscaled PaperHeight ; enddef ;
+def SetPageCoverPage = path CoverPage ; CoverPage := unitsquare xscaled CoverWidth      yscaled CoverHeight ; enddef ;
+def SetPageSpine     = path Spine     ; Spine     := unitsquare xscaled SpineWidth      yscaled CoverHeight shifted (BackPageWidth,0) ; enddef ;
+def SetPageBackPage  = path BackPage  ; BackPage  := unitsquare xscaled BackPageWidth   yscaled CoverHeight ; enddef ;
+def SetPageFrontPage = path FrontPage ; FrontPage := unitsquare xscaled FrontPageWidth  yscaled CoverHeight shifted (BackPageWidth+SpineWidth,0) ; enddef ;
+
+def mfun_page_Page      = hide(SetPagePage     ;) Page      enddef ;
+def mfun_page_CoverPage = hide(SetPageCoverPage;) CoverPage enddef ;
+def mfun_page_Spine     = hide(SetPageSpine    ;) Spine     enddef ;
+def mfun_page_BackPage  = hide(SetPageBackPage ;) BackPage  enddef ;
+def mfun_page_FrontPage = hide(SetPageFrontPage;) FrontPage enddef ;
+
+def SetPageVariables =
+    SetAreaVariables ;
+    %
+    let Page      = mfun_page_Page ;
+    let CoverPage = mfun_page_CoverPage ;
+    let Spine     = mfun_page_Spine ;
+    let BackPage  = mfun_page_BackPage ;
+    let FrontPage = mfun_page_FrontPage ;
+enddef ;
+
+SetPageVariables ;
+
+let SetPageAreas = SetPageVariables ;  % compatiblity
+
+def BoundPageAreas =
+    % pickup pencircle scaled 0pt ;
+    bboxmargin := 0 ; setbounds currentpicture to Page ;
+enddef ;
+
+def StartPage =
+    begingroup ;
+    if mfun_first_run :
+        if PageStateAvailable :
+            LoadPageState ;
+            SwapPageState ;
+        fi ;
+        SetPageVariables ;
+    fi ;
+    BoundPageAreas ;
+enddef ;
+
+def StopPage =
+    BoundPageAreas ;
+    endgroup ;
+enddef ;
+
+% cover pages
+
+def BoundCoverAreas =
+    % todo: add cropmarks
+    bboxmargin := 0 ; setbounds currentpicture to CoverPage enlarged PaperBleed ;
+enddef ;
+
+let SetCoverAreas = SetPageVariables ;  % compatiblity
+
+def StartCover =
+    begingroup ;
+    if mfun_first_run :
+        if PageStateAvailable :
+            LoadPageState ;
+         %  SwapPageState ;
+        fi ;
+        SetPageVariables ; % was SetPageAreas ;
+        SetCoverAreas ;
+    fi ;
+    BoundCoverAreas ;
+enddef ;
+
+def StopCover =
+    BoundCoverAreas ;
+    endgroup ;
+enddef ;
+
+% overlays:
+
+def OverlayBox =
+    (unitsquare xyscaled (OverlayWidth,OverlayHeight))
+enddef ;
+
+% handy
+
+def innerenlarged =
+      hide(LoadPageState)
+      if OnRightPage : leftenlarged  else : rightenlarged fi
+enddef ;
+
+def outerenlarged =
+      hide(LoadPageState)
+      if OnRightPage : rightenlarged else : leftenlarged  fi
+enddef ;
+
+% obsolete
+
+def llEnlarged (expr p,d) = (llcorner p shifted (-d,-d)) enddef ;
+def lrEnlarged (expr p,d) = (lrcorner p shifted (+d,-d)) enddef ;
+def urEnlarged (expr p,d) = (urcorner p shifted (+d,+d)) enddef ;
+def ulEnlarged (expr p,d) = (ulcorner p shifted (-d,+d)) enddef ;
+
+def Enlarged (expr p, d) =
+      (llEnlarged (p,d) --
+       lrEnlarged (p,d) --
+       urEnlarged (p,d) --
+       ulEnlarged (p,d) -- cycle)
+enddef ;