% Diagram of layout areas
% 2023 by Henning Hraban Ramm, hraban@fiee.net
% license: GNU FDL 1.3+ & CC-BY-SA 3.0+

definecolor [name="boxColor", c=.15, k=.1];
definecolor [name="boxTextColor", c=.4, k=.5];
definecolor [name="pageColor", m=.2, y=.5, k=.1];
definecolor [name="pageTextColor", m=.2, y=.5, k=.25];
definecolor [name="arrowColor", k=1];
definecolor [name="arrowTextColor", k=1];
definecolor [name="distanceArrowColor", k=1];
definecolor [name="distanceTextColor", k=1];
defaultfont  := "\truefontname{Mono}*default" ;
pickup pencircle scaled 1;

distance := 15bp;
abit := distance/3;

edgewidth := 40bp;
marginwidth := 60bp;
textwidth := 200bp;

topheight := 40bp;
headerheight := 50bp;
textheight := 300bp;

leftedgestart := 0bp;
leftmarginstart := edgewidth + distance;
textleftstart := leftmarginstart + marginwidth + distance;
rightmarginstart := textleftstart + textwidth + distance;
rightedgestart := rightmarginstart + marginwidth + distance;

arrowleftstart := textleftstart + textwidth/2;

bottomstart := 0bp;
footerstart := topheight + distance;
textfootstart := footerstart + headerheight + distance;
headerstart := textfootstart + textheight + distance;
topstart := headerstart + headerheight + distance;

pageleftstart := edgewidth/2;
pagefootstart := topheight/2;
pagewidth := rightedgestart;
pageheight := topstart;

picture Layout;
Layout := image(
  % bottom
  fill unitsquare xscaled edgewidth   yscaled topheight shifted (leftedgestart,bottomstart) withcolor "boxColor";
  fill unitsquare xscaled marginwidth yscaled topheight shifted (leftmarginstart,bottomstart) withcolor "boxColor";
  fill unitsquare xscaled textwidth   yscaled topheight shifted (textleftstart,bottomstart) withcolor "boxColor";
  fill unitsquare xscaled marginwidth yscaled topheight shifted (rightmarginstart,bottomstart) withcolor "boxColor";
  fill unitsquare xscaled edgewidth   yscaled topheight shifted (rightedgestart,bottomstart) withcolor "boxColor";
  label.urt("bottom", (bottomstart,-leftedgestart)) rotated 90 withcolor "boxTextColor";
  % footer
  fill unitsquare xscaled edgewidth   yscaled headerheight shifted (leftedgestart,footerstart) withcolor "boxColor";
  fill unitsquare xscaled marginwidth yscaled headerheight shifted (leftmarginstart,footerstart) withcolor "boxColor";
  fill unitsquare xscaled textwidth   yscaled headerheight shifted (textleftstart,footerstart) withcolor "boxColor";
  fill unitsquare xscaled marginwidth yscaled headerheight shifted (rightmarginstart,footerstart) withcolor "boxColor";
  fill unitsquare xscaled edgewidth   yscaled headerheight shifted (rightedgestart,footerstart) withcolor "boxColor";
  label.urt("footer", (footerstart,-leftedgestart)) rotated 90 withcolor "boxTextColor";
  % text
  fill unitsquare xscaled edgewidth   yscaled textheight shifted (leftedgestart,textfootstart) withcolor "boxColor";
  fill unitsquare xscaled marginwidth yscaled textheight shifted (leftmarginstart,textfootstart) withcolor "boxColor";
  fill unitsquare xscaled textwidth   yscaled textheight shifted (textleftstart,textfootstart) withcolor "boxColor";
  fill unitsquare xscaled marginwidth yscaled textheight shifted (rightmarginstart,textfootstart) withcolor "boxColor";
  fill unitsquare xscaled edgewidth   yscaled textheight shifted (rightedgestart,textfootstart) withcolor "boxColor";
  label.urt("text", (textfootstart,-leftedgestart)) rotated 90 withcolor "boxTextColor";
  % header
  fill unitsquare xscaled edgewidth   yscaled headerheight shifted (leftedgestart,headerstart) withcolor "boxColor";
  fill unitsquare xscaled marginwidth yscaled headerheight shifted (leftmarginstart,headerstart) withcolor "boxColor";
  fill unitsquare xscaled textwidth   yscaled headerheight shifted (textleftstart,headerstart) withcolor "boxColor";
  fill unitsquare xscaled marginwidth yscaled headerheight shifted (rightmarginstart,headerstart) withcolor "boxColor";
  fill unitsquare xscaled edgewidth   yscaled headerheight shifted (rightedgestart,headerstart) withcolor "boxColor";
  label.urt("header", (headerstart,-leftedgestart)) rotated 90 withcolor "boxTextColor";
  % top
  fill unitsquare xscaled edgewidth   yscaled topheight shifted (leftedgestart,topstart) withcolor "boxColor";
  fill unitsquare xscaled marginwidth yscaled topheight shifted (leftmarginstart,topstart) withcolor "boxColor";
  fill unitsquare xscaled textwidth   yscaled topheight shifted (textleftstart,topstart) withcolor "boxColor";
  fill unitsquare xscaled marginwidth yscaled topheight shifted (rightmarginstart,topstart) withcolor "boxColor";
  fill unitsquare xscaled edgewidth   yscaled topheight shifted (rightedgestart,topstart) withcolor "boxColor";
  label.urt("top", (topstart,-leftedgestart)) rotated 90 withcolor "boxTextColor";

  % vertical areas
  label.urt("leftedge\strut", (leftedgestart,topstart+topheight)) withcolor "boxTextColor";
  label.urt("leftmargin\strut", (leftmarginstart,topstart+topheight)) withcolor "boxTextColor";
  label.urt("text\strut", (textleftstart,topstart+topheight)) withcolor "boxTextColor";
  label.urt("rightmargin\strut", (rightmarginstart,topstart+topheight)) withcolor "boxTextColor";
  label.urt("rightedge\strut", (rightedgestart,topstart+topheight)) withcolor "boxTextColor";

  % vertical distances
  label.lrt("topdistance", (textleftstart+abit,topstart)) withcolor "distanceTextColor";
  drawdblarrow (textleftstart+2,topstart)--(textleftstart+2,topstart-distance) withcolor "distanceArrowColor";
  label.lrt("headerdistance", (textleftstart+abit,headerstart)) withcolor "distanceTextColor";
  drawdblarrow (textleftstart+2,headerstart)--(textleftstart+2,headerstart-distance) withcolor "distanceArrowColor";
  label.lrt("footerdistance", (textleftstart+abit,textfootstart)) withcolor "distanceTextColor";
  drawdblarrow (textleftstart+2,textfootstart)--(textleftstart+2,textfootstart-distance) withcolor "distanceArrowColor";
  label.lrt("bottomdistance", (textleftstart+abit,footerstart)) withcolor "distanceTextColor";
  drawdblarrow (textleftstart+2,footerstart)--(textleftstart+2,footerstart-distance) withcolor "distanceArrowColor";

  % horizontal distances
  label.lrt("margindistance, rightmargindistance", (textfootstart+abit,-textleftstart-textwidth)) rotated 90 withcolor "distanceTextColor";
  drawdblarrow (leftmarginstart,textfootstart)--(leftmarginstart-distance,textfootstart) withcolor "distanceArrowColor";
  label.lrt("edgedistance, rightedgedistance", (textfootstart+abit,-rightmarginstart-marginwidth)) rotated 90 withcolor "distanceTextColor";
  drawdblarrow (textleftstart,textfootstart)--(textleftstart-distance,textfootstart) withcolor "distanceArrowColor";
  label.lrt("margindistance, leftmargindistance", (textfootstart+abit,-leftmarginstart-marginwidth)) rotated 90 withcolor "distanceTextColor";
  drawdblarrow (rightmarginstart,textfootstart)--(rightmarginstart-distance,textfootstart) withcolor "distanceArrowColor";
  label.lrt("edgedistance, leftedgedistance", (textfootstart+abit,-leftedgestart-edgewidth)) rotated 90 withcolor "distanceTextColor";
  drawdblarrow (rightedgestart,textfootstart)--(rightedgestart-distance,textfootstart) withcolor "distanceArrowColor";

  % page
  draw unitsquare xscaled pagewidth yscaled pageheight shifted (pageleftstart,pagefootstart) withcolor "pageColor" dashed evenly withpen pencircle scaled 2;
  label.urt("pagewidth",  (pageleftstart,pagefootstart+pageheight)) withcolor "pageTextColor";
  label.urt("pageheight", (pagefootstart,-pageleftstart)) rotated 90 withcolor "pageTextColor";

  % horizontal measures
  drawdblarrow (pageleftstart,headerstart-2*distance)--(textleftstart,headerstart-2*distance) withcolor "arrowColor";
  label.urt("backspace", (pageleftstart,headerstart-2*distance)) withcolor "arrowTextColor";
  drawdblarrow (textleftstart,headerstart-3.5*distance)--(textleftstart+textwidth,headerstart-3.5*distance) withcolor "arrowColor";
  label.urt("width\strut", (textleftstart,headerstart-3.5*distance)) withcolor "arrowTextColor";

  drawdblarrow (rightmarginstart,headerstart-5*distance)--(rightmarginstart+marginwidth,headerstart-5*distance) withcolor "arrowColor";
  label.urt("margin,", (rightmarginstart,headerstart-5*distance)) withcolor "arrowTextColor";
  label.lrt("rightmargin", (rightmarginstart,headerstart-5*distance)) withcolor "arrowTextColor";

  drawdblarrow (leftmarginstart+marginwidth,headerstart-5*distance)--(leftmarginstart,headerstart-5*distance) withcolor "arrowColor";
  label.urt("margin,", (leftmarginstart,headerstart-5*distance)) withcolor "arrowTextColor";
  label.lrt("leftmargin", (leftmarginstart,headerstart-5*distance)) withcolor "arrowTextColor";

  drawdblarrow (rightedgestart,headerstart-7*distance)--(rightedgestart+edgewidth,headerstart-7*distance) withcolor "arrowColor";
  label.urt("edge,", (rightedgestart,headerstart-7*distance)) withcolor "arrowTextColor";
  label.lrt("rightedge", (rightedgestart,headerstart-7*distance)) withcolor "arrowTextColor";

  drawdblarrow (leftedgestart+edgewidth,headerstart-7*distance)--(leftedgestart,headerstart-7*distance) withcolor "arrowColor";
  label.urt("edge,", (leftedgestart,headerstart-7*distance)) withcolor "arrowTextColor";
  label.lrt("leftedge", (leftedgestart,headerstart-7*distance)) withcolor "arrowTextColor";

  % vertical measures
  drawdblarrow (arrowleftstart,pagefootstart+pageheight)--(arrowleftstart,headerstart+headerheight) withcolor "arrowColor";
  label.ulft("topspace\strut", (pagefootstart+pageheight,-arrowleftstart)) rotated 90 withcolor "arrowTextColor";

  drawdblarrow (arrowleftstart+2*distance,headerstart+headerheight)--(arrowleftstart+2*distance,footerstart) withcolor "arrowColor";
  label.ulft("height\strut", (headerstart+headerheight,-arrowleftstart-2*distance)) rotated 90 withcolor "arrowTextColor";

  drawdblarrow (arrowleftstart+4*distance,headerstart+headerheight)--(arrowleftstart+4*distance,headerstart) withcolor "arrowColor";
  label.ulft("header\strut", (headerstart+headerheight,-arrowleftstart-4*distance)) rotated 90 withcolor "arrowTextColor";

  drawdblarrow (arrowleftstart+4*distance,footerstart+headerheight)--(arrowleftstart+4*distance,footerstart) withcolor "arrowColor";
  label.ulft("footer\strut", (footerstart+headerheight,-arrowleftstart-4*distance)) rotated 90 withcolor "arrowTextColor";

  drawdblarrow (arrowleftstart+5*distance,topstart+topheight)--(arrowleftstart+5*distance,topstart) withcolor "arrowColor";
  label.ulft("top\strut", (topstart+topheight,-arrowleftstart-5*distance)) rotated 90 withcolor "arrowTextColor";

  drawdblarrow (arrowleftstart+5*distance,bottomstart+topheight)--(arrowleftstart+5*distance,bottomstart) withcolor "arrowColor";
  label.ulft("bottom\strut", (bottomstart+topheight,-arrowleftstart-5*distance)) rotated 90 withcolor "arrowTextColor";
);