nix: generate postscript file from include files

Generates the committed postscript and runs diff to make sure that the
reconstruction was faithful. Currently this simply reproduces the
existing code, though it autogenerates the numbers to make it easier
to rearrange things and/or add blank pages.

Later PRs will abstract out the setup code, improve best practices (e.g.
wrapping every page in "10 dict ... end") and add additional targets
which produce e.g. individual worksheets in their own postscript.

We will also use the Nix mechanism to add illustrations, rather than
using PHP.

.gitignore

@@ -6,3 +6,5 @@ mathematical-companion/*.log
 mathematical-companion/*.out
 mathematical-companion/*.pdf
 mathematical-companion/*.toc
+
+result

default.nix

@@ -0,0 +1,222 @@
+{ pkgs ? import <nixpkgs> { }
+, stdenv ? pkgs.stdenv
+, lib ? pkgs.lib
+, ghostscript ? pkgs.ghostscript
+, ref ? null
+, doPdfGeneration ? true
+  # Checks whether the generated output matches the checked-in SSS32.ps.
+  # When doing development you may want to shut this off to obtain the
+  # output file that you need to check in.
+, doOutputDiff ? true
+}:
+
+let
+  src =
+    if isNull ref
+    then lib.sourceFilesBySuffices ./. [ ".ps" ".inc" ]
+    else
+      fetchGit {
+        url = ./.;
+        inherit ref;
+      };
+  shortId = lib.optionalString (! isNull ref) ("-" + builtins.substring 0 8 src.rev);
+
+
+  setup = rec {
+    # Will be broken into multiple sub-files in a later PR.
+    fullSetup = {
+      content = builtins.readFile "${src}/include/setup.ps.inc";
+      dependencies = [ ];
+    };
+  };
+  # Dependencies that every page has
+  standardDependencies = [ setup.fullSetup ];
+
+  allPages = {
+    title = {
+      sourceHeader = "Title Page";
+      content = builtins.readFile "${src}/include/title.ps.inc";
+      dependencies = [ ];
+    };
+    license = {
+      sourceHeader = "License Information";
+      drawPageContent = true;
+      content = builtins.readFile "${src}/include/license.ps.inc";
+      dependencies = [ ];
+    };
+    reference = {
+      sourceHeader = "Reference Sheet";
+      drawPageContent = true;
+      content = builtins.readFile "${src}/include/reference.ps.inc";
+      dependencies = [ ];
+    };
+    principalTables = {
+      sourceHeader = "Arithmetic Tables";
+      content = builtins.readFile "${src}/include/principal-tables.ps.inc";
+      dependencies = [ ];
+    };
+
+    additionBottom = {
+      content = "{xor} (Addition) code dup perm drawBottomWheelPage\n";
+      dependencies = [ ];
+    };
+    additionTop = {
+      content = "showTopWheelPage\n";
+      dependencies = [ ];
+    };
+    recovery = {
+      content = builtins.readFile "${src}/include/volvelle-recovery.ps.inc";
+      dependencies = [ ];
+    };
+    fusionInner = {
+      content = builtins.readFile "${src}/include/volvelle-fusion-1.ps.inc";
+      dependencies = [ ];
+    };
+    fusionOuter = {
+      content = builtins.readFile "${src}/include/volvelle-fusion-2.ps.inc";
+      dependencies = [ ];
+    };
+
+    generationInstructions = {
+      content = builtins.readFile "${src}/include/page7.ps.inc";
+      dependencies = [ ];
+    };
+
+    checksumTable1 = {
+      content = builtins.readFile "${src}/include/checksum-table-1.ps.inc";
+      isLandscape = true;
+      dependencies = [ ];
+    };
+    checksumTable2 = {
+      content = builtins.readFile "${src}/include/checksum-table-2.ps.inc";
+      isLandscape = true;
+      dependencies = [ ];
+    };
+    checksumWorksheet = {
+      content = builtins.readFile "${src}/include/checksum-worksheet.ps.inc";
+      isLandscape = true;
+      dependencies = [ ];
+    };
+
+    shareTable = a: b: c: d: {
+      content = "${toString a} ${toString b} ${toString c} ${toString d} showShareTablePage\n";
+      dependencies = [ ];
+    };
+  };
+
+  fullBooklet = {
+    name = "SSS32.ps";
+    pages = with allPages; [
+      title
+      license
+      reference
+      principalTables
+      additionBottom
+      additionTop
+      generationInstructions
+      (shareTable 29 24 13 25)
+      (shareTable 9 8 23 18)
+      (shareTable 22 31 27 19)
+      (shareTable 1 0 3 16)
+      (shareTable 11 28 12 14)
+      (shareTable 6 4 2 15)
+      (shareTable 10 17 21 20)
+      (shareTable 26 30 7 5)
+      recovery
+      fusionInner
+      fusionOuter
+      checksumTable1
+      checksumTable2
+      checksumWorksheet
+    ];
+  };
+
+  dependencyContentRecur = content: builtins.concatMap
+    (item: (dependencyContentRecur item.dependencies) ++ [ item.content ])
+    content;
+  dependencyContent = pages: lib.lists.unique (
+    (map (dep: dep.content) standardDependencies) ++
+    (builtins.concatMap (page: dependencyContentRecur page.dependencies) pages)
+  );
+
+  renderBooklet = booklet:
+    let
+      addPage = content: pageData: {
+        content = content.content + lib.optionalString (pageData ? sourceHeader) ''
+          %****************************************************************
+          %*
+          %* ${pageData.sourceHeader}
+          %*
+          %****************************************************************
+        '' + ''
+          %%Page: ${toString content.nextPgIdx} ${toString content.nextPgIdx}
+          ${lib.optionalString (pageData ? isLandscape) "%%PageOrientation: Landscape\n"}%%BeginPageSetup
+          /pgsave save def
+          %%EndPageSetup
+        '' + (
+          if pageData ? drawPageContent
+          then
+            if pageData ? isLandscape
+            then "landscapePage begin ${toString content.nextCtIdx} drawPageContent\n"
+            else "portraitPage begin ${toString content.nextCtIdx} drawPageContent\n"
+          else
+            if pageData ? isLandscape
+            then "90 rotate\n"
+            else ""
+        ) + ''
+          ${pageData.content}
+          ${lib.optionalString (pageData ? drawPageContent) "end\n"}pgsave restore
+          showpage
+        '';
+        nextCtIdx = content.nextCtIdx + (if pageData ? drawPageContent then 1 else 0);
+        nextPgIdx = content.nextPgIdx + 1;
+      };
+      initialContent = {
+        content = ''
+          %!PS-Adobe-3.0
+          %%Orientation: Portrait
+          %%Pages: ${toString (builtins.length booklet.pages)}
+          %%EndComments
+          %%BeginSetup
+          ${toString (dependencyContent (booklet.pages))}%%EndSetup
+
+          %************************************************************************
+          %************************************************************************
+          %*
+          %* Section Three: Page Rendering
+          %*
+          %************************************************************************
+          %************************************************************************
+
+        '';
+        nextPgIdx = 1;
+        nextCtIdx = 1;
+      };
+      finalContent = builtins.foldl' addPage initialContent booklet.pages;
+    in
+    pkgs.writeTextFile {
+      name = booklet.name;
+      text = finalContent.content + ''
+        %%EOF
+      '';
+    };
+in
+stdenv.mkDerivation {
+  name = "codex32${shortId}";
+
+  buildInputs = if doPdfGeneration then [ ghostscript ] else [ ];
+
+  phases = [ "buildPhase" ];
+  buildPhase = ''
+    set -e
+
+    mkdir "$out"
+    cd "$out"
+    cp ${renderBooklet fullBooklet} SSS32.ps
+
+    ${lib.optionalString doOutputDiff "diff -C 5 ${src}/SSS32.ps SSS32.ps"}
+    sed -i 's/(revision \(.*\))/(revision \1${shortId})/' ./SSS32.ps
+    ${lib.optionalString doPdfGeneration "ps2pdf -dPDFSETTINGS=/prepress SSS32.ps"}
+  '';
+}
+

include/checksum-table-1.ps.inc

@@ -0,0 +1,19 @@
+10 dict begin
+pgsize aload pop
+/pageW exch def
+/pageH exch def
+
+0 pageH neg translate
+
+/Helvetica-Bold findfont 10 scalefont setfont
+pageW 2 div pageH 48 sub moveto (MS32 Checksum Table) centreshow
+
+/Courier findfont 8.5 scalefont setfont
+36 pageH 64 sub  % x y
+pageW 64 sub pageH 144 sub 2 div % w h
+0 drawChecksumTable
+
+36 pageH 2 div 16 sub % x y
+pageW 64 sub pageH 144 sub 2 div % w h
+8 drawChecksumTable
+end

include/checksum-table-2.ps.inc

@@ -0,0 +1,19 @@
+10 dict begin
+pgsize aload pop
+/pageW exch def
+/pageH exch def
+
+0 pageH neg translate
+
+/Helvetica-Bold findfont 10 scalefont setfont
+pageW 2 div pageH 48 sub moveto (MS32 Checksum Table) centreshow
+
+/Courier findfont 8.5 scalefont setfont
+36 pageH 64 sub  % x y
+pageW 64 sub pageH 144 sub 2 div % w h
+16 drawChecksumTable
+
+36 pageH 2 div 16 sub % x y
+pageW 64 sub pageH 144 sub 2 div % w h
+24 drawChecksumTable
+end

include/checksum-worksheet.ps.inc

@@ -0,0 +1,83 @@
+% 0 pgsize aload pop pop neg translate
+0 -750 translate
+
+/Helvetica-Bold findfont 10 scalefont setfont
+pgsize aload pop exch pop 2 div 700
+moveto (ms32 Checksum Worksheet) centreshow
+
+gsave
+50 680 translate
+ladder begin
+ drawgrid
+% (2NAMES5GS8YDXGMLUW34LEN0PRDAK9GLF307N04SN6SKL) fillgrid
+% (2NAMES5GS8YDXGMLUW34LEN0PRDAK9GL             ) fillgrid
+end
+grestore
+
+100 420 moveto
+/Helvetica-Bold findfont 10 scalefont setfont
+(Verifying Checksums) show
+100 400 moveto
+/Helvetica findfont 9 scalefont setfont
+(Write out the 45 character data portion in the) show
+100 390 moveto
+(bold boxes, two at a time, starting on the top) show
+100 380 moveto
+(row.  Working from the top row down, look up) show
+100 370 moveto
+(the first two characters of each odd row in the) show
+100 360 moveto
+(ms32 Checksum Table and write the ) polymodulus length 10 string cvs concatstrings show
+100 350 moveto
+(character word into the even row below it.  Fill) show
+100 340 moveto
+(in the odd rows by adding the two characters) show
+100 330 moveto
+(above each cell.  You may use either the) show
+100 320 moveto
+(addition wheel table.  The first few boxes are) show
+100 310 moveto
+(already filled in for you.  The last row will sum) show
+100 300 moveto
+(to ) show checksumstring {glyphshow} forall ( if the checksum is valid.) show
+100 260 moveto
+/Helvetica-Bold findfont 10 scalefont setfont
+(Creating Checksums) show
+100 240 moveto
+/Helvetica findfont 9 scalefont setfont
+(Follow the "Verifying Checksums" instructions) show
+100 230 moveto
+(to fill in everything but the shaded cells. To fill in) show
+100 220 moveto
+(the shaded cells, write ) show checksumstring {glyphshow} forall ( into the bottom) show
+100 210 moveto
+(row.  Working from the bottom up, fill in the) show
+100 200 moveto
+(shaded cells by adding the two characters below) show
+100 190 moveto
+(each cell.  The ) polymodulus length 10 string cvs ( characters in the bold shaded) concatstrings concatstrings show
+100 180 moveto
+(boxes will be the checksum.) show
+
+450 650
+/offsety exch def
+/offsetx exch def
+/Courier findfont 10 scalefont setfont
+20 offsetx add offsety moveto (Addition Table) show
+/Courier-Bold findfont 8 scalefont setfont
+0 1 31 {
+dup 2 add 7 mul offsetx add offsety 10 sub moveto
+perm exch get
+code exch get glyphshow
+} for
+
+0 1 31 {
+/Courier-Bold findfont 8 scalefont setfont
+offsetx 34.5 7 mul add offsety 20 sub 2 index 8 mul sub moveto
+dup code exch perm exch get get glyphshow
+/Courier findfont 8 scalefont setfont
+dup 1 31 {
+dup 2 add 7 mul offsetx add offsety 20 sub 3 index 8 mul sub moveto
+perm exch get
+perm 2 index get gf32add code exch get glyphshow
+} for pop } for

include/license.ps.inc

@@ -0,0 +1,8 @@
+/Helvetica findfont 6 scalefont setfont
+marginX1 marginY1 16 sub moveto
+MIT {gsave ((c)) search {show pop /copyright glyphshow} if show grestore 0 -8 rmoveto} forall
+/Helvetica findfont 6 scalefont setfont
+warning {gsave show grestore 0 -7 rmoveto} forall
+0 -16 rmoveto
+/Helvetica findfont 8 scalefont setfont
+README {gsave show grestore 0 -10 rmoveto} forall