TextPrinter.Mod

MODULE TextPrinter; (** CAS/MH/HM 23.9.1993 **)
    IMPORT
        Files, Display, Fonts, Printer, Texts, TextFrames;

    CONST
        Unit* = 3048;   (**unit for a 300 dpi printer**)
        unit = TextFrames.Unit;
        mm = TextFrames.mm; Scale = mm DIV 10;

        gridAdj = TextFrames.gridAdj;
        leftAdj = TextFrames.leftAdj; rightAdj = TextFrames.rightAdj; AdjMask = {leftAdj, rightAdj};
        pageBreak = TextFrames.pageBreak;
        twoColumns = TextFrames.twoColumns;
        AdjustSpan = 30; MinTabWidth = 1 * Scale; StdTabWidth = 4 * mm;
        ColumnGap = 7*mm;

        TAB = 9X; CR = 0DX;
        MaxDict = 32;   MaxLine = 512;

    TYPE
        PrintMsg* = RECORD (Texts.ElemMsg)
            prepare*: BOOLEAN;
            indent*: LONGINT;   (**prepare => width already consumed in line, in units**)
            fnt*: Fonts.Font;
            col*: SHORTINT;
            pos*: LONGINT;  (**position in host text**)
            X0*, Y0*, pno*: INTEGER (**receiver origin in screen space; page number**)
        END;

        PrintLine = RECORD
            eot: BOOLEAN;   (*marked to skip, contains end of text*)
            indent: LONGINT;
            w, h, dsr: INTEGER; (*bounding box clipped to frame*)
            nob: INTEGER;   (*number of contained blanks; > 0 if text line wraps around*)
            org, len, span: LONGINT;    (*len w/o; span w/ trailing CR or white space, if any*)
            pbeg: LONGINT   (*position of corresponding parc*)
        END;

    VAR
        P: TextFrames.Parc;
        pbeg: LONGINT;
        R: Texts.Reader;
        nextCh: CHAR;
        fname: ARRAY 32 OF CHAR;

        fonts: RECORD
            num: SHORTINT;
            dict: ARRAY MaxDict OF Fonts.Font;
            dx: ARRAY MaxDict, 256 OF SHORTINT
        END;
        line: RECORD
            first: BOOLEAN;
            fno: SHORTINT;
            px, x, y: INTEGER;
            len: INTEGER;
            buf: ARRAY MaxLine OF CHAR
        END;


    PROCEDURE Min (x, y: LONGINT): LONGINT;
    BEGIN
        IF x < y THEN RETURN x ELSE RETURN y END
    END Min;

    PROCEDURE Max (x, y: INTEGER): INTEGER;
    BEGIN
        IF x > y THEN RETURN x ELSE RETURN y END
    END Max;

    PROCEDURE Append (VAR s1: ARRAY OF CHAR; i: INTEGER; s2: ARRAY OF CHAR);
        VAR j: INTEGER;
    BEGIN j := 0;   (*s1 large enough*)
        WHILE s2[j] # 0X DO s1[i] := s2[j]; INC(i); INC(j) END;
        s1[i] := 0X
    END Append;


    (** Printer Metrics **)

    PROCEDURE SetMetrics (fno: SHORTINT; fnt: Fonts.Font);
        VAR f: Files.File; r: Files.Rider; pat: Display.Pattern;
            off, i, j, k, dx, x, y, w, h: INTEGER; size, s: SHORTINT; mod, m: CHAR;
            name: ARRAY 32 OF CHAR;
    BEGIN COPY(fnt.name, name);
        i := 0; WHILE name[i] > "9" DO INC(i) END;
        j := i; WHILE ("0" <= name[j]) & (name[j] < "9") DO INC(j) END;
        k := j; WHILE (name[k] # ".") & (name[k] # 0X) DO INC(k) END;
        IF k > j THEN mod := name[k-1] ELSE mod := " " END;
        size := 0; k := i; WHILE i < j DO size := 10 * size + SHORT(ORD(name[i]) - 30H); INC(i) END;
        Append(name, k, ".Lm3.Fnt"); f := Files.Old(name);
        IF f # NIL THEN Files.Set(r, f, 2); Files.ReadInt(r, off); Files.Set(r, f, 6); i := -1;
            REPEAT INC(i); Files.Read(r, s); Files.Read(r, m) UNTIL (s = size) & (m = mod) OR (Files.Pos(r) >= off);
            IF (s = size) & (m = mod) THEN Files.Set(r, f, off + i * 260 + 4); Files.ReadBytes(r, fonts.dx[fno], 256)
            ELSE f := NIL
            END
        END;
        IF f = NIL THEN i := 0; (*no printer metrics file found - construct from screen metrics*)
            WHILE i < 256 DO Display.GetChar(fnt.raster, CHR(i), dx, x, y, w, h, pat);
                fonts.dx[fno, i] := SHORT(SHORT(LONG(dx) * unit * 12 DIV 10 DIV Unit)); INC(i)
                (*+20% : heuristical correction*)
            END
        END
    END SetMetrics;

    PROCEDURE FontNo* (fnt: Fonts.Font): SHORTINT;
        VAR fno: SHORTINT;
    BEGIN fno := 0; fonts.dict[fonts.num] := fnt;
        WHILE fonts.dict[fno] # fnt DO INC(fno) END;
        IF fno = fonts.num THEN SetMetrics(fno, fnt); INC(fonts.num) END;
        RETURN fno
    END FontNo;

    PROCEDURE Font* (fno: SHORTINT): Fonts.Font;
    BEGIN RETURN fonts.dict[fno]
    END Font;

    PROCEDURE DX* (fno: SHORTINT; ch: CHAR): LONGINT;
    BEGIN RETURN LONG(LONG(fonts.dx[fno, ORD(ch)])) * Unit
    END DX;

    PROCEDURE Get* (fno: SHORTINT; ch: CHAR; VAR dx, x, y, w, h: LONGINT);
        VAR pat: Display.Pattern; dx0, x0, y0, w0, h0: INTEGER;
    BEGIN Display.GetChar(fonts.dict[fno].raster, ch, dx0, x0, y0, w0, h0, pat);
        x := LONG(x0) * unit; y := LONG(y0) * unit; h := LONG(h0) * unit;
        dx := LONG(LONG(fonts.dx[fno, ORD(ch)])) * Unit; w := dx
    END Get;

    PROCEDURE GetChar* (fno: SHORTINT; targetUnit: LONGINT; ch: CHAR;
                VAR pdx: LONGINT; VAR dx, x, y, w, h: INTEGER; VAR pat: Display.Pattern);
    BEGIN Display.GetChar(fonts.dict[fno].raster, ch, dx, x, y, w, h, pat);
        x := SHORT(x * LONG(unit) DIV targetUnit); y := SHORT(y * LONG(unit) DIV targetUnit);
        h := SHORT(h * LONG(unit) DIV targetUnit);
        pdx := LONG(LONG(fonts.dx[fno, ORD(ch)])) * Unit;
        dx := SHORT(pdx DIV targetUnit); w := dx
    END GetChar;

    PROCEDURE InitFonts*;
        VAR fno: SHORTINT;
    BEGIN fonts.num := 0; fno := FontNo(Fonts.Default)
    END InitFonts;

    PROCEDURE Width (fno: SHORTINT; VAR s: ARRAY OF CHAR): INTEGER;
        VAR i, w: INTEGER;
    BEGIN i := 0; w := 0;
        WHILE s[i] # 0X DO INC(w, LONG(fonts.dx[fno, ORD(s[i])]) ); INC(i) END;
        RETURN w
    END Width;

    PROCEDURE GetPrintChar (fnt: Fonts.Font; ch: CHAR; VAR fno: SHORTINT; VAR dx, x, y, w, h: INTEGER);
        VAR pat: Display.Pattern;
    BEGIN Display.GetChar(fnt.raster, ch, dx, x, y, w, h, pat);
        x := SHORT(x * LONG(unit) DIV Unit); y := -SHORT((-y) * LONG(unit) DIV Unit);
        h := SHORT(h * LONG(unit) DIV Unit);
        fno := FontNo(fnt); dx := fonts.dx[fno, ORD(ch)]; w := dx
    END GetPrintChar;

    PROCEDURE Tab (dw: INTEGER; VAR dx: INTEGER);   (*P set*)
        VAR i, n: INTEGER; w: LONGINT;
    BEGIN i := 0; n := P.nofTabs; w := LONG(dw) * Unit + MinTabWidth;
        IF dw < 0 THEN dx := -dw
        ELSE
            WHILE (i < n) & (P.tab[i] < w) DO INC(i) END;
            IF i < n THEN dx := SHORT((P.tab[i] - LONG(dw) * Unit) DIV Unit)
            ELSE dx := StdTabWidth DIV Unit
            END
        END
    END Tab;

    PROCEDURE Offset (): INTEGER;   (*R set*)
    BEGIN
        IF R.voff = 0 THEN RETURN 0
        ELSE RETURN SHORT(R.fnt.height * R.voff * LONG(unit) DIV 64 DIV Unit)
        END
    END Offset;

    PROCEDURE MeasureSpecial (pno, dw: INTEGER; VAR fno: SHORTINT; VAR dx, x, y, w, h: INTEGER);
        (*P, R, nextCh set*)
        VAR e: Texts.Elem; i: INTEGER; msg: PrintMsg;
    BEGIN
        IF nextCh = " " THEN GetPrintChar(R.fnt, nextCh, fno, dx, x, y, w, h);
            x := 0; y := 0; w := dx; h := 0
        ELSIF nextCh = TAB THEN Tab(dw, dx); x := 0; y := 0; w := dx; h := 0
        ELSIF R.elem # NIL THEN e := R.elem;
            msg.prepare := TRUE; msg.indent := LONG(dw) * Unit;
            msg.fnt := R.fnt; msg.col := R.col; msg.pos := Texts.Pos(R) - 1; msg.pno := pno;
            msg.Y0 := -SHORT(P.dsr DIV Unit);
            e.handle(e, msg);
            w := SHORT(e.W DIV Unit); dx := w; h := SHORT(e.H DIV Unit);
            x := 0; y := msg.Y0
        ELSE GetPrintChar(R.fnt, nextCh, fno, dx, x, y, w, h)
        END
    END MeasureSpecial;

    PROCEDURE GetSpecial (VAR n: INTEGER; maxW, cn, ddx, dw: INTEGER;
            VAR fno: SHORTINT; VAR dx, x, y, w, h: INTEGER);    (*P, R, nextCh set*)
        VAR e: Texts.Elem;
    BEGIN
        IF nextCh = " " THEN GetPrintChar(R.fnt, nextCh, fno, dx, x, y, w, h);
            x := 0; y := 0; INC(dx, ddx); INC(n); IF n <= cn THEN INC(dx) END;  (*space correction for block adjustment*)
            w := dx; h := 0
        ELSIF nextCh = TAB THEN Tab(dw, dx); x := 0; y := 0; w := dx; h := 0
        ELSIF R.elem # NIL THEN e := R.elem;
                IF e IS TextFrames.Parc THEN w := SHORT(Min(P.width DIV Unit, maxW)); e.W := LONG(w) * Unit
                ELSE w := SHORT(e.W DIV Unit)
                END;
                dx := w; x := 0; y := -SHORT(P.dsr DIV Unit); h := SHORT(e.H DIV Unit)
        ELSE GetPrintChar(R.fnt, nextCh, fno, dx, x, y, w, h)
        END
    END GetSpecial;

    PROCEDURE AdjustMetrics (T: Texts.Text; VAR t: PrintLine; left: INTEGER; VAR pw, tw, ddx, cn: INTEGER);
        (*sets P, pbeg*)
    BEGIN pw := left; tw := t.w; ddx := 0; cn := 0;
        TextFrames.ParcBefore(T, t.org, P, pbeg);
        IF pbeg # t.org THEN
            INC(pw, SHORT((P.left + t.indent) DIV Unit));
            DEC(tw, SHORT(t.indent DIV Unit));
            IF leftAdj IN P.opts THEN
                IF (rightAdj IN P.opts) & (t.nob > 0) THEN
                    tw := SHORT((P.width - t.indent) DIV Unit); ddx := (tw - t.w) DIV t.nob; cn := (tw - t.w) MOD t.nob
                END
            ELSIF rightAdj IN P.opts THEN INC(pw, SHORT(P.width DIV Unit) - t.w)
            ELSE (*center*) INC(pw, (SHORT(P.width DIV Unit) - t.w) DIV 2)
            END
        END
    END AdjustMetrics;


    (* Printer Line Casting *)

    PROCEDURE MeasureLine (T: Texts.Text; pno, maxW: INTEGER; VAR t: PrintLine);    (*R, nextCh set*)
        VAR len, bklen, d: LONGINT; eol: BOOLEAN; fno: SHORTINT;
            nob, bknob, width, minY, bkminY, maxY, bkmaxY, tw, bktw, lsp, dsr, dx, x, y, w, h: INTEGER;
            R1: Texts.Reader; peekCh: CHAR;
    BEGIN len := 0; nob := 0; bklen := -999; tw := 0; dx := 0; minY := 0; maxY := 0;
        TextFrames.ParcBefore(T, t.org, P, pbeg);
        lsp := SHORT(P.lsp DIV Unit); dsr := SHORT(P.dsr DIV Unit); width := SHORT(P.width DIV Unit);
        t.indent := 0;
        IF t.org > 0 THEN Texts.OpenReader(R1, T, t.org - 1); Texts.Read(R1, peekCh);
            IF (peekCh = CR) OR (R1.elem # NIL) & (R1.elem IS TextFrames.Parc) THEN t.indent := P.first END;
        END;
        DEC(width, SHORT(t.indent DIV Unit));
        LOOP INC(tw, dx);
            IF R.eot OR (nextCh = CR) THEN nob := 0; eol := ~R.eot; EXIT END;
            IF nextCh <= " " THEN MeasureSpecial(pno, tw + SHORT(t.indent DIV Unit), fno, dx, x, y, w, h)
            ELSE GetPrintChar(R.fnt, nextCh, fno, dx, x, y, w, h)
            END;
            IF tw + x + dx > width THEN d := len - bklen;
                IF (0 <= d) & (d < AdjustSpan) & (nextCh > " ") THEN eol := TRUE;
                    Texts.OpenReader(R, T, Texts.Pos(R) - d);
                    nob := bknob; len := bklen; tw := bktw; minY := bkminY; maxY := bkmaxY
                ELSIF len = 0 THEN  (*force at least one character on each line*)
                    INC(len); INC(y, Offset()); minY := SHORT(Min(minY, y)); maxY := Max(maxY, y + h);
                    Texts.Read(R, nextCh); eol := FALSE
                ELSE eol := (nextCh <= " ") & (nextCh # Texts.ElemChar)
                END;
                EXIT
            END;
            IF (nextCh <= " ") & (nextCh # Texts.ElemChar) THEN
                bknob := nob; bklen := len; bktw := tw; bkminY := minY; bkmaxY := maxY;
                IF nextCh = " " THEN INC(nob) END
            END;
            INC(len); INC(y, Offset()); minY := SHORT(Min(minY, y)); maxY := Max(maxY, y + h);
            Texts.Read(R, nextCh)
        END;
        IF gridAdj IN P.opts THEN
            WHILE dsr < -minY DO INC(dsr, lsp) END;
            t.h := Max(lsp, dsr + maxY); INC(t.h, (-t.h) MOD lsp)
        ELSE dsr := Max(dsr, -minY); t.h := Max(lsp, dsr + maxY)
        END;
        t.len := len; t.w := SHORT(Min(tw, maxW)); t.dsr := dsr; t.nob := nob; t.eot := R.eot; t.pbeg := pbeg;
        IF eol THEN Texts.Read(R, nextCh); t.span := len + 1 ELSE t.span := len END
    END MeasureLine;


    (** Printer Page Placement **)

    PROCEDURE FlushLine;
    BEGIN
        IF line.len > 0 THEN line.buf[line.len] := 0X; line.len := 0;
            IF line.first THEN Printer.String(line.px, line.y, line.buf, fonts.dict[line.fno].name); line.first := FALSE
            ELSE Printer.ContString(line.buf, fonts.dict[line.fno].name)
            END
        END
    END FlushLine;

    PROCEDURE PlaceChar (ch: CHAR; fno: SHORTINT; x, y, dx: INTEGER);
    BEGIN
        IF line.len > 0 THEN
            IF (x # line.x) OR (y # line.y) THEN FlushLine; line.first := TRUE; line.px := x
            ELSIF fno # line.fno THEN FlushLine
            END
        ELSE line.px := x
        END;
        line.fno := fno; line.x := x + dx; line.y := y; line.buf[line.len] := ch; INC(line.len)
    END PlaceChar;

    PROCEDURE PlaceSpecial (fno: SHORTINT; pno, nob, px, py, x, y, dx: INTEGER);    (*R, nextCh set*)
        VAR e: Texts.Elem; msg: PrintMsg;
    BEGIN
        IF (nextCh = " ") & (P.opts * AdjMask = AdjMask) & (nob > 0) OR (nextCh = TAB) THEN (*skip*)
        ELSIF R.elem # NIL THEN e := R.elem;
            FlushLine; line.first := TRUE;
            msg.prepare := FALSE;
            msg.fnt := R.fnt; msg.col := R.col; msg.pos := Texts.Pos(R) - 1;
            msg.X0 := px + x; msg.Y0 := py + y; msg.pno := pno;
            e.handle(e, msg)
        ELSE PlaceChar(nextCh, fno, px, py, dx)
        END
    END PlaceSpecial;

    PROCEDURE PlaceLine (T: Texts.Text; pno: INTEGER; VAR t: PrintLine; left, width, py: INTEGER);
        VAR i: LONGINT; n, cn, lm, rm, px, pw, tw, ddx, dx, x, y, w, h: INTEGER; fno: SHORTINT;
    BEGIN Texts.OpenReader(R, T, t.org); AdjustMetrics(T, t, left, pw, tw, ddx, cn);
        lm := left + SHORT(P.left DIV Unit); rm := left + width; px := pw; INC(py, t.dsr); i := 0; n := 0;
        line.first := TRUE; line.len := 0;
        WHILE i < t.len DO Texts.Read(R, nextCh);
            IF nextCh <= " " THEN GetSpecial(n, width, cn, ddx, px - lm, fno, dx, x, y, w, h)
            ELSE GetPrintChar(R.fnt, nextCh, fno, dx, x, y, w, h)
            END;
            IF px + x + w <= rm THEN
                IF nextCh <= " " THEN PlaceSpecial(fno, pno, t.nob, px, py, x, y + Offset(), dx)
                ELSE PlaceChar(nextCh, fno, px, py + Offset(), dx)
                END;
                INC(px, dx); INC(i)
            ELSE i := t.len
            END
        END;
        FlushLine
    END PlaceLine;


    PROCEDURE PlaceHeader* (headerX, headerY, headerW: INTEGER;
            pno: INTEGER; fnt: Fonts.Font; VAR header: ARRAY OF CHAR; alt: BOOLEAN);
        VAR i, j: INTEGER; fno: SHORTINT; digits, pageno: ARRAY 16 OF CHAR;
    BEGIN alt := alt & ~ODD(pno); fno := FontNo(fnt);
        IF (pno >= 0) OR (pno < -30) THEN pno := ABS(pno); i := 0; j := 0;
            REPEAT digits[i] := CHR(pno MOD 10 + 30H); INC(i); pno := pno DIV 10 UNTIL pno = 0;
            REPEAT DEC(i); pageno[j] := digits[i]; INC(j) UNTIL i = 0;
            pageno[j] := 0X
        ELSE pno := ABS(pno); i := 0;
            WHILE pno >= 10 DO DEC(pno, 10); pageno[i] := "x"; INC(i) END;
            CASE pno OF
                0:
            |   1..3: WHILE pno > 0 DO DEC(pno); pageno[i] := "i"; INC(i) END
            |   4: pageno[i] := "i"; INC(i); pageno[i] := "v"; INC(i)
            |   5..8: DEC(pno, 5); pageno[i] := "v"; INC(i);
                    WHILE pno > 0 DO DEC(pno); pageno[i] := "i"; INC(i) END
            |   9: pageno[i] := "i"; INC(i); pageno[i] := "x"; INC(i)
            END;
            pageno[i] := 0X
        END;
        IF alt THEN Printer.String(headerX, headerY, pageno, fonts.dict[fno].name);
            IF header[0] # 0X THEN
                Printer.String(headerX + headerW - Width(fno, header), headerY, header, fonts.dict[fno].name)
            END
        ELSE Printer.String(headerX + headerW - Width(fno, pageno), headerY, pageno, fonts.dict[fno].name);
            IF header[0] # 0X THEN Printer.String(headerX, headerY, header, fonts.dict[fno].name) END
        END
    END PlaceHeader;


    PROCEDURE ClaimPrinter; (*send null-command to keep printer connection alive*)
        VAR i: INTEGER; dmy: ARRAY 32 OF CHAR;
    BEGIN dmy[0] := 0X; i := 10;
        WHILE i > 0 DO Printer.String(0, 0, dmy, fname); DEC(i) END
    END ClaimPrinter;

    (*PROCEDURE PrintDraft* (t: Texts.Text; header: ARRAY OF CHAR; copies: INTEGER);
        CONST left = 160; bot = 100; lsp = 32;
        VAR top, y, pno, i: INTEGER; r: Texts.Reader; ch: CHAR; s: ARRAY 256 OF CHAR;
    
        PROCEDURE PrintHeader;
        BEGIN
            Printer.String(left, Printer.PageHeight - 125, header, Fonts.Default.name);
            IF pno < 10 THEN s[0] := " " ELSE s[0] := CHR(30H + pno MOD 100 DIV 10) END;
            s[1] := CHR(30H + pno MOD 10); s[2] := 0X;
            Printer.String(Printer.PageWidth - 236, Printer.PageHeight - 125, s, Fonts.Default.name)
        END PrintHeader;
    
    BEGIN
        pno := 0; top := Printer.PageHeight - 225; y := top;
        Printer.UseListFont(Fonts.Default.name);
        PrintHeader;
        Texts.OpenReader(r, t, 0);
        REPEAT Texts.Read(r, ch);
            i := 0; WHILE ~r.eot & (ch # CR) DO s[i] := ch; INC(i); Texts.Read(r, ch) END;
            s[i] := 0X;
            Printer.String(left, y, s, Fonts.Default.name);
            y := y - lsp;
            IF y < bot THEN Printer.Page(copies); INC(pno); PrintHeader; y := top END
        UNTIL r.eot;
        IF y < top THEN Printer.Page(copies) END
    END PrintDraft;*)

    PROCEDURE PrintDraft* (t: Texts.Text; header: ARRAY OF CHAR; copies: INTEGER);
        CONST left = 160; bot = 100; lsp = 32; maxLineLen = 120;
        VAR top, y, pno, i, b: INTEGER; org: LONGINT; r: Texts.Reader; ch: CHAR; s: ARRAY maxLineLen + 1 OF CHAR;
    
        PROCEDURE PrintHeader;
        BEGIN
            Printer.String(left, Printer.PageHeight - 125, header, Fonts.Default.name);
            IF pno < 10 THEN s[0] := " " ELSE s[0] := CHR(30H + pno MOD 100 DIV 10) END;
            s[1] := CHR(30H + pno MOD 10); s[2] := 0X;
            Printer.String(Printer.PageWidth - 236, Printer.PageHeight - 125, s, Fonts.Default.name)
        END PrintHeader;
    
    BEGIN
        pno := 0; top := Printer.PageHeight - 225; y := top;
        Printer.UseListFont(Fonts.Default.name);
        PrintHeader;
        Texts.OpenReader(r, t, 0);
        REPEAT
            org := Texts.Pos(r); Texts.Read(r, ch); i := 0; b := 0;
            WHILE ~r.eot & (ch # CR) & (i < maxLineLen) DO
                IF ch = " " THEN b := i END;
                s[i] := ch; INC(i); Texts.Read(r, ch)
            END;
            IF (i = maxLineLen) & (ch # CR) & ~r.eot THEN
                IF b > 0 THEN i := b; org := org + i + 1 ELSE org := org + i END;
                Texts.OpenReader(r, t, org)
            END;
            s[i] := 0X;
            Printer.String(left, y, s, Fonts.Default.name);
            y := y - lsp;
            IF y < bot THEN Printer.Page(copies); INC(pno); PrintHeader; y := top END
        UNTIL r.eot;
        IF y < top THEN Printer.Page(copies) END
    END PrintDraft;

(*---version without two-column printing
    PROCEDURE PlaceBody* (bodyX, bodyY, bodyW, bodyH: INTEGER;
            T: Texts.Text; VAR pos: LONGINT; pno: INTEGER; place: BOOLEAN);
        VAR t: PrintLine; org: LONGINT; py: INTEGER; inPage: BOOLEAN;
    BEGIN py := bodyY + bodyH; inPage := FALSE;
        LOOP org := pos; Texts.OpenReader(R, T, org); Texts.Read(R, nextCh);
            t.org := org; MeasureLine(T, pno, bodyW, t);
            IF pbeg = org THEN
                IF inPage & (pageBreak IN P.opts) THEN EXIT (*parc enforced early page break*)
                ELSIF py - bodyY < SHORT((3 * P.lsp + P.lead) DIV Unit) THEN    (*widow window*)
                    INC(pos, t.span); EXIT
                ELSIF inPage OR (pageBreak IN P.opts) THEN DEC(py, SHORT(P.lead DIV Unit)); inPage := TRUE
                END
            ELSE inPage := inPage OR (t.len > 0);
                IF inPage THEN DEC(py, t.h) END;
                IF py < bodyY THEN EXIT END;
                IF place THEN PlaceLine(T, pno, t, bodyX, bodyW + (5 * mm DIV Unit), py)
                ELSE ClaimPrinter
                END
            END;
            INC(pos, t.span);
            IF t.eot THEN EXIT END
        END
    END PlaceBody;
*)
(*---*)
    PROCEDURE MeasureColumns (pno, py, y0, w0: INTEGER; T: Texts.Text; VAR pos: LONGINT;
            VAR t: ARRAY OF PrintLine; VAR nl, nr, bh: INTEGER; VAR eofPage: BOOLEAN);
        VAR yl, yr, hl, hr, dh: INTEGER; inColumn, break: BOOLEAN;

        PROCEDURE MeasureColumn (VAR inCol, break: BOOLEAN; lastCol: BOOLEAN; VAR py: INTEGER; VAR n: INTEGER);
            VAR org: LONGINT; eot: BOOLEAN;
        BEGIN
            LOOP org := pos; Texts.OpenReader(R, T, org); Texts.Read(R, nextCh);
                t[n].org := org; MeasureLine(T, pno, w0, t[n]); eot := t[n].eot;
                IF ~(twoColumns IN P.opts) OR (n = LEN(t)) THEN EXIT END;
                IF pbeg = org THEN
                    IF inCol & (pageBreak IN P.opts) THEN break := TRUE; EXIT   (*parc enforced early page break*)
                    ELSIF lastCol & (py - y0 < SHORT((3 * P.lsp + P.lead) DIV Unit)) THEN   (*widow window*)
                        t[n].h := SHORT(P.lead DIV Unit); INC(pos, t[n].span); eofPage := TRUE; EXIT
                    ELSIF inCol OR (pageBreak IN P.opts) THEN inCol := TRUE;
                        t[n].h := SHORT(P.lead DIV Unit); DEC(py, t[n].h)
                    END;
                    INC(pos, t[n].span); INC(n)
                ELSIF inCol OR (t[n].len > 0) THEN inCol := TRUE;
                    IF py - t[n].h >= y0 THEN DEC(py, t[n].h); INC(pos, t[n].span); INC(n)
                    ELSE eofPage := TRUE; EXIT
                    END
                ELSE INC(pos, t[n].span)
                END;
                ClaimPrinter;
                IF eot THEN EXIT END
            END
        END MeasureColumn;

    BEGIN inColumn := FALSE; break := FALSE; dh := 0;
        yl := py; nl := 0; MeasureColumn(inColumn, break, FALSE, yl, nl); hl := py - yl;
        yr := py; nr := nl;
        IF ~break THEN MeasureColumn(inColumn, break, TRUE, yr, nr) END;
        hr := py - yr;
        LOOP    (*balance columns*)
            IF nl = 0 THEN EXIT
            ELSIF t[nl-1].len = 0 THEN DEC(nl); dh := t[nl].h;
            ELSIF (hl - t[nl - 1].h > hr) & (yr - t[nl - 1].h >= y0) THEN DEC(nl);
                DEC(hl, t[nl].h); INC(yl, t[nl].h); INC(hr, t[nl].h + dh); DEC(yr, t[nl].h + dh); dh := 0
            ELSE EXIT
            END
        END;
        bh := Max(hl, hr)
    END MeasureColumns;

    PROCEDURE PlaceColumns (T: Texts.Text; VAR t: ARRAY OF PrintLine; pno, px, py, w0, nl, nr: INTEGER);
        VAR i, x, y, w: INTEGER;
    BEGIN i := 0;
        x := px; y := py; w := w0 + (5 * mm DIV Unit);
        WHILE i < nl DO DEC(y, t[i].h); PlaceLine(T, pno, t[i], x, w, y); INC(i) END;
        x := px + (w0 + ColumnGap DIV Unit) DIV 2;
        y := py; w := w0 DIV 2 + (5 * mm DIV Unit);
        WHILE (i < nr) & ((t[i].len = 0) OR (t[i].pbeg = t[i].org)) DO INC(i) END;
        WHILE i < nr DO DEC(y, t[i].h); PlaceLine(T, pno, t[i], x, w, y); INC(i) END
    END PlaceColumns;

    PROCEDURE PlaceBody* (bodyX, bodyY, bodyW, bodyH: INTEGER;
            T: Texts.Text; VAR pos: LONGINT; pno: INTEGER; place: BOOLEAN);
        VAR t: PrintLine; org: LONGINT; py, bh, nl, nr: INTEGER; inPage, eofPage: BOOLEAN;
            bt: ARRAY 254 OF PrintLine;
    BEGIN py := bodyY + bodyH; inPage := FALSE;
        LOOP org := pos; Texts.OpenReader(R, T, org); Texts.Read(R, nextCh);
            t.org := org; MeasureLine(T, pno, bodyW, t);
            IF pbeg = org THEN
                IF inPage & (pageBreak IN P.opts) THEN EXIT (*parc enforced early page break*)
                ELSIF py - bodyY < SHORT((3 * P.lsp + P.lead) DIV Unit) THEN    (*widow window*)
                    INC(pos, t.span); EXIT
                ELSIF inPage OR (pageBreak IN P.opts) THEN DEC(py, SHORT(P.lead DIV Unit)); inPage := TRUE
                END;
                INC(pos, t.span)
            ELSIF twoColumns IN P.opts THEN eofPage := FALSE;
                MeasureColumns(pno, py, bodyY, bodyW, T, pos, bt, nl, nr, bh, eofPage);
                IF (nl = 0) OR (bh = 0) THEN EXIT END;
                IF place THEN PlaceColumns(T, bt, pno, bodyX, py, bodyW, nl, nr) END;
                DEC(py, bh); inPage := TRUE;
                IF eofPage THEN EXIT END
            ELSE inPage := inPage OR (t.len > 0);
                IF inPage THEN DEC(py, t.h) END;
                IF py < bodyY THEN
                    IF t.h > bodyH THEN INC(pos, t.span) END;   (*line is higher than page: skip*)
                    EXIT
                END;
                IF place THEN PlaceLine(T, pno, t, bodyX, bodyW + (5 * mm DIV Unit), py)
                ELSE ClaimPrinter
                END;
                INC(pos, t.span)
            END;
            IF t.eot THEN EXIT END
        END
    END PlaceBody;
(*---*)

BEGIN fname := "Syntax10.Scn.Fnt"
END TextPrinter.