]> git.cameronkatri.com Git - mandoc.git/blobdiff - term.c
1. Eliminate struct eqn, instead use the existing members
[mandoc.git] / term.c
diff --git a/term.c b/term.c
index e9171013e04b1748d14a00f6643bfc5dc9d78668..595390b671b44eb8549fadb092d7d3c4214955a6 100644 (file)
--- a/term.c
+++ b/term.c
@@ -1,7 +1,7 @@
-/*     $Id: term.c,v 1.256 2016/01/07 21:03:54 schwarze Exp $ */
+/*     $Id: term.c,v 1.273 2017/06/14 23:24:18 schwarze Exp $ */
 /*
  * Copyright (c) 2008, 2009, 2010, 2011 Kristaps Dzonsons <kristaps@bsd.lv>
- * Copyright (c) 2010-2015 Ingo Schwarze <schwarze@openbsd.org>
+ * Copyright (c) 2010-2017 Ingo Schwarze <schwarze@openbsd.org>
  *
  * Permission to use, copy, modify, and distribute this software for any
  * purpose with or without fee is hereby granted, provided that the above
 #include "main.h"
 
 static size_t           cond_width(const struct termp *, int, int *);
-static void             adjbuf(struct termp *p, size_t);
+static void             adjbuf(struct termp_col *, size_t);
 static void             bufferc(struct termp *, char);
 static void             encode(struct termp *, const char *, size_t);
 static void             encode1(struct termp *, int);
+static void             endline(struct termp *);
 
 
 void
-term_free(struct termp *p)
+term_setcol(struct termp *p, size_t maxtcol)
 {
+       if (maxtcol > p->maxtcol) {
+               p->tcols = mandoc_recallocarray(p->tcols,
+                   p->maxtcol, maxtcol, sizeof(*p->tcols));
+               p->maxtcol = maxtcol;
+       }
+       p->lasttcol = maxtcol - 1;
+       p->tcol = p->tcols;
+}
 
-       free(p->buf);
+void
+term_free(struct termp *p)
+{
+       for (p->tcol = p->tcols; p->tcol < p->tcols + p->maxtcol; p->tcol++)
+               free(p->tcol->buf);
+       free(p->tcols);
        free(p->fontq);
        free(p);
 }
@@ -84,69 +98,54 @@ term_end(struct termp *p)
  *    to be broken, start the next line at the right margin instead
  *    of at the offset.  Used together with TERMP_NOBREAK for the tags
  *    in various kinds of tagged lists.
- *  - TERMP_DANGLE: Do not break the output line at the right margin,
+ *  - TERMP_HANG: Do not break the output line at the right margin,
  *    append the next chunk after it even if this one is too long.
  *    To be used together with TERMP_NOBREAK.
- *  - TERMP_HANG: Like TERMP_DANGLE, and also suppress padding before
- *    the next chunk if this column is not full.
+ *  - TERMP_NOPAD: Start writing at the current position,
+ *    do not pad with blank characters up to the offset.
  */
 void
 term_flushln(struct termp *p)
 {
-       size_t           i;     /* current input position in p->buf */
-       int              ntab;  /* number of tabs to prepend */
        size_t           vis;   /* current visual position on output */
        size_t           vbl;   /* number of blanks to prepend to output */
        size_t           vend;  /* end of word visual position on output */
        size_t           bp;    /* visual right border position */
        size_t           dv;    /* temporary for visual pos calculations */
-       size_t           j;     /* temporary loop index for p->buf */
+       size_t           j;     /* temporary loop index for p->tcol->buf */
        size_t           jhy;   /* last hyph before overflow w/r/t j */
        size_t           maxvis; /* output position of visible boundary */
-
-       /*
-        * First, establish the maximum columns of "visible" content.
-        * This is usually the difference between the right-margin and
-        * an indentation, but can be, for tagged lists or columns, a
-        * small set of values.
-        *
-        * The following unsigned-signed subtractions look strange,
-        * but they are actually correct.  If the int p->overstep
-        * is negative, it gets sign extended.  Subtracting that
-        * very large size_t effectively adds a small number to dv.
-        */
-       dv = p->rmargin > p->offset ? p->rmargin - p->offset : 0;
-       maxvis = (int)dv > p->overstep ? dv - (size_t)p->overstep : 0;
-
-       if (p->flags & TERMP_NOBREAK) {
-               dv = p->maxrmargin > p->offset ?
-                    p->maxrmargin - p->offset : 0;
-               bp = (int)dv > p->overstep ?
-                    dv - (size_t)p->overstep : 0;
-       } else
-               bp = maxvis;
-
-       /*
-        * Calculate the required amount of padding.
-        */
-       vbl = p->offset + p->overstep > p->viscol ?
-             p->offset + p->overstep - p->viscol : 0;
-
+       int              ntab;  /* number of tabs to prepend */
+       int              breakline; /* after this word */
+
+       vbl = (p->flags & TERMP_NOPAD) || p->tcol->offset < p->viscol ?
+           0 : p->tcol->offset - p->viscol;
+       if (p->minbl && vbl < p->minbl)
+               vbl = p->minbl;
+       maxvis = p->tcol->rmargin > p->viscol + vbl ?
+           p->tcol->rmargin - p->viscol - vbl : 0;
+       bp = !(p->flags & TERMP_NOBREAK) ? maxvis :
+           p->maxrmargin > p->viscol + vbl ?
+           p->maxrmargin - p->viscol - vbl : 0;
        vis = vend = 0;
-       i = 0;
 
-       while (i < p->col) {
+       if ((p->flags && TERMP_MULTICOL) == 0)
+               p->tcol->col = 0;
+       while (p->tcol->col < p->tcol->lastcol) {
+
                /*
                 * Handle literal tab characters: collapse all
                 * subsequent tabs into a single huge set of spaces.
                 */
+
                ntab = 0;
-               while (i < p->col && '\t' == p->buf[i]) {
-                       vend = (vis / p->tabwidth + 1) * p->tabwidth;
+               while (p->tcol->col < p->tcol->lastcol &&
+                   p->tcol->buf[p->tcol->col] == '\t') {
+                       vend = term_tab_next(vis);
                        vbl += vend - vis;
                        vis = vend;
                        ntab++;
-                       i++;
+                       p->tcol->col++;
                }
 
                /*
@@ -156,84 +155,98 @@ term_flushln(struct termp *p)
                 * space is printed according to regular spacing rules).
                 */
 
-               for (j = i, jhy = 0; j < p->col; j++) {
-                       if (' ' == p->buf[j] || '\t' == p->buf[j])
+               jhy = 0;
+               breakline = 0;
+               for (j = p->tcol->col; j < p->tcol->lastcol; j++) {
+                       if (p->tcol->buf[j] == '\n') {
+                               if ((p->flags & TERMP_BRIND) == 0)
+                                       breakline = 1;
+                               continue;
+                       }
+                       if (p->tcol->buf[j] == ' ' || p->tcol->buf[j] == '\t')
                                break;
 
-                       /* Back over the the last printed character. */
-                       if (8 == p->buf[j]) {
+                       /* Back over the last printed character. */
+                       if (p->tcol->buf[j] == '\b') {
                                assert(j);
-                               vend -= (*p->width)(p, p->buf[j - 1]);
+                               vend -= (*p->width)(p, p->tcol->buf[j - 1]);
                                continue;
                        }
 
                        /* Regular word. */
                        /* Break at the hyphen point if we overrun. */
                        if (vend > vis && vend < bp &&
-                           (ASCII_HYPH == p->buf[j] ||
-                            ASCII_BREAK == p->buf[j]))
+                           (p->tcol->buf[j] == ASCII_HYPH||
+                            p->tcol->buf[j] == ASCII_BREAK))
                                jhy = j;
 
                        /*
                         * Hyphenation now decided, put back a real
                         * hyphen such that we get the correct width.
                         */
-                       if (ASCII_HYPH == p->buf[j])
-                               p->buf[j] = '-';
+                       if (p->tcol->buf[j] == ASCII_HYPH)
+                               p->tcol->buf[j] = '-';
 
-                       vend += (*p->width)(p, p->buf[j]);
+                       vend += (*p->width)(p, p->tcol->buf[j]);
                }
 
                /*
                 * Find out whether we would exceed the right margin.
                 * If so, break to the next line.
                 */
-               if (vend > bp && 0 == jhy && vis > 0) {
+
+               if (vend > bp && jhy == 0 && vis > 0 &&
+                   (p->flags & TERMP_BRNEVER) == 0) {
+                       if (p->flags & TERMP_MULTICOL)
+                               return;
+
+                       endline(p);
                        vend -= vis;
-                       (*p->endline)(p);
-                       p->viscol = 0;
-                       if (TERMP_BRIND & p->flags) {
-                               vbl = p->rmargin;
-                               vend += p->rmargin;
-                               vend -= p->offset;
-                       } else
-                               vbl = p->offset;
 
-                       /* use pending tabs on the new line */
+                       /* Use pending tabs on the new line. */
 
-                       if (0 < ntab)
-                               vbl += ntab * p->tabwidth;
+                       vbl = 0;
+                       while (ntab--)
+                               vbl = term_tab_next(vbl);
 
-                       /*
-                        * Remove the p->overstep width.
-                        * Again, if p->overstep is negative,
-                        * sign extension does the right thing.
-                        */
+                       /* Re-establish indentation. */
 
-                       bp += (size_t)p->overstep;
-                       p->overstep = 0;
+                       if (p->flags & TERMP_BRIND)
+                               vbl += p->tcol->rmargin;
+                       else
+                               vbl += p->tcol->offset;
+                       maxvis = p->tcol->rmargin > vbl ?
+                           p->tcol->rmargin - vbl : 0;
+                       bp = !(p->flags & TERMP_NOBREAK) ? maxvis :
+                           p->maxrmargin > vbl ?  p->maxrmargin - vbl : 0;
                }
 
-               /* Write out the [remaining] word. */
-               for ( ; i < p->col; i++) {
-                       if (vend > bp && jhy > 0 && i > jhy)
+               /*
+                * Write out the rest of the word.
+                */
+
+               for ( ; p->tcol->col < p->tcol->lastcol; p->tcol->col++) {
+                       if (vend > bp && jhy > 0 && p->tcol->col > jhy)
                                break;
-                       if ('\t' == p->buf[i])
+                       if (p->tcol->buf[p->tcol->col] == '\n')
+                               continue;
+                       if (p->tcol->buf[p->tcol->col] == '\t')
                                break;
-                       if (' ' == p->buf[i]) {
-                               j = i;
-                               while (i < p->col && ' ' == p->buf[i])
-                                       i++;
-                               dv = (i - j) * (*p->width)(p, ' ');
+                       if (p->tcol->buf[p->tcol->col] == ' ') {
+                               j = p->tcol->col;
+                               while (p->tcol->col < p->tcol->lastcol &&
+                                   p->tcol->buf[p->tcol->col] == ' ')
+                                       p->tcol->col++;
+                               dv = (p->tcol->col - j) * (*p->width)(p, ' ');
                                vbl += dv;
                                vend += dv;
                                break;
                        }
-                       if (ASCII_NBRSP == p->buf[i]) {
+                       if (p->tcol->buf[p->tcol->col] == ASCII_NBRSP) {
                                vbl += (*p->width)(p, ' ');
                                continue;
                        }
-                       if (ASCII_BREAK == p->buf[i])
+                       if (p->tcol->buf[p->tcol->col] == ASCII_BREAK)
                                continue;
 
                        /*
@@ -247,61 +260,83 @@ term_flushln(struct termp *p)
                                vbl = 0;
                        }
 
-                       (*p->letter)(p, p->buf[i]);
-                       if (8 == p->buf[i])
-                               p->viscol -= (*p->width)(p, p->buf[i-1]);
+                       (*p->letter)(p, p->tcol->buf[p->tcol->col]);
+                       if (p->tcol->buf[p->tcol->col] == '\b')
+                               p->viscol -= (*p->width)(p,
+                                   p->tcol->buf[p->tcol->col - 1]);
                        else
-                               p->viscol += (*p->width)(p, p->buf[i]);
+                               p->viscol += (*p->width)(p,
+                                   p->tcol->buf[p->tcol->col]);
                }
                vis = vend;
+
+               if (breakline == 0)
+                       continue;
+
+               /* Explicitly requested output line break. */
+
+               if (p->flags & TERMP_MULTICOL)
+                       return;
+
+               endline(p);
+               breakline = 0;
+               vis = vend = 0;
+
+               /* Re-establish indentation. */
+
+               vbl = p->tcol->offset;
+               maxvis = p->tcol->rmargin > vbl ?
+                   p->tcol->rmargin - vbl : 0;
+               bp = !(p->flags & TERMP_NOBREAK) ? maxvis :
+                   p->maxrmargin > vbl ?  p->maxrmargin - vbl : 0;
        }
 
        /*
         * If there was trailing white space, it was not printed;
         * so reset the cursor position accordingly.
         */
+
        if (vis > vbl)
                vis -= vbl;
        else
                vis = 0;
 
-       p->col = 0;
-       p->overstep = 0;
-       p->flags &= ~(TERMP_BACKAFTER | TERMP_BACKBEFORE);
+       p->col = p->tcol->col = p->tcol->lastcol = 0;
+       p->minbl = p->trailspace;
+       p->flags &= ~(TERMP_BACKAFTER | TERMP_BACKBEFORE | TERMP_NOPAD);
 
-       if ( ! (TERMP_NOBREAK & p->flags)) {
-               p->viscol = 0;
-               (*p->endline)(p);
-               return;
-       }
-
-       if (TERMP_HANG & p->flags) {
-               p->overstep += (int)(p->offset + vis - p->rmargin +
-                   p->trailspace * (*p->width)(p, ' '));
-
-               /*
-                * If we have overstepped the margin, temporarily move
-                * it to the right and flag the rest of the line to be
-                * shorter.
-                * If there is a request to keep the columns together,
-                * allow negative overstep when the column is not full.
-                */
-               if (p->trailspace && p->overstep < 0)
-                       p->overstep = 0;
-               return;
-
-       } else if (TERMP_DANGLE & p->flags)
+       if (p->flags & TERMP_MULTICOL)
                return;
 
        /* Trailing whitespace is significant in some columns. */
+
        if (vis && vbl && (TERMP_BRTRSP & p->flags))
                vis += vbl;
 
        /* If the column was overrun, break the line. */
-       if (maxvis < vis + p->trailspace * (*p->width)(p, ' ')) {
-               (*p->endline)(p);
-               p->viscol = 0;
+       if ((p->flags & TERMP_NOBREAK) == 0 ||
+           ((p->flags & TERMP_HANG) == 0 &&
+            vis + p->trailspace * (*p->width)(p, ' ') > maxvis))
+               endline(p);
+}
+
+static void
+endline(struct termp *p)
+{
+       if ((p->flags & (TERMP_NEWMC | TERMP_ENDMC)) == TERMP_ENDMC) {
+               p->mc = NULL;
+               p->flags &= ~TERMP_ENDMC;
+       }
+       if (p->mc != NULL) {
+               if (p->viscol && p->maxrmargin >= p->viscol)
+                       (*p->advance)(p, p->maxrmargin - p->viscol + 1);
+               p->flags |= TERMP_NOBUF | TERMP_NOSPACE;
+               term_word(p, p->mc);
+               p->flags &= ~(TERMP_NOBUF | TERMP_NEWMC);
        }
+       p->viscol = 0;
+       p->minbl = 0;
+       (*p->endline)(p);
 }
 
 /*
@@ -314,7 +349,7 @@ term_newln(struct termp *p)
 {
 
        p->flags |= TERMP_NOSPACE;
-       if (p->col || p->viscol)
+       if (p->tcol->lastcol || p->viscol)
                term_flushln(p);
 }
 
@@ -330,6 +365,7 @@ term_vspace(struct termp *p)
 
        term_newln(p);
        p->viscol = 0;
+       p->minbl = 0;
        if (0 < p->skipvsp)
                p->skipvsp--;
        else
@@ -397,30 +433,31 @@ term_fontpop(struct termp *p)
 void
 term_word(struct termp *p, const char *word)
 {
+       struct roffsu    su;
        const char       nbrsp[2] = { ASCII_NBRSP, 0 };
        const char      *seq, *cp;
        int              sz, uc;
-       size_t           ssz;
+       size_t           csz, lsz, ssz;
        enum mandoc_esc  esc;
 
-       if ( ! (TERMP_NOSPACE & p->flags)) {
-               if ( ! (TERMP_KEEP & p->flags)) {
-                       bufferc(p, ' ');
-                       if (TERMP_SENTENCE & p->flags)
+       if ((p->flags & TERMP_NOBUF) == 0) {
+               if ((p->flags & TERMP_NOSPACE) == 0) {
+                       if ((p->flags & TERMP_KEEP) == 0) {
                                bufferc(p, ' ');
-               } else
-                       bufferc(p, ASCII_NBRSP);
+                               if (p->flags & TERMP_SENTENCE)
+                                       bufferc(p, ' ');
+                       } else
+                               bufferc(p, ASCII_NBRSP);
+               }
+               if (p->flags & TERMP_PREKEEP)
+                       p->flags |= TERMP_KEEP;
+               if (p->flags & TERMP_NONOSPACE)
+                       p->flags |= TERMP_NOSPACE;
+               else
+                       p->flags &= ~TERMP_NOSPACE;
+               p->flags &= ~(TERMP_SENTENCE | TERMP_NONEWLINE);
+               p->skipvsp = 0;
        }
-       if (TERMP_PREKEEP & p->flags)
-               p->flags |= TERMP_KEEP;
-
-       if ( ! (p->flags & TERMP_NONOSPACE))
-               p->flags &= ~TERMP_NOSPACE;
-       else
-               p->flags |= TERMP_NOSPACE;
-
-       p->flags &= ~(TERMP_SENTENCE | TERMP_NONEWLINE);
-       p->skipvsp = 0;
 
        while ('\0' != *word) {
                if ('\\' != *word) {
@@ -479,12 +516,88 @@ term_word(struct termp *p, const char *word)
                case ESCAPE_FONTPREV:
                        term_fontlast(p);
                        continue;
+               case ESCAPE_BREAK:
+                       bufferc(p, '\n');
+                       continue;
                case ESCAPE_NOSPACE:
                        if (p->flags & TERMP_BACKAFTER)
                                p->flags &= ~TERMP_BACKAFTER;
                        else if (*word == '\0')
                                p->flags |= (TERMP_NOSPACE | TERMP_NONEWLINE);
                        continue;
+               case ESCAPE_HORIZ:
+                       if (*seq == '|') {
+                               seq++;
+                               uc = -p->col;
+                       } else
+                               uc = 0;
+                       if (a2roffsu(seq, &su, SCALE_EM) == NULL)
+                               continue;
+                       uc += term_hen(p, &su);
+                       if (uc > 0)
+                               while (uc-- > 0)
+                                       bufferc(p, ASCII_NBRSP);
+                       else if (p->col > (size_t)(-uc))
+                               p->col += uc;
+                       else {
+                               uc += p->col;
+                               p->col = 0;
+                               if (p->tcol->offset > (size_t)(-uc)) {
+                                       p->ti += uc;
+                                       p->tcol->offset += uc;
+                               } else {
+                                       p->ti -= p->tcol->offset;
+                                       p->tcol->offset = 0;
+                               }
+                       }
+                       continue;
+               case ESCAPE_HLINE:
+                       if ((cp = a2roffsu(seq, &su, SCALE_EM)) == NULL)
+                               continue;
+                       uc = term_hen(p, &su);
+                       if (uc <= 0) {
+                               if (p->tcol->rmargin <= p->tcol->offset)
+                                       continue;
+                               lsz = p->tcol->rmargin - p->tcol->offset;
+                       } else
+                               lsz = uc;
+                       if (*cp == seq[-1])
+                               uc = -1;
+                       else if (*cp == '\\') {
+                               seq = cp + 1;
+                               esc = mandoc_escape(&seq, &cp, &sz);
+                               switch (esc) {
+                               case ESCAPE_UNICODE:
+                                       uc = mchars_num2uc(cp + 1, sz - 1);
+                                       break;
+                               case ESCAPE_NUMBERED:
+                                       uc = mchars_num2char(cp, sz);
+                                       break;
+                               case ESCAPE_SPECIAL:
+                                       uc = mchars_spec2cp(cp, sz);
+                                       break;
+                               default:
+                                       uc = -1;
+                                       break;
+                               }
+                       } else
+                               uc = *cp;
+                       if (uc < 0x20 || (uc > 0x7E && uc < 0xA0))
+                               uc = '_';
+                       if (p->enc == TERMENC_ASCII) {
+                               cp = ascii_uc2str(uc);
+                               csz = term_strlen(p, cp);
+                               ssz = strlen(cp);
+                       } else
+                               csz = (*p->width)(p, uc);
+                       while (lsz >= csz) {
+                               if (p->enc == TERMENC_ASCII)
+                                       encode(p, cp, ssz);
+                               else
+                                       encode1(p, uc);
+                               lsz -= csz;
+                       }
+                       continue;
                case ESCAPE_SKIPCHAR:
                        p->flags |= TERMP_BACKAFTER;
                        continue;
@@ -504,8 +617,12 @@ term_word(struct termp *p, const char *word)
                                }
                        }
                        /* Trim trailing backspace/blank pair. */
-                       if (p->col > 2 && p->buf[p->col - 1] == ' ')
-                               p->col -= 2;
+                       if (p->tcol->lastcol > 2 &&
+                           (p->tcol->buf[p->tcol->lastcol - 1] == ' ' ||
+                            p->tcol->buf[p->tcol->lastcol - 1] == '\t'))
+                               p->tcol->lastcol -= 2;
+                       if (p->col > p->tcol->lastcol)
+                               p->col = p->tcol->lastcol;
                        continue;
                default:
                        continue;
@@ -530,25 +647,28 @@ term_word(struct termp *p, const char *word)
 }
 
 static void
-adjbuf(struct termp *p, size_t sz)
+adjbuf(struct termp_col *c, size_t sz)
 {
-
-       if (0 == p->maxcols)
-               p->maxcols = 1024;
-       while (sz >= p->maxcols)
-               p->maxcols <<= 2;
-
-       p->buf = mandoc_reallocarray(p->buf, p->maxcols, sizeof(int));
+       if (c->maxcols == 0)
+               c->maxcols = 1024;
+       while (c->maxcols <= sz)
+               c->maxcols <<= 2;
+       c->buf = mandoc_reallocarray(c->buf, c->maxcols, sizeof(*c->buf));
 }
 
 static void
 bufferc(struct termp *p, char c)
 {
-
-       if (p->col + 1 >= p->maxcols)
-               adjbuf(p, p->col + 1);
-
-       p->buf[p->col++] = c;
+       if (p->flags & TERMP_NOBUF) {
+               (*p->letter)(p, c);
+               return;
+       }
+       if (p->col + 1 >= p->tcol->maxcols)
+               adjbuf(p->tcol, p->col + 1);
+       if (p->tcol->lastcol <= p->col || (c != ' ' && c != ASCII_NBRSP))
+               p->tcol->buf[p->col] = c;
+       if (p->tcol->lastcol < ++p->col)
+               p->tcol->lastcol = p->col;
 }
 
 /*
@@ -561,31 +681,40 @@ encode1(struct termp *p, int c)
 {
        enum termfont     f;
 
-       if (p->col + 7 >= p->maxcols)
-               adjbuf(p, p->col + 7);
+       if (p->flags & TERMP_NOBUF) {
+               (*p->letter)(p, c);
+               return;
+       }
+
+       if (p->col + 7 >= p->tcol->maxcols)
+               adjbuf(p->tcol, p->col + 7);
 
        f = (c == ASCII_HYPH || c > 127 || isgraph(c)) ?
            p->fontq[p->fonti] : TERMFONT_NONE;
 
        if (p->flags & TERMP_BACKBEFORE) {
-               if (p->buf[p->col - 1] == ' ')
+               if (p->tcol->buf[p->col - 1] == ' ' ||
+                   p->tcol->buf[p->col - 1] == '\t')
                        p->col--;
                else
-                       p->buf[p->col++] = 8;
+                       p->tcol->buf[p->col++] = '\b';
                p->flags &= ~TERMP_BACKBEFORE;
        }
-       if (TERMFONT_UNDER == f || TERMFONT_BI == f) {
-               p->buf[p->col++] = '_';
-               p->buf[p->col++] = 8;
+       if (f == TERMFONT_UNDER || f == TERMFONT_BI) {
+               p->tcol->buf[p->col++] = '_';
+               p->tcol->buf[p->col++] = '\b';
        }
-       if (TERMFONT_BOLD == f || TERMFONT_BI == f) {
-               if (ASCII_HYPH == c)
-                       p->buf[p->col++] = '-';
+       if (f == TERMFONT_BOLD || f == TERMFONT_BI) {
+               if (c == ASCII_HYPH)
+                       p->tcol->buf[p->col++] = '-';
                else
-                       p->buf[p->col++] = c;
-               p->buf[p->col++] = 8;
+                       p->tcol->buf[p->col++] = c;
+               p->tcol->buf[p->col++] = '\b';
        }
-       p->buf[p->col++] = c;
+       if (p->tcol->lastcol <= p->col || (c != ' ' && c != ASCII_NBRSP))
+               p->tcol->buf[p->col] = c;
+       if (p->tcol->lastcol < ++p->col)
+               p->tcol->lastcol = p->col;
        if (p->flags & TERMP_BACKAFTER) {
                p->flags |= TERMP_BACKBEFORE;
                p->flags &= ~TERMP_BACKAFTER;
@@ -597,16 +726,39 @@ encode(struct termp *p, const char *word, size_t sz)
 {
        size_t            i;
 
-       if (p->col + 2 + (sz * 5) >= p->maxcols)
-               adjbuf(p, p->col + 2 + (sz * 5));
+       if (p->flags & TERMP_NOBUF) {
+               for (i = 0; i < sz; i++)
+                       (*p->letter)(p, word[i]);
+               return;
+       }
+
+       if (p->col + 2 + (sz * 5) >= p->tcol->maxcols)
+               adjbuf(p->tcol, p->col + 2 + (sz * 5));
 
        for (i = 0; i < sz; i++) {
                if (ASCII_HYPH == word[i] ||
                    isgraph((unsigned char)word[i]))
                        encode1(p, word[i]);
-               else
-                       p->buf[p->col++] = word[i];
+               else {
+                       if (p->tcol->lastcol <= p->col ||
+                           (word[i] != ' ' && word[i] != ASCII_NBRSP))
+                               p->tcol->buf[p->col] = word[i];
+                       p->col++;
+
+                       /*
+                        * Postpone the effect of \z while handling
+                        * an overstrike sequence from ascii_uc2str().
+                        */
+
+                       if (word[i] == '\b' &&
+                           (p->flags & TERMP_BACKBEFORE)) {
+                               p->flags &= ~TERMP_BACKBEFORE;
+                               p->flags |= TERMP_BACKAFTER;
+                       }
+               }
        }
+       if (p->tcol->lastcol < p->col)
+               p->tcol->lastcol = p->col;
 }
 
 void
@@ -630,7 +782,7 @@ term_setwidth(struct termp *p, const char *wstr)
                default:
                        break;
                }
-               if (a2roffsu(wstr, &su, SCALE_MAX))
+               if (a2roffsu(wstr, &su, SCALE_MAX) != NULL)
                        width = term_hspan(p, &su);
                else
                        iop = 0;
@@ -819,7 +971,7 @@ term_vspan(const struct termp *p, const struct roffsu *su)
 }
 
 /*
- * Convert a scaling width to basic units, rounding down.
+ * Convert a scaling width to basic units, rounding towards 0.
  */
 int
 term_hspan(const struct termp *p, const struct roffsu *su)
@@ -827,3 +979,17 @@ term_hspan(const struct termp *p, const struct roffsu *su)
 
        return (*p->hspan)(p, su);
 }
+
+/*
+ * Convert a scaling width to basic units, rounding to closest.
+ */
+int
+term_hen(const struct termp *p, const struct roffsu *su)
+{
+       int bu;
+
+       if ((bu = (*p->hspan)(p, su)) >= 0)
+               return (bu + 11) / 24;
+       else
+               return -((-bu + 11) / 24);
+}