ref: d6a2897ca2b39a839c3fd45d0b7eb73367ffd26b
dir: /adj.c/
/* adjustment buffer for putting words into lines */
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "roff.h"
#define ADJ_LLEN(a) MAX(0, (a)->ll - ((a)->lt >= 0 ? (a)->lt : (a)->li))
struct adj {
struct wb wbs[NWORDS]; /* words in buf */
int gaps[NWORDS]; /* gaps before words */
int nwords;
int wid; /* total width of buf */
int swid; /* current space width */
int gap; /* space before the next word */
int nls; /* newlines before the next word */
int l, i, t; /* current .l, .i and ti */
int ll, li, lt; /* current line's .l, .i and ti */
int filled; /* filled all words in the last adj_fill() */
};
void adj_ll(struct adj *adj, int ll)
{
adj->l = ll;
}
void adj_ti(struct adj *adj, int ti)
{
adj->t = ti;
}
void adj_in(struct adj *adj, int in)
{
adj->i = in;
}
/* .ll, .in and .ti are delayed until the partial line is output */
static void adj_confupdate(struct adj *adj)
{
adj->ll = adj->l;
adj->li = adj->i;
adj->lt = adj->t;
adj->t = -1;
}
/* does the adjustment buffer need to be flushed without filling? */
static int adj_fullnf(struct adj *a)
{
/* blank lines; indented lines; newlines when buffer is empty */
return a->nls > 1 || (a->nls && a->gap) ||
(a->nls - a->filled > 0 && !a->nwords);
}
/* does the adjustment buffer need to be flushed? */
int adj_full(struct adj *a, int fill)
{
if (!fill)
return a->nls - a->filled > 0;
if (adj_fullnf(a))
return 1;
return a->nwords && a->wid > ADJ_LLEN(a);
}
/* is the adjustment buffer empty? */
int adj_empty(struct adj *a, int fill)
{
return !fill ? a->nls - a->filled <= 0 : !a->nwords && !adj_fullnf(a);
}
/* set space width */
void adj_swid(struct adj *adj, int swid)
{
adj->swid = swid;
}
/* move words inside an adj struct */
static void adj_movewords(struct adj *a, int dst, int src, int len)
{
memmove(a->wbs + dst, a->wbs + src, len * sizeof(a->wbs[0]));
memmove(a->gaps + dst, a->gaps + src, len * sizeof(a->gaps[0]));
}
static int adj_linewid(struct adj *a, int n)
{
int i, w = 0;
for (i = 0; i < n; i++)
w += wb_wid(&a->wbs[i]) + a->gaps[i];
return w;
}
static int adj_linefit(struct adj *a, int llen)
{
int i, w = 0;
for (i = 0; i < a->nwords; i++) {
w += wb_wid(&a->wbs[i]) + a->gaps[i];
if (w > llen)
return i;
}
return i;
}
/* move n words from the adjustment buffer to s */
static int adj_move(struct adj *a, int n, struct sbuf *s, int *els_neg, int *els_pos)
{
struct wb *cur;
int w = 0;
int i;
*els_neg = 0;
*els_pos = 0;
for (i = 0; i < n; i++) {
cur = &a->wbs[i];
sbuf_printf(s, "%ch'%du'", c_ec, a->gaps[i]);
sbuf_append(s, sbuf_buf(&cur->sbuf));
w += wb_wid(cur) + a->gaps[i];
if (cur->els_neg < *els_neg)
*els_neg = cur->els_neg;
if (cur->els_pos > *els_pos)
*els_pos = cur->els_pos;
wb_done(cur);
}
if (!n)
return 0;
a->nwords -= n;
adj_movewords(a, 0, n, a->nwords);
a->wid = adj_linewid(a, a->nwords);
if (a->nwords) /* apply the new .l and .i */
adj_confupdate(a);
return w;
}
/* try to hyphenate the n-th word */
static void adj_hyph(struct adj *a, int n, int w, int hyph)
{
struct wb w1, w2;
int flg = hyph | (n ? 0 : HY_ANY);
wb_init(&w1);
wb_init(&w2);
if (wb_hyph(&a->wbs[n], w, &w1, &w2, flg)) {
wb_done(&w1);
wb_done(&w2);
return;
}
adj_movewords(a, n + 2, n + 1, a->nwords - n);
wb_done(&a->wbs[n]);
memcpy(&a->wbs[n], &w1, sizeof(w1));
memcpy(&a->wbs[n + 1], &w2, sizeof(w2));
a->nwords++;
a->gaps[n + 1] = 0;
a->wid = adj_linewid(a, a->nwords);
}
/* fill and copy a line into s */
int adj_fill(struct adj *a, int ad_b, int fill, int hyph, struct sbuf *s,
int *ll, int *in, int *ti, int *els_neg, int *els_pos)
{
int adj_div, adj_rem;
int w = 0;
int i, n;
int llen = ADJ_LLEN(a);
*ll = a->ll;
*in = a->li;
*ti = a->lt;
if (!fill || adj_fullnf(a)) {
a->filled = 0;
a->nls--;
return adj_move(a, a->nwords, s, els_neg, els_pos);
}
n = adj_linefit(a, llen);
if (n < a->nwords)
adj_hyph(a, n, llen - adj_linewid(a, n) - a->gaps[n], hyph);
n = adj_linefit(a, llen);
if (!n && a->nwords)
n = 1;
w = adj_linewid(a, n);
if (ad_b && n > 1) {
adj_div = (llen - w) / (n - 1);
adj_rem = (llen - w) % (n - 1);
for (i = 0; i < n - 1; i++)
a->gaps[i + 1] += adj_div + (i < adj_rem);
}
w = adj_move(a, n, s, els_neg, els_pos);
if (a->nwords)
a->wid -= a->gaps[0];
a->gaps[0] = 0;
a->filled = n && !a->nwords;
return w;
}
void adj_sp(struct adj *adj)
{
adj->gap += adj->swid;
}
void adj_nl(struct adj *adj)
{
adj->nls++;
adj->gap = 0;
}
/* ignore the previous newline */
void adj_nonl(struct adj *adj)
{
if (adj->nls)
adj->gap += adj->swid;
adj->nls = 0;
}
static void adj_word(struct adj *adj, struct wb *wb)
{
int i = adj->nwords++;
wb_init(&adj->wbs[i]);
adj->gaps[i] = adj->filled ? 0 : adj->gap;
adj->filled = 0;
adj->wid += wb_wid(wb) + adj->gap;
wb_cat(&adj->wbs[i], wb);
}
static int adj_eos(struct adj *adj)
{
return adj->nwords && wb_eos(&adj->wbs[adj->nwords - 1]);
}
/* insert wb into the adjustment buffer */
void adj_wb(struct adj *adj, struct wb *wb)
{
if (wb_empty(wb) || adj->nwords == NWORDS)
return;
if (!adj->nwords) /* apply the new .l and .i */
adj_confupdate(adj);
if (adj->nls && !adj->gap && adj->nwords >= 1)
adj->gap = adj_eos(adj) ? adj->swid * 2 : adj->swid;
adj_word(adj, wb);
adj->nls = 0;
adj->gap = 0;
}
struct adj *adj_alloc(void)
{
struct adj *adj = malloc(sizeof(*adj));
memset(adj, 0, sizeof(*adj));
return adj;
}
void adj_free(struct adj *adj)
{
free(adj);
}
int adj_wid(struct adj *adj)
{
return adj->wid + (adj->nls ? adj->swid : adj->gap);
}