/*
 * Copyright 1990 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

/*      Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T */
/*        All Rights Reserved   */

/*
 * Copyright (c) 1980 Regents of the University of California.
 * All rights reserved. The Berkeley software License Agreement
 * specifies the terms and conditions for redistribution.
 */

 /* tt.c: subroutines for drawing horizontal lines */
# include "t..c"

int
ctype(int il, int ic)
{
if (instead[il])
        return(0);
if (fullbot[il])
        return(0);
il = stynum[il];
return(style[il][ic]);
}

int
min(int a, int b)
{
return(a<b ? a : b);
}

int
fspan(int i, int c)
{
c++;
return(c<ncol && ctype(i,c)=='s');
}

int
lspan(int i, int c)
{
int k;
if (ctype(i,c) != 's') return(0);
c++;
if (c < ncol && ctype(i,c)== 's')
        return(0);
for(k=0; ctype(i,--c) == 's'; k++);
return(k);
}

int
ctspan(int i, int c)
{
int k;
c++;
for(k=1; c<ncol && ctype(i,c)=='s'; k++)
        c++;
return(k);
}

void
tohcol(int ic)
{
                        if (ic==0)
                                fprintf(tabout, "\\h'|0'");
                        else
                                fprintf(tabout, "\\h'(|\\n(%du+|\\n(%du)/2u'", ic+CLEFT, ic+CRIGHT-1);
}

int
allh(int i)
{
/* return true if every element in line i is horizontal */
/* also at least one must be horizontl */
int c, one, k;
if (fullbot[i]) return(1);
for(one=c=0; c<ncol; c++)
        {
        k = thish(i,c);
        if (k==0) return(0);
        if (k==1) continue;
        one=1;
        }
return(one);
}

int
thish(int i, int c)
{
        int t;
        char *s;
        struct colstr *pc;
        if (c<0)return(0);
        if (i<0) return(0);
        t = ctype(i,c);
        if (t=='_' || t == '-')
                return('-');
        if (t=='=')return('=');
        if (t=='^') return(1);
        if (fullbot[i] )
                return(fullbot[i]);
        if (t=='s') return(thish(i,c-1));
        if (t==0) return(1);
        pc = &table[i][c];
        s = (t=='a' ? pc->rcol : pc->col);
        if (s==0 || (point(s) && *s==0))
                return(1);
        if (vspen(s)) return(1);
        if (t=barent( s))
                return(t);
        return(0);
}