usr/src/usr.bin/window/wwclreol.c

#ifndef lint
static  char *sccsid = "@(#)wwclreol.c  3.7 83/08/18";
#endif

#include "ww.h"
#include "tt.h"

wwclreol(w, line, col)
struct ww *w;
{
        wwclreol1(w, line, col, 0);
}

/*
 * Clear w to the end of line.
 * If cleared is true, then the screen line has already been cleared
 * previously.
 */
wwclreol1(w, line, col, cleared)
register struct ww *w;
int line, col;
char cleared;
{
        register i;
        int row = line - w->ww_scroll;
        int srow = w->ww_w.t + row;
        int scol = w->ww_w.l + col;
        register union ww_char *s, *buf;
        register char *smap, *win;
        char *touched;
        int nblank, ncleared;

        if (row < 0 || row >= w->ww_w.nr) {
                /* can't even see it, so just clear the buffer */
                buf = &w->ww_buf[line][col];
                for (i = w->ww_w.nc - col; --i >= 0;)
                        buf++->c_w = ' ';
                return;
        }
        smap = &wwsmap[srow][scol];
        s = &wwns[srow][scol];
        touched = &wwtouched[srow];
        win = &w->ww_win[row][col];
        buf = &w->ww_buf[line][col];
        ncleared = nblank = 0;
        for (i = w->ww_w.nc - col; --i >= 0;) {
                buf++->c_w = ' ';
                if (*smap++ != w->ww_index) {
                        if (s++->c_w == ' ')
                                nblank++;
                        win++;
                        continue;
                }
                ncleared++;
                *touched = 1;
                if (*win == 0) {
                        nblank++;
                        s++->c_w = ' ';
                        win++;
                } else
                        s++->c_w = ' ' | *win++ << WWC_MSHIFT;
        }
        if (!cleared && tt.tt_clreol != 0
            && ncleared > wwncol - scol - nblank
            && nblank > (wwncol - scol) / 2) {
                /* clear to the end */
                (*tt.tt_move)(srow, scol);
                (*tt.tt_clreol)();
                s = &wwos[srow][scol];
                for (i = wwncol - scol; --i >= 0;)
                        s++->c_w = ' ';
        }
}