/* vview.c - drawing for the c64 vim clone: scroll, rows, status row. */

extern char *bfr;
extern unsigned blen;
extern unsigned lptr[];
extern int nlines, cy, cx, top, leftcol, mode, dirty;
extern char *note;
extern char fname[];
extern char ybuf[];
extern int ylen, yok;

/* decimal of v into t at p, returns the position after it */
dnum(t, p, v)
char *t;
int p, v;
{
    char d[6];
    int n;

    n = 0;
    if (v == 0) {
        t[p++] = 48;
        return p;
    }
    while (v > 0 && n < 5) {
        d[n++] = 48 + (v % 10);
        v = v / 10;
    }
    while (n > 0) t[p++] = d[--n];
    return p;
}

/* bring the cursor back into view */
scroll()
{
    if (cy < top) top = cy;
    if (cy > top + 23) top = cy - 23;
    if (top < 0) top = 0;
    if (cx < leftcol) leftcol = cx;
    if (cx > leftcol + 39) leftcol = cx - 39;
    if (leftcol < 0) leftcol = 0;
    return 0;
}

/* draw screen row sr from buffer line top+sr */
drow(sr)
int sr;
{
    int ln, n, cc;
    unsigned i, e, d;

    d = 1024 + sr * 40;                         /* screen RAM address of the row */
    ln = top + sr;
    if (ln >= nlines) {
        mlrow(0, 0, d, 255, 0);
        return 0;
    }
    i = lptr[ln] + leftcol;
    e = linend(ln);
    n = 0;
    if (e > i) n = e - i;
    if (n > 40) n = 40;
    cc = 255;                                   /* cursor column, 255 = not here */
    if (ln == cy) {
        cc = cx - leftcol;
        if (cc < 0) cc = 255;
        if (cc > 39) cc = 255;
    }
    mlrow((unsigned) bfr + i, n, d, cc, 0);     /* machine code does the rest */
    return 0;
}

/* the status row: message, mode or name on the left; modified flag; line/total */
dstat()
{
    char t[40];
    char *s;
    int i, n, p;

    if (note != 0) s = note;
    else if (mode) s = "-- insert --";
    else if (fname[0] == 0) s = "[no name]";
    else s = fname;

    n = 0;
    for (i = 0; s[i] && i < 26; i++) t[n++] = s[i];
    while (n < 28) t[n++] = 32;
    if (dirty) t[n++] = 43;                     /* + */
    else t[n++] = 32;
    while (n < 31) t[n++] = 32;
    p = dnum(t, n, cy + 1);
    t[p++] = 47;                                /* / */
    p = dnum(t, p, nlines);

    mlrow((unsigned) t, p, 1984, 255, 128);     /* row 24 = $0400 + 960, reverse */
    return 0;
}

dall()
{
    int r;

    for (r = 0; r < 24; r++) drow(r);
    dstat();
    return 0;
}


/* end of vview.c */