C64-dev/vim/vview.pet

/* 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;
Û
    CHAR D[6];
    INT N;

    N = 0;
    IF (V == 0) Û
        T[P++] = 48;
        RETURN P;
    Ý
    WHILE (V > 0 && N < 5) Û
        D[N++] = 48 + (V % 10);
        V = V / 10;
    Ý
    WHILE (N > 0) T[P++] = D[--N];
    RETURN P;
Ý

/* BRING THE CURSOR BACK INTO VIEW */
SCROLL()
Û
    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;
Ý

/* DRAW SCREEN ROW SR FROM BUFFER LINE TOP+SR */
DROW(SR)
INT SR;
Û
    INT LN, N, CC;
    UNSIGNED I, E, D;

    D = 1024 + SR * 40;                         /* SCREEN ÒÁÍ ADDRESS OF THE ROW */
    LN = TOP + SR;
    IF (LN >= NLINES) Û
        MLROW(0, 0, D, 255, 0);
        RETURN 0;
    Ý
    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) Û
        CC = CX - LEFTCOL;
        IF (CC < 0) CC = 255;
        IF (CC > 39) CC = 255;
    Ý
    MLROW((UNSIGNED) BFR + I, N, D, CC, 0);     /* MACHINE CODE DOES THE REST */
    RETURN 0;
Ý

/* THE STATUS ROW: MESSAGE, MODE OR NAME ON THE LEFT; MODIFIED FLAG; LINE/TOTAL */
DSTAT()
Û
    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;
Ý

DALL()
Û
    INT R;

    FOR (R = 0; R < 24; R++) DROW(R);
    DSTAT();
    RETURN 0;
Ý


/* END OF VVIEW.C */