Mac-Source 1994 July/Mac-Source_July_1994.iso/C and C++/Entertainment/tblt/tblt⁄file.c

Text File | 1986-09-06 | 5.0 KB | 190 lines | [TEXT/MACA]

/*
 * file.c - file handling for the game of Tablut.
 */

#include <quickdraw.h>
#include <window.h>
#include <dialog.h>
#include <toolutil.h>
#include <memory.h>
#include <pb.h>
#include <syserr.h>
#include "progerr.h"
#include "tablut.h"

#define ALTSAVECHANGE    400    /* "Save changes..." alert ID        */
#define DONTSAVE    3    /* "don't save changes" item        */
#define FILESTRS    130    /* ID for the File I/O strings        */
#define F_SAVE        1    /* the "save doc as..." prompt        */
#define F_NOTITLE    2    /* the name of an untitled file        */

/*
 * newgame() - start a new, untitled game.
 */
newgame()
{
    GetIndString(gamename, FILESTRS, F_NOTITLE);
    SetWTitle(mywindow, gamename);
    needsname = 1;
    drawwindow();    /* ...to make sure the window is up-to-date */
    setpieces(); winner = NOWIN; seekboard(0); writeboard(); ischanged = 0;
    setsetup(0);
}

/*
 * maysave() - if necessary, ask if the user wants to save the old game.
 *  If desired, save the old game.
 */
int    /* return TRUE if ok, FALSE if the user cancelled    */
maysave()
{
    short itemhit;

    if (!ischanged) return(1);
    ParamText(gamename, (char *) 0, (char *) 0, (char *) 0);
    itemhit = Alert(ALTSAVECHANGE, (ProcPtr) 0);
    ResetAlrtStage();
    if (itemhit == DONTSAVE) return(1);
    if (itemhit != OK) return(0);    /* user cancelled    */
    return(savegame(0));
}

/*
 * savegame() - save the current game.
 */
int    /* return TRUE if ok, FALSE if cancelled    */
savegame(saveas)
int saveas;    /* if TRUE, let the user choose a new name    */
{
    char str[80];    /* (pascal) prompt string        */

    GetIndString(str, FILESTRS, F_SAVE);
    do {
    if (!FileCreate(needsname || saveas, gamename, &gamevnum,
      MYFILE, MYSIGN, str)) {
        return(0);
    }
    SetWTitle(mywindow, gamename);
    } while ((needsname = !writegamefile()));
    return(1);
}

/*
 * opengame() - open a previously-saved game.
 */
int    /* return TRUE if ok, FALSE if cancelled    */
opengame()
{
    do {
    if (!FileFetch(gamename, &gamevnum, MYFILE)) return(0);
    SetWTitle(mywindow, gamename);
    } while ((needsname = !readgamefile()));
}

/*
 * writegamefile() - write the game out to the existing gamefile.
 */
int    /* TRUE = ok, FALSE = aborted.    */
writegamefile()
{
    OSErr err;
    short fd;            /* reference to the open file        */
    struct moveblock *blk;    /* current chunk to write out        */
    long count;            /* # of bytes to write            */
    short moves;        /* # of moves that have been written    */
    long len;            /* # of bytes in the file        */

    if ((err = FSOpen(gamename, gamevnum, &fd)) != noErr) {
    diskerr(err); return(0);
    }
    for (moves = 0, blk = &firstblock; moves < nummoves;
      moves += BDPERBLK, blk = blk->nxtblk) {
    count = nummoves - moves;
    if (count > BDPERBLK) count = BDPERBLK;
    count *= BOARDBYTES;
    if ((err = FSWrite(fd, &count, &(blk->bytes[0]))) != noErr) {
        goto clean1;
    }
    }
    if ((err = GetFPos(fd, &len)) != noErr) goto clean1;
    if ((err = SetEOF(fd, len)) != noErr) goto clean1;
    if ((err = FSClose(fd)) != noErr) goto clean2;
    if ((err = FlushVol((char *) 0, gamevnum)) != noErr) {
    diskerr(err); return(0);
    }
    ischanged = 0;
    return(1);

clean1:
    (void) FSClose(fd);
clean2:
    (void) FlushVol((char *) 0, gamevnum);
    diskerr(err);
    return(0);
}

/*
 * readgamefile() - read the gamefile.
 *   Note: if the reading fails in the middle, readgamefile()
 *  does a newgame() to avoid leaving a corrupt game record.
 */
int    /* TRUE = ok, FALSE = aborted.    */
readgamefile()
{
    OSErr err;
    short fd;            /* reference to the open file        */
    struct moveblock *blk;    /* current chunk to write out        */
    long count;            /* # of bytes to write            */
    short moves;        /* # of moves that have been written    */
    long total;            /* # of moves in the file        */
    char *malloc();

    if ((err = FSOpen(gamename, gamevnum, &fd)) != noErr) {
    diskerr(err); return(0);
    }
    if ((err = GetEOF(fd, &total)) != noErr) {
    diskerr(err); return(0);
    }
    total /= BOARDBYTES;
    if (total < 1) {    /* the file is corrupted    */
    progstop(PE_CORRUPT);
    return(0);
    }
    /* the point of no return.  The next line wrecks the old game */
    nummoves = total; ischanged = 0;
    for (moves = 0, blk = &firstblock; moves < nummoves;
      moves += BDPERBLK, blk = blk->nxtblk) {
    count = nummoves - moves;
    if (count > BDPERBLK) count = BDPERBLK;
    count *= BOARDBYTES;
    if ((err = FSRead(fd, &count, &(blk->bytes[0]))) != noErr) {
        goto clean1;
    }
    if (moves + BDPERBLK < nummoves) {
        if (!blk->nxtblk) {
        if (!(blk->nxtblk = (struct moveblock *)
          malloc(sizeof(struct moveblock)))) {
            err = memFullErr;
            goto clean1;
        }
        blk->nxtblk->nxtblk = (struct movevblock *) 0;
        }
    }
    }
    (void) FSClose(fd);
    (void) FlushVol((char *) 0, gamevnum);

    drawwindow();    /* ...to make sure the screen is up-to-date */
    seekboard(nummoves - 1);
    readboard();
    setsetup(0);
    return(1);

clean1:
    (void) FSClose(fd);
    (void) FlushVol((char *) 0, gamevnum);
    diskerr(err);
    newgame();        /* ...to clean up the botched game record  */
    return(0);
}