xbi.c

数据挖掘中的bridgit算法的例子。 非常经典

  assert(bridge != BI_NONE);    /* check the function arguments */
  if (hint) color = (hint > 0)                     ? green : white;
  else      color = (bi_player(bridge) == BI_HORZ) ? blue  : red;
  XSetForeground(display, gc, color);       /* set the color */
  x1 = bi_col(bridge) *PTDIST/2 +PTOFFSET;  /* get the coordinates */
  y1 = bi_row(bridge) *PTDIST/2 +PTOFFSET;  /* of the crossing point */
  if (bi_dir(bridge) == BI_HORZ)/* draw a horizontal bridge */
    XFillRectangle(display, window, gc, x1-PTDIST/2+2,y1-1, PTDIST-4,3);
  else                          /* draw a vertical   bridge */
    XFillRectangle(display, window, gc, x1-1,y1-PTDIST/2+2, 3,PTDIST-4);
  if (hint >= 0) return;        /* if not to undraw a bridge, abort */
  x2 = x1 -= PTSIZE/2;          /* get upper left corner */
  y2 = y1 -= PTSIZE/2;          /* of crossing point */
  if (bi_dir(bridge) == BI_HORZ) {   /* if the bridge is horizontal, */
    x1 -= PTDIST/2; x2 += PTDIST/2;  /* adapt the horizontal coords. */
    a   = 315*64; }                  /* get right quarter circle */
  else {                             /* if the bridge is vertical, */
    y1 -= PTDIST/2; y2 += PTDIST/2;  /* adapt the vertical coords. */
    a   = 225*64;                    /* get top quarter circle */
  }
  XSetForeground(display, gc,   /* set the player color */
                 (bi_player(bridge) == BI_HORZ) ? blue : red);
  XFillArc(display, window, gc, x1, y1, PTSIZE,PTSIZE, a,        90*64);
  XFillArc(display, window, gc, x2, y2, PTSIZE,PTSIZE, a+180*64, 90*64);
  XSetForeground(display, gc, black);
  XDrawArc(display, window, gc, x1, y1, PTSIZE,PTSIZE, a,        90*64);
  XDrawArc(display, window, gc, x2, y2, PTSIZE,PTSIZE, a+180*64, 90*64);
}  /* b_draw() */               /* redraw the support points */

/*----------------------------------------------------------------------
  Dialog Box Callback Functions
----------------------------------------------------------------------*/

static void dcb_load (Widget widget, XtPointer ok, XtPointer fname)
{                               /* --- 'Load Game...' callback */
  FILE    *file;                /* output file */
  BRIDGIT *new;                 /* loaded bridg-it game */
  int     bridge;               /* a bridge built in the game */

  mn_enable(menu, MN_MENU, 1);  /* enable menu bar */
  file = fopen(fname, "r");     /* open the input file */
  if (!file) { error(E_FOPEN, fname); return; }
  new = bi_load(file);          /* load the bridg-it game */
  fclose(file);                 /* and close the input file */
  if (!new)  { error(E_FREAD, fname); return; }
  if (bi) bi_delete(bi);        /* delete the old bridg-it game */
  bi = new;                     /* and set the new one */
  do {                          /* find player to move next */
    bridge = bi_redo(bi);       /* either by going forward */
    if (bridge != BI_NONE) {    /* and getting the player */
      bi_undo(bi); bip.next = bi_player(bridge);         break; }
    bridge = bi_undo(bi);       /* or by going backwards */
    if (bridge != BI_NONE) {    /* and getting the opponent */
      bi_redo(bi); bip.next = bi_opp(bi_player(bridge)); break; }
    bridge = bip.first;         /* if there is no move, */
  } while (0);                  /* simply get the first player */
  bip.hint = bi_hint(bi, bip.next, drand);
  bip.size = bi_size(bi);       /* get the size of the board */
  resize(bip.size);             /* and resize the board */
  redraw(NULL,NULL,NULL,NULL);  /* redraw the window contents */
}  /* dcb_load() */

/*--------------------------------------------------------------------*/

static void dcb_save (Widget widget, XtPointer ok, XtPointer fname)
{                               /* --- 'Save File...' callback */
  FILE *file;                   /* output file */
  int  r;                       /* result of save function */

  mn_enable(menu, MN_MENU, 1);  /* enable menu bar */
  file = fopen(fname, "w");     /* open the output file */
  if (!file) { error(E_FOPEN, fname); return; }
  r = bi_save(bi, file);        /* save the bridg-it game */
  if ((fclose(file) != 0) || (r != 0)) {
    error(E_FWRITE, fname); return; }
}  /* dcb_save() */

/*--------------------------------------------------------------------*/

static void dcb_setup (Widget widget, XtPointer ok, XtPointer call)
{                               /* --- 'Setup...' callback */
  mn_enable(menu, MN_MENU, 1);  /* enable menu bar */
  if (!ok) return;              /* if not ok pressed, abort */
  bip.size = atoi(psh_getval(psh, "size"));
  if (bip.size < MINSIZE) bip.size = MINSIZE;
  if (bip.size > MAXSIZE) bip.size = MAXSIZE;
  bip.first = ((int)psh_getval(psh, "first") == 0) ? BI_HORZ : BI_VERT;
  start(NULL,NULL,NULL,NULL);   /* get the values from the gadgets */
}  /* dcb_setup() */            /* and restart the game */

/*----------------------------------------------------------------------
  Menu Callback Functions
----------------------------------------------------------------------*/

static void mcb_load   (Widget widget, XtPointer client, XtPointer call)
{ load(NULL, NULL, NULL, NULL); }

static void mcb_save   (Widget widget, XtPointer client, XtPointer call)
{ save(NULL, NULL, NULL, NULL); }

static void mcb_quit   (Widget widget, XtPointer client, XtPointer call)
{ quit(NULL, NULL, NULL, NULL); }

static void mcb_start  (Widget widget, XtPointer client, XtPointer call)
{ start(NULL, NULL, NULL, NULL); }

static void mcb_flip   (Widget widget, XtPointer client, XtPointer call)
{ flip(NULL, NULL, NULL, NULL); }

static void mcb_undo   (Widget widget, XtPointer client, XtPointer call)
{ undo(NULL, NULL, NULL, NULL); }

static void mcb_redo   (Widget widget, XtPointer client, XtPointer call)
{ redo(NULL, NULL, NULL, NULL); }

static void mcb_hint   (Widget widget, XtPointer client, XtPointer call)
{ hint(NULL, NULL, NULL, NULL); }

static void mcb_setup  (Widget widget, XtPointer client, XtPointer call)
{ setup(NULL, NULL, NULL, NULL); }

static void mcb_redraw (Widget widget, XtPointer client, XtPointer call)
{ redraw(NULL, NULL, NULL, NULL); }

static void mcb_about  (Widget widget, XtPointer client, XtPointer call)
{ about(NULL, NULL, NULL, NULL); }

/*----------------------------------------------------------------------
  Action Functions
----------------------------------------------------------------------*/

static void mouse (Widget w, XEvent *e, String *s, Cardinal *c)
{                               /* --- mouse button pressed */
  int x, y, px, py;             /* (pixel) coordinates */
  int size;                     /* size of the board */
  int bridge;                   /* bridge to draw */

  assert(bi && gc);             /* check for game and graph. context */
  if (bip.hint == BI_NONE)      /* if the game has already ended, */
    return;                     /* abort the function */
  b_draw(bip.hint, -1);         /* undraw the hint bridge (if any) */

  size = bi_size(bi);           /* get the size of the bridg-it board */
  px = e->xbutton.x -PTOFFSET;  /* get the coordinates at which */
  py = e->xbutton.y -PTOFFSET;  /* the mouse button was pressed */
  x  = px / (PTDIST/2); px %= PTDIST/2;
  y  = py / (PTDIST/2); py %= PTDIST/2;
  if ((x+y) & 1) { if (px > py) x++; else y++; }
  else           { if (px+py > PTDIST/2) { x++; y++; } }
  if ((x <= 0) || (x >= 2*size) /* compute the coordinates of */
  ||  (y <= 0) || (y >= 2*size) /* the closest crossing point */
  ||  (bi_state(bi, x, y) != BI_NONE))
    return;                     /* check for a valid crossing point */

  bridge = bi_bridge(bip.next, x, y);
  bi_build(bi, bridge);         /* construct a bridge, */
  b_draw(bridge, 0);            /* build and draw it */
  XFlush(display);              /* flush buffered drawing commands */
  bip.next = bi_opp(bip.next);  /* switch to the other player */
  bip.hint = bi_hint(bi, bip.next, drand);
  if (bip.hint == BI_NONE) {    /* if there is no new hint */
    db_alert(w_top, dcb_nop, (bip.next == BI_HORZ) ? REDWIN : BLUEWIN);
    return;                     /* notify that the game has ended */
  }                             /* and abort the function */
  bi_build(bi, bip.hint);       /* build the computed bridge */
  b_draw(bip.hint, 0);          /* and draw it */
  bip.next = bi_opp(bip.next);  /* switch to the other player */
  bip.hint = bi_hint(bi, bip.next, drand);
  if (bip.hint == BI_NONE)      /* if there is no new hint */
    db_alert(w_top, dcb_nop, (bip.next == BI_HORZ) ? REDWIN : BLUEWIN);
}  /* mouse() */                /* notify that the game has ended */

/*--------------------------------------------------------------------*/

static void load (Widget w, XEvent *e, String *s, Cardinal *c)
{                               /* --- File > Load... */
  const char *t;                /* buffer for dialog box title */

  mn_enable(menu, MN_MENU, 0);  /* disable menu bar */
  XtVaGetValues(XtNameToWidget(mn_menubar(menu), "*load"),
    XtNlabel, &t, NULL);        /* get name of menu entry */
  if (fselect(w_top, t, NULL, NULL, dcb_load) != 0) {
    error(E_DIALOG); mn_enable(menu, MN_MENU, 1); }
}  /* load() */

/*--------------------------------------------------------------------*/

static void save (Widget w, XEvent *e, String *s, Cardinal *c)
{                               /* --- File > Save... */
  const char *t;                /* buffer for dialog box title */

  mn_enable(menu, MN_MENU, 0);  /* disable menu bar */
  XtVaGetValues(XtNameToWidget(mn_menubar(menu), "*save"),
    XtNlabel, &t, NULL);        /* get name of menu entry */
  if (fselect(w_top, t, NULL, NULL, dcb_save) != 0) {
    error(E_DIALOG); mn_enable(menu, MN_MENU, 1); }
}  /* save() */

/*--------------------------------------------------------------------*/

static void quit (Widget w, XEvent *e, String *s, Cardinal *c)
{                               /* --- File > Quit */
  if (w_top) XtDestroyApplicationContext(appctx);
  exit(0);                      /* terminate program */
}  /* quit() */

/*--------------------------------------------------------------------*/

static void start (Widget w, XEvent *e, String *s, Cardinal *c)
{                               /* --- Actions > New Game */
  BRIDGIT *new;                 /* new bridg-it game */

  assert(bi);                   /* check for an existing game */
  if (bip.size != bi_size(bi)){ /* if the size has been changed, */
    new = bi_create(bip.size);  /* create a new bridg-it game */
    if (!new) { error(E_NOMEM); return; }
    if (bi) bi_delete(bi);      /* delete the old bridg-it game */
    bi = new;                   /* and set the new one */
    resize(bip.size);           /* resize the window to accomodate */
  }                             /* the new board size */
  bi_init(bi);                  /* initialize the game and */
  bip.next = bip.first;         /* the player to move first */
  bip.hint = bi_hint(bi, bip.next, drand);
  redraw(NULL,NULL,NULL,NULL);  /* get a hint for the first move */
}  /* start() */                /* and redraw the window contents */

/*--------------------------------------------------------------------*/

static void flip (Widget w, XEvent *e, String *s, Cardinal *c)
{                               /* --- Actions > Flip Sides */
  assert(bi && gc);             /* check for game and graph. context */
  if (bip.hint == BI_NONE)      /* if the game has already ended, */
    return;                     /* abort the function */
  bi_build(bi, bip.hint);       /* build the hint bridge */
  b_draw(bip.hint, 0);          /* and draw it */
  bip.next = bi_opp(bip.next);  /* switch to other player and */
  bip.hint = bi_hint(bi, bip.next, drand);  /* get a new hint */
  if (bip.hint == BI_NONE)      /* if there is no new hint */
    db_alert(w_top, dcb_nop, (bip.next == BI_HORZ) ? REDWIN : BLUEWIN);
}  /* flip() */                 /* notify that the game has ended */

/*--------------------------------------------------------------------*/

static void hint (Widget w, XEvent *e, String *s, Cardinal *c)
{                               /* --- Actions > Give a Hint */
  assert(bi && gc);             /* check for game and graph. context */
  if (bip.hint != BI_NONE)      /* if there is a hint bridge, */
    b_draw(bip.hint, 1);        /* draw the hint bridge */
}  /* hint() */

/*--------------------------------------------------------------------*/

static void undo (Widget w, XEvent *e, String *s, Cardinal *c)
{                               /* --- Actions > Undo Move */
  int bridge;                   /* bridge to delete */