sprite.c

数据挖掘中de一个算法 hamster的实例

/*----------------------------------------------------------------------
  File    : sprite.c
  Contents: sprite management (Microsoft Windows Version)
  Author  : Christian Borgelt
  History : 15.10.1997 file created
            16.10.1997 first version completed
            31.10.1997 device context stored in SPRITE structure
            16.06.1998 switching to new sprite image improved
----------------------------------------------------------------------*/
#include <stdio.h>
#include <stdlib.h>
#include <time.h>
#include "sprite.h"

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

SPRITE* spr_create (HWND hwnd, int xext, int yext,
                    HBITMAP bitmap, HBITMAP mask)
{                               /* --- create a sprite */
  SPRITE *spr;                  /* created sprite */

  spr = (SPRITE*)malloc(sizeof(SPRITE));
  if (!spr) return NULL;        /* allocate sprite body */
  spr->xext    = xext;          /* and initialize fields */
  spr->yext    = yext;          /* note sprite extensions */
  spr->xoff    = spr->yoff = 0; /* select first image of first series */
  spr->xnew    = spr->ynew = 0; /* for the current and the new image */
  spr->xpos    = spr->ypos = 0; /* initialize position */
  spr->drawn   = 0;             /* sprite is not drawn */
  spr->hwnd    = hwnd;          /* note window handle */
  spr->hdc_win = GetDC(hwnd);   /* get device context for window */
  if (!spr->hdc_win) { free(spr); return NULL; }
  spr->hdc_bmp = CreateCompatibleDC(spr->hdc_win);
  spr->hdc_msk = CreateCompatibleDC(spr->hdc_win);
  spr->hdc_buf = CreateCompatibleDC(spr->hdc_win);
  spr->buffer  = CreateCompatibleBitmap(spr->hdc_win, xext, yext);
  spr->bitmap  = bitmap;        /* create device contexts and buffer */
  spr->mask    = mask;          /* note sprite bitmap and mask bitmap */
  if (!spr->hdc_bmp || !spr->hdc_msk || !spr->hdc_buf || !spr->buffer) {
    spr_delete(spr, 0); return NULL; }
  SelectObject(spr->hdc_bmp, bitmap);
  SelectObject(spr->hdc_msk, mask);
  SelectObject(spr->hdc_buf, spr->buffer);
  return spr;                   /* return created sprite */
}  /* spr_create() */

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

void spr_delete (SPRITE *spr, int del)
{                               /* --- delete a sprite */
  if (spr->hdc_buf)             DeleteDC(spr->hdc_buf);
  if (spr->buffer)              DeleteObject(spr->buffer);
  if (spr->hdc_msk)             DeleteDC(spr->hdc_msk);
  if (spr->mask   && (del & 1)) DeleteObject(spr->mask);
  if (spr->hdc_bmp)             DeleteDC(spr->hdc_bmp);
  if (spr->bitmap && (del & 2)) DeleteObject(spr->bitmap);
  if (spr->hdc_win)             ReleaseDC(spr->hwnd, spr->hdc_win);
  free(spr);                    /* delete objects and sprite body */
}  /* spr_delete() */

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

void spr_select (SPRITE *spr, int series, int index)
{                               /* --- select a sprite image */
  spr->xnew = (index  > 0) ? index  *spr->xext : 0;
  spr->ynew = (series > 0) ? series *spr->yext : 0;
}  /* spr_select() */

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

int spr_draw (SPRITE *spr, int x, int y)
{                               /* --- draw a sprite */
  if (spr->drawn) {             /* if sprite is currently drawn, */
    if (((x == INT_MIN) || (x == spr->xpos))
    &&  ((y == INT_MIN) || (y == spr->ypos))
    &&  (spr->xoff == spr->xnew)
    &&  (spr->yoff == spr->ynew))
      return 0;                 /* if sprite is already drawn at the */
    spr_undraw(spr);            /* correct position, abort function, */
    spr->xoff = spr->xnew;      /* otherwise undraw sprite */
    spr->yoff = spr->ynew;      /* and get the offsets for */
  }                             /* the new sprite image */
  if (x > INT_MIN) spr->xpos = x;  /* if new coordinates given, */
  if (y > INT_MIN) spr->ypos = y;  /* note coordinates */
  BitBlt(spr->hdc_buf, 0,         0,         spr->xext, spr->yext,
         spr->hdc_win, spr->xpos, spr->ypos, SRCCOPY);
  BitBlt(spr->hdc_win, spr->xpos, spr->ypos, spr->xext, spr->yext,
         spr->hdc_msk, spr->xoff, spr->yoff, SRCAND);
  BitBlt(spr->hdc_win, spr->xpos, spr->ypos, spr->xext, spr->yext,
         spr->hdc_bmp, spr->xoff, spr->yoff, SRCPAINT);
  spr->drawn = 1;               /* copy background, draw sprite, */
  return 0;                     /* return 'ok' */
}  /* spr_draw() */

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

int spr_undraw (SPRITE *spr)
{                               /* --- undraw a sprite */
  if (!spr->drawn) return -1;   /* if sprite is not drawn, abort */
  BitBlt(spr->hdc_win, spr->xpos, spr->ypos, spr->xext, spr->yext,
         spr->hdc_buf, 0,         0,         SRCCOPY);
  spr->drawn = 0;               /* copy background to device */
  return 0;                     /* return 'ok' */
}  /* spr_undraw() */

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

int spr_move (SPRITE *spr, int dx, int dy, int di, int cnt, float delay)
{                               /* --- animate a sprite */
  int t, dt;                    /* time buffer for delay loop */

  if (!spr->drawn)              /* if sprite is not drawn, */
    spr_draw(spr, INT_MIN, INT_MIN);            /* draw it */
  t  = clock();                 /* get time and compute increment */
  dt = (delay <= 1/100.0) ? 0 : (int)(delay *CLOCKS_PER_SEC);
  while (--cnt >= 0) {          /* animation loop */
    t += dt;                    /* compute next end time */
    while (clock() < t);        /* delay loop */
    BitBlt(spr->hdc_win, spr->xpos, spr->ypos, spr->xext, spr->yext,
           spr->hdc_buf, 0,         0,         SRCCOPY);
    spr->xpos += dx;            /* undraw sprite and */
    spr->ypos += dy;            /* move to new position */
    spr->xoff = spr->xnew += di *spr->xext;
    spr->yoff = spr->ynew;      /* move to new image */
    BitBlt(spr->hdc_buf, 0,         0,         spr->xext, spr->yext,
           spr->hdc_win, spr->xpos, spr->ypos, SRCCOPY);
    BitBlt(spr->hdc_win, spr->xpos, spr->ypos, spr->xext, spr->yext,
           spr->hdc_msk, spr->xoff, spr->yoff, SRCAND);
    BitBlt(spr->hdc_win, spr->xpos, spr->ypos, spr->xext, spr->yext,
           spr->hdc_bmp, spr->xoff, spr->yoff, SRCPAINT);
  }                             /* draw sprite at new position */
  return 0;                     /* return 'ok' */
}  /* spr_move() */