gui_gif.c

ucgui的3.98版本的源代码

    default:
      return 1;
    }
  } while (Introducer != GIF_INTRO_TERMINATOR); /* We do not support more than one image, so stop when the first terminator has been read */
  pInfo->NumImages = ImageCnt;
  return 0;
}

/*********************************************************************
*
*       _GetImageInfo
*/
static int _GetImageInfo(const U8 * pData, U32 NumBytes, GUI_GIF_IMAGE_INFO * pInfo, int Index) {
  U8 Flags, Introducer;
  int NumColors, ImageCnt;
  /* Initialize decoding and get size and global color table */
  if (_GetSizeAndColorTable(pData, NumBytes, NULL, NULL, &NumColors)) {
    return 1; /* Error */
  }
  ImageCnt = 0;
  /* Iterate over the blocks */
  do {
    Introducer = _ReadU8();
    switch (Introducer) {
    case GIF_INTRO_IMAGE:
      if (Index == ImageCnt) {
        pInfo->xPos  = _ReadU16();
        pInfo->xPos  = _ReadU16();
        pInfo->xSize = _ReadU16();
        pInfo->ySize = _ReadU16();
        return 0;
      }
      _SkipBytes(8);                /* Skip the first 8 bytes of the image descriptor */
      Flags = _ReadU8();            /* Only 'Flags' are intresting */
      if (Flags & 0x80) {
        _SkipBytes(NumColors * 3);  /* Skip local color table */
      }
      _SkipBytes(1);                /* Skip codesize */
      while (_GetDataBlock(0) > 0); /* Skip data blocks */
      ImageCnt++;
      break;
    case GIF_INTRO_TERMINATOR:
      break;
    case GIF_INTRO_EXTENSION:
      if (_ReadExtension(NULL, (Index == ImageCnt) ? pInfo : NULL, NULL)) {
        return 1;
      }
      break;
    default:
      return 1;
    }
  } while (Introducer != GIF_INTRO_TERMINATOR); /* We do not support more than one image, so stop when the first terminator has been read */
  return 0;
}

/*********************************************************************
*
*       _GetGIFComment
*
* Purpose:
*   Returns the given comment of the GIF image.
*
* Parameters:
*   pData            - Pointer to start of the GIF file
*   NumBytes         - Number of bytes in the file
*   pBuffer          - Pointer to buffer to be filled by the routine
*   MaxSize          - Number of bytes in buffer
*   Index            - Index of the comment to be returned
*
* Return value:
*   0 on success, 1 on error
*/
static int _GetGIFComment(const U8 * pData, U32 NumBytes, U8 * pBuffer, int MaxSize, int Index) {
  U8 Flags, Introducer;
  int NumColors, CommentCnt, Size;
  /* Initialize decoding and skip size and global color table */
  if (_GetSizeAndColorTable(pData, NumBytes, NULL, NULL, &NumColors)) {
    return 1; /* Error */
  }
  CommentCnt = Size = 0;
  /* Iterate over the blocks */
  do {
    Introducer = _ReadU8();
    switch (Introducer) {
    case GIF_INTRO_IMAGE:
      _SkipBytes(8);                /* Skip the first 8 bytes of the image descriptor */
      Flags = _ReadU8();            /* Only 'Flags' are intresting */
      if (Flags & 0x80) {
        _SkipBytes(NumColors * 3);  /* Skip local color table */
      }
      _SkipBytes(1);                /* Skip codesize */
      while (_GetDataBlock(0) > 0); /* Skip data blocks */
      break;
    case GIF_INTRO_TERMINATOR:
      break;
    case GIF_INTRO_EXTENSION:
      _ReadComment((Index == CommentCnt) ? pBuffer : NULL, MaxSize, &Size);
      if ((Size) && (Index == CommentCnt)) {
        return 0;
      }
      break;
    default:
      return 1;
    }
  } while (Introducer != GIF_INTRO_TERMINATOR); /* We do not support more than one image, so stop when the first terminator has been read */
  return 1;
}

/*********************************************************************
*
*       _ClearUnusedPixels
*
* Purpose:
*   Clears the pixels between the border of the previous drawn image and
*   the current image.
*/
static void _ClearUnusedPixels(int x0, int y0, IMAGE_DESCRIPTOR * pDescriptor, GUI_GIF_IMAGE_INFO * pInfo) {
  LCD_SetColorIndex(LCD_GetBkColorIndex());
  if (pDescriptor->YPos > pInfo->yPos) {
    LCD_FillRect(x0 + pInfo->xPos,
                 y0 + pInfo->yPos,
                 x0 + pInfo->xPos + pInfo->xSize - 1,
                 y0 + pDescriptor->YPos - 1);
  }
  if (pDescriptor->XPos > pInfo->xPos) {
    LCD_FillRect(x0 + pInfo->xPos,
                 y0 + pInfo->yPos,
                 x0 + pDescriptor->XPos - 1,
                 y0 + pInfo->yPos + pInfo->ySize - 1);
  }
  if ((pDescriptor->YPos + pDescriptor->YSize) < (pInfo->yPos + pInfo->ySize)) {
    LCD_FillRect(x0 + pInfo->xPos,
                 y0 + pDescriptor->YPos + pDescriptor->YSize - 1,
                 x0 + pInfo->xPos + pInfo->xSize - 1,
                 y0 + pInfo->yPos + pInfo->ySize - 1);
  }
  if ((pDescriptor->XPos + pDescriptor->XSize) < (pInfo->xPos + pInfo->xSize)) {
    LCD_FillRect(x0 + pDescriptor->XPos + pDescriptor->XSize - 1,
                 y0 + pInfo->yPos,
                 x0 + pInfo->xPos + pInfo->xSize - 1,
                 y0 + pInfo->yPos + pInfo->ySize - 1);
  }
}

/*********************************************************************
*
*       _DrawGIFImage
*
* Purpose:
*   Draws the given sub image of a GIF file.
*
* Parameters:
*   pData    - Pointer to start of the GIF file
*   NumBytes - Number of bytes in the file
*   x0       - Drawing position x
*   y0       - Drawing position y
*   Index    - Index of sub image to be drawn
*
* Return value:
*   0 on success, 1 on error
*/
static int _DrawGIFImage(const U8 * pData, U32 NumBytes, int x0, int y0, int Index) {
  U8 Disposal;
  int XSize, YSize, TransIndex, ImageCnt;
  IMAGE_DESCRIPTOR Descriptor = {0};
  GUI_GIF_IMAGE_INFO Info = {0};
  U8 Introducer;
  ImageCnt   =  0;
  TransIndex = -1;
  /* Initialize decoding and get size and global color table */
  if (_GetSizeAndColorTable(pData, NumBytes, &XSize, &YSize, &Descriptor.NumColors)) {
    return 1; /* Error */
  }
  /* Iterate over the blocks */
  do {
    Introducer = _ReadU8();
    switch (Introducer) {
    case GIF_INTRO_IMAGE:
      /* Read image descriptor */
      Descriptor.XPos  = _ReadU16();
      Descriptor.YPos  = _ReadU16();
      Descriptor.XSize = _ReadU16();
      Descriptor.YSize = _ReadU16();
      Descriptor.Flags = _ReadU8 ();
      if (_Source.RemBytes < 0) {
        return 1; /* Error */
      }
      if (Descriptor.Flags & 0x80) {
        /* Read local color table */
        if (_ReadColorMap(Descriptor.NumColors)) {
          return 1; /* Error */
        }
      }
      if (ImageCnt == Index - 1) {
        Info.xPos  = Descriptor.XPos;
        Info.yPos  = Descriptor.YPos;
        Info.xSize = Descriptor.XSize;
        Info.ySize = Descriptor.YSize;
      }
      if (Index == ImageCnt) {
        if (Disposal == 2) {
          _ClearUnusedPixels(x0, y0, &Descriptor, &Info);
        }
        if (_DispGIFImage(&Descriptor, x0 + Descriptor.XPos, y0 + Descriptor.YPos, TransIndex, Disposal)) {
          return 1; /* Error */
        }
        if (_ReadU8() != 0) {
          return 1; /* Error */
        }
        return 0;
      } else {
        _ReadU8();                    /* Skip codesize */
        while (_GetDataBlock(0) > 0); /* Skip data blocks */
      }
      ImageCnt++;
      break;
    case GIF_INTRO_TERMINATOR:
      break;
    case GIF_INTRO_EXTENSION:
      /* Read image extension */
      if (_ReadExtension(&TransIndex, (Index == ImageCnt) ? &Info : NULL, (Index == ImageCnt) ? &Disposal : NULL)) {
        return 1;
      }
      break;
    default:
      return 1;
    }
  } while (Introducer != GIF_INTRO_TERMINATOR); /* We do not support more than one image, so stop when the first terminator has been read */
  return 0;
}

/*********************************************************************
*
*       Public code
*
**********************************************************************
*/
/*********************************************************************
*
*       GUI_GIF_GetXSize
*
* Purpose:
*   Returns the XSize of the given GIF image without further tests.
*/
int GUI_GIF_GetXSize(const void * pGIF) {
  const U8 * pSrc;
  if (!pGIF) {
    return 0;
  }
  pSrc = (const U8 *)pGIF + 6;
  return GUI__Read16(&pSrc);
}

/*********************************************************************
*
*       GUI_GIF_GetYSize
*
* Purpose:
*   Returns the YSize of the given GIF image without further tests.
*/
int GUI_GIF_GetYSize(const void * pGIF) {
  const U8 * pSrc;
  if (!pGIF) {
    return 0;
  }
  pSrc = (const U8 *)pGIF + 8;
  return GUI__Read16(&pSrc);
}

/*********************************************************************
*
*       GUI_GIF_DrawEx
*/
int GUI_GIF_DrawEx(const void * pGIF, U32 NumBytes, int x0, int y0, int Index) {
  const U8 * pSrc;
  int Result, OldColorIndex;
  #if (GUI_WINSUPPORT)
    int Width, Height;
    GUI_RECT r;
    Width  = GUI_GIF_GetXSize(pGIF);
    Height = GUI_GIF_GetYSize(pGIF);
  #endif
  GUI_LOCK();
  OldColorIndex = LCD_GetColorIndex();
  pSrc          = (const U8 *)pGIF;
  #if (GUI_WINSUPPORT)
    WM_ADDORG(x0,y0);
    r.x1 = (r.x0 = x0) + Width - 1;
    r.y1 = (r.y0 = y0) + Height - 1;
    WM_ITERATE_START(&r) {
  #endif
  Result = _DrawGIFImage(pSrc, NumBytes, x0, y0, Index);
  #if (GUI_WINSUPPORT)
    } WM_ITERATE_END();
  #endif
  LCD_SetColorIndex(OldColorIndex);
  GUI_UNLOCK();
  return Result;
}

/*********************************************************************
*
*       GUI_GIF_Draw
*/
int GUI_GIF_Draw(const void * pGIF, U32 NumBytes, int x0, int y0) {
  return GUI_GIF_DrawEx(pGIF, NumBytes, x0, y0, 0);
}

/*********************************************************************
*
*       GUI_GIF_GetInfo
*/
int GUI_GIF_GetInfo(const void * pGIF, U32 NumBytes, GUI_GIF_INFO * pInfo) {
  const U8 * pSrc;
  pSrc = (const U8 *)pGIF;
  if (_GetGIFInfo(pSrc, NumBytes, pInfo)) {
    return 1;
  }
  return 0;
}

/*********************************************************************
*
*       GUI_GIF_GetImageInfo
*/
int GUI_GIF_GetImageInfo(const void * pGIF, U32 NumBytes, GUI_GIF_IMAGE_INFO * pInfo, int Index) {
  const U8 * pSrc;
  pSrc = (const U8 *)pGIF;
  if (_GetImageInfo(pSrc, NumBytes, pInfo, Index)) {
    return 1;
  }
  return 0;
}

/*********************************************************************
*
*       GUI_GIF_GetComment
*/
int GUI_GIF_GetComment(const void * pGIF, U32 NumBytes, U8 * pBuffer, int MaxSize, int Index) {
  const U8 * pSrc;
  pSrc = (const U8 *)pGIF;
  if (_GetGIFComment(pSrc, NumBytes, pBuffer, MaxSize, Index)) {
    return 1;
  }
  return 0;
}

/*************************** End of file ****************************/