/* r4bit.c   (c)Copyright Sequiter Software Inc., 1991-1994.  All rights reserved. */

#include "d4all.h"

#ifdef S4WINDOWS

#define ABS(x)                ((x<0)?-1*(x):x)
#define MIN(a,b) (((a) < (b)) ? (a) : (b))
#define MAX(a,b) (((a) > (b)) ? (a) : (b))

#define DIB_HEADER_MARKER   ((WORD) ('M' << 8) | 'B')
#define BYTES_PER_READ  32767


#define WIDTHBYTES(bits)      (((bits) + 31) / 32 * 4)
#define IS_WIN30_DIB(lpbi)  ((*(LPDWORD) (lpbi)) == sizeof (BITMAPINFOHEADER))


DWORD PASCAL kwrite ( int, VOID FAR *, DWORD );

WORD S4FUNCTION DIBNumColors (LPSTR lpbi)
{
  WORD wBitCount;


  /* If this is a Windows style DIB, the number of colors in the  */
  /*  color table can be less than the number of bits per pixel   */
  /*  allows for (i.e. lpbi->biClrUsed can be set to some value). */
  /*  If this is the case, return the appropriate value.          */

  if (IS_WIN30_DIB (lpbi))
  {
    DWORD dwClrUsed;

    dwClrUsed = ((LPBITMAPINFOHEADER) lpbi)->biClrUsed;

    if (dwClrUsed)
      return (WORD) dwClrUsed;
  }


  /* Calculate the number of colors in the color table based on */
  /*  the number of bits per pixel for the DIB.                 */

  if (IS_WIN30_DIB (lpbi))
    wBitCount = ((LPBITMAPINFOHEADER) lpbi)->biBitCount;
  else
    wBitCount = ((LPBITMAPCOREHEADER) lpbi)->bcBitCount;

  switch (wBitCount)
  {
  case 1:
    return 2;

  case 4:
    return 16;

  case 8:
    return 256;

  default:
    return 0;
  }
}


WORD S4FUNCTION PaletteSize (LPSTR lpbi)
{
  if (IS_WIN30_DIB (lpbi))
    return (DIBNumColors (lpbi) * sizeof (RGBQUAD));
  else
    return (DIBNumColors (lpbi) * sizeof (RGBTRIPLE));
}

LPSTR S4FUNCTION FindDIBBits (LPSTR lpbi)
{
  return (lpbi + *(LPDWORD)lpbi + PaletteSize (lpbi));
}



HANDLE S4FUNCTION GetDIB ( LPSTR fname, CODE4 *code_base )
{

  int      hFile;
  OFSTRUCT ofs;
  HANDLE   hDIB;
  char     fname2[14];
  FILE4    file;

  u4name_piece( fname2, sizeof(fname2), fname, 0, 1 );
  SetCursor(LoadCursor(NULL, IDC_WAIT));

  if( file4open( &file, code_base, fname2, 1 ) == 0 )
  {
    file4close( &file );
    if ((hFile = OpenFile (fname2, &ofs, OF_READ)) != -1)
    {
      hDIB = ReadDIBFile (hFile);
      _lclose (hFile);
      SetCursor(LoadCursor(NULL, IDC_ARROW));
      return hDIB;
    }
  }
  else
    e4set( code_base, 0 );



  if ((hFile = OpenFile (fname, &ofs, OF_READ)) != -1)
  {
    hDIB = ReadDIBFile (hFile);
    _lclose (hFile);
    SetCursor(LoadCursor(NULL, IDC_ARROW));
    return hDIB;
  }

  SetCursor(LoadCursor(NULL, IDC_ARROW));
  return NULL;
}

/*************************************************************************

  Function:  MyRead (int, LPSTR, DWORD)

  Purpose:  Routine to read files greater than 64K in size.

  Returns:  TRUE if successful.
  FALSE if an error occurs.

  Comments:

  History:   Date     Reason

  6/1/91    Created

  *************************************************************************/

BOOL MyRead (int hFile, LPSTR lpBuffer, DWORD dwSize)
{
#ifndef S4WIN32
  char huge *lpInBuf = (char huge *) lpBuffer;
#else
  char *lpInBuf = (char *) lpBuffer;
#endif
  int       nBytes;


  while (dwSize)
  {
    nBytes = (int) (dwSize > (DWORD) BYTES_PER_READ ? BYTES_PER_READ :
                    LOWORD (dwSize));

    if (_lread (hFile, (LPSTR) lpInBuf, nBytes) != (WORD) nBytes)
      return FALSE;

    dwSize  -= nBytes;
    lpInBuf += nBytes;
  }

  return TRUE;
}


/*************************************************************************

  Function:  ReadDIBFile (int)

  Purpose:  Reads in the specified DIB file into a global chunk of
  memory.

  Returns:  A handle to a dib (hDIB) if successful.
  NULL if an error occurs.

  Comments:  BITMAPFILEHEADER is stripped off of the DIB.  Everything
  from the end of the BITMAPFILEHEADER structure on is
  returned in the global memory handle.

  History:   Date      Author      Reason

  6/1/91    Created
  6/27/91   Removed PM bitmap conversion routines.
  6/31/91   Removed logic which overallocated memory
  (to account for bad display drivers).
  11/08/91   Again removed logic which overallocated
  memory (it had creeped back in!)

  *************************************************************************/

HANDLE S4FUNCTION ReadDIBFile (int hFile)
{
  BITMAPFILEHEADER   bmfHeader;
  DWORD              dwBitsSize;
  HANDLE             hDIB;
  LPSTR              pDIB;


  /* get length of DIB in bytes for use when reading */

  dwBitsSize = filelength (hFile);

  /* Go read the DIB file header and check if it's valid. */

  if ((_lread (hFile, (LPSTR) &bmfHeader, sizeof (bmfHeader)) != sizeof (bmfHeader)) ||
      (bmfHeader.bfType != DIB_HEADER_MARKER))
  {
    /*      DIBError (ERR_NOT_DIB); */
    return NULL;
  }

  /* Allocate memory for DIB */

  hDIB = GlobalAlloc (GMEM_MOVEABLE | GMEM_ZEROINIT, dwBitsSize - sizeof(BITMAPFILEHEADER));

  if (hDIB == 0)
  {
    /*     DIBError (ERR_MEMORY); */
    return NULL;
  }

  pDIB = GlobalLock (hDIB);

  /* Go read the bits. */

  if (!MyRead (hFile, pDIB, dwBitsSize - sizeof(BITMAPFILEHEADER)))
  {
    GlobalUnlock (hDIB);
    GlobalFree   (hDIB);
    return NULL;
  }


  GlobalUnlock (hDIB);
  return hDIB;
}

/****************************************************************************

  FUNCTION   : lwrite(int fh, VOID FAR *pv, DWORD ul)

  PURPOSE    : Writes data in steps of 32k till all the data is written.

  RETURNS    : 0 - If write did not proceed correctly.
  number of bytes written otherwise.

  ****************************************************************************/
DWORD PASCAL kwrite (int fh, VOID FAR *pv, DWORD ul)
{
  DWORD     ulT = ul;
#ifndef S4WIN32
  BYTE huge *hp = (unsigned char huge *)pv;
#else
  BYTE *hp = pv;
#endif
  while (ul > BYTES_PER_READ)
  {
    if (_lwrite(fh, (LPSTR)hp, (WORD)BYTES_PER_READ) != BYTES_PER_READ)
      return 0;

    ul -= BYTES_PER_READ;
    hp += BYTES_PER_READ;
  }

  if (_lwrite(fh, (LPSTR)hp, (WORD)ul) != (WORD)ul)
    return 0;

  return ulT;
}


/****************************************************************************

  FUNCTION   : WriteDIB(LPSTR szFile,HANDLE hdib)

  PURPOSE    : Write a global handle in CF_DIB format to a file.

  RETURNS    : TRUE  - if successful.
  FALSE - otherwise

  ****************************************************************************/
BOOL S4FUNCTION WriteDIB (LPSTR szFile, HANDLE hdib)
{
  BITMAPFILEHEADER    hdr;
  LPBITMAPINFOHEADER  lpbi;
  int                 fh;
  OFSTRUCT            of;

  if (!hdib)
    return FALSE;

  fh = OpenFile (szFile, &of, OF_CREATE|OF_READWRITE);
  if (fh == -1)
    return FALSE;

  lpbi = (LPBITMAPINFOHEADER)GlobalLock (hdib);

  /* Fill in the fields of the file header */
  hdr.bfType          = DIB_HEADER_MARKER;
  hdr.bfSize          = GlobalSize (hdib) + sizeof (BITMAPFILEHEADER);
  hdr.bfReserved1     = 0;
  hdr.bfReserved2     = 0;
  hdr.bfOffBits       = (DWORD)sizeof(BITMAPFILEHEADER) + lpbi->biSize +
    PaletteSize((LPSTR)lpbi);

  /* Write the file header */
  if (!_lwrite (fh, (LPSTR)&hdr, sizeof (BITMAPFILEHEADER)))
  {
    GlobalUnlock (hdib);
    _lclose (fh);
    return FALSE;
  }

  /* Write the DIB header and the bits */
  if (!kwrite (fh, (LPSTR)lpbi, GlobalSize (hdib)))
  {
    GlobalUnlock (hdib);
    _lclose (fh);
    return FALSE;
  }

  GlobalUnlock (hdib);
  _lclose (fh);
  return TRUE;
}
#endif