/*
 * $XConsortium: bitmaputil.c,v 1.1 91/05/10 16:51:48 keith Exp $
 *
 * Copyright 1990 Massachusetts Institute of Technology
 *
 * Permission to use, copy, modify, distribute, and sell this software and its
 * documentation for any purpose is hereby granted without fee, provided that
 * the above copyright notice appear in all copies and that both that
 * copyright notice and this permission notice appear in supporting
 * documentation, and that the name of M.I.T. not be used in advertising or
 * publicity pertaining to distribution of the software without specific,
 * written prior permission.  M.I.T. makes no representations about the
 * suitability of this software for any purpose.  It is provided "as is"
 * without express or implied warranty.
 *
 * M.I.T. DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO EVENT SHALL M.I.T.
 * BE LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
 * OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN 
 * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 *
 * Author:  Keith Packard, MIT X Consortium
 */

/* Utility functions for reformating font bitmaps */

static unsigned char _reverse_byte[0x100] = {
	0x00, 0x80, 0x40, 0xc0, 0x20, 0xa0, 0x60, 0xe0,
	0x10, 0x90, 0x50, 0xd0, 0x30, 0xb0, 0x70, 0xf0,
	0x08, 0x88, 0x48, 0xc8, 0x28, 0xa8, 0x68, 0xe8,
	0x18, 0x98, 0x58, 0xd8, 0x38, 0xb8, 0x78, 0xf8,
	0x04, 0x84, 0x44, 0xc4, 0x24, 0xa4, 0x64, 0xe4,
	0x14, 0x94, 0x54, 0xd4, 0x34, 0xb4, 0x74, 0xf4,
	0x0c, 0x8c, 0x4c, 0xcc, 0x2c, 0xac, 0x6c, 0xec,
	0x1c, 0x9c, 0x5c, 0xdc, 0x3c, 0xbc, 0x7c, 0xfc,
	0x02, 0x82, 0x42, 0xc2, 0x22, 0xa2, 0x62, 0xe2,
	0x12, 0x92, 0x52, 0xd2, 0x32, 0xb2, 0x72, 0xf2,
	0x0a, 0x8a, 0x4a, 0xca, 0x2a, 0xaa, 0x6a, 0xea,
	0x1a, 0x9a, 0x5a, 0xda, 0x3a, 0xba, 0x7a, 0xfa,
	0x06, 0x86, 0x46, 0xc6, 0x26, 0xa6, 0x66, 0xe6,
	0x16, 0x96, 0x56, 0xd6, 0x36, 0xb6, 0x76, 0xf6,
	0x0e, 0x8e, 0x4e, 0xce, 0x2e, 0xae, 0x6e, 0xee,
	0x1e, 0x9e, 0x5e, 0xde, 0x3e, 0xbe, 0x7e, 0xfe,
	0x01, 0x81, 0x41, 0xc1, 0x21, 0xa1, 0x61, 0xe1,
	0x11, 0x91, 0x51, 0xd1, 0x31, 0xb1, 0x71, 0xf1,
	0x09, 0x89, 0x49, 0xc9, 0x29, 0xa9, 0x69, 0xe9,
	0x19, 0x99, 0x59, 0xd9, 0x39, 0xb9, 0x79, 0xf9,
	0x05, 0x85, 0x45, 0xc5, 0x25, 0xa5, 0x65, 0xe5,
	0x15, 0x95, 0x55, 0xd5, 0x35, 0xb5, 0x75, 0xf5,
	0x0d, 0x8d, 0x4d, 0xcd, 0x2d, 0xad, 0x6d, 0xed,
	0x1d, 0x9d, 0x5d, 0xdd, 0x3d, 0xbd, 0x7d, 0xfd,
	0x03, 0x83, 0x43, 0xc3, 0x23, 0xa3, 0x63, 0xe3,
	0x13, 0x93, 0x53, 0xd3, 0x33, 0xb3, 0x73, 0xf3,
	0x0b, 0x8b, 0x4b, 0xcb, 0x2b, 0xab, 0x6b, 0xeb,
	0x1b, 0x9b, 0x5b, 0xdb, 0x3b, 0xbb, 0x7b, 0xfb,
	0x07, 0x87, 0x47, 0xc7, 0x27, 0xa7, 0x67, 0xe7,
	0x17, 0x97, 0x57, 0xd7, 0x37, 0xb7, 0x77, 0xf7,
	0x0f, 0x8f, 0x4f, 0xcf, 0x2f, 0xaf, 0x6f, 0xef,
	0x1f, 0x9f, 0x5f, 0xdf, 0x3f, 0xbf, 0x7f, 0xff
};

/*
 *	Invert bit order within each BYTE of an array.
 */
void
BitOrderInvert(buf, nbytes)
    register unsigned char *buf;
    register int nbytes;
{
    register unsigned char *rev = _reverse_byte;

    for (; --nbytes >= 0; buf++)
	*buf = rev[*buf];
}

/*
 *	Invert byte order within each 16-bits of an array.
 */
void
TwoByteSwap(buf, nbytes)
    register unsigned char *buf;
    register int nbytes;
{
    register unsigned char c;

    for (; nbytes > 0; nbytes -= 2, buf += 2)
    {
	c = buf[0];
	buf[0] = buf[1];
	buf[1] = c;
    }
}

/*
 *	Invert byte order within each 32-bits of an array.
 */
void
FourByteSwap(buf, nbytes)
    register unsigned char *buf;
    register int nbytes;
{
    register unsigned char c;

    for (; nbytes > 0; nbytes -= 4, buf += 4) 
    {
	c = buf[0];
	buf[0] = buf[3];
	buf[3] = c;
	c = buf[1];
	buf[1] = buf[2];
	buf[2] = c;
    }
}

/*
 *	Repad a bitmap
 */

int
RepadBitmap (pSrc, pDst, srcPad, dstPad, width, height)
    char	*pSrc, *pDst;
    unsigned	srcPad, dstPad;
    int		width, height;
{
    int	    srcWidthBytes,dstWidthBytes;
    int	    row,col;
    char    *pTmpSrc,*pTmpDst;

    switch (srcPad) {
    case 1:	
	srcWidthBytes = (width+7)>>3;
	break;
    case 2:
	srcWidthBytes = ((width+15)>>4)<<1;
	break;
    case 4:	
	srcWidthBytes = ((width+31)>>5)<<2;
	break;
    case 8:	
	srcWidthBytes = ((width+63)>>6)<<3; 
	break;
    default:
	return 0;
    }
    switch (dstPad) {
    case 1:	
	dstWidthBytes = (width+7)>>3;
	break;
    case 2:
	dstWidthBytes = ((width+15)>>4)<<1;
	break;
    case 4:	
	dstWidthBytes = ((width+31)>>5)<<2;
	break;
    case 8:	
	dstWidthBytes = ((width+63)>>6)<<3; 
	break;
    default:
	return 0;
    }

    width = srcWidthBytes;
    if (width > dstWidthBytes)
	width = dstWidthBytes;
    pTmpSrc= pSrc;
    pTmpDst= pDst;
    for (row = 0; row < height; row++)
    {
	for (col = 0; col < width; col++)
	    *pTmpDst++ = *pTmpSrc++;
	while (col < dstWidthBytes)
 	{
	    *pTmpDst++ = '\0';
	    col++;
	}
	pTmpSrc += srcWidthBytes - width;
    }
    return dstWidthBytes * height;
}
