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      1 /*
      2  * Copyright  2002 Keith Packard
      3  *
      4  * Permission to use, copy, modify, distribute, and sell this software and its
      5  * documentation for any purpose is hereby granted without fee, provided that
      6  * the above copyright notice appear in all copies and that both that
      7  * copyright notice and this permission notice appear in supporting
      8  * documentation, and that the name of Keith Packard not be used in
      9  * advertising or publicity pertaining to distribution of the software without
     10  * specific, written prior permission.  Keith Packard makes no
     11  * representations about the suitability of this software for any purpose.  It
     12  * is provided "as is" without express or implied warranty.
     13  *
     14  * KEITH PACKARD DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
     15  * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
     16  * EVENT SHALL KEITH PACKARD BE LIABLE FOR ANY SPECIAL, INDIRECT OR
     17  * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
     18  * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
     19  * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
     20  * PERFORMANCE OF THIS SOFTWARE.
     21  */
     22 
     23 #include "xftint.h"
     24 
     25 _X_HIDDEN int
     26 XftNativeByteOrder (void)
     27 {
     28     int	    whichbyte = 1;
     29 
     30     if (*((char *) &whichbyte))
     31 	return LSBFirst;
     32     return MSBFirst;
     33 }
     34 
     35 /* byte swap a 32-bit value */
     36 #define swapl(x, n) { \
     37 		 n = ((char *) (x))[0];\
     38 		 ((char *) (x))[0] = ((char *) (x))[3];\
     39 		 ((char *) (x))[3] = n;\
     40 		 n = ((char *) (x))[1];\
     41 		 ((char *) (x))[1] = ((char *) (x))[2];\
     42 		 ((char *) (x))[2] = n; }
     43 
     44 /* byte swap a short */
     45 #define swaps(x, n) { \
     46 		 n = ((char *) (x))[0];\
     47 		 ((char *) (x))[0] = ((char *) (x))[1];\
     48 		 ((char *) (x))[1] = n; }
     49 
     50 /* byte swap a three-byte unit */
     51 #define swapt(x, n) { \
     52 		 n = ((char *) (x))[0];\
     53 		 ((char *) (x))[0] = ((char *) (x))[2];\
     54 		 ((char *) (x))[2] = n; }
     55 
     56 _X_HIDDEN void
     57 XftSwapCARD32 (CARD32 *data, int u)
     58 {
     59     char    n;
     60     while (u--)
     61     {
     62 	swapl (data, n);
     63 	data++;
     64     }
     65 }
     66 
     67 _X_HIDDEN void
     68 XftSwapCARD24 (CARD8 *data, int width, int height)
     69 {
     70     int	    units, u;
     71     char    n;
     72     CARD8   *d;
     73 
     74     units = width / 3;
     75     while (height--)
     76     {
     77 	d = data;
     78 	data += width;
     79 	u = units;
     80 	while (u--)
     81 	{
     82 	    swapt (d, n);
     83 	    d += 3;
     84 	}
     85     }
     86 }
     87 
     88 _X_HIDDEN void
     89 XftSwapCARD16 (CARD16 *data, int u)
     90 {
     91     char    n;
     92     while (u--)
     93     {
     94 	swaps (data, n);
     95 	data++;
     96     }
     97 }
     98 
     99 _X_HIDDEN void
    100 XftSwapImage (XImage *image)
    101 {
    102     switch (image->bits_per_pixel) {
    103     case 32:
    104 	XftSwapCARD32 ((CARD32 *) image->data,
    105 		       image->height * image->bytes_per_line >> 2);
    106 	break;
    107     case 24:
    108 	XftSwapCARD24 ((CARD8 *) image->data,
    109 		       image->bytes_per_line,
    110 		       image->height);
    111 	break;
    112     case 16:
    113 	XftSwapCARD16 ((CARD16 *) image->data,
    114 		       image->height * image->bytes_per_line >> 1);
    115 	break;
    116     default:
    117 	break;
    118     }
    119 }
    120