Sweden-Number/dlls/wineps.drv/encode.c

107 lines
3.2 KiB
C
Raw Normal View History

/*
* PostScript filter functions
*
* Copyright 2003 Huw D M Davies
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
*/
#include <ctype.h>
#include <stdio.h>
#include <string.h>
#include "psdrv.h"
DWORD RLE_encode(BYTE *in_buf, DWORD len, BYTE *out_buf)
{
BYTE *next_in = in_buf, *next_out = out_buf;
DWORD rl;
while(next_in < in_buf + len) {
if(next_in + 1 < in_buf + len) {
if(*next_in == *(next_in + 1)) {
next_in += 2;
rl = 2;
while(next_in < in_buf + len && *next_in == *(next_in - 1) && rl < 128) {
next_in++;
rl++;
}
*next_out++ = 257 - rl;
*next_out++ = *(next_in - 1);
} else {
rl = 0;
next_out++;
while(next_in < in_buf + len && rl < 128) {
if(next_in + 2 < in_buf + len && *next_in == *(next_in + 1)) {
if(rl == 127 || *next_in == *(next_in + 2))
break;
}
*next_out++ = *next_in++;
rl++;
}
*(next_out - rl - 1) = rl - 1;
}
} else { /* special case: begin of run on last byte */
*next_out++ = 0;
*next_out++ = *next_in;
break;
}
}
*next_out++ = 128;
return next_out - out_buf;
}
DWORD ASCII85_encode(BYTE *in_buf, DWORD len, BYTE *out_buf)
{
DWORD number;
BYTE *next_in = in_buf, *next_out = out_buf;
int i;
while(next_in + 3 < in_buf + len) {
number = (next_in[0] << 24) |
(next_in[1] << 16) |
(next_in[2] << 8) |
(next_in[3] );
next_in += 4;
if(number == 0)
*next_out++ = 'z';
else {
for(i = 4; i >= 0; i--) {
next_out[i] = number % 85 + '!';
number /= 85;
}
next_out += 5;
}
}
if(next_in != in_buf + len) {
number = (*next_in++ << 24) & 0xff000000;
if(next_in < in_buf + len)
number |= ((*next_in++ << 16) & 0x00ff0000);
if(next_in < in_buf + len)
number |= ((*next_in++ << 8) & 0x0000ff00);
for(i = len % 4 + 1; i < 5; i++)
number /= 85;
for(i = len % 4; i >= 0; i--) {
next_out[i] = number % 85 + '!';
number /= 85;
}
next_out += len % 4 + 1;
}
return next_out - out_buf;
}