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/* ASCII85 and Hex encoding for PostScript Level 2 and PDF */
/* (C) Thomas Merz 1994-99 */
#include <stdio.h>
#include <fcntl.h>
#ifdef WIN32
#define DOS
#endif
#ifdef DOS
#include <io.h>
#include <stdlib.h>
#endif
#include "psimage.h"
typedef unsigned char byte;
static unsigned char buf[4];
static unsigned long power85[5] = { 1L, 85L, 85L*85, 85L*85*85, 85L*85*85*85};
static int outbytes; /* Number of characters in an output line */
/* read 0-4 Bytes. result: number of bytes read */
static int
ReadSomeBytes P1(FILE *, in)
{
register int count, i;
for (count = 0; count < 4; count++) {
if ((i = getc(in)) == EOF)
break;
else
buf[count] = (byte) i;
}
return count;
}
/* Two percent characters at the start of a line will cause trouble
* with some post-processing software. In order to avoid this, we
* simply insert a line break if we encounter a percent character
* at the start of the line. Of course, this rather simplistic
* algorithm may lead to a large line count in pathological cases,
* but the chance for hitting such a case is very small, and even
* so it's only a cosmetic flaw and not a functional restriction.
*/
static void
outbyte P2(byte, c, FILE *, out)
{ /* output one byte */
if (fputc(c, out) == EOF) {
fprintf(stderr, "jpeg2ps: write error - exit!\n");
exit(1);
}
if (++outbytes > 63 || /* line limit reached */
(outbytes == 1 && c == '%') ) { /* caution: percent character at start of line */
fputc('\n', out); /* insert line feed */
outbytes = 0;
}
}
int
ASCII85Encode P2(FILE *, in, FILE *, out)
{
register int i, count;
unsigned long word, v;
outbytes = 0;
/* 4 bytes read ==> output 5 bytes */
while ((count = ReadSomeBytes(in)) == 4) {
word = ((unsigned long)(((unsigned int)buf[0] << 8) + buf[1]) << 16) +
(((unsigned int)buf[2] << 8) + buf[3]);
if (word == 0)
outbyte('z', out); /* shortcut for 0 */
else
/* calculate 5 ASCII85 bytes and output them */
for (i = 4; i >= 0; i--) {
v = word / power85[i];
outbyte((byte) (v + '!'), out);
word -= v * power85[i];
}
}
word = 0;
if (count != 0) { /* 1-3 bytes left */
for (i = count-1; i >= 0; i--) /* accumulate bytes */
word += (unsigned long)buf[i] << 8 * (3-i);
/* encoding as above, but output only count+1 bytes */
for (i = 4; i >= 4-count; i--) {
v = word / power85[i];
outbyte((byte) (v + '!'), out);
word -= v * power85[i];
}
}
fputc('~', out); /* EOD marker */
fputc('>', out);
return 0;
}
void
ASCIIHexEncode P2(FILE *, in, FILE *, out) {
static char buffer[512];
static char BinToHex[] = "0123456789ABCDEF";
int CharsPerLine;
size_t i, n;
unsigned char *p;
CharsPerLine = 0;
fputc('\n', out);
while ((n = fread(buffer, 1, sizeof(buffer), in)) != 0)
for (i = 0, p = (unsigned char *) buffer; i < n; i++, p++) {
fputc(BinToHex[*p>>4], out); /* first nibble */
fputc(BinToHex[*p & 0x0F], out); /* second nibble */
if ((CharsPerLine += 2) >= 64) {
fputc('\n', out);
CharsPerLine = 0;
}
}
fputc('>', out); /* EOD marker for PostScript hex strings */
}
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