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The World of Computer Software
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dvips551.zip
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DVIPS.ZIP
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DVIINPUT.C
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C/C++ Source or Header
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1993-01-18
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90 lines
/*
* Input bytes from the dvi file or the current virtual character.
* These routines could probably be sped up significantly; but they are
* very machine dependent, so I will leave such tuning to the installer.
* They simply get and return bytes in batches of one, two, three, and four,
* updating the current position as necessary.
*/
#include "dvips.h" /* The copyright notice in that file is included too! */
void error() ;
extern FILE *dvifile ;
extern quarterword *curpos, *curlim ;
void
abortpage()
{
error("! unexpected eof on DVI file") ;
}
shalfword /* the value returned is, however, between 0 and 255 */
dvibyte()
{
register shalfword i ;
if (curpos) {
if (curpos>=curlim) return((shalfword)140) ;
return (*curpos++) ;
}
if ((i=getc(dvifile))==EOF)
abortpage() ;
return(i) ;
}
halfword
twobytes()
{
register halfword i ;
i = dvibyte() ;
return(i*256+dvibyte()) ; }
integer
threebytes()
{
register integer i ;
i = twobytes() ;
return(i*256+dvibyte()) ; }
shalfword
signedbyte()
{
register shalfword i ;
if (curpos) {
if (curpos>=curlim)
error("! unexpected end of virtual packet") ;
i = *curpos++ ;
} else if ((i=getc(dvifile))==EOF)
abortpage() ;
if (i<128) return(i) ;
else return(i-256) ;
}
shalfword
signedpair()
{
register shalfword i ;
i = signedbyte() ;
return(i*256+dvibyte()) ;
}
integer
signedtrio()
{
register integer i ;
i = signedpair() ;
return(i*256+dvibyte()) ;
}
integer
signedquad()
{
register integer i ;
i = signedpair() ;
return(i*65536+twobytes()) ;
}
void
skipover(i)
int i ;
{
while (i-->0) (void)dvibyte() ;
}