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/*=============================================================================
pamenlarge
===============================================================================
By Bryan Henderson 2004.09.26. Contributed to the public domain by its
author.
=============================================================================*/
#include "pam.h"
#include "mallocvar.h"
struct cmdlineInfo {
/* All the information the user supplied in the command line,
in a form easy for the program to use.
*/
const char *inputFilespec;
unsigned int scaleFactor;
};
static void
parseCommandLine(int argc, char ** const argv,
struct cmdlineInfo * const cmdlineP) {
/*----------------------------------------------------------------------------
Note that the file spec array we return is stored in the storage that
was passed to us as the argv array.
-----------------------------------------------------------------------------*/
if (argc-1 < 1)
pm_error("You must specify at least one argument: The scale factor");
else {
cmdlineP->scaleFactor = atoi(argv[1]);
if (cmdlineP->scaleFactor < 1)
pm_error("Scale factor must be an integer at least 1. "
"You specified '%s'", argv[1]);
if (argc-1 >= 2)
cmdlineP->inputFilespec = argv[2];
else
cmdlineP->inputFilespec = "-";
}
}
static void
makeOutputRowMap(tuple ** const outTupleRowP,
struct pam * const outpamP,
struct pam * const inpamP,
tuple * const inTuplerow) {
/*----------------------------------------------------------------------------
Create a tuple *outTupleRowP which is actually a row of pointers into
inTupleRow[], so as to map input pixels to output pixels by stretching.
-----------------------------------------------------------------------------*/
tuple * newtuplerow;
int col;
MALLOCARRAY_NOFAIL(newtuplerow, outpamP->width);
for (col = 0 ; col < inpamP->width; ++col) {
unsigned int const scaleFactor = outpamP->width / inpamP->width;
unsigned int subcol;
for (subcol = 0; subcol < scaleFactor; ++subcol)
newtuplerow[col * scaleFactor + subcol] = inTuplerow[col];
}
*outTupleRowP = newtuplerow;
}
int
main(int argc,
char * argv[]) {
struct cmdlineInfo cmdline;
FILE * ifP;
struct pam inpam;
struct pam outpam;
tuple * tuplerow;
tuple * newtuplerow;
int row;
pnm_init(&argc, argv);
parseCommandLine(argc, argv, &cmdline);
ifP = pm_openr(cmdline.inputFilespec);
pnm_readpaminit(ifP, &inpam, PAM_STRUCT_SIZE(tuple_type));
outpam = inpam;
outpam.file = stdout;
outpam.width = inpam.width * cmdline.scaleFactor;
outpam.height = inpam.height * cmdline.scaleFactor;
pnm_writepaminit(&outpam);
tuplerow = pnm_allocpamrow(&inpam);
makeOutputRowMap(&newtuplerow, &outpam, &inpam, tuplerow);
for (row = 0; row < inpam.height; ++row) {
pnm_readpamrow(&inpam, tuplerow);
pnm_writepamrowmult(&outpam, newtuplerow, cmdline.scaleFactor);
}
free(newtuplerow);
pnm_freepamrow(tuplerow);
pm_close(ifP);
pm_close(stdout);
return 0;
}
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