This is ppmrelief.c in view mode; [Download] [Up]
/* ppmrelief.c - generate a relief map of a portable pixmap
**
** Copyright (C) 1990 by Wilson H. Bent, Jr.
**
** Permission to use, copy, modify, and distribute this software and its
** documentation for any purpose and without fee is hereby granted, provided
** that the above copyright notice appear in all copies and that both that
** copyright notice and this permission notice appear in supporting
** documentation. This software is provided "as is" without express or
** implied warranty.
*/
#include <stdio.h>
#include "ppm.h"
int
main( argc, argv )
int argc;
char* argv[];
{
FILE* ifp;
pixel** inputbuf;
pixel* outputrow;
int argn, rows, cols, format, row, rowa, rowb;
register int col;
pixval maxval, mv2, r, g, b;
char* usage = "[ppmfile]";
ppm_init( &argc, argv );
argn = 1;
if ( argn != argc )
{
ifp = pm_openr( argv[argn] );
++argn;
}
else
ifp = stdin;
if ( argn != argc )
pm_usage( usage );
ppm_pbmmaxval = PPM_MAXMAXVAL; /* use larger value for better results */
ppm_readppminit( ifp, &cols, &rows, &maxval, &format );
mv2 = maxval / 2;
/* Allocate space for 3 input rows, plus an output row. */
inputbuf = ppm_allocarray( cols, 3 );
outputrow = ppm_allocrow( cols );
ppm_writeppminit( stdout, cols, rows, maxval, 0 );
/* Read in the first two rows. */
ppm_readppmrow( ifp, inputbuf[0], cols, maxval, format );
ppm_readppmrow( ifp, inputbuf[1], cols, maxval, format );
/* Write out the first row, all zeros. */
for ( col = 0; col < cols; ++col )
PPM_ASSIGN( outputrow[col], 0, 0, 0 );
ppm_writeppmrow( stdout, outputrow, cols, maxval, 0 );
/* Now the rest of the image - read in the 3rd row of inputbuf,
** and convolve with the first row into the output buffer.
*/
for ( row = 2 ; row < rows; ++row )
{
rowa = row % 3;
rowb = (row + 2) % 3;
ppm_readppmrow( ifp, inputbuf[rowa], cols, maxval, format );
for ( col = 0; col < cols - 2; ++col )
{
r = PPM_GETR( inputbuf[rowa][col] ) +
( mv2 - PPM_GETR( inputbuf[rowb][col + 2] ) );
g = PPM_GETG( inputbuf[rowa][col] ) +
( mv2 - PPM_GETG( inputbuf[rowb][col + 2] ) );
b = PPM_GETB( inputbuf[rowa][col] ) +
( mv2 - PPM_GETB( inputbuf[rowb][col + 2] ) );
PPM_ASSIGN( outputrow[col + 1], r, g, b );
}
ppm_writeppmrow( stdout, outputrow, cols, maxval, 0 );
}
/* And write the last row, zeros again. */
for ( col = 0; col < cols; ++col )
PPM_ASSIGN( outputrow[col], 0, 0, 0 );
ppm_writeppmrow( stdout, outputrow, cols, maxval, 0 );
pm_close( ifp );
pm_close( stdout );
exit( 0 );
}
These are the contents of the former NiCE NeXT User Group NeXTSTEP/OpenStep software archive, currently hosted by Netfuture.ch.