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pnmarith.c
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C/C++ Source or Header
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1993-10-04
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5KB
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207 lines
/* pnmarith.c - perform arithmetic on two portable anymaps
**
** slightly modified by Marcel Wijkstra <wijkstra@fwi.uva.nl>
**
**
** Copyright (C) 1989, 1991 by Jef Poskanzer.
**
** 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 "pnm.h"
int
main( argc, argv )
int argc;
char* argv[];
{
FILE* ifp1;
FILE* ifp2;
register xel* xelrow1;
register xel* xelrow2;
register xel* x1P;
register xel* x2P;
xelval maxval1, maxval2, maxval3;
int argn, rows1, cols1, format1, rows2, cols2, format2, format3, row, col;
char function;
char* usage = "-add|-subtract|-multiply|-difference pnmfile1 pnmfile2";
pnm_init( &argc, argv );
argn = 1;
function = ' ';
/* Check for flags. */
if ( argn < argc && argv[argn][0] == '-' && argv[argn][1] != '\0' )
{
if ( pm_keymatch( argv[argn], "-add", 2 ) )
function = '+';
else if ( pm_keymatch( argv[argn], "-subtract", 2 ) )
function = '-';
else if ( pm_keymatch( argv[argn], "-multiply", 2 ) )
function = '*';
else if ( pm_keymatch( argv[argn], "-difference", 2 ) )
function = 'D';
else
pm_usage( usage );
++argn;
}
if ( function == ' ' )
pm_usage( usage );
if ( argn == argc )
pm_usage( usage );
ifp1 = pm_openr( argv[argn] );
++argn;
if ( argn == argc )
pm_usage( usage );
ifp2 = pm_openr( argv[argn] );
++argn;
if ( argn != argc )
pm_usage( usage );
pnm_readpnminit( ifp1, &cols1, &rows1, &maxval1, &format1 );
xelrow1 = pnm_allocrow( cols1 );
pnm_readpnminit( ifp2, &cols2, &rows2, &maxval2, &format2 );
if ( cols2 != cols1 || rows2 != rows1 )
pm_error(
"the two anymaps must be the same width and height" );
xelrow2 = pnm_allocrow( cols1 );
maxval3 = max( maxval1, maxval2 );
format3 = max( PNM_FORMAT_TYPE(format1), PNM_FORMAT_TYPE(format2) );
if ( PNM_FORMAT_TYPE(format1) != format3 ||
PNM_FORMAT_TYPE(format2) != format3 )
{
switch ( PNM_FORMAT_TYPE(format3) )
{
case PPM_TYPE:
if ( PNM_FORMAT_TYPE(format1) != format3 )
pm_message( "promoting first file to PPM" );
if ( PNM_FORMAT_TYPE(format2) != format3 )
pm_message( "promoting second file to PPM" );
break;
case PGM_TYPE:
if ( PNM_FORMAT_TYPE(format1) != format3 )
pm_message( "promoting first file to PGM" );
if ( PNM_FORMAT_TYPE(format2) != format3 )
pm_message( "promoting second file to PGM" );
break;
}
}
pnm_writepnminit( stdout, cols1, rows1, maxval3, format3, 0 );
for ( row = 0; row < rows1; ++row )
{
pnm_readpnmrow( ifp1, xelrow1, cols1, maxval1, format1 );
if ( maxval1 != maxval3 || PNM_FORMAT_TYPE(format1) != format3 )
pnm_promoteformatrow(
xelrow1, cols1, maxval1, format1, maxval3, format3 );
pnm_readpnmrow( ifp2, xelrow2, cols1, maxval2, format2 );
if ( maxval2 != maxval3 || PNM_FORMAT_TYPE(format2) != format3 )
pnm_promoteformatrow(
xelrow2, cols1, maxval2, format2, maxval3, format3 );
for ( col = 0, x1P = xelrow1, x2P = xelrow2;
col < cols1; ++col, ++x1P, ++x2P )
{
switch ( PNM_FORMAT_TYPE(format3) )
{
case PPM_TYPE:
{
int r1, g1, b1, r2, g2, b2;
r1 = PPM_GETR( *x1P );
g1 = PPM_GETG( *x1P );
b1 = PPM_GETB( *x1P );
r2 = PPM_GETR( *x2P );
g2 = PPM_GETG( *x2P );
b2 = PPM_GETB( *x2P );
switch ( function )
{
case '+':
r1 += r2;
g1 += g2;
b1 += b2;
break;
case '-':
r1 -= r2;
g1 -= g2;
b1 -= b2;
break;
case '*':
r1 = r1 * r2 / maxval3;
g1 = g1 * g2 / maxval3;
b1 = b1 * b2 / maxval3;
break;
case 'D':
r1 = (r1>r2)?(r1-r2):(r2-r1);
g1 = (g1>g2)?(g1-g2):(g2-g1);
b1 = (b1>b2)?(b1-b2):(b2-b1);
break;
default:
pm_error( "can't happen" );
}
if ( r1 < 0 ) r1 = 0;
else if ( r1 > maxval3 ) r1 = maxval3;
if ( g1 < 0 ) g1 = 0;
else if ( g1 > maxval3 ) g1 = maxval3;
if ( b1 < 0 ) b1 = 0;
else if ( b1 > maxval3 ) b1 = maxval3;
PPM_ASSIGN( *x1P, r1, g1, b1 );
}
break;
default:
{
int g1, g2;
g1 = PNM_GET1( *x1P );
g2 = PNM_GET1( *x2P );
switch ( function )
{
case '+':
g1 += g2;
break;
case '-':
g1 -= g2;
break;
case '*':
g1 = g1 * g2 / maxval3;
break;
default:
pm_error( "can't happen" );
}
if ( g1 < 0 ) g1 = 0;
else if ( g1 > maxval3 ) g1 = maxval3;
PNM_ASSIGN1( *x1P, g1 );
}
break;
}
}
pnm_writepnmrow( stdout, xelrow1, cols1, maxval3, format3, 0 );
}
pm_close( ifp1 );
pm_close( ifp2 );
exit( 0 );
}