libvips/libsrc/other/im_zone.c

128 lines
2.8 KiB
C

/* @(#) square zone plate of size
* @(#) The center of the zone plate is at (xpos/2, ypos/2)
* @(#)
* @(#) Usage:
* @(#)
* @(#) int im_zone( image, size )
* @(#) IMAGE *image;
* @(#) int size;
* @(#)
* @(#) int im_fzone( image, size )
* @(#) IMAGE *image;
* @(#) int size;
* @(#)
* @(#) Returns 0 on sucess and -1 on error
* @(#)
* N. Dessipris 01/02/1991
*
* 22/7/93 JC
* - externs removed
* - im_outcheck() added
* 30/8/95 JC
* - modernized
* - memory leaks fixed
* - split into im_zone() and im_fzone()
*/
/*
This file is part of VIPS.
VIPS is free software; you can redistribute it and/or modify
it under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
/*
These files are distributed with VIPS - http://www.vips.ecs.soton.ac.uk
*/
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif /*HAVE_CONFIG_H*/
#include <vips/intl.h>
#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#include <vips/vips.h>
#ifdef WITH_DMALLOC
#include <dmalloc.h>
#endif /*WITH_DMALLOC*/
int
im_fzone( IMAGE *image, int size )
{
int x, y;
int i, j;
float *buf;
const int size2 = size/2;
/* Check args.
*/
if( im_outcheck( image ) )
return( -1 );
if( size <= 0 || (size % 2) != 0 ) {
im_errormsg( "im_zone: size must be even and positive" );
return( -1 );
}
/* Set up output image.
*/
im_initdesc( image, size, size, 1, IM_BBITS_FLOAT, IM_BANDFMT_FLOAT,
IM_CODING_NONE, IM_TYPE_B_W, 1.0, 1.0, 0, 0 );
if( im_setupout( image ) )
return( -1 );
/* Create output buffer.
*/
if( !(buf = IM_ARRAY( image, size, float )) )
return( -1 );
/* Make zone plate.
*/
for( y = 0, j = -size2; j < size2; j++, y++ ) {
for( x = 0, i = -size2; i < size2; i++, x++ )
buf[x] = cos( (IM_PI/size) * (i*i + j*j) );
if( im_writeline( y, image, (PEL *) buf ) )
return( -1 );
}
return( 0 );
}
/* As above, but make a IM_BANDFMT_UCHAR image.
*/
int
im_zone( IMAGE *im, int size )
{
IMAGE *t1 = im_open_local( im, "im_zone:1", "p" );
IMAGE *t2 = im_open_local( im, "im_zone:2", "p" );
if( !t1 || !t2 )
return( -1 );
if( im_fzone( t1, size ) ||
im_lintra( 127.5, t1, 127.5, t2 ) ||
im_clip( t2, im ) )
return( -1 );
return( 0 );
}