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/* square zone plate of size
*
* 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()
* 1/2/11
* - gtk-doc
* 13/6/13
* - redo as a class
*/
/*
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., 51 Franklin Street, Fifth Floor, Boston, MA
02110-1301 USA
*/
/*
These files are distributed with VIPS - http://www.vips.ecs.soton.ac.uk
*/
/*
#define VIPS_DEBUG
*/
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif /*HAVE_CONFIG_H*/
#include <glib/gi18n-lib.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <math.h>
#include <vips/vips.h>
#include "pcreate.h"
#include "point.h"
typedef VipsPoint VipsZone;
typedef VipsPointClass VipsZoneClass;
G_DEFINE_TYPE( VipsZone, vips_zone, VIPS_TYPE_POINT );
static float
vips_zone_point( VipsPoint *point, int x, int y )
{
VipsZone *zone = (VipsZone *) point;
int hwidth = point->width / 2;
int hheight = point->height / 2;
int h2 = (x - hwidth) * (x - hwidth);
int v2 = (y - hheight) * (y - hheight);
double c = VIPS_PI / zone->width;
return( cos( c * (v2 + h2) ) );
}
static void
vips_zone_class_init( VipsZoneClass *class )
{
VipsObjectClass *vobject_class = VIPS_OBJECT_CLASS( class );
VipsPointClass *point_class = VIPS_POINT_CLASS( class );
vobject_class->nickname = "zone";
vobject_class->description = _( "make a zone plate" );
point_class->point = vips_zone_point;
}
static void
vips_zone_init( VipsZone *zone )
{
}
/**
* vips_zone:
* @out: (out): output image
* @width: image size
* @height: image size
* @...: %NULL-terminated list of optional named arguments
*
* Optional arguments:
*
* * @uchar: output a uchar image
*
* Create a one-band image of a zone plate.
*
* Pixels are normally in [-1, +1], set @uchar to output [0, 255].
*
* See also: vips_eye(), vips_xyz().
*
* Returns: 0 on success, -1 on error
*/
int
vips_zone( VipsImage **out, int width, int height, ... )
{
va_list ap;
int result;
va_start( ap, height );
result = vips_call_split( "zone", ap, out, width, height );
va_end( ap );
return( result );
}
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