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/* creates a 2d sinewave
*
* Copyright: 1990, N. Dessipris.
*
* Author: Nicos Dessipris
* Written on: 02/02/1990
* Modified on:
* 22/7/93 JC
* - externs removed
* - im_outcheck() added
* 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 struct _VipsSines {
VipsPoint parent_instance;
double hfreq;
double vfreq;
double c;
double sintheta;
double costheta;
} VipsSines;
typedef VipsPointClass VipsSinesClass;
G_DEFINE_TYPE( VipsSines, vips_sines, VIPS_TYPE_POINT );
static float
vips_sines_point( VipsPoint *point, int x, int y )
{
VipsSines *sines = (VipsSines *) point;
return( cos( sines->c * (x * sines->costheta - y * sines->sintheta) ) );
}
static int
vips_sines_build( VipsObject *object )
{
VipsPoint *point = VIPS_POINT( object );
VipsSines *sines = (VipsSines *) object;
double theta;
double factor;
if( VIPS_OBJECT_CLASS( vips_sines_parent_class )->build( object ) )
return( -1 );
theta = sines->hfreq == 0.0 ?
VIPS_PI / 2.0 : atan( sines->vfreq / sines->hfreq );
factor = sqrt( sines->hfreq * sines->hfreq +
sines->vfreq * sines->vfreq );
sines->costheta = cos( theta );
sines->sintheta = sin( theta );
sines->c = factor * VIPS_PI * 2.0 / point->width;
return( 0 );
}
static void
vips_sines_class_init( VipsSinesClass *class )
{
GObjectClass *gobject_class = G_OBJECT_CLASS( class );
VipsObjectClass *vobject_class = VIPS_OBJECT_CLASS( class );
VipsPointClass *point_class = VIPS_POINT_CLASS( class );
gobject_class->set_property = vips_object_set_property;
gobject_class->get_property = vips_object_get_property;
vobject_class->nickname = "sines";
vobject_class->description = _( "make a 2D sine wave" );
vobject_class->build = vips_sines_build;
point_class->point = vips_sines_point;
VIPS_ARG_DOUBLE( class, "hfreq", 6,
_( "hfreq" ),
_( "Horizontal spatial frequency" ),
VIPS_ARGUMENT_OPTIONAL_INPUT,
G_STRUCT_OFFSET( VipsSines, hfreq ),
0.0, 10000.0, 0.5 );
VIPS_ARG_DOUBLE( class, "vfreq", 7,
_( "vfreq" ),
_( "Vertical spatial frequency" ),
VIPS_ARGUMENT_OPTIONAL_INPUT,
G_STRUCT_OFFSET( VipsSines, vfreq ),
0.0, 10000.0, 0.5 );
}
static void
vips_sines_init( VipsSines *sines )
{
sines->hfreq = 0.5;
sines->vfreq = 0.5;
}
/**
* vips_sines:
* @out: (out): output image
* @width: image size
* @height: image size
* @...: %NULL-terminated list of optional named arguments
*
* Optional arguments:
*
* * @hfreq: horizontal frequency
* * @vreq: vertical frequency
* * @uchar: output a uchar image
*
* Creates a float one band image of the a sine waveform in two
* dimensions.
*
* The number of horizontal and vertical spatial frequencies are
* determined by the variables @hfreq and @vfreq respectively. The
* function is useful for creating displayable sine waves and
* square waves in two dimensions.
*
* If horfreq and verfreq are integers the resultant image is periodical
* and therfore the Fourier transform does not present spikes
*
* Pixels are normally in [-1, +1], set @uchar to output [0, 255].
*
* See also: vips_grey(), vips_xyz().
*
* Returns: 0 on success, -1 on error
*/
int
vips_sines( VipsImage **out, int width, int height, ... )
{
va_list ap;
int result;
va_start( ap, height );
result = vips_call_split( "sines", ap, out, width, height );
va_end( ap );
return( result );
}
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