/* base class for all Fourier stuff
 *
 * properties:
 * 	- single output image
 */

/*

	Copyright (C) 1991-2005 The National Gallery

	This library 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 2.1 of the License, or (at your option) any later version.

	This library 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 library; 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 DEBUG
 */

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif /*HAVE_CONFIG_H*/
#include <glib/gi18n-lib.h>

#include <stdio.h>
#include <stdlib.h>
#include <math.h>

#include <vips/vips.h>
#include <vips/internal.h>

#include "pfreqfilt.h"

/**
 * SECTION: freqfilt
 * @short_description: fourier transforms and frequency-domin filters
 * @stability: Stable
 * @see_also: <link linkend="VipsImage">image</link>
 * @include: vips/vips.h
 *
 * To and from Fourier space, filter in Fourier space, convert Fourier-space
 * images to a displayable form.
 */

G_DEFINE_ABSTRACT_TYPE(VipsFreqfilt, vips_freqfilt, VIPS_TYPE_OPERATION);

static int
vips_freqfilt_build(VipsObject *object)
{
	VipsFreqfilt *freqfilt = VIPS_FREQFILT(object);

#ifdef DEBUG
	printf("vips_freqfilt_build: ");
	vips_object_print_name(object);
	printf("\n");
#endif /*DEBUG*/

	g_object_set(freqfilt, "out", vips_image_new(), NULL);

	if (VIPS_OBJECT_CLASS(vips_freqfilt_parent_class)->build(object))
		return -1;

	return 0;
}

static void
vips_freqfilt_class_init(VipsFreqfiltClass *class)
{
	GObjectClass *gobject_class = G_OBJECT_CLASS(class);
	VipsObjectClass *vobject_class = VIPS_OBJECT_CLASS(class);

	gobject_class->set_property = vips_object_set_property;
	gobject_class->get_property = vips_object_get_property;

	vobject_class->nickname = "freqfilt";
	vobject_class->description = _("frequency-domain filter operations");
	vobject_class->build = vips_freqfilt_build;

	VIPS_ARG_IMAGE(class, "in", -1,
		_("Input"),
		_("Input image"),
		VIPS_ARGUMENT_REQUIRED_INPUT,
		G_STRUCT_OFFSET(VipsFreqfilt, in));

	VIPS_ARG_IMAGE(class, "out", 1,
		_("Output"),
		_("Output image"),
		VIPS_ARGUMENT_REQUIRED_OUTPUT,
		G_STRUCT_OFFSET(VipsFreqfilt, out));
}

static void
vips_freqfilt_init(VipsFreqfilt *freqfilt)
{
}

/* Transform an n-band image with a 1-band processing function.
 *
 * Memory strategy: we need memory buffers for the input and the output of
 * fftw. In some modes fftw generates only half the output and we construct
 * the rest.
 *
 * input pipeline ->
 *   bandsplit ->
 *     full memory image, freed when im_*fft*() exits ->
 *       fftw ->
 *         half memory image, freed when im_*fft*() exits ->
 *           full memory image, freed when @out is freed ->
 *             partial bandjoin ->
 *               output pipeline
 *
 * vips__fftproc() needs to just call VipsFftProcessFn directly for 1 band images,
 * so we can't cache the output in this fn.
 */
int
vips__fftproc(VipsObject *context,
	VipsImage *in, VipsImage **out, VipsFftProcessFn fn)
{
	VipsImage **bands = (VipsImage **)
		vips_object_local_array(context, in->Bands);
	VipsImage **fft = (VipsImage **)
		vips_object_local_array(context, in->Bands);

	int b;

	if (in->Bands == 1)
		return fn(context, in, out);

	for (b = 0; b < in->Bands; b++)
		if (vips_extract_band(in, &bands[b], b, NULL) ||
			fn(context, bands[b], &fft[b]))
			return -1;

	if (vips_bandjoin(fft, out, in->Bands, NULL))
		return -1;

	return 0;
}

/* Called from iofuncs to init all operations in this dir. Use a plugin system
 * instead?
 */
void
vips_freqfilt_operation_init(void)
{
#ifdef HAVE_FFTW
	extern GType vips_fwfft_get_type(void);
	extern GType vips_invfft_get_type(void);
#endif /*HAVE_FFTW*/
	extern GType vips_freqmult_get_type(void);
	extern GType vips_spectrum_get_type(void);
	extern GType vips_phasecor_get_type(void);

#ifdef HAVE_FFTW
	vips_fwfft_get_type();
	vips_invfft_get_type();
#endif /*HAVE_FFTW*/
	vips_freqmult_get_type();
	vips_spectrum_get_type();
	vips_phasecor_get_type();
}
