/* VipsBandjoin -- bandwise join of a set of images
 *
 * Copyright: 1991, N. Dessipris, modification of im_bandjoin()
 *
 * Author: N. Dessipris
 * Written on: 17/04/1991
 * Modified on :
 * 16/3/94 JC
 *	- rewritten for partials
 *	- now in ANSI C
 *	- now works for any number of input images, except zero
 * 7/10/94 JC
 *	- new IM_NEW()
 * 16/4/07
 * 	- fall back to im_copy() for 1 input image
 * 17/1/09
 * 	- cleanups
 * 	- gtk-doc
 * 	- im_bandjoin() just calls this
 * 	- works for RAD coding too
 * 27/1/10
 * 	- formatalike inputs
 * 17/5/11
 * 	- sizealike inputs
 * 27/10/11
 * 	- rewrite as a class
 * 7/11/15
 * 	- added bandjoin_const
 */

/*

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

#include "bandary.h"

typedef struct _VipsBandjoin {
	VipsBandary parent_instance;

	/* The input images.
	 */
	VipsArrayImage *in;
} VipsBandjoin;

typedef VipsBandaryClass VipsBandjoinClass;

G_DEFINE_TYPE(VipsBandjoin, vips_bandjoin, VIPS_TYPE_BANDARY);

static void
vips_bandjoin_buffer(VipsBandarySequence *seq,
	VipsPel *q, VipsPel **p, int width)
{
	VipsBandary *bandary = seq->bandary;
	VipsConversion *conversion = (VipsConversion *) bandary;
	VipsImage **in = bandary->ready;

	/* Output pel size.
	 */
	const int ops = VIPS_IMAGE_SIZEOF_PEL(conversion->out);

	int i;

	/* Loop for each input image. Scattered write is faster than
	 * scattered read.
	 */
	for (i = 0; i < bandary->n; i++) {
		/* Input pel size.
		 */
		int ips = VIPS_IMAGE_SIZEOF_PEL(in[i]);

		VipsPel *restrict p1;
		VipsPel *restrict q1;
		int x, z;

		q1 = q;
		p1 = p[i];

		if (ips == 1) {
			for (x = 0; x < width; x++) {
				q1[0] = p1[x];

				q1 += ops;
			}

			q += ips;
		}
		else if (ips == 3) {
			for (x = 0; x < width; x++) {
				q1[0] = p1[0];
				q1[1] = p1[1];
				q1[2] = p1[2];

				p1 += ips;
				q1 += ops;
			}

			q += ips;
		}
		else {
			for (x = 0; x < width; x++) {
				for (z = 0; z < ips; z++)
					q1[z] = p1[z];

				p1 += ips;
				q1 += ops;
			}

			q += ips;
		}
	}
}

static int
vips_bandjoin_build(VipsObject *object)
{
	VipsBandary *bandary = (VipsBandary *) object;
	VipsBandjoin *bandjoin = (VipsBandjoin *) object;

	if (bandjoin->in) {
		bandary->in = vips_array_image_get(bandjoin->in, &bandary->n);

		if (bandary->n == 1)
			return vips_bandary_copy(bandary);
		else {
			int i;

			bandary->out_bands = 0;
			for (i = 0; i < bandary->n; i++)
				if (bandary->in[i])
					bandary->out_bands +=
						bandary->in[i]->Bands;
		}
	}

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

	return 0;
}

static void
vips_bandjoin_class_init(VipsBandjoinClass *class)
{
	GObjectClass *gobject_class = G_OBJECT_CLASS(class);
	VipsObjectClass *vobject_class = VIPS_OBJECT_CLASS(class);
	VipsBandaryClass *bandary_class = VIPS_BANDARY_CLASS(class);

	VIPS_DEBUG_MSG("vips_bandjoin_class_init\n");

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

	vobject_class->nickname = "bandjoin";
	vobject_class->description = _("bandwise join a set of images");
	vobject_class->build = vips_bandjoin_build;

	bandary_class->process_line = vips_bandjoin_buffer;

	VIPS_ARG_BOXED(class, "in", 0,
		_("Input"),
		_("Array of input images"),
		VIPS_ARGUMENT_REQUIRED_INPUT,
		G_STRUCT_OFFSET(VipsBandjoin, in),
		VIPS_TYPE_ARRAY_IMAGE);
}

static void
vips_bandjoin_init(VipsBandjoin *bandjoin)
{
	/* Init our instance fields.
	 */
}

static int
vips_bandjoinv(VipsImage **in, VipsImage **out, int n, va_list ap)
{
	VipsArrayImage *array;
	int result;

	array = vips_array_image_new(in, n);
	result = vips_call_split("bandjoin", ap, array, out);
	vips_area_unref(VIPS_AREA(array));

	return result;
}

/**
 * vips_bandjoin:
 * @in: (array length=n) (transfer none): array of input images
 * @out: (out): output image
 * @n: number of input images
 * @...: %NULL-terminated list of optional named arguments
 *
 * Join a set of images together, bandwise.
 *
 * If the images
 * have n and m bands, then the output image will have n + m
 * bands, with the first n coming from the first image and the last m
 * from the second.
 *
 * If the images differ in size, the smaller images are enlarged to match the
 * larger by adding zero pixels along the bottom and right.
 *
 * The input images are cast up to the smallest common type (see table
 * Smallest common format in
 * <link linkend="libvips-arithmetic">arithmetic</link>).
 *
 * See also: vips_insert().
 *
 * Returns: 0 on success, -1 on error
 */
int
vips_bandjoin(VipsImage **in, VipsImage **out, int n, ...)
{
	va_list ap;
	int result;

	va_start(ap, n);
	result = vips_bandjoinv(in, out, n, ap);
	va_end(ap);

	return result;
}

/**
 * vips_bandjoin2:
 * @in1: first input image
 * @in2: second input image
 * @out: (out): output image
 * @...: %NULL-terminated list of optional named arguments
 *
 * Join a pair of images together, bandwise. See vips_bandjoin().
 *
 * Returns: 0 on success, -1 on error
 */
int
vips_bandjoin2(VipsImage *in1, VipsImage *in2, VipsImage **out, ...)
{
	va_list ap;
	int result;
	VipsImage *in[2];

	in[0] = in1;
	in[1] = in2;

	va_start(ap, out);
	result = vips_bandjoinv(in, out, 2, ap);
	va_end(ap);

	return result;
}

typedef struct _VipsBandjoinConst {
	VipsBandary parent_instance;

	VipsImage *in;
	VipsArrayDouble *c;

	/* The constant expanded to in's format, ready to be appended to each
	 * pixel.
	 */
	int n;
	VipsPel *c_ready;

} VipsBandjoinConst;

typedef VipsBandaryClass VipsBandjoinConstClass;

G_DEFINE_TYPE(VipsBandjoinConst, vips_bandjoin_const, VIPS_TYPE_BANDARY);

static void
vips_bandjoin_const_finalize(GObject *object)
{
	VipsBandjoinConst *bandjoin = (VipsBandjoinConst *) object;

	VIPS_FREE(bandjoin->c_ready);

	G_OBJECT_CLASS(vips_bandjoin_const_parent_class)->finalize(object);
}

static void
vips_bandjoin_const_buffer(VipsBandarySequence *seq,
	VipsPel *q, VipsPel **p, int width)
{
	VipsBandary *bandary = seq->bandary;
	VipsConversion *conversion = (VipsConversion *) bandary;
	VipsBandjoinConst *bandjoin = (VipsBandjoinConst *) bandary;
	VipsImage *in = bandary->ready[0];

	/* Output pel size.
	 */
	const int ops = VIPS_IMAGE_SIZEOF_PEL(conversion->out);

	/* Input pel size.
	 */
	const int ips = VIPS_IMAGE_SIZEOF_PEL(in);

	/* Extra bands size.
	 */
	const int ebs = ops - ips;

	VipsPel *restrict p1;
	VipsPel *restrict q1;
	int x, z;

	q1 = q;
	p1 = p[0];

	/* Special path for 8-bit RGB -> RGBA ... it's a common case.
	 */
	if (ips == 3 &&
		ebs == 1) {
		int c = bandjoin->c_ready[0];

		for (x = 0; x < width; x++) {
			q1[0] = p1[0];
			q1[1] = p1[1];
			q1[2] = p1[2];
			q1[3] = c;

			p1 += 3;
			q1 += 4;
		}
	}
	else {
		for (x = 0; x < width; x++) {
			for (z = 0; z < ips; z++)
				q1[z] = p1[z];

			p1 += ips;
			q1 += ips;

			for (z = 0; z < ebs; z++)
				q1[z] = bandjoin->c_ready[z];

			q1 += ebs;
		}
	}
}

static int
vips_bandjoin_const_build(VipsObject *object)
{
	VipsObjectClass *class = VIPS_OBJECT_GET_CLASS(object);
	VipsBandary *bandary = (VipsBandary *) object;
	VipsBandjoinConst *bandjoin = (VipsBandjoinConst *) object;

	if (bandjoin->c &&
		bandjoin->in) {
		double *c;
		int n;

		c = vips_array_double_get(bandjoin->c, &n);

		if (n == 0)
			return vips_bandary_copy(bandary);
		else
			bandary->out_bands = bandjoin->in->Bands + n;

		bandary->n = 1;
		bandary->in = &bandjoin->in;

		if (!(bandjoin->c_ready = vips__vector_to_pels(class->nickname,
				  n, bandjoin->in->BandFmt, bandjoin->in->Coding,
				  c, NULL, n)))
			return -1;
	}

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

	return 0;
}

static void
vips_bandjoin_const_class_init(VipsBandjoinConstClass *class)
{
	GObjectClass *gobject_class = G_OBJECT_CLASS(class);
	VipsObjectClass *vobject_class = VIPS_OBJECT_CLASS(class);
	VipsBandaryClass *bandary_class = VIPS_BANDARY_CLASS(class);

	VIPS_DEBUG_MSG("vips_bandjoin_const_class_init\n");

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

	vobject_class->nickname = "bandjoin_const";
	vobject_class->description = _("append a constant band to an image");
	vobject_class->build = vips_bandjoin_const_build;

	bandary_class->process_line = vips_bandjoin_const_buffer;

	VIPS_ARG_IMAGE(class, "in", 0,
		_("Input"),
		_("Input image"),
		VIPS_ARGUMENT_REQUIRED_INPUT,
		G_STRUCT_OFFSET(VipsBandjoinConst, in));

	VIPS_ARG_BOXED(class, "c", 12,
		_("Constants"),
		_("Array of constants to add"),
		VIPS_ARGUMENT_REQUIRED_INPUT,
		G_STRUCT_OFFSET(VipsBandjoinConst, c),
		VIPS_TYPE_ARRAY_DOUBLE);
}

static void
vips_bandjoin_const_init(VipsBandjoinConst *bandjoin)
{
	/* Init our instance fields.
	 */
}

static int
vips_bandjoin_constv(VipsImage *in, VipsImage **out,
	double *c, int n, va_list ap)
{
	VipsArrayDouble *array;
	int result;

	array = vips_array_double_new(c, n);
	result = vips_call_split("bandjoin_const", ap, in, out, array);
	vips_area_unref(VIPS_AREA(array));

	return result;
}

/**
 * vips_bandjoin_const: (method)
 * @in: input image
 * @out: (out): output image
 * @c: (array length=n): array of constants to append
 * @n: number of constants
 * @...: %NULL-terminated list of optional named arguments
 *
 * Append a set of constant bands to an image.
 *
 * See also: vips_bandjoin().
 *
 * Returns: 0 on success, -1 on error
 */
int
vips_bandjoin_const(VipsImage *in, VipsImage **out, double *c, int n, ...)
{
	va_list ap;
	int result;

	va_start(ap, n);
	result = vips_bandjoin_constv(in, out, c, n, ap);
	va_end(ap);

	return result;
}

/**
 * vips_bandjoin_const1: (method)
 * @in: input image
 * @out: (out): output image
 * @c: constant to append
 * @...: %NULL-terminated list of optional named arguments
 *
 * Append a single constant band to an image.
 *
 * Returns: 0 on success, -1 on error
 */
int
vips_bandjoin_const1(VipsImage *in, VipsImage **out, double c, ...)
{
	va_list ap;
	int result;

	va_start(ap, c);
	result = vips_bandjoin_constv(in, out, &c, 1, ap);
	va_end(ap);

	return result;
}

/**
 * vips_addalpha: (method)
 * @in: input image
 * @out: (out): output image
 * @...: %NULL-terminated list of optional named arguments
 *
 * Append an alpha channel.
 *
 * See also: vips_image_hasalpha().
 *
 * Returns: 0 on success, -1 on error
 */
int
vips_addalpha(VipsImage *in, VipsImage **out, ...)
{
	if (vips_bandjoin_const1(in, out,
		vips_interpretation_max_alpha(in->Type), NULL))
		return -1;

	return 0;
}
