/* im_wrap
 *
 * Copyright: 2008, Nottingham Trent University
 * Author: Tom Vajzovic
 * Written on: 2008-01-15
 * 2/2/10
 * 	- rewritten in terms of im_replicate()/im_extract_area()
 * 	- gtkdoc
 * 	- allows any x/y
 * 31/5/13
 * 	- redone as a class
 * 	- added rotquad behaviour if x/y not set
 */

/*

	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

 */

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

#include <vips/vips.h>

#include "pconversion.h"

typedef struct _VipsWrap {
	VipsConversion parent_instance;

	VipsImage *in;

	int x;
	int y;

} VipsWrap;

typedef VipsConversionClass VipsWrapClass;

G_DEFINE_TYPE(VipsWrap, vips_wrap, VIPS_TYPE_CONVERSION);

static int
vips_wrap_build(VipsObject *object)
{
	VipsConversion *conversion = VIPS_CONVERSION(object);
	VipsWrap *wrap = (VipsWrap *) object;
	VipsImage **t = (VipsImage **) vips_object_local_array(object, 7);

	int x;
	int y;

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

	if (!vips_object_argument_isset(object, "x"))
		wrap->x = wrap->in->Xsize / 2;
	if (!vips_object_argument_isset(object, "y"))
		wrap->y = wrap->in->Ysize / 2;

	/* Clock arithmetic: we want negative x/y to wrap around
	 * nicely.
	 */
	x = wrap->x < 0
		? -wrap->x % wrap->in->Xsize
		: wrap->in->Xsize - wrap->x % wrap->in->Xsize;
	y = wrap->y < 0
		? -wrap->y % wrap->in->Ysize
		: wrap->in->Ysize - wrap->y % wrap->in->Ysize;

	if (vips_replicate(wrap->in, &t[0], 2, 2, NULL) ||
		vips_extract_area(t[0], &t[1],
			x, y, wrap->in->Xsize, wrap->in->Ysize, NULL) ||
		vips_image_write(t[1], conversion->out))
		return -1;

	conversion->out->Xoffset = x;
	conversion->out->Yoffset = y;

	return 0;
}

static void
vips_wrap_class_init(VipsWrapClass *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 = "wrap";
	vobject_class->description = _("wrap image origin");
	vobject_class->build = vips_wrap_build;

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

	VIPS_ARG_INT(class, "x", 3,
		_("x"),
		_("Left edge of input in output"),
		VIPS_ARGUMENT_OPTIONAL_INPUT,
		G_STRUCT_OFFSET(VipsWrap, x),
		-VIPS_MAX_COORD, VIPS_MAX_COORD, 0);

	VIPS_ARG_INT(class, "y", 4,
		_("y"),
		_("Top edge of input in output"),
		VIPS_ARGUMENT_OPTIONAL_INPUT,
		G_STRUCT_OFFSET(VipsWrap, y),
		-VIPS_MAX_COORD, VIPS_MAX_COORD, 0);
}

static void
vips_wrap_init(VipsWrap *wrap)
{
}

/**
 * vips_wrap: (method)
 * @in: input image
 * @out: (out): output image
 * @...: %NULL-terminated list of optional named arguments
 *
 * Optional arguments:
 *
 * * @x: horizontal displacement
 * * @y: vertical displacement
 *
 * Slice an image up and move the segments about so that the pixel that was
 * at 0, 0 is now at @x, @y. If @x and @y are not set, they default to the
 * centre of the image.
 *
 * See also: vips_embed(), vips_replicate().
 *
 * Returns: 0 on success, -1 on error
 */
int
vips_wrap(VipsImage *in, VipsImage **out, ...)
{
	va_list ap;
	int result;

	va_start(ap, out);
	result = vips_call_split("wrap", ap, in, out);
	va_end(ap);

	return result;
}
