/* replicate an image x times horizontally and vertically
 *
 * JC, 30 sep 03
 *
 * 15/4/04
 *	- some optimisations for some cases
 * 1/2/10
 * 	- gtkdoc
 * 26/10/11
 * 	- redone 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 <vips/vips.h>
#include <vips/internal.h>
#include <vips/debug.h>

#include "pconversion.h"

typedef struct _VipsReplicate {
	VipsConversion parent_instance;

	/* The input image.
	 */
	VipsImage *in;

	int across;
	int down;

} VipsReplicate;

typedef VipsConversionClass VipsReplicateClass;

G_DEFINE_TYPE(VipsReplicate, vips_replicate, VIPS_TYPE_CONVERSION);

static int
vips_replicate_gen(VipsRegion *out_region,
	void *seq, void *a, void *b, gboolean *stop)
{
	VipsRegion *ir = (VipsRegion *) seq;
	VipsImage *in = (VipsImage *) a;
	VipsRect *r = &out_region->valid;
	int twidth = in->Xsize;
	int theight = in->Ysize;

	int x, y;
	VipsRect tile;

	/* Find top left of tiles we need.
	 */
	int xs = (r->left / twidth) * twidth;
	int ys = (r->top / theight) * theight;

	/* The tile enclosing the top-left corner of the requested area.
	 */
	tile.left = xs;
	tile.top = ys;
	tile.width = twidth;
	tile.height = theight;

	/* If the request fits inside a single tile, we can just pointer-copy.
	 */
	if (vips_rect_includesrect(&tile, r)) {
		VipsRect irect;

		/* Translate request to input space.
		 */
		irect = *r;
		irect.left -= xs;
		irect.top -= ys;
		if (vips_region_prepare(ir, &irect))
			return -1;

		if (vips_region_region(out_region, ir, r, irect.left, irect.top))
			return -1;

		return 0;
	}

	for (y = ys; y < VIPS_RECT_BOTTOM(r); y += theight)
		for (x = xs; x < VIPS_RECT_RIGHT(r); x += twidth) {
			VipsRect paint;

			/* Whole tile at x, y
			 */
			tile.left = x;
			tile.top = y;
			tile.width = twidth;
			tile.height = theight;

			/* Which parts touch the area of the output we are
			 * building.
			 */
			vips_rect_intersectrect(&tile, r, &paint);

			/* Translate back to ir coordinates.
			 */
			paint.left -= x;
			paint.top -= y;

			g_assert(!vips_rect_isempty(&paint));

			/* Render into out_region.
			 */
			if (vips_region_prepare_to(ir, out_region, &paint,
					paint.left + x,
					paint.top + y))
				return -1;
		}

	return 0;
}

static int
vips_replicate_build(VipsObject *object)
{
	VipsConversion *conversion = VIPS_CONVERSION(object);
	VipsReplicate *replicate = (VipsReplicate *) object;

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

	if (vips_image_pio_input(replicate->in))
		return -1;

	if (vips_image_pipelinev(conversion->out,
			VIPS_DEMAND_STYLE_SMALLTILE, replicate->in, NULL))
		return -1;

	conversion->out->Xsize *= replicate->across;
	conversion->out->Ysize *= replicate->down;

	if (vips_image_generate(conversion->out,
			vips_start_one, vips_replicate_gen, vips_stop_one,
			replicate->in, replicate))
		return -1;

	return 0;
}

static void
vips_replicate_class_init(VipsReplicateClass *class)
{
	GObjectClass *gobject_class = G_OBJECT_CLASS(class);
	VipsObjectClass *vobject_class = VIPS_OBJECT_CLASS(class);

	VIPS_DEBUG_MSG("vips_replicate_class_init\n");

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

	vobject_class->nickname = "replicate";
	vobject_class->description = _("replicate an image");
	vobject_class->build = vips_replicate_build;

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

	VIPS_ARG_INT(class, "across", 4,
		_("Across"),
		_("Repeat this many times horizontally"),
		VIPS_ARGUMENT_REQUIRED_INPUT,
		G_STRUCT_OFFSET(VipsReplicate, across),
		1, 1000000, 1);

	VIPS_ARG_INT(class, "down", 5,
		_("Down"),
		_("Repeat this many times vertically"),
		VIPS_ARGUMENT_REQUIRED_INPUT,
		G_STRUCT_OFFSET(VipsReplicate, down),
		1, 1000000, 1);
}

static void
vips_replicate_init(VipsReplicate *replicate)
{
}

/**
 * vips_replicate: (method)
 * @in: input image
 * @out: (out): output image
 * @across: repeat input this many times across
 * @down: repeat input this many times down
 * @...: %NULL-terminated list of optional named arguments
 *
 * Repeats an image many times.
 *
 * See also: vips_extract_area().
 *
 * Returns: 0 on success, -1 on error
 */
int
vips_replicate(VipsImage *in, VipsImage **out, int across, int down, ...)
{
	va_list ap;
	int result;

	va_start(ap, down);
	result = vips_call_split("replicate", ap, in, out, across, down);
	va_end(ap);

	return result;
}
