/* extract an area and/or a set of bands
 *
 * Copyright: 1990, J. Cupitt
 *
 * Author: J. Cupitt
 * Written on: 12/02/1990
 * Modified on: 4/6/92, J.Cupitt
 *	- speed up! why wasn't this done before? Why am I stupid?
 *	- layout, messages fixed
 * now extracts IM_CODING_LABQ to IM_CODING_LABQ file: K.Martinez 1/7/93
 * 2/7/93 JC
 *	- adapted for partial v2
 *	- ANSIfied
 * 7/7/93 JC
 *	- behaviour for IM_CODING_LABQ fixed
 *	- better messages
 * 7/10/94 JC
 *	- new IM_NEW()
 * 22/2/95 JC
 *	- new use of im_region_region()
 * 6/7/98 JC
 *	- im_extract_area() and im_extract_band() added
 * 11/7/01 JC
 *	- im_extract_band() now numbers from zero
 * 7/11/01 JC
 *	- oh what pain, im_extract now numbers bands from zero as well
 * 6/9/02 JC
 *	- zero xoff/yoff for extracted area
 * 14/4/04 JC
 *	- nope, -ve the origin
 * 17/7/04
 *	- added im_extract_bands(), remove many bands from image
 * 24/3/09
 * 	- added IM_CODING_RAD support
 * 29/1/10
 * 	- cleanups
 * 	- 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"

#include "bandary.h"

typedef struct _VipsExtractArea {
	VipsConversion parent_instance;

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

	int left;
	int top;
	int width;
	int height;

} VipsExtractArea;

typedef VipsConversionClass VipsExtractAreaClass;

G_DEFINE_TYPE(VipsExtractArea, vips_extract_area, VIPS_TYPE_CONVERSION);

/* Extract an area. Can just use pointers.
 */
static int
vips_extract_area_gen(VipsRegion *out_region,
	void *seq, void *a, void *b, gboolean *stop)
{
	VipsRegion *ir = (VipsRegion *) seq;
	VipsExtractArea *extract = (VipsExtractArea *) b;
	VipsRect iarea;

	/* Ask for input we need. Translate from demand in or's space to
	 * demand in ir's space.
	 */
	iarea = out_region->valid;
	iarea.left += extract->left;
	iarea.top += extract->top;
	if (vips_region_prepare(ir, &iarea))
		return -1;

	/* Attach or to ir.
	 */
	if (vips_region_region(out_region, ir,
			&out_region->valid, iarea.left, iarea.top))
		return -1;

	return 0;
}

static int
vips_extract_area_build(VipsObject *object)
{
	VipsObjectClass *class = VIPS_OBJECT_GET_CLASS(object);
	VipsConversion *conversion = VIPS_CONVERSION(object);
	VipsExtractArea *extract = (VipsExtractArea *) object;

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

	if (extract->left + extract->width > extract->in->Xsize ||
		extract->top + extract->height > extract->in->Ysize ||
		extract->left < 0 || extract->top < 0 ||
		extract->width <= 0 || extract->height <= 0) {
		vips_error(class->nickname, "%s", _("bad extract area"));
		return -1;
	}

	if (vips_image_pio_input(extract->in) ||
		vips_check_coding_known(class->nickname, extract->in))
		return -1;

	if (vips_image_pipelinev(conversion->out,
			VIPS_DEMAND_STYLE_THINSTRIP, extract->in, NULL))
		return -1;

	conversion->out->Xsize = extract->width;
	conversion->out->Ysize = extract->height;
	conversion->out->Xoffset = -extract->left;
	conversion->out->Yoffset = -extract->top;

	if (vips_image_generate(conversion->out,
			vips_start_one, vips_extract_area_gen, vips_stop_one,
			extract->in, extract))
		return -1;

	return 0;
}

static void
vips_extract_area_class_init(VipsExtractAreaClass *class)
{
	GObjectClass *gobject_class = G_OBJECT_CLASS(class);
	VipsObjectClass *vobject_class = VIPS_OBJECT_CLASS(class);
	VipsOperationClass *operation_class = VIPS_OPERATION_CLASS(class);

	VIPS_DEBUG_MSG("vips_extract_area_class_init\n");

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

	vobject_class->nickname = "extract_area";
	vobject_class->description = _("extract an area from an image");
	vobject_class->build = vips_extract_area_build;

	operation_class->flags = VIPS_OPERATION_SEQUENTIAL;

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

	VIPS_ARG_INT(class, "left", 3,
		_("Left"),
		_("Left edge of extract area"),
		VIPS_ARGUMENT_REQUIRED_INPUT,
		G_STRUCT_OFFSET(VipsExtractArea, left),
		-VIPS_MAX_COORD, VIPS_MAX_COORD, 0);

	VIPS_ARG_INT(class, "top", 4,
		_("Top"),
		_("Top edge of extract area"),
		VIPS_ARGUMENT_REQUIRED_INPUT,
		G_STRUCT_OFFSET(VipsExtractArea, top),
		-VIPS_MAX_COORD, VIPS_MAX_COORD, 0);

	VIPS_ARG_INT(class, "width", 5,
		_("Width"),
		_("Width of extract area"),
		VIPS_ARGUMENT_REQUIRED_INPUT,
		G_STRUCT_OFFSET(VipsExtractArea, width),
		1, VIPS_MAX_COORD, 1);

	VIPS_ARG_INT(class, "height", 6,
		_("Height"),
		_("Height of extract area"),
		VIPS_ARGUMENT_REQUIRED_INPUT,
		G_STRUCT_OFFSET(VipsExtractArea, height),
		1, VIPS_MAX_COORD, 1);
}

#ifdef __EMSCRIPTEN__
static void
vips_crop_init_adapter(VipsExtractArea *extract, void *dummy)
{
	vips_extract_area_init(extract);
}
#endif

static void
vips_extract_area_init(VipsExtractArea *extract)
{
}

/**
 * vips_extract_area: (method)
 * @in: input image
 * @out: (out): output image
 * @left: left edge of area to extract
 * @top: top edge of area to extract
 * @width: width of area to extract
 * @height: height of area to extract
 * @...: %NULL-terminated list of optional named arguments
 *
 * Extract an area from an image. The area must fit within @in.
 *
 * See also: vips_extract_bands(), vips_smartcrop().
 *
 * Returns: 0 on success, -1 on error.
 */
int
vips_extract_area(VipsImage *in, VipsImage **out,
	int left, int top, int width, int height, ...)
{
	va_list ap;
	int result;

	va_start(ap, height);
	result = vips_call_split("extract_area", ap, in, out,
		left, top, width, height);
	va_end(ap);

	return result;
}

/* A synonym for extract_area.
 */

GType
vips_crop_get_type(void)
{
	static gsize gtype_id = 0;

	if (g_once_init_enter(&gtype_id)) {
		GType new_type = g_type_register_static_simple(VIPS_TYPE_CONVERSION,
			g_intern_static_string("crop"),
			sizeof(VipsExtractAreaClass),
			(GClassInitFunc) (void (*)(void)) vips_extract_area_class_intern_init,
			sizeof(VipsExtractArea),
#ifdef __EMSCRIPTEN__
			(GInstanceInitFunc) vips_crop_init_adapter,
#else
			(GInstanceInitFunc) (void (*)(void)) vips_extract_area_init,
#endif
			(GTypeFlags) 0);

		g_once_init_leave(&gtype_id, new_type);
	}

	return (GType) gtype_id;
}

/**
 * vips_crop: (method)
 * @in: input image
 * @out: (out): output image
 * @left: left edge of area to extract
 * @top: top edge of area to extract
 * @width: width of area to extract
 * @height: height of area to extract
 * @...: %NULL-terminated list of optional named arguments
 *
 * A synonym for vips_extract_area().
 *
 * See also: vips_extract_bands(), vips_smartcrop().
 *
 * Returns: 0 on success, -1 on error.
 */
int
vips_crop(VipsImage *in, VipsImage **out,
	int left, int top, int width, int height, ...)
{
	va_list ap;
	int result;

	va_start(ap, height);
	result = vips_call_split("crop", ap, in, out,
		left, top, width, height);
	va_end(ap);

	return result;
}

typedef struct _VipsExtractBand {
	VipsBandary parent_instance;

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

	int band;
	int n;
} VipsExtractBand;

typedef VipsBandaryClass VipsExtractBandClass;

G_DEFINE_TYPE(VipsExtractBand, vips_extract_band, VIPS_TYPE_BANDARY);

static void
vips_extract_band_buffer(VipsBandarySequence *seq,
	VipsPel *out, VipsPel **in, int width)
{
	VipsBandary *bandary = seq->bandary;
	VipsConversion *conversion = (VipsConversion *) bandary;
	VipsExtractBand *extract = (VipsExtractBand *) bandary;
	VipsImage *im = bandary->ready[0];
	int es = VIPS_IMAGE_SIZEOF_ELEMENT(im);
	int ips = VIPS_IMAGE_SIZEOF_PEL(im);
	const int ops = VIPS_IMAGE_SIZEOF_PEL(conversion->out);

	VipsPel *restrict p;
	VipsPel *restrict q;
	int x, z;

	p = in[0] + extract->band * es;
	q = out;
	if (ops == 1) {
		for (x = 0; x < width; x++) {
			q[x] = p[0];
			p += ips;
		}
	}
	else {
		for (x = 0; x < width; x++) {
			for (z = 0; z < ops; z++)
				q[z] = p[z];

			p += ips;
			q += ops;
		}
	}
}

static int
vips_extract_band_build(VipsObject *object)
{
	VipsObjectClass *class = VIPS_OBJECT_GET_CLASS(object);
	VipsBandary *bandary = (VipsBandary *) object;
	VipsExtractBand *extract = (VipsExtractBand *) object;

	if (extract->in) {
		int bands;

		vips_image_decode_predict(extract->in, &bands, NULL);

		bandary->n = 1;
		bandary->in = &extract->in;
		bandary->out_bands = extract->n;

		if (extract->band + extract->n > bands) {
			vips_error(class->nickname,
				"%s", _("bad extract band"));
			return -1;
		}

		if (extract->band == 0 &&
			extract->n == bands)
			return vips_bandary_copy(bandary);
	}

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

	return 0;
}

static void
vips_extract_band_class_init(VipsExtractBandClass *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_extract_band_class_init\n");

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

	vobject_class->nickname = "extract_band";
	vobject_class->description = _("extract band from an image");
	vobject_class->build = vips_extract_band_build;

	bandary_class->process_line = vips_extract_band_buffer;

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

	VIPS_ARG_INT(class, "band", 3,
		_("Band"),
		_("Band to extract"),
		VIPS_ARGUMENT_REQUIRED_INPUT,
		G_STRUCT_OFFSET(VipsExtractBand, band),
		0, VIPS_MAX_COORD, 0);

	VIPS_ARG_INT(class, "n", 4,
		_("n"),
		_("Number of bands to extract"),
		VIPS_ARGUMENT_OPTIONAL_INPUT,
		G_STRUCT_OFFSET(VipsExtractBand, n),
		1, VIPS_MAX_COORD, 1);
}

static void
vips_extract_band_init(VipsExtractBand *extract)
{
	extract->n = 1;
}

/**
 * vips_extract_band: (method)
 * @in: input image
 * @out: (out): output image
 * @band: band to extract
 * @...: %NULL-terminated list of optional named arguments
 *
 * Optional arguments:
 *
 * * @n: number of bands to extract
 *
 * Extract a band or bands from an image. Extracting out of range is an error.
 *
 * See also: vips_extract_area().
 *
 * Returns: 0 on success, -1 on error.
 */
int
vips_extract_band(VipsImage *in, VipsImage **out, int band, ...)
{
	va_list ap;
	int result;

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

	return result;
}
