/* remainder.c
 *
 * 2/8/99 JC
 *	- im_divide adapted to make im_remainder
 * 8/5/02 JC
 *	- im_remainderconst added
 *	- im_remainderconst_vec added
 * 27/9/04
 *	- updated for 1 band $op n band image -> n band image case
 * 26/2/07
 * 	- oop, broken for _vec case :-(
 * 14/5/08
 * 	- better /0 test
 * 27/8/08
 * 	- revise upcasting system
 * 	- add gtkdoc comments
 * 23/6/10
 * 	- constant ops clip to target range
 * 12/11/11
 * 	- redone as a class
 */

/*

	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 "binary.h"
#include "unaryconst.h"

typedef VipsBinary VipsRemainder;
typedef VipsBinaryClass VipsRemainderClass;

G_DEFINE_TYPE(VipsRemainder, vips_remainder, VIPS_TYPE_BINARY);

static int
vips_remainder_build(VipsObject *object)
{
	VipsObjectClass *class = VIPS_OBJECT_GET_CLASS(object);
	VipsBinary *binary = (VipsBinary *) object;

	if (binary->left &&
		vips_check_noncomplex(class->nickname, binary->left))
		return -1;
	if (binary->right &&
		vips_check_noncomplex(class->nickname, binary->right))
		return -1;

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

	return 0;
}

/* Integer remainder-after-division.
 */
#define IREMAINDER(TYPE) \
	{ \
		TYPE *restrict p1 = (TYPE *) in[0]; \
		TYPE *restrict p2 = (TYPE *) in[1]; \
		TYPE *restrict q = (TYPE *) out; \
\
		for (x = 0; x < sz; x++) \
			q[x] = p2[x] ? p1[x] % p2[x] : -1; \
	}

/* Float remainder-after-division.
 */
#define FREMAINDER(TYPE) \
	{ \
		TYPE *restrict p1 = (TYPE *) in[0]; \
		TYPE *restrict p2 = (TYPE *) in[1]; \
		TYPE *restrict q = (TYPE *) out; \
\
		for (x = 0; x < sz; x++) { \
			double a = p1[x]; \
			double b = p2[x]; \
\
			q[x] = b ? a - b * VIPS_FLOOR(a / b) : -1; \
		} \
	}

static void
vips_remainder_buffer(VipsArithmetic *arithmetic,
	VipsPel *out, VipsPel **in, int width)
{
	VipsImage *im = arithmetic->ready[0];
	const int sz = width * vips_image_get_bands(im);

	int x;

	switch (vips_image_get_format(im)) {
	case VIPS_FORMAT_CHAR:
		IREMAINDER(signed char);
		break;
	case VIPS_FORMAT_UCHAR:
		IREMAINDER(unsigned char);
		break;
	case VIPS_FORMAT_SHORT:
		IREMAINDER(signed short);
		break;
	case VIPS_FORMAT_USHORT:
		IREMAINDER(unsigned short);
		break;
	case VIPS_FORMAT_INT:
		IREMAINDER(signed int);
		break;
	case VIPS_FORMAT_UINT:
		IREMAINDER(unsigned int);
		break;
	case VIPS_FORMAT_FLOAT:
		FREMAINDER(float);
		break;
	case VIPS_FORMAT_DOUBLE:
		FREMAINDER(double);
		break;

	default:
		g_assert_not_reached();
	}
}

/* Save a bit of typing.
 */
#define UC VIPS_FORMAT_UCHAR
#define C VIPS_FORMAT_CHAR
#define US VIPS_FORMAT_USHORT
#define S VIPS_FORMAT_SHORT
#define UI VIPS_FORMAT_UINT
#define I VIPS_FORMAT_INT
#define F VIPS_FORMAT_FLOAT
#define X VIPS_FORMAT_COMPLEX
#define D VIPS_FORMAT_DOUBLE
#define DX VIPS_FORMAT_DPCOMPLEX

/* Type promotion for remainder. Keep in sync with remainder_buffer() above.
 */
static const VipsBandFormat vips_remainder_format_table[10] = {
	/* Band format:  UC  C  US  S  UI  I  F  X  D  DX */
	/* Promotion: */ UC, C, US, S, UI, I, F, X, D, DX
};

static void
vips_remainder_class_init(VipsRemainderClass *class)
{
	GObjectClass *gobject_class = G_OBJECT_CLASS(class);
	VipsObjectClass *object_class = (VipsObjectClass *) class;
	VipsArithmeticClass *aclass = VIPS_ARITHMETIC_CLASS(class);

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

	object_class->nickname = "remainder";
	object_class->description =
		_("remainder after integer division of two images");
	object_class->build = vips_remainder_build;

	aclass->process_line = vips_remainder_buffer;

	vips_arithmetic_set_format_table(aclass,
		vips_remainder_format_table);
}

static void
vips_remainder_init(VipsRemainder *remainder)
{
}

/**
 * vips_remainder:
 * @left: left-hand input #VipsImage
 * @right: right-hand input #VipsImage
 * @out: (out): output #VipsImage
 * @...: %NULL-terminated list of optional named arguments
 *
 * This operation calculates @left % @right (remainder after integer division)
 * and writes the result to @out. The images may have any
 * non-complex format. For float formats, vips_remainder() calculates @in1 -
 * @in2 * floor (@in1 / @in2).
 *
 * If the images differ in size, the smaller image is enlarged to match the
 * larger by adding zero pixels along the bottom and right.
 *
 * If the number of bands differs, one of the images
 * must have one band. In this case, an n-band image is formed from the
 * one-band image by joining n copies of the one-band image together, and then
 * the two n-band images are operated upon.
 *
 * The two input images are cast up to the smallest common format (see table
 * Smallest common format in
 * <link linkend="libvips-arithmetic">arithmetic</link>), and that format is the
 * result type.
 *
 * See also: vips_remainder_const(), vips_divide(), vips_round().
 *
 * Returns: 0 on success, -1 on error
 */
int
vips_remainder(VipsImage *left, VipsImage *right, VipsImage **out, ...)
{
	va_list ap;
	int result;

	va_start(ap, out);
	result = vips_call_split("remainder", ap, left, right, out);
	va_end(ap);

	return result;
}

typedef VipsUnaryConst VipsRemainderConst;
typedef VipsUnaryConstClass VipsRemainderConstClass;

G_DEFINE_TYPE(VipsRemainderConst,
	vips_remainder_const, VIPS_TYPE_UNARY_CONST);

static int
vips_remainder_const_build(VipsObject *object)
{
	VipsObjectClass *class = VIPS_OBJECT_GET_CLASS(object);
	VipsUnary *unary = (VipsUnary *) object;

	if (unary->in &&
		vips_check_noncomplex(class->nickname, unary->in))
		return -1;

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

	return 0;
}

/* Integer remainder-after-divide, per-band constant.
 */
#define IREMAINDERCONST(TYPE) \
	{ \
		TYPE *restrict p = (TYPE *) in[0]; \
		TYPE *restrict q = (TYPE *) out; \
		int *restrict c = uconst->c_int; \
\
		for (i = 0, x = 0; x < width; x++) \
			for (b = 0; b < bands; b++, i++) \
				q[i] = p[i] % c[b]; \
	}

/* Float remainder-after-divide, per-band constant.
 */
#define FREMAINDERCONST(TYPE) \
	{ \
		TYPE *restrict p = (TYPE *) in[0]; \
		TYPE *restrict q = (TYPE *) out; \
		int *restrict c = uconst->c_int; \
\
		for (i = 0, x = 0; x < width; x++) \
			for (b = 0; b < bands; b++, i++) { \
				double left = p[i]; \
				double right = c[b]; \
\
				q[i] = right ? left - right * floor(left / right) : -1; \
			} \
	}

static void
vips_remainder_const_buffer(VipsArithmetic *arithmetic,
	VipsPel *out, VipsPel **in, int width)
{
	VipsUnaryConst *uconst = (VipsUnaryConst *) arithmetic;
	VipsImage *im = arithmetic->ready[0];
	int bands = im->Bands;

	int i, x, b;

	switch (vips_image_get_format(im)) {
	case VIPS_FORMAT_CHAR:
		IREMAINDERCONST(signed char);
		break;
	case VIPS_FORMAT_UCHAR:
		IREMAINDERCONST(unsigned char);
		break;
	case VIPS_FORMAT_SHORT:
		IREMAINDERCONST(signed short);
		break;
	case VIPS_FORMAT_USHORT:
		IREMAINDERCONST(unsigned short);
		break;
	case VIPS_FORMAT_INT:
		IREMAINDERCONST(signed int);
		break;
	case VIPS_FORMAT_UINT:
		IREMAINDERCONST(unsigned int);
		break;
	case VIPS_FORMAT_FLOAT:
		FREMAINDERCONST(float);
		break;
	case VIPS_FORMAT_DOUBLE:
		FREMAINDERCONST(double);
		break;

	default:
		g_assert_not_reached();
	}
}

static void
vips_remainder_const_class_init(VipsRemainderConstClass *class)
{
	GObjectClass *gobject_class = G_OBJECT_CLASS(class);
	VipsObjectClass *object_class = (VipsObjectClass *) class;
	VipsArithmeticClass *aclass = VIPS_ARITHMETIC_CLASS(class);

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

	object_class->nickname = "remainder_const";
	object_class->description =
		_("remainder after integer division of an image and a constant");
	object_class->build = vips_remainder_const_build;

	aclass->process_line = vips_remainder_const_buffer;

	vips_arithmetic_set_format_table(aclass, vips_remainder_format_table);
}

static void
vips_remainder_const_init(VipsRemainderConst *remainder_const)
{
}

static int
vips_remainder_constv(VipsImage *in, VipsImage **out,
	const double *c, int n, va_list ap)
{
	VipsArea *area_c;
	double *array;
	int result;
	int i;

	area_c = vips_area_new_array(G_TYPE_DOUBLE, sizeof(double), n);
	array = (double *) area_c->data;
	for (i = 0; i < n; i++)
		array[i] = c[i];

	result = vips_call_split("remainder_const", ap, in, out, area_c);

	vips_area_unref(area_c);

	return result;
}

/**
 * vips_remainder_const: (method)
 * @in: input image
 * @out: (out): output image
 * @c: (array length=n): array of constants
 * @n: number of constants in @c
 * @...: %NULL-terminated list of optional named arguments
 *
 * This operation calculates @in % @c (remainder after division by an
 * array of constants)
 * and writes the result to @out.
 * The image may have any
 * non-complex format. For float formats, vips_remainder_const() calculates
 * @in - @c * floor (@in / @c).
 *
 * If the array of constants has just one element, that constant is used for
 * all image bands. If the array has more than one element and they have
 * the same number of elements as there are bands in the image, then
 * one array element is used for each band. If the arrays have more than one
 * element and the image only has a single band, the result is a many-band
 * image where each band corresponds to one array element.
 *
 * See also: vips_remainder(), vips_divide(), vips_round().
 *
 * Returns: 0 on success, -1 on error
 */
int
vips_remainder_const(VipsImage *in, VipsImage **out,
	const double *c, int n, ...)
{
	va_list ap;
	int result;

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

	return result;
}

/**
 * vips_remainder_const1: (method)
 * @in: input image
 * @out: (out): output image
 * @c: constant
 * @...: %NULL-terminated list of optional named arguments
 *
 * This operation calculates @in % @c (remainder after division by a
 * constant)
 * and writes the result to @out.
 * The image may have any
 * non-complex format. For float formats, vips_remainder_const() calculates
 * @in - @c * floor (@in / @c).
 *
 * If the array of constants has just one element, that constant is used for
 * all image bands. If the array has more than one element and they have
 * the same number of elements as there are bands in the image, then
 * one array element is used for each band. If the arrays have more than one
 * element and the image only has a single band, the result is a many-band
 * image where each band corresponds to one array element.
 *
 * See also: vips_remainder(), vips_divide(), vips_round().
 *
 * Returns: 0 on success, -1 on error
 */
int
vips_remainder_const1(VipsImage *in, VipsImage **out, double c, ...)
{
	va_list ap;
	int result;

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

	return result;
}
