/* photographic negative ... just an example, really
 *
 * Copyright: 1990, N. Dessipris.
 *
 * Author: Nicos Dessipris
 * Written on: 12/02/1990
 * Modified on :
 * 7/7/93 JC
 *      - memory leaks fixed
 *      - adapted for partial v2
 *      - ANSIfied
 * 22/2/95 JC
 *	- tidied up again
 * 2/9/09
 * 	- gtk-doc comment
 * 23/8/11
 * 	- rewrite as a class
 * 7/12/12
 * 	- only invert real part of complex
 */

/*

	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 "unary.h"

typedef VipsUnary VipsInvert;
typedef VipsUnaryClass VipsInvertClass;

G_DEFINE_TYPE(VipsInvert, vips_invert, VIPS_TYPE_UNARY);

#define LOOP(TYPE, L) \
	{ \
		TYPE *restrict p = (TYPE *) in[0]; \
		TYPE *restrict q = (TYPE *) out; \
\
		for (x = 0; x < sz; x++) \
			q[x] = (L) -p[x]; \
	}

#define LOOPN(TYPE) \
	{ \
		TYPE *restrict p = (TYPE *) in[0]; \
		TYPE *restrict q = (TYPE *) out; \
\
		for (x = 0; x < sz; x++) \
			q[x] = -1 * p[x]; \
	}

#define LOOPC(TYPE) \
	{ \
		TYPE *restrict p = (TYPE *) in[0]; \
		TYPE *restrict q = (TYPE *) out; \
\
		for (x = 0; x < sz; x++) { \
			q[0] = -1 * p[0]; \
			q[1] = p[1]; \
\
			p += 2; \
			q += 2; \
		} \
	}

static void
vips_invert_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_UCHAR:
		LOOP(unsigned char, UCHAR_MAX);
		break;
	case VIPS_FORMAT_CHAR:
		LOOPN(signed char);
		break;
	case VIPS_FORMAT_USHORT:
		LOOP(unsigned short, USHRT_MAX);
		break;
	case VIPS_FORMAT_SHORT:
		LOOPN(signed short);
		break;
	case VIPS_FORMAT_UINT:
		LOOP(unsigned int, UINT_MAX);
		break;
	case VIPS_FORMAT_INT:
		LOOPN(signed int);
		break;

	case VIPS_FORMAT_FLOAT:
		LOOPN(float);
		break;
	case VIPS_FORMAT_DOUBLE:
		LOOPN(double);
		break;

	case VIPS_FORMAT_COMPLEX:
		LOOPC(float);
		break;
	case VIPS_FORMAT_DPCOMPLEX:
		LOOPC(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

/* Format doesn't change with invert.
 */
static const VipsBandFormat vips_invert_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_invert_class_init(VipsInvertClass *class)
{
	VipsObjectClass *object_class = (VipsObjectClass *) class;
	VipsArithmeticClass *aclass = VIPS_ARITHMETIC_CLASS(class);

	object_class->nickname = "invert";
	object_class->description = _("invert an image");

	aclass->process_line = vips_invert_buffer;

	vips_arithmetic_set_format_table(aclass, vips_invert_format_table);
}

static void
vips_invert_init(VipsInvert *invert)
{
}

/**
 * vips_invert: (method)
 * @in: input image
 * @out: (out): output image
 * @...: %NULL-terminated list of optional named arguments
 *
 * For unsigned formats, this operation calculates (max - @in), eg. (255 -
 * @in) for uchar. For signed and float formats, this operation calculates (-1
 * @in).
 *
 * For complex images, only the real part is inverted. See also vips_conj().
 *
 * See also: vips_linear().
 *
 * Returns: 0 on success, -1 on error
 */
int
vips_invert(VipsImage *in, VipsImage **out, ...)
{
	va_list ap;
	int result;

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

	return result;
}
