/* base class for all conversion operations
 *
 * properties:
 * 	- single output image
 */

/*

    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 <vips/internal.h>

#include "pconversion.h"

/** 
 * SECTION: conversion
 * @short_description: convert images in some way: change band format, change header, insert, extract, join
 * @see_also: <link linkend="libvips-resample">resample</link>
 * @stability: Stable
 * @include: vips/vips.h
 *
 * These operations convert an image in some way. They can be split into a two
 * main groups.
 *
 * The first set of operations change an image's format in some way. You
 * can change the band format (for example, cast to 32-bit unsigned
 * int), form complex images from real images, convert images to
 * matrices and back, change header fields, and a few others.
 *
 * The second group move pixels about in some way. You can flip, rotate,
 * extract, insert and join pairs of images in various ways.
 *
 */

/**
 * vips_composite:
 * @in: (array length=n) (transfer none): array of input images
 * @out: (out): output image
 * @n: number of input images
 * @mode: array of (@n - 1) #VipsBlendMode
 * @...: %NULL-terminated list of optional named arguments
 *
 * Optional arguments:
 *
 * * @compositing_space: #VipsInterpretation to composite in
 * * @premultiplied: %gboolean, images are already premultiplied
 * * @x: #VipsArrayInt, position of subimages
 * * @y: #VipsArrayInt, position of subimages
 *
 * Composite an array of images together. 
 *
 * Images are placed in a stack, with @in[0] at the bottom and @in[@n - 1] at
 * the top. Pixels are blended together working from the bottom upwards, with 
 * the blend mode at each step being set by the corresponding #VipsBlendMode
 * in @mode.
 *
 * Images are transformed to a compositing space before processing. This is
 * #VIPS_INTERPRETATION_sRGB, #VIPS_INTERPRETATION_B_W,
 * #VIPS_INTERPRETATION_RGB16, or #VIPS_INTERPRETATION_GREY16 
 * by default, depending on 
 * how many bands and bits the input images have. You can select any other 
 * space, such as #VIPS_INTERPRETATION_LAB or #VIPS_INTERPRETATION_scRGB.
 *
 * The output image is in the compositing space. It will always be 
 * #VIPS_FORMAT_FLOAT unless one of the inputs is #VIPS_FORMAT_DOUBLE, in 
 * which case the output will be double as well.
 *
 * Complex images are not supported.
 *
 * The output image will always have an alpha band. A solid alpha is
 * added to any input missing an alpha. 
 *
 * The images do not need to match in size or format. They will be expanded to
 * the smallest common size and format in the usual way. Images are positioned
 * using the @x and @y parameters, if set. 
 *
 * Image are normally treated as unpremultiplied, so this operation can be used
 * directly on PNG images. If your images have been through vips_premultiply(),
 * set @premultiplied. 
 *
 * See also: vips_insert().
 *
 * Returns: 0 on success, -1 on error
 */

/**
 * vips_composite2: (method)
 * @base: first input image
 * @overlay: second input image
 * @out: (out): output image
 * @mode: composite with this blend mode
 * @...: %NULL-terminated list of optional named arguments
 *
 * Optional arguments:
 *
 * * @compositing_space: #VipsInterpretation to composite in
 * * @premultiplied: %gboolean, images are already premultiplied
 * * @x: %gint, position of overlay
 * * @y: %gint, position of overlay
 *
 * Composite @overlay on top of @base with @mode. See vips_composite().
 *
 * Returns: 0 on success, -1 on error
 */

/**
 * VipsBlendMode:
 * @VIPS_BLEND_MODE_CLEAR: where the second object is drawn, the first is removed
 * @VIPS_BLEND_MODE_SOURCE: the second object is drawn as if nothing were below
 * @VIPS_BLEND_MODE_OVER: the image shows what you would expect if you held two semi-transparent slides on top of each other
 * @VIPS_BLEND_MODE_IN: the first object is removed completely, the second is only drawn where the first was
 * @VIPS_BLEND_MODE_OUT: the second is drawn only where the first isn't
 * @VIPS_BLEND_MODE_ATOP: this leaves the first object mostly intact, but mixes both objects in the overlapping area
 * @VIPS_BLEND_MODE_DEST: leaves the first object untouched, the second is discarded completely
 * @VIPS_BLEND_MODE_DEST_OVER: like OVER, but swaps the arguments
 * @VIPS_BLEND_MODE_DEST_IN: like IN, but swaps the arguments
 * @VIPS_BLEND_MODE_DEST_OUT: like OUT, but swaps the arguments
 * @VIPS_BLEND_MODE_DEST_ATOP: like ATOP, but swaps the arguments
 * @VIPS_BLEND_MODE_XOR: something like a difference operator
 * @VIPS_BLEND_MODE_ADD: a bit like adding the two images
 * @VIPS_BLEND_MODE_SATURATE: a bit like the darker of the two
 * @VIPS_BLEND_MODE_MULTIPLY: at least as dark as the darker of the two inputs
 * @VIPS_BLEND_MODE_SCREEN: at least as light as the lighter of the inputs
 * @VIPS_BLEND_MODE_OVERLAY: multiplies or screens colors, depending on the lightness
 * @VIPS_BLEND_MODE_DARKEN: the darker of each component
 * @VIPS_BLEND_MODE_LIGHTEN: the lighter of each component
 * @VIPS_BLEND_MODE_COLOUR_DODGE: brighten first by a factor second
 * @VIPS_BLEND_MODE_COLOUR_BURN: darken first by a factor of second
 * @VIPS_BLEND_MODE_HARD_LIGHT: multiply or screen, depending on lightness
 * @VIPS_BLEND_MODE_SOFT_LIGHT: darken or lighten, depending on lightness
 * @VIPS_BLEND_MODE_DIFFERENCE: difference of the two
 * @VIPS_BLEND_MODE_EXCLUSION: somewhat like DIFFERENCE, but lower-contrast
 *
 * The various Porter-Duff and PDF blend modes. See vips_composite(), 
 * for example.
 *
 * The Cairo docs have a nice explanation of all the blend modes:
 *
 * https://www.cairographics.org/operators
 *
 * The non-separable modes are not implemented.
 */

/** 
 * VipsAlign:
 * @VIPS_ALIGN_LOW: align low coordinate edge
 * @VIPS_ALIGN_CENTRE: align centre
 * @VIPS_ALIGN_HIGH: align high coordinate edge
 *
 * See vips_join() and so on.
 *
 * Operations like vips_join() need to be told whether to align images on the
 * low or high coordinate edge, or centre.
 *
 * See also: vips_join().
 */

/** 
 * VipsAngle:
 * @VIPS_ANGLE_D0: no rotate
 * @VIPS_ANGLE_D90: 90 degrees clockwise
 * @VIPS_ANGLE_D180: 180 degree rotate
 * @VIPS_ANGLE_D270: 90 degrees anti-clockwise
 *
 * See vips_rot() and so on.
 *
 * Fixed rotate angles.
 *
 * See also: vips_rot().
 */

/** 
 * VipsInteresting:
 * @VIPS_INTERESTING_NONE: do nothing
 * @VIPS_INTERESTING_CENTRE: just take the centre
 * @VIPS_INTERESTING_ENTROPY: use an entropy measure
 * @VIPS_INTERESTING_ATTENTION: look for features likely to draw human attention
 * @VIPS_INTERESTING_LOW: position the crop towards the low coordinate
 * @VIPS_INTERESTING_HIGH: position the crop towards the high coordinate
 * @VIPS_INTERESTING_ALL: everything is interesting
 *
 * Pick the algorithm vips uses to decide image "interestingness". This is used
 * by vips_smartcrop(), for example, to decide what parts of the image to
 * keep.
 *
 * #VIPS_INTERESTING_NONE and #VIPS_INTERESTING_LOW mean the same -- the
 * crop is positioned at the top or left. #VIPS_INTERESTING_HIGH positions at
 * the bottom or right. 
 *
 * See also: vips_smartcrop().
 */

/**
 * VipsCompassDirection:
 * @VIPS_COMPASS_DIRECTION_CENTRE: centre
 * @VIPS_COMPASS_DIRECTION_NORTH: north
 * @VIPS_COMPASS_DIRECTION_EAST: east
 * @VIPS_COMPASS_DIRECTION_SOUTH: south
 * @VIPS_COMPASS_DIRECTION_WEST: west
 * @VIPS_COMPASS_DIRECTION_NORTH_EAST: north-east
 * @VIPS_COMPASS_DIRECTION_SOUTH_EAST: south-east
 * @VIPS_COMPASS_DIRECTION_SOUTH_WEST: south-west
 * @VIPS_COMPASS_DIRECTION_NORTH_WEST: north-west
 *
 * A direction on a compass. Used for vips_gravity(), for example. 
 */

/**
 * VipsAngle45:
 * @VIPS_ANGLE45_D0: no rotate
 * @VIPS_ANGLE45_D45: 45 degrees clockwise 
 * @VIPS_ANGLE45_D90: 90 degrees clockwise
 * @VIPS_ANGLE45_D135: 135 degrees clockwise
 * @VIPS_ANGLE45_D180: 180 degrees 
 * @VIPS_ANGLE45_D225: 135 degrees anti-clockwise
 * @VIPS_ANGLE45_D270: 90 degrees anti-clockwise
 * @VIPS_ANGLE45_D315: 45 degrees anti-clockwise
 *
 * See vips_rot45() and so on.
 *
 * Fixed rotate angles.
 *
 * See also: vips_rot45().
 */

/** 
 * VipsExtend:
 * @VIPS_EXTEND_BLACK: extend with black (all 0) pixels
 * @VIPS_EXTEND_COPY: copy the image edges
 * @VIPS_EXTEND_REPEAT: repeat the whole image
 * @VIPS_EXTEND_MIRROR: mirror the whole image
 * @VIPS_EXTEND_WHITE: extend with white (all bits set) pixels
 * @VIPS_EXTEND_BACKGROUND: extend with colour from the @background property
 *
 * See vips_embed(), vips_conv(), vips_affine() and so on.
 *
 * When the edges of an image are extended, you can specify
 * how you want the extension done. 
 *
 * #VIPS_EXTEND_BLACK --- new pixels are black, ie. all bits are zero. 
 *
 * #VIPS_EXTEND_COPY --- each new pixel takes the value of the nearest edge
 * pixel
 *
 * #VIPS_EXTEND_REPEAT --- the image is tiled to fill the new area
 *
 * #VIPS_EXTEND_MIRROR --- the image is reflected and tiled to reduce hash
 * edges
 *
 * #VIPS_EXTEND_WHITE --- new pixels are white, ie. all bits are set
 *
 * #VIPS_EXTEND_BACKGROUND --- colour set from the @background property
 *
 * We have to specify the exact value of each enum member since we have to 
 * keep these frozen for back compat with vips7.
 *
 * See also: vips_embed().
 */

/** 
 * VipsDirection:
 * @VIPS_DIRECTION_HORIZONTAL: left-right 
 * @VIPS_DIRECTION_VERTICAL: top-bottom
 *
 * See vips_flip(), vips_join() and so on.
 *
 * Operations like vips_flip() need to be told whether to flip left-right or
 * top-bottom. 
 *
 * See also: vips_flip(), vips_join().
 */

G_DEFINE_ABSTRACT_TYPE( VipsConversion, vips_conversion, VIPS_TYPE_OPERATION );

static int
vips_conversion_build( VipsObject *object )
{
	VipsConversion *conversion = VIPS_CONVERSION( object );

#ifdef DEBUG
	printf( "vips_conversion_build: " );
	vips_object_print_name( object );
	printf( "\n" );
#endif /*DEBUG*/

	g_object_set( conversion, "out", vips_image_new(), NULL ); 

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

	return( 0 );
}

static void
vips_conversion_class_init( VipsConversionClass *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 = "conversion";
	vobject_class->description = _( "conversion operations" );
	vobject_class->build = vips_conversion_build;

	VIPS_ARG_IMAGE( class, "out", 2, 
		_( "Output" ), 
		_( "Output image" ),
		VIPS_ARGUMENT_REQUIRED_OUTPUT, 
		G_STRUCT_OFFSET( VipsConversion, out ) );
}

static void
vips_conversion_init( VipsConversion *conversion )
{
}

/* Called from iofuncs to init all operations in this dir. Use a plugin system
 * instead?
 */
void
vips_conversion_operation_init( void )
{
	extern GType vips_copy_get_type( void ); 
	extern GType vips_tile_cache_get_type( void ); 
	extern GType vips_line_cache_get_type( void ); 
	extern GType vips_sequential_get_type( void ); 
	extern GType vips_cache_get_type( void ); 
	extern GType vips_embed_get_type( void ); 
	extern GType vips_gravity_get_type( void ); 
	extern GType vips_flip_get_type( void ); 
	extern GType vips_insert_get_type( void ); 
	extern GType vips_join_get_type( void ); 
	extern GType vips_arrayjoin_get_type( void ); 
	extern GType vips_extract_area_get_type( void ); 
	extern GType vips_crop_get_type( void ); 
	extern GType vips_smartcrop_get_type( void ); 
	extern GType vips_extract_band_get_type( void ); 
	extern GType vips_replicate_get_type( void ); 
	extern GType vips_cast_get_type( void ); 
	extern GType vips_bandjoin_get_type( void ); 
	extern GType vips_bandjoin_const_get_type( void ); 
	extern GType vips_bandrank_get_type( void ); 
	extern GType vips_black_get_type( void ); 
	extern GType vips_rot_get_type( void ); 
	extern GType vips_rot45_get_type( void ); 
	extern GType vips_autorot_get_type( void ); 
	extern GType vips_ifthenelse_get_type( void ); 
	extern GType vips_switch_get_type( void ); 
	extern GType vips_recomb_get_type( void ); 
	extern GType vips_bandmean_get_type( void ); 
	extern GType vips_bandfold_get_type( void ); 
	extern GType vips_bandunfold_get_type( void ); 
	extern GType vips_flatten_get_type( void ); 
	extern GType vips_premultiply_get_type( void ); 
	extern GType vips_unpremultiply_get_type( void ); 
	extern GType vips_bandbool_get_type( void ); 
	extern GType vips_gaussnoise_get_type( void ); 
	extern GType vips_grid_get_type( void ); 
	extern GType vips_transpose3d_get_type( void ); 
	extern GType vips_scale_get_type( void ); 
	extern GType vips_wrap_get_type( void ); 
	extern GType vips_zoom_get_type( void ); 
	extern GType vips_subsample_get_type( void ); 
	extern GType vips_msb_get_type( void ); 
	extern GType vips_byteswap_get_type( void ); 
	extern GType vips_xyz_get_type( void ); 
	extern GType vips_falsecolour_get_type( void ); 
	extern GType vips_gamma_get_type( void ); 
	extern GType vips_composite_get_type( void ); 
	extern GType vips_composite2_get_type( void ); 

	vips_copy_get_type();
	vips_tile_cache_get_type(); 
	vips_line_cache_get_type(); 
	vips_sequential_get_type(); 
	vips_cache_get_type(); 
	vips_embed_get_type();
	vips_gravity_get_type();
	vips_flip_get_type();
	vips_insert_get_type();
	vips_join_get_type();
	vips_arrayjoin_get_type();
	vips_extract_area_get_type();
	vips_crop_get_type();
	vips_smartcrop_get_type();
	vips_extract_band_get_type();
	vips_replicate_get_type();
	vips_cast_get_type();
	vips_bandjoin_get_type();
	vips_bandjoin_const_get_type();
	vips_bandrank_get_type();
	vips_black_get_type();
	vips_rot_get_type();
	vips_rot45_get_type();
	vips_autorot_get_type();
	vips_ifthenelse_get_type();
	vips_switch_get_type(); 
	vips_recomb_get_type(); 
	vips_bandmean_get_type(); 
	vips_bandfold_get_type(); 
	vips_bandunfold_get_type(); 
	vips_flatten_get_type(); 
	vips_premultiply_get_type(); 
	vips_unpremultiply_get_type(); 
	vips_bandbool_get_type(); 
	vips_gaussnoise_get_type(); 
	vips_grid_get_type(); 
	vips_transpose3d_get_type(); 
	vips_scale_get_type(); 
	vips_wrap_get_type(); 
	vips_zoom_get_type(); 
	vips_subsample_get_type(); 
	vips_msb_get_type(); 
	vips_byteswap_get_type(); 
	vips_xyz_get_type(); 
	vips_falsecolour_get_type(); 
	vips_gamma_get_type(); 
	vips_composite_get_type(); 
	vips_composite2_get_type(); 
}