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/*
Copyright (C) 2017-2020, Dirk Krause
SPDX-License-Identifier: BSD-3-Clause
*/

/*
	WARNING: This file was generated by the dkct program (see
	http://dktools.sourceforge.net/ for details).
	Changes you make here will be lost if dkct is run again!
	You should modify the original source and run dkct on it.
	Original source: dk4pxres.ctr
*/

#ifndef DK4PXRES_H_INCLUDED
/** Avoid multiple inclusions. */
#define DK4PXRES_H_INCLUDED 1


#line 9 "dk4pxres.ctr"

/**	@file	dk4pxres.h	Pixel resampling.
*/

#ifndef	DK4CONF_H_INCLUDED
#if DK4_BUILDING_DKTOOLS4
#include "dk4conf.h"
#else
#include <dktools-4/dk4conf.h>
#endif
#endif

#ifndef	DK4PXBIT_H_INCLUDED
#if DK4_BUILDING_DKTOOLS4
#include "dk4pxbit.h"
#else
#include <dktools-4/dk4pxbit.h>
#endif
#endif

/**	Structure to resample pixels.
*/
typedef struct {
	unsigned long	nom;		/**< Nominator in scale factor. */
	unsigned long	denom;		/**< Denominator in scale factor. */
	unsigned long	denom2;		/**< Half of the denominator. */
} dk4_px_resample_t;

#ifdef	__cplusplus
extern "C" {
#endif

/**	Initialize resampler structure.
	@param	pxrptr	Resampler structure to initialize.
*/

void
dk4pxres_init(dk4_px_resample_t *pxrptr);


/**	Set up resample structure for conversions.
	@param	pxrptr	Resample structure to set up.
	@param	ibits	Number of input bits.
	@param	obits	Number of output (result) bits.
	@return	1 on success, 0 on error.
*/

int
dk4pxres_setup(
	dk4_px_resample_t	*pxrptr,
	size_t				 ibits,
	size_t				 obits
);


/**	Set up resample structure for conversions for unusual maxval values.
	Input is from a range with unusual maxval, output is prepared
	for a given bit depth.
	@param	pxrptr	Resample structure to set up.
	@param	imaxval	Maximum value for input pixel data.
	@param	obits	Number of output (result) bits.
	@return	1 on success, 0 on error.
*/

int
dk4pxres_setup_from_maxval(
	dk4_px_resample_t	*pxrptr,
	dk4_px_t			 imaxval,
	size_t				 obits
);


/**	Set up resample structure for conversions for unusual maxval values.
	Input has a given bit depth, output must be in the range up to s
	specified maxval.
	@param	pxrptr	Resample structure to set up.
	@param	ibits	Input bit depth.
	@param	omaxval	Maximum value for output pixel data.
	@return	1 on success, 0 on error.
*/
int
dk4pxres_setup_to_maxval(
	dk4_px_resample_t	*pxrptr,
	size_t				 ibits,
	dk4_px_t			 omaxval
);


/**	Resample pixel component from old bit width to new bit width.
	@param	pxrptr	Resample structure to use.
	@param	in		Component value in old bit depth.
	@return	Resampling result (component value in new bit depth).
*/

dk4_px_t
dk4pxres_get(
	dk4_px_resample_t const	*pxrptr,
	dk4_px_t				 in
);


/**	Check whether a component value can be resampled without quality loss.
	@param	pxrptr	Resample structure to use.
	@param	in		Component value in old bit depth.
	@return	1 on success (no division remainder), 0 on error
	(skipped division remainder results in quality loss).
*/

int
dk4pxres_check(
	dk4_px_resample_t const	*pxrptr,
	dk4_px_t				 in
);


/**	Resample multiple values to new bit depth.
	@param	dptr	Array containing values to resample, results on output.
	@param	dsz		Number of elements in array.
	@param	pxrptr	Resample structure to use.
	@return	1 on success, 0 on error.
*/

int
dk4pxres_multiple(
	dk4_px_t				*dptr,
	size_t					 dsz,
	dk4_px_resample_t const	*pxrptr
);


#ifdef	__cplusplus
}
#endif


/* vim: set ai sw=4 ts=4 : */



#endif