libvips/libsrc/arithmetic/im_remainder.c

/* @(#) Remainder after integer division
 *
 * 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 :-(
 */

/*

    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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

 */

/*

    These files are distributed with VIPS - http://www.vips.ecs.soton.ac.uk

 */

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif /*HAVE_CONFIG_H*/
#include <vips/intl.h>

#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#include <assert.h>

#include <vips/vips.h>
#include <vips/internal.h>

#ifdef WITH_DMALLOC
#include <dmalloc.h>
#endif /*WITH_DMALLOC*/

#define loop(TYPE) \
{\
	TYPE *p1 = (TYPE *) in[0];\
	TYPE *p2 = (TYPE *) in[1];\
	TYPE *q = (TYPE *) out;\
	\
	for( x = 0; x < sz; x++ )\
		if( p2[x] )\
			q[x] = p1[x] % p2[x];\
		else\
			q[x] = -1;\
}

static void
remainder_buffer( PEL **in, PEL *out, int width, IMAGE *im )
{
	int x;
	int sz = width * im->Bands;

        switch( im->BandFmt ) {
        case IM_BANDFMT_CHAR: 		loop( signed char ); break; 
        case IM_BANDFMT_UCHAR: 		loop( unsigned char ); break; 
        case IM_BANDFMT_SHORT: 		loop( signed short ); break; 
        case IM_BANDFMT_USHORT: 	loop( unsigned short ); break; 
        case IM_BANDFMT_INT: 		loop( signed int ); break; 
        case IM_BANDFMT_UINT: 		loop( unsigned int ); break; 

        default:
		assert( 0 );
        }
}

int 
im_remainder( IMAGE *in1, IMAGE *in2, IMAGE *out )
{	
	/* Basic checks.
	 */
	if( im_piocheck( in1, out ) || im_pincheck( in2 ) )
		return( -1 );
	if( in1->Xsize != in2->Xsize || in1->Ysize != in2->Ysize ) {
		im_error( "im_remainder", _( "not same size" ) );
		return( -1 );
	}
	if( in1->Bands != in2->Bands &&
		(in1->Bands != 1 && in2->Bands != 1) ) {
		im_error( "im_remainder", _( "not same number of bands" ) );
		return( -1 );
	}
	if( in1->Coding != IM_CODING_NONE || in2->Coding != IM_CODING_NONE ) {
		im_error( "im_remainder", _( "not uncoded" ) );
		return( -1 );
	}
	if( im_cp_descv( out, in1, in2, NULL ) )
		return( -1 );

	/* What number of bands will we write?
	 */
	out->Bands = IM_MAX( in1->Bands, in2->Bands );

	/* What output type will we write? Same as LHS type, except float
	 * and double become signed int.
	 */
	if( im_isfloat( in1 ) || im_iscomplex( in1 ) ) 
		out->BandFmt = IM_BANDFMT_INT;

	/* And process!
	 */
	if( im__cast_and_call( in1, in2, out, 
		(im_wrapmany_fn) remainder_buffer, NULL ) )
		return( -1 );

	/* Success!
	 */
	return( 0 );
}

/* Parameters saved here.
 */
typedef struct _Remainderconst {
	IMAGE *in;
	IMAGE *out;
	int n;	
	int *c;
} Remainderconst;

#define const1_loop(TYPE) \
{\
	TYPE *p = (TYPE *) in; \
	TYPE *q = (TYPE *) out; \
	\
	for( x = 0; x < sz; x++ ) \
		q[x] = p[x] % c; \
}

static void
remainderconst1_buffer( PEL *in, PEL *out, int width, Remainderconst *rc )
{
	IMAGE *im = rc->in;
	int sz = width * im->Bands;
	int c = rc->c[0];
	int x;

        switch( im->BandFmt ) {
        case IM_BANDFMT_CHAR: 		const1_loop( signed char ); break; 
        case IM_BANDFMT_UCHAR: 		const1_loop( unsigned char ); break; 
        case IM_BANDFMT_SHORT: 		const1_loop( signed short ); break; 
        case IM_BANDFMT_USHORT: 	const1_loop( unsigned short ); break; 
        case IM_BANDFMT_INT: 		const1_loop( signed int ); break; 
        case IM_BANDFMT_UINT: 		const1_loop( unsigned int ); break; 

        default:
		assert( 0 );
        }
}

#define const_loop(TYPE) \
{\
	TYPE *p = (TYPE *) in; \
	TYPE *q = (TYPE *) out; \
	\
	for( i = 0, x = 0; x < width; x++ ) \
		for( k = 0; k < b; k++, i++ ) \
			q[i] = p[i] % c[k]; \
}

static void
remainderconst_buffer( PEL *in, PEL *out, int width, Remainderconst *rc )
{
	IMAGE *im = rc->in;
	int b = im->Bands;
	int *c = rc->c;
	int i, x, k; 

        switch( im->BandFmt ) {
        case IM_BANDFMT_CHAR: 		const_loop( signed char ); break; 
        case IM_BANDFMT_UCHAR: 		const_loop( unsigned char ); break; 
        case IM_BANDFMT_SHORT: 		const_loop( signed short ); break; 
        case IM_BANDFMT_USHORT: 	const_loop( unsigned short ); break; 
        case IM_BANDFMT_INT: 		const_loop( signed int ); break; 
        case IM_BANDFMT_UINT: 		const_loop( unsigned int ); break; 

        default:
		assert( 0 );
        }
}

int 
im_remainderconst_vec( IMAGE *in, IMAGE *out, int n, double *c )
{
	Remainderconst *rc;
	int i;

	/* Basic checks.
	 */
	if( im_piocheck( in, out ) )
		return( -1 );
	if( in->Coding != IM_CODING_NONE ) {
		im_error( "im_remainderconst_vec", _( "not uncoded" ) );
		return( -1 );
	}
	if( n != 1 && n != in->Bands ) {
		im_error( "im_remainderconst_vec",
			_( "not 1 or %d elements in vector" ), in->Bands );
		return( -1 );
	}
	if( im_cp_desc( out, in ) )
		return( -1 );

	/* Make space for a little buffer.
	 */
	if( !(rc = IM_NEW( out, Remainderconst )) ||
		!(rc->c = IM_ARRAY( out, n, int )) )
		return( -1 );
	rc->in = in;
	rc->out = out;
	rc->n = n;
	for( i = 0; i < n; i++ ) {
		/* Cast down to int ... we pass in double for consistency with
		 * the other _vec functions.
		 */
		rc->c[i] = c[i];

		if( c[i] == 0 ) {
			im_error( "im_remainderconst_vec",
				_( "division by zero" ) );
			return( -1 );
		}
	}

	/* What output type will we write? Same as input type, except float
	 * and double become signed int.
	 */
	if( im_isfloat( in ) || im_iscomplex( in ) ) {
		IMAGE *t = im_open_local( out, "im_remainderconst:1", "p" );

		out->BandFmt = IM_BANDFMT_INT;
		out->Bbits = IM_BBITS_INT;
		if( !t || im_clip2fmt( in, t, out->BandFmt ) )
			return( -1 );

		rc->in = in = t;
	}

	if( n == 1 ) {
		if( im_wrapone( in, out, 
			(im_wrapone_fn) remainderconst1_buffer, rc, NULL ) )
			return( -1 );
	}
	else {
		if( im_wrapone( in, out, 
			(im_wrapone_fn) remainderconst_buffer, rc, NULL ) )
			return( -1 );
	}

	return( 0 );
}

int 
im_remainderconst( IMAGE *in, IMAGE *out, double c )
{
	return( im_remainderconst_vec( in, out, 1, &c ) );
}