libvips/libsrc/conversion/im_wrap.c

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2008-01-22 11:56:14 +01:00
/* Wrap an image so that what was the origin is at (x,y).
*
* int im_wrap( IMAGE *in, IMAGE *out, int x, int y );
*
* All functions return 0 on success and -1 on error
*
* Copyright: 2008, Nottingham Trent University
* Author: Tom Vajzovic
* Written on: 2008-01-15
*/
/*
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 <stdlib.h>
#include <string.h>
#include <vips/vips.h>
#ifdef WITH_DMALLOC
#include <dmalloc.h>
#endif /*WITH_DMALLOC*/
static int wrap( REGION *out, void *seq, void *a, void *b ){
#define IM ((IMAGE*)a)
#define X (((int*)b)[0])
#define Y (((int*)b)[1])
int left= out-> valid. left - X;
int top= out-> valid. top - Y;
int right= left + out-> valid. width;
int bot= top + out-> valid. height;
Rect source_a= {
left: IM-> Xsize + left,
top: IM-> Ysize + top,
width: 0 < right ? -left : out-> valid. width,
height: 0 < bot ? -top : out-> valid. height
};
Rect source_b= {
left: source_a. left,
top: 0 > top ? 0 : top,
width: source_a. width,
height: 0 > top ? bot : out-> valid. height
};
Rect source_c= {
left: 0 > left ? 0 : left,
top: source_a. top,
width: 0 > left ? right : out-> valid. width,
height: source_a. height
};
Rect source_d= {
left: source_c. left,
top: source_b. top,
width: source_c. width,
height: source_b. height
};
if( 0 > left ){
if( 0 > top && im_prepare_to( (REGION*)seq, out, & source_a,
out-> valid. left, out-> valid. top ))
return -1;
if( 0 < bot && im_prepare_to( (REGION*)seq, out, & source_b,
out-> valid. left, 0 > top ? Y : out-> valid. top ))
return -1;
}
if( 0 < right ){
if( 0 > top && im_prepare_to( (REGION*)seq, out, & source_c,
0 > left ? X : out-> valid. left, out-> valid. top ))
return -1;
if( 0 < bot && im_prepare_to( (REGION*)seq, out, & source_d,
0 > left ? X : out-> valid. left, 0 > top ? Y : out-> valid. top ))
return -1;
}
return 0;
#undef IM
#undef X
#undef Y
}
int im_wrap( IMAGE *in, IMAGE *out, int x, int y ){
if( im_piocheck( in, out ))
return -1;
{
int *params= IM_ARRAY( out, 2, int );
if( ! params )
return -1;
params[ 0 ]= x % in-> Xsize;
params[ 1 ]= y % in-> Ysize;
if( 0 > x )
params[ 0 ]+= in-> Xsize;
if( 0 > y )
params[ 1 ]+= in-> Ysize;
return im_cp_desc( out, in )
|| im_demand_hint( out, IM_THINSTRIP, in, NULL )
|| im_generate( out, im_start_one, wrap, im_stop_one, (void*)in, (void*)params );
}
}