libvips/libsrc/conversion/im_black.c

124 lines
2.7 KiB
C

/* @(#) Make a black uchar image of a specified size. Sometimes useful for
* @(#) building masks.
* @(#) IMAGE out should nhave been set by the calling program
* @(#)
* @(#) int
* @(#) im_black(out, x, y, bands)
* @(#) IMAGE *out;
* @(#) int x, y;
* @(#) int bands;
* @(#)
* @(#) Returns 0 on success and -1 on error.
*
* Copyright: 1990, J. Cupitt
*
* Author: J. Cupitt
* Written on: 02/08/1990
* Modified on : 16/04/1991 by N. Dessipris to work on a line by line basis
* 15/8/94 JC
* - adapted for partials
* - ANSIfied
* - memory leaks fixed!
* 2/3/98 JC
* - IM_ANY added
*/
/*
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 <string.h>
#include <vips/vips.h>
#ifdef WITH_DMALLOC
#include <dmalloc.h>
#endif /*WITH_DMALLOC*/
/* Generate function --- just black out the region.
*/
static int
black_gen( REGION *or, void *seq, void *a, void *b )
{
int y;
int sz = IM_REGION_SIZEOF_LINE( or );
int ls = IM_REGION_LSKIP( or );
char *q = IM_REGION_ADDR( or, or->valid.left, or->valid.top );
for( y = 0; y < or->valid.height; y++, q += ls )
memset( q, 0, sz );
return( 0 );
}
/* Make a one band black uchar image of a specified size.
*/
int
im_black( IMAGE *out, int x, int y, int bands )
{
int type;
/* Check parameters.
*/
if( x < 0 || y < 0 || bands < 0 ) {
im_errormsg( "im_black: bad parameter" );
return( -1 );
}
/* Check descriptor.
*/
if( im_poutcheck( out ) )
return( -1 );
/* Set fields.
*/
if( bands == 1 )
type = IM_TYPE_B_W;
else
type = IM_TYPE_MULTIBAND;
im_initdesc( out,
x, y, bands,
IM_BBITS_BYTE, IM_BANDFMT_UCHAR, IM_CODING_NONE, type,
1.0, 1.0, 0, 0 );
/* Set hints - ANY is ok with us.
*/
if( im_demand_hint( out, IM_ANY, NULL ) )
return( -1 );
/* Generate image.
*/
if( im_generate( out, NULL, black_gen, NULL, NULL, NULL ) )
return( -1 );
return( 0 );
}