libvips/libsrc/inplace/plot_point.c

120 lines
2.5 KiB
C

/* @(#) Read a pel out of an image and into a buffer, plot a pel back into
* @(#) the image again.
* @(#)
* @(#) int
* @(#) im_readpoint( IMAGE *im, int x, int y, PEL *ink )
* @(#)
* @(#) int
* @(#) im_plotpoint( IMAGE *im, int x, int y, PEL *ink )
* @(#)
*
* Copyright: J. Cupitt
* Written: 15/06/1992
* 22/7/93 JC
* - im_incheck() added
* 16/8/94 JC
* - im_incheck() changed to im_makerw()
* 5/12/06
* - im_invalidate() after paint
*/
/*
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 <vips/vips.h>
#ifdef WITH_DMALLOC
#include <dmalloc.h>
#endif /*WITH_DMALLOC*/
/* Read a colour from an image.
*/
int
im_readpoint( IMAGE *im, int x, int y, PEL *pel )
{
int es = im->Bbits >> 3;
int ps = es * im->Bands;
int ls = ps * im->Xsize;
int b;
PEL *from;
if( im_rwcheck( im ) )
return( -1 );
/* Check coordinates in range.
*/
if( x > im->Xsize || x < 0 || y > im->Ysize || y < 0 ) {
im_errormsg( "im_readpoint: invalid cooordinates" );
return( 1 );
}
/* Suck single pixel.
*/
from = (PEL *) im->data + x * ps + y * ls;
for( b = 0; b < ps; b++ )
*pel++ = *from++;
return( 0 );
}
/* Plot a point in an image.
*/
int
im_plotpoint( IMAGE *im, int x, int y, PEL *pel )
{
int es = im->Bbits >> 3;
int ps = es * im->Bands;
int ls = ps * im->Xsize;
int b;
PEL *to;
if( im_rwcheck( im ) )
return( -1 );
/* Check coordinates in range.
*/
if( x > im->Xsize || x < 0 || y > im->Ysize || y < 0 )
return( 0 );
/* Paint single pixel.
*/
to = (PEL *) im->data + x * ps + y * ls;
for( b = 0; b < ps; b++ )
*to++ = *pel++;
im_invalidate( im );
return( 0 );
}