libvips/libsrc/inplace/line_draw.c

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2007-08-29 18:23:50 +02:00
/* @(#) Line drawer. Faster than the old im_line. Any number of bands,
* @(#) any type including complex. Instead of passing a PEL value, pass a
* @(#) pointer to the pel value you wish to plot. The correct number of
* @(#) bytes must be there! Both start and end points should be in the
* @(#) image.
* @(#)
* @(#) int
* @(#) im_fastline( im, x1, y1, x2, y2, pel )
* @(#) IMAGE *im;
* @(#) int x1, x2, y1, y2;
* @(#) PEL *pel;
* @(#)
* @(#) As above, but rather than plotting a point, call a passed function
* @(#) for every point on the line. Up to three extra args passed down too.
* @(#) If the passed function returns non-zero, im_fastlineuser stops and
* @(#) returns non-zero. Start and end points may be outside the image -
* @(#) clipping is the responsibility of the user function.
* @(#)
* @(#) int
* @(#) im_fastlineuser( im, x1, y1, x2, y2, plot_fn,
* @(#) client1, client2, client3 )
* @(#) IMAGE *im;
* @(#) int x1, x2, y1, y2;
* @(#) int (*plot_fn)();
* @(#) void *client1, *client2, *client3;
* @(#)
* @(#) int
* @(#) plot_fn( im, x, y, client1, client2, client3 )
* @(#) IMAGE *im;
* @(#) int x, y;
* @(#) void *client1, *client2, *client3;
* @(#)
*
* Copyright: J. Cupitt
* Written: 15/06/1992
* Modified : 22/10/92 - clipping constraints changed
* 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*/
#define SWAP(A,B) {int t; t = (A); (A) = (B); (B) = t;}
/* Draw a line on a image.
*/
int
im_fastline( IMAGE *im, int x1, int y1, int x2, int y2, PEL *pel )
{
int es = im->Bbits >> 3;
int ps = es * im->Bands;
int ls = ps * im->Xsize;
PEL *p;
int x, y, dx, dy;
int err;
int b;
if( im_rwcheck( im ) )
return( -1 );
/* Check coordinates in range.
*/
if( x1 > im->Xsize || x1 < 0 ||
y1 > im->Ysize || y1 < 0 ||
x2 > im->Xsize || x2 < 0 ||
y2 > im->Ysize || y2 < 0 ) {
im_errormsg( "im_fastline: invalid line cooordinates" );
return( -1 );
}
/* Find offsets.
*/
dx = x2 - x1;
dy = y2 - y1;
/* Swap endpoints to reduce number of cases.
*/
if( abs( dx ) >= abs( dy ) && dx < 0 ) {
/* Swap to get all x greater or equal cases going to the
* right. Do diagonals here .. just have up and right and down
* and right now.
*/
SWAP( x1, x2 );
SWAP( y1, y2 );
}
else if( abs( dx ) < abs( dy ) && dy < 0 ) {
/* Swap to get all y greater cases going down the screen.
*/
SWAP( x1, x2 );
SWAP( y1, y2 );
}
/* Recalculate dx, dy.
*/
dx = x2 - x1;
dy = y2 - y1;
/* Start point and offset.
*/
x = x1;
y = y1;
p = (PEL *) im->data + x * ps + y * ls;
/* Plot point macro.
*/
#define PLOT \
for( b = 0; b < ps; b++ ) \
p[b] = pel[b];
/* Special case: zero width and height is single point.
*/
if( dx == 0 && dy == 0 ) {
PLOT;
}
/* Special case vertical and horizontal lines for speed.
*/
else if( dx == 0 ) {
/* Vertical line going down.
*/
for( ; y <= y2; y++ ) {
PLOT;
p += ls;
}
}
else if( dy == 0 ) {
/* Horizontal line to the right.
*/
for( ; x <= x2; x++ ) {
PLOT;
p += ps;
}
}
/* Special case diagonal lines.
*/
else if( abs( dy ) == abs( dx ) && dy > 0 ) {
/* Diagonal line going down and right.
*/
for( ; x <= x2; x++ ) {
PLOT;
p += ps + ls;
}
}
else if( abs( dy ) == abs( dx ) && dy < 0 ) {
/* Diagonal line going up and right.
*/
for( ; x <= x2; x++ ) {
PLOT;
p += ps - ls;
}
}
else if( abs( dy ) < abs( dx ) && dy > 0 ) {
/* Between -45 and 0 degrees.
*/
for( err = 0; x <= x2; x++ ) {
PLOT;
p += ps;
err += dy;
if( err >= dx ) {
err -= dx;
p += ls;
}
}
}
else if( abs( dy ) < abs( dx ) && dy < 0 ) {
/* Between 0 and 45 degrees.
*/
for( err = 0; x <= x2; x++ ) {
PLOT;
p += ps;
err -= dy;
if( err >= dx ) {
err -= dx;
p -= ls;
}
}
}
else if( abs( dy ) > abs( dx ) && dx > 0 ) {
/* Between -45 and -90 degrees.
*/
for( err = 0; y <= y2; y++ ) {
PLOT;
p += ls;
err += dx;
if( err >= dy ) {
err -= dy;
p += ps;
}
}
}
else if( abs( dy ) > abs( dx ) && dx < 0 ) {
/* Between -90 and -135 degrees.
*/
for( err = 0; y <= y2; y++ ) {
PLOT;
p += ls;
err -= dx;
if( err >= dy ) {
err -= dy;
p -= ps;
}
}
}
else
error_exit( "internal error #9872659823475982375" );
im_invalidate( im );
return( 0 );
}
/* Draw a line on a image with a user plot function. We do no clipping: the
* user function should check ranges for each pixel when it is called.
*/
int
im_fastlineuser( IMAGE *im,
int x1, int y1, int x2, int y2,
int (*fn)(), void *client1, void *client2, void *client3 )
{
int x, y, dx, dy;
int err;
if( im_rwcheck( im ) )
return( -1 );
/* Find offsets.
*/
dx = x2 - x1;
dy = y2 - y1;
/* Swap endpoints to reduce number of cases.
*/
if( abs( dx ) >= abs( dy ) && dx < 0 ) {
/* Swap to get all x greater or equal cases going to the
* right. Do diagonals here .. just have up and right and down
* and right now.
*/
SWAP( x1, x2 );
SWAP( y1, y2 );
}
else if( abs( dx ) < abs( dy ) && dy < 0 ) {
/* Swap to get all y greater cases going down the screen.
*/
SWAP( x1, x2 );
SWAP( y1, y2 );
}
/* Recalculate dx, dy.
*/
dx = x2 - x1;
dy = y2 - y1;
/* Start point and offset.
*/
x = x1;
y = y1;
/* Special case: zero width and height is single point.
*/
if( dx == 0 && dy == 0 ) {
if( fn( im, x, y, client1, client2, client3 ) )
return( 1 );
}
/* Special case vertical and horizontal lines for speed.
*/
else if( dx == 0 ) {
/* Vertical line going down.
*/
for( ; y <= y2; y++ ) {
if( fn( im, x, y, client1, client2, client3 ) )
return( 1 );
}
}
else if( dy == 0 ) {
/* Horizontal line to the right.
*/
for( ; x <= x2; x++ ) {
if( fn( im, x, y, client1, client2, client3 ) )
return( 1 );
}
}
/* Special case diagonal lines.
*/
else if( abs( dy ) == abs( dx ) && dy > 0 ) {
/* Diagonal line going down and right.
*/
for( ; x <= x2; x++, y++ ) {
if( fn( im, x, y, client1, client2, client3 ) )
return( 1 );
}
}
else if( abs( dy ) == abs( dx ) && dy < 0 ) {
/* Diagonal line going up and right.
*/
for( ; x <= x2; x++, y-- ) {
if( fn( im, x, y, client1, client2, client3 ) )
return( 1 );
}
}
else if( abs( dy ) < abs( dx ) && dy > 0 ) {
/* Between -45 and 0 degrees.
*/
for( err = 0; x <= x2; x++ ) {
if( fn( im, x, y, client1, client2, client3 ) )
return( 1 );
err += dy;
if( err >= dx ) {
err -= dx;
y++;
}
}
}
else if( abs( dy ) < abs( dx ) && dy < 0 ) {
/* Between 0 and 45 degrees.
*/
for( err = 0; x <= x2; x++ ) {
if( fn( im, x, y, client1, client2, client3 ) )
return( 1 );
err -= dy;
if( err >= dx ) {
err -= dx;
y--;
}
}
}
else if( abs( dy ) > abs( dx ) && dx > 0 ) {
/* Between -45 and -90 degrees.
*/
for( err = 0; y <= y2; y++ ) {
if( fn( im, x, y, client1, client2, client3 ) )
return( 1 );
err += dx;
if( err >= dy ) {
err -= dy;
x++;
}
}
}
else if( abs( dy ) > abs( dx ) && dx < 0 ) {
/* Between -90 and -135 degrees.
*/
for( err = 0; y <= y2; y++ ) {
if( fn( im, x, y, client1, client2, client3 ) )
return( 1 );
err -= dx;
if( err >= dy ) {
err -= dy;
x--;
}
}
}
else
error_exit( "internal error #9872659823475982375" );
im_invalidate( im );
return( 0 );
}
/* Draw a set of lines with an ink and a mask. A non-inplace operation, handy
* for nip2.
*/
int
im_lineset( IMAGE *in, IMAGE *out, IMAGE *mask, IMAGE *ink,
int n, int *x1v, int *y1v, int *x2v, int *y2v )
{
Rect mask_rect;
int i;
if( mask->Bands != 1 || mask->BandFmt != IM_BANDFMT_UCHAR ||
mask->Coding != IM_CODING_NONE ) {
im_error( "im_lineset",
_( "mask image not 1 band 8 bit uncoded" ) );
return( -1 );
}
if( ink->Bands != in->Bands || ink->BandFmt != in->BandFmt ||
ink->Coding != in->Coding ) {
im_error( "im_lineset",
_( "ink image does not match in image" ) );
return( -1 );
}
if( ink->Xsize != 1 || ink->Ysize != 1 ) {
im_error( "im_lineset", _( "ink image not 1x1 pixels" ) );
return( -1 );
}
/* Copy the image thenm fastline to it ... this will render to a "t"
* usually.
*/
if( im_incheck( mask ) ||
im_incheck( ink ) ||
im_copy( in, out ) )
return( -1 );
mask_rect.left = mask->Xsize / 2;
mask_rect.top = mask->Ysize / 2;
mask_rect.width = mask->Xsize;
mask_rect.height = mask->Ysize;
for( i = 0; i < n; i++ ) {
if( im_fastlineuser( out, x1v[i], y1v[i], x2v[i], y2v[i],
im_plotmask, ink->data, mask->data, &mask_rect ) )
return( -1 );
}
return( 0 );
}