libvips/libsrc/inplace/im_flood.c

422 lines
8.7 KiB
C

/* int im_flood( IMAGE *im, int x, int y, PEL *ink, Rect *dout )
*
* Flood fill from point (x,y) with colour ink. Flood up to boundary == ink.
* Any type, any number of bands, IM_CODING_LABQ too. Returns the bounding box
* of the modified pixels in dout, whether it succeeds or not.
*
* Currently a rather inefficient pixel-based algorithm, should put something
* better in, really. Speed isn't likely to be a problem, except for very
* large images.
*
* JC 30/8/97
* - VIPSified, cleaned up, from "John Robinson's prog to fill
* enclosed areas"
* - something Kirk gave me, so thanks John
* JC 1/10/97
* - swapped inner memcmp/cpy for a loop ... faster for small pixels
* 13/7/02 JC
* - im_flood_blob() added
* 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 <string.h>
#include <vips/vips.h>
#ifdef WITH_DMALLOC
#include <dmalloc.h>
#endif /*WITH_DMALLOC*/
/* Size of a point buffer. We allocate a list of these to hold points we need
* to visit.
*/
#define PBUFSIZE (1000)
/* An xy position.
*/
typedef struct {
int x, y;
} Point;
/* A buffer of points, and how many of them have been used. When full, alloc a
* new buffer, and link it on.
*/
typedef struct _Buffer {
struct _Buffer *next;
int n;
Point points[PBUFSIZE];
} Buffer;
/* Our state.
*/
typedef struct {
/* Parameters.
*/
IMAGE *im;
int x, y;
PEL *ink; /* Copy of ink param */
Rect *dout; /* Write dirty here at end */
/* Derived stuff.
*/
PEL *edge; /* Boundary colour */
int equal; /* Fill to == edge, or != edge */
int ps; /* sizeof( one pel ) */
int ls; /* sizeof( one line ) */
int left, right; /* Area will fill within */
int top, bottom;
Rect dirty; /* Bounding box of pixels we have changed */
/* Two buffers of points which we know need checking.
*/
Buffer *buf1;
Buffer *buf2;
} State;
/* Alloc a new buffer.
*/
static Buffer *
build_buffer( void )
{
Buffer *buf = IM_NEW( NULL, Buffer );
if( !buf )
return( NULL );
buf->next = NULL;
buf->n = 0;
return( buf );
}
/* Free a chain of buffers.
*/
static void
free_buffer( Buffer *buf )
{
IM_FREE( buf->next );
im_free( buf );
}
/* Free a state.
*/
static void
free_state( State *st )
{
/* Write dirty back to caller.
*/
if( st->dout )
*st->dout = st->dirty;
/* Free our stuff.
*/
IM_FREE( st->ink );
IM_FREEF( free_buffer, st->buf1 );
IM_FREEF( free_buffer, st->buf2 );
im_free( st );
}
/* Build a state.
*/
static State *
build_state( IMAGE *im, int x, int y, PEL *ink, Rect *dout )
{
State *st = IM_NEW( NULL, State );
if( !st )
return( NULL );
st->im = im;
st->x = x;
st->y = y;
st->ink = NULL;
st->dout = dout;
st->ps = IM_IMAGE_SIZEOF_PEL( im );
st->ls = IM_IMAGE_SIZEOF_LINE( im );
st->buf1 = NULL;
st->buf2 = NULL;
st->left = 0;
st->top = 0;
st->right = im->Xsize;
st->bottom = im->Ysize;
st->dirty.left = x;
st->dirty.top = y;
st->dirty.width = 0;
st->dirty.height = 0;
if( !(st->ink = (PEL *) im_malloc( NULL, st->ps )) ||
!(st->edge = (PEL *) im_malloc( NULL, st->ps )) ||
!(st->buf1 = build_buffer()) ||
!(st->buf2 = build_buffer()) ) {
free_state( st );
return( NULL );
}
memcpy( st->ink, ink, st->ps );
return( st );
}
/* Add xy to buffer, move buffer on on overflow.
*/
#define ADD( BUF, X, Y ) { \
BUF->points[BUF->n].x = X; \
BUF->points[BUF->n].y = Y; \
BUF->n++; \
if( BUF->n == PBUFSIZE ) { \
if( !BUF->next ) { \
if( !(BUF->next = build_buffer()) ) \
return( -1 ); \
} \
BUF = BUF->next; \
BUF->n = 0; \
} \
}
/* If point != edge, add it to out.
*/
#define ADDIFNOTEDGE( P, X, Y ) { \
PEL *p1 = (P); \
\
for( j = 0; j < st->ps; j++ ) \
if( p1[j] != st->edge[j] ) { \
ADD( out, X, Y ); \
break; \
} \
}
/* If point == edge, add it to out.
*/
#define ADDIFEDGE( P, X, Y ) { \
PEL *p1 = (P); \
\
for( j = 0; j < st->ps; j++ ) \
if( p1[j] != st->edge[j] ) \
break; \
if( j == st->ps ) \
ADD( out, X, Y ); \
}
/* Read points to fill from in, write new points to out.
*/
static int
dofill( State *st, Buffer *in, Buffer *out )
{
int i, j;
/* Clear output buffer.
*/
out->n = 0;
/* Loop over chain of input buffers.
*/
for(;;) {
/* Loop for this buffer.
*/
for( i = 0; i < in->n; i++ ) {
/* Find this pixel.
*/
int x = in->points[i].x;
int y = in->points[i].y;
PEL *p = (PEL *) st->im->data + x*st->ps + y*st->ls;
/* Is it still not fore? May have been set by us
* earlier.
*/
for( j = 0; j < st->ps; j++ )
if( p[j] != st->ink[j] )
break;
if( j == st->ps )
continue;
/* Set this pixel.
*/
for( j = 0; j < st->ps; j++ )
p[j] = st->ink[j];
/* Changes bb of dirty area?
*/
if( x < st->dirty.left ) {
st->dirty.left -= x;
st->dirty.width += x;
}
else if( x > st->dirty.left + st->dirty.width )
st->dirty.width += x;
if( y < st->dirty.top ) {
st->dirty.top -= y;
st->dirty.height += y;
}
else if( y > st->dirty.top + st->dirty.height )
st->dirty.height += y;
/* Propogate to neighbours.
*/
if( st->equal ) {
if( x < st->right - 1 )
ADDIFEDGE( p + st->ps, x + 1, y );
if( x > st->left )
ADDIFEDGE( p - st->ps, x - 1, y );
if( y < st->bottom - 1 )
ADDIFEDGE( p + st->ls, x, y + 1 );
if( y > st->top )
ADDIFEDGE( p - st->ls, x, y - 1 );
}
else {
if( x < st->right - 1 )
ADDIFNOTEDGE( p + st->ps, x + 1, y );
if( x > st->left )
ADDIFNOTEDGE( p - st->ps, x - 1, y );
if( y < st->bottom - 1 )
ADDIFNOTEDGE( p + st->ls, x, y + 1 );
if( y > st->top )
ADDIFNOTEDGE( p - st->ls, x, y - 1 );
}
}
if( in->n == PBUFSIZE )
/* Buffer full ... must be another one.
*/
in = in->next;
else
break;
}
return( 0 );
}
int
im_flood( IMAGE *im, int x, int y, PEL *ink, Rect *dout )
{
State *st;
Buffer *in, *out, *t;
PEL *p;
if( im_rwcheck( im ) )
return( -1 );
if( im->Coding != IM_CODING_NONE && im->Coding != IM_CODING_LABQ ) {
im_error( "im_flood", _( "uncoded or IM_CODING_LABQ only" ) );
return( -1 );
}
if( !(st = build_state( im, x, y, ink, dout )) )
return( -1 );
/* Test start pixel ... nothing to do?
*/
p = (PEL *) im->data + x*st->ps + y*st->ls;
if( memcmp( p, ink, st->ps ) == 0 ) {
free_state( st );
return( 0 );
}
/* Flood to != ink.
*/
memcpy( st->edge, ink, st->ps );
st->equal = 0;
/* Add start pixel to the work buffer, and loop.
*/
ADD( st->buf1, x, y )
for( in = st->buf1, out = st->buf2;
in->n > 0; t = in, in = out, out = t )
if( dofill( st, in, out ) ) {
free_state( st );
return( -1 );
}
free_state( st );
im_invalidate( im );
return( 0 );
}
int
im_flood_blob( IMAGE *im, int x, int y, PEL *ink, Rect *dout )
{
State *st;
Buffer *in, *out, *t;
PEL *p;
if( im_rwcheck( im ) )
return( -1 );
if( im->Coding != IM_CODING_NONE && im->Coding != IM_CODING_LABQ ) {
im_error( "im_flood", _( "uncoded or IM_CODING_LABQ only" ) );
return( -1 );
}
if( !(st = build_state( im, x, y, ink, dout )) )
return( -1 );
/* Edge is set by colour of start pixel.
*/
p = (PEL *) im->data + x*st->ps + y*st->ls;
memcpy( st->edge, p, st->ps );
st->equal = 1;
/* Add start pixel to the work buffer, and loop.
*/
ADD( st->buf1, x, y )
for( in = st->buf1, out = st->buf2;
in->n > 0; t = in, in = out, out = t )
if( dofill( st, in, out ) ) {
free_state( st );
return( -1 );
}
free_state( st );
im_invalidate( im );
return( 0 );
}
/* A Flood blob we can call from nip. Grr! Should be a way to wrap these
* automatically. Maybe nip could do it if it seems a RW image argument?
*/
int
im_flood_blob_copy( IMAGE *in, IMAGE *out, int x, int y, PEL *ink )
{
IMAGE *t;
if( !(t = im_open_local( out, "im_flood_blob_copy", "t" )) ||
im_copy( in, t ) ||
im_flood_blob( t, x, y, ink, NULL ) ||
im_copy( t, out ) )
return( -1 );
return( 0 );
}