1131 lines
26 KiB
C++
1131 lines
26 KiB
C++
/* Copyright (C) 2001-2015 Peter Selinger.
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* This file is part of Potrace. It is free software and it is covered
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* by the GNU General Public License. See the file COPYING for details. */
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/* Routines for manipulating bitmaps, including reading pbm files. */
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#ifdef HAVE_CONFIG_H
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#include <config.h>
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#endif
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#include <stdio.h>
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#include "bitmap.h"
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#include "bitops.h"
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#define INTBITS ( 8 * sizeof(int) )
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static int bm_readbody_bmp( FILE* f, double threshold, potrace_bitmap_t** bmp );
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static int bm_readbody_pnm( FILE* f, double threshold, potrace_bitmap_t** bmp, int magic );
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/* ---------------------------------------------------------------------- */
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/* routines for reading pnm streams */
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/* read next character after whitespace and comments. Return EOF on
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* end of file or error. */
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static int fgetc_ws( FILE* f )
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{
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int c;
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while( 1 )
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{
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c = fgetc( f );
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if( c=='#' )
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{
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while( 1 )
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{
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c = fgetc( f );
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if( c=='\n' || c==EOF )
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{
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break;
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}
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}
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}
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/* space, tab, line feed, carriage return, form-feed */
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if( c!=' ' && c!='\t' && c!='\r' && c!='\n' && c!=12 )
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{
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return c;
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}
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}
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}
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/* skip whitespace and comments, then read a non-negative decimal
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* number from a stream. Return -1 on EOF. Tolerate other errors (skip
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* bad characters). Do not the read any characters following the
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* number (put next character back into the stream) */
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static int readnum( FILE* f )
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{
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int c;
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int acc;
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/* skip whitespace and comments */
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while( 1 )
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{
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c = fgetc_ws( f );
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if( c==EOF )
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{
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return -1;
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}
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if( c>='0' && c<='9' )
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{
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break;
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}
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}
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/* first digit is already in c */
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acc = c - '0';
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while( 1 )
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{
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c = fgetc( f );
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if( c==EOF )
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{
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break;
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}
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if( c<'0' || c>'9' )
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{
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ungetc( c, f );
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break;
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}
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acc *= 10;
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acc += c - '0';
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}
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return acc;
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}
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/* similar to readnum, but read only a single 0 or 1, and do not read
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* any characters after it. */
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static int readbit( FILE* f )
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{
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int c;
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/* skip whitespace and comments */
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while( 1 )
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{
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c = fgetc_ws( f );
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if( c==EOF )
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{
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return -1;
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}
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if( c>='0' && c<='1' )
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{
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break;
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}
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}
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return c - '0';
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}
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/* ---------------------------------------------------------------------- */
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/* read a PNM stream: P1-P6 format (see pnm(5)), or a BMP stream, and
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* convert the output to a bitmap. Return bitmap in *bmp. Return 0 on
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* success, -1 on error with errno set, -2 on bad file format (with
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* error message in bm_read_error), and 1 on premature end of file, -3
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* on empty file (including files which contain only whitespace and
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* comments), -4 if wrong magic number. If the return value is >=0,
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* bmp is valid. */
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const char* bm_read_error = NULL;
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int bm_read( FILE* f, double threshold, potrace_bitmap_t** bmp )
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{
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int magic[2];
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/* read magic number. We ignore whitespace and comments before the
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* magic, for the benefit of concatenated files in P1-P3 format.
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* Multiple P1-P3 images in a single file are not formally allowed
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* by the PNM standard, but there is no harm in being lenient. */
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magic[0] = fgetc_ws( f );
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if( magic[0] == EOF )
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{
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return -3;
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}
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magic[1] = fgetc( f );
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if( magic[0] == 'P' && magic[1] >= '1' && magic[1] <= '6' )
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{
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return bm_readbody_pnm( f, threshold, bmp, magic[1] );
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}
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if( magic[0] == 'B' && magic[1] == 'M' )
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{
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return bm_readbody_bmp( f, threshold, bmp );
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}
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return -4;
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}
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/* ---------------------------------------------------------------------- */
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/* read PNM format */
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/* read PNM stream after magic number. Return values as for bm_read */
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static int bm_readbody_pnm( FILE* f, double threshold, potrace_bitmap_t** bmp, int magic )
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{
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potrace_bitmap_t* bm;
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int x, y, i, b, b1, sum;
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int bpr; /* bytes per row (as opposed to 4*bm->c) */
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int w, h, max;
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bm = NULL;
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w = readnum( f );
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if( w<0 )
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{
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goto format_error;
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}
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h = readnum( f );
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if( h<0 )
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{
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goto format_error;
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}
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/* allocate bitmap */
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bm = bm_new( w, h );
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if( !bm )
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{
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return -1;
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}
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/* zero it out */
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bm_clear( bm, 0 );
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switch( magic )
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{
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default:
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/* not reached */
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goto format_error;
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case '1':
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/* read P1 format: PBM ascii */
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for( y = h - 1; y>=0; y-- )
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{
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for( x = 0; x<w; x++ )
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{
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b = readbit( f );
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if( b<0 )
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{
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goto eof;
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}
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BM_UPUT( bm, x, y, b );
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}
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}
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break;
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case '2':
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/* read P2 format: PGM ascii */
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max = readnum( f );
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if( max<1 )
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{
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goto format_error;
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}
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for( y = h - 1; y>=0; y-- )
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{
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for( x = 0; x<w; x++ )
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{
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b = readnum( f );
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if( b<0 )
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{
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goto eof;
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}
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BM_UPUT( bm, x, y, b > threshold * max ? 0 : 1 );
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}
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}
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break;
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case '3':
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/* read P3 format: PPM ascii */
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max = readnum( f );
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if( max<1 )
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{
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goto format_error;
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}
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for( y = h - 1; y>=0; y-- )
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{
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for( x = 0; x<w; x++ )
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{
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sum = 0;
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for( i = 0; i<3; i++ )
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{
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b = readnum( f );
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if( b<0 )
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{
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goto eof;
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}
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sum += b;
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}
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BM_UPUT( bm, x, y, sum > 3 * threshold * max ? 0 : 1 );
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}
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}
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break;
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case '4':
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/* read P4 format: PBM raw */
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b = fgetc( f ); /* read single white-space character after height */
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if( b==EOF )
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{
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goto format_error;
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}
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bpr = (w + 7) / 8;
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for( y = h - 1; y>=0; y-- )
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{
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for( i = 0; i<bpr; i++ )
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{
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b = fgetc( f );
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if( b==EOF )
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{
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goto eof;
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}
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*bm_index( bm, i * 8,
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y ) |= ( (potrace_word) b ) <<
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( 8 * ( BM_WORDSIZE - 1 - (i % BM_WORDSIZE) ) );
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}
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}
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break;
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case '5':
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/* read P5 format: PGM raw */
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max = readnum( f );
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if( max<1 )
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{
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goto format_error;
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}
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b = fgetc( f ); /* read single white-space character after max */
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if( b==EOF )
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{
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goto format_error;
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}
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for( y = h - 1; y>=0; y-- )
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{
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for( x = 0; x<w; x++ )
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{
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b = fgetc( f );
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if( b==EOF )
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goto eof;
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if( max>=256 )
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{
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b <<= 8;
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b1 = fgetc( f );
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if( b1==EOF )
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goto eof;
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b |= b1;
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}
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BM_UPUT( bm, x, y, b > threshold * max ? 0 : 1 );
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}
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}
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break;
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case '6':
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/* read P6 format: PPM raw */
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max = readnum( f );
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if( max<1 )
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{
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goto format_error;
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}
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b = fgetc( f ); /* read single white-space character after max */
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if( b==EOF )
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{
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goto format_error;
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}
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for( y = h - 1; y>=0; y-- )
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{
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for( x = 0; x<w; x++ )
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{
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sum = 0;
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for( i = 0; i<3; i++ )
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{
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b = fgetc( f );
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if( b==EOF )
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{
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goto eof;
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}
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if( max>=256 )
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{
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b <<= 8;
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b1 = fgetc( f );
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if( b1==EOF )
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goto eof;
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b |= b1;
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}
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sum += b;
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}
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BM_UPUT( bm, x, y, sum > 3 * threshold * max ? 0 : 1 );
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}
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}
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break;
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}
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*bmp = bm;
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return 0;
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eof:
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*bmp = bm;
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return 1;
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format_error:
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bm_free( bm );
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if( magic == '1' || magic == '4' )
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{
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bm_read_error = "invalid pbm file";
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}
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else if( magic == '2' || magic == '5' )
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{
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bm_read_error = "invalid pgm file";
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}
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else
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{
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bm_read_error = "invalid ppm file";
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}
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return -2;
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}
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/* ---------------------------------------------------------------------- */
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/* read BMP format */
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struct bmp_info_s
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{
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unsigned int FileSize;
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unsigned int reserved;
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unsigned int DataOffset;
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unsigned int InfoSize;
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unsigned int w; /* width */
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unsigned int h; /* height */
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unsigned int Planes;
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unsigned int bits; /* bits per sample */
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unsigned int comp; /* compression mode */
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unsigned int ImageSize;
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unsigned int XpixelsPerM;
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unsigned int YpixelsPerM;
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unsigned int ncolors; /* number of colors in palette */
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unsigned int ColorsImportant;
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unsigned int RedMask;
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unsigned int GreenMask;
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unsigned int BlueMask;
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unsigned int AlphaMask;
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unsigned int ctbits; /* sample size for color table */
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int topdown; /* top-down mode? */
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};
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typedef struct bmp_info_s bmp_info_t;
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/* auxiliary */
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static int bmp_count = 0; /* counter for byte padding */
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static int bmp_pos = 0; /* counter from start of BMP data */
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/* read n-byte little-endian integer. Return 1 on EOF or error, else
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* 0. Assume n<=4. */
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static int bmp_readint( FILE* f, int n, unsigned int* p )
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{
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int i;
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unsigned int sum = 0;
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int b;
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for( i = 0; i<n; i++ )
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{
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b = fgetc( f );
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if( b==EOF )
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{
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return 1;
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}
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sum += b << (8 * i);
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}
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bmp_count += n;
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bmp_pos += n;
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*p = sum;
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return 0;
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}
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/* reset padding boundary */
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static void bmp_pad_reset( void )
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{
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bmp_count = 0;
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}
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/* read padding bytes to 4-byte boundary. Return 1 on EOF or error,
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* else 0. */
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static int bmp_pad( FILE* f )
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{
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int c, i, b;
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c = (-bmp_count) & 3;
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for( i = 0; i<c; i++ )
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{
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b = fgetc( f );
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if( b==EOF )
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{
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return 1;
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}
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}
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bmp_pos += c;
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bmp_count = 0;
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return 0;
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}
|
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|
|
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/* forward to the new file position. Return 1 on EOF or error, else 0 */
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static int bmp_forward( FILE* f, int pos )
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{
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int b;
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while( bmp_pos < pos )
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{
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b = fgetc( f );
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if( b==EOF )
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{
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return 1;
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}
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bmp_pos++;
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bmp_count++;
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}
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return 0;
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}
|
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|
|
|
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#define TRY( x ) if( x ) \
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goto try_error
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#define TRY_EOF( x ) if( x ) \
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goto eof
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|
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/* correct y-coordinate for top-down format */
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#define ycorr( y ) (bmpinfo.topdown ? bmpinfo.h - 1 - y : y)
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|
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/* safe colortable access */
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#define COLTABLE( c ) ( (c) < bmpinfo.ncolors ? coltable[(c)] : 0 )
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|
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/* read BMP stream after magic number. Return values as for bm_read.
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* We choose to be as permissive as possible, since there are many
|
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* programs out there which produce BMP. For instance, ppmtobmp can
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* produce codings with anywhere from 1-8 or 24 bits per sample,
|
|
* although most specifications only allow 1,4,8,24,32. We can also
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* read both the old and new OS/2 BMP formats in addition to the
|
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* Windows BMP format. */
|
|
static int bm_readbody_bmp( FILE* f, double threshold, potrace_bitmap_t** bmp )
|
|
{
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|
bmp_info_t bmpinfo;
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int* coltable;
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|
unsigned int b, c;
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|
unsigned int i;
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potrace_bitmap_t* bm;
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int mask;
|
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unsigned int x, y;
|
|
int col[2];
|
|
unsigned int bitbuf;
|
|
unsigned int n;
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unsigned int redshift, greenshift, blueshift;
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int col1[2];
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|
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bm_read_error = NULL;
|
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bm = NULL;
|
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coltable = NULL;
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bmp_pos = 2; /* set file position */
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|
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/* file header (minus magic number) */
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TRY( bmp_readint( f, 4, &bmpinfo.FileSize ) );
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TRY( bmp_readint( f, 4, &bmpinfo.reserved ) );
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TRY( bmp_readint( f, 4, &bmpinfo.DataOffset ) );
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/* info header */
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TRY( bmp_readint( f, 4, &bmpinfo.InfoSize ) );
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|
|
|
if( bmpinfo.InfoSize == 40 || bmpinfo.InfoSize == 64
|
|
|| bmpinfo.InfoSize == 108 || bmpinfo.InfoSize == 124 )
|
|
{
|
|
/* Windows or new OS/2 format */
|
|
bmpinfo.ctbits = 32; /* sample size in color table */
|
|
TRY( bmp_readint( f, 4, &bmpinfo.w ) );
|
|
TRY( bmp_readint( f, 4, &bmpinfo.h ) );
|
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TRY( bmp_readint( f, 2, &bmpinfo.Planes ) );
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TRY( bmp_readint( f, 2, &bmpinfo.bits ) );
|
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TRY( bmp_readint( f, 4, &bmpinfo.comp ) );
|
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TRY( bmp_readint( f, 4, &bmpinfo.ImageSize ) );
|
|
TRY( bmp_readint( f, 4, &bmpinfo.XpixelsPerM ) );
|
|
TRY( bmp_readint( f, 4, &bmpinfo.YpixelsPerM ) );
|
|
TRY( bmp_readint( f, 4, &bmpinfo.ncolors ) );
|
|
TRY( bmp_readint( f, 4, &bmpinfo.ColorsImportant ) );
|
|
|
|
if( bmpinfo.InfoSize >= 108 ) /* V4 and V5 bitmaps */
|
|
{
|
|
TRY( bmp_readint( f, 4, &bmpinfo.RedMask ) );
|
|
TRY( bmp_readint( f, 4, &bmpinfo.GreenMask ) );
|
|
TRY( bmp_readint( f, 4, &bmpinfo.BlueMask ) );
|
|
TRY( bmp_readint( f, 4, &bmpinfo.AlphaMask ) );
|
|
}
|
|
|
|
if( bmpinfo.w > 0x7fffffff )
|
|
{
|
|
goto format_error;
|
|
}
|
|
|
|
if( bmpinfo.h > 0x7fffffff )
|
|
{
|
|
bmpinfo.h = (-bmpinfo.h) & 0xffffffff;
|
|
bmpinfo.topdown = 1;
|
|
}
|
|
else
|
|
{
|
|
bmpinfo.topdown = 0;
|
|
}
|
|
|
|
if( bmpinfo.h > 0x7fffffff )
|
|
{
|
|
goto format_error;
|
|
}
|
|
}
|
|
else if( bmpinfo.InfoSize == 12 )
|
|
{
|
|
/* old OS/2 format */
|
|
bmpinfo.ctbits = 24; /* sample size in color table */
|
|
TRY( bmp_readint( f, 2, &bmpinfo.w ) );
|
|
TRY( bmp_readint( f, 2, &bmpinfo.h ) );
|
|
TRY( bmp_readint( f, 2, &bmpinfo.Planes ) );
|
|
TRY( bmp_readint( f, 2, &bmpinfo.bits ) );
|
|
bmpinfo.comp = 0;
|
|
bmpinfo.ncolors = 0;
|
|
bmpinfo.topdown = 0;
|
|
}
|
|
else
|
|
{
|
|
goto format_error;
|
|
}
|
|
|
|
if( bmpinfo.comp == 3 && bmpinfo.InfoSize < 108 )
|
|
{
|
|
/* bitfield feature is only understood with V4 and V5 format */
|
|
goto format_error;
|
|
}
|
|
|
|
if( bmpinfo.comp > 3 || bmpinfo.bits > 32 )
|
|
{
|
|
goto format_error;
|
|
}
|
|
|
|
/* forward to color table (e.g., if bmpinfo.InfoSize == 64) */
|
|
TRY( bmp_forward( f, 14 + bmpinfo.InfoSize ) );
|
|
|
|
if( bmpinfo.Planes != 1 )
|
|
{
|
|
bm_read_error = "cannot handle bmp planes";
|
|
goto format_error; /* can't handle planes */
|
|
}
|
|
|
|
if( bmpinfo.ncolors == 0 )
|
|
{
|
|
bmpinfo.ncolors = 1 << bmpinfo.bits;
|
|
}
|
|
|
|
/* color table, present only if bmpinfo.bits <= 8. */
|
|
if( bmpinfo.bits <= 8 )
|
|
{
|
|
coltable = (int*) calloc( bmpinfo.ncolors, sizeof(int) );
|
|
|
|
if( !coltable )
|
|
{
|
|
goto std_error;
|
|
}
|
|
|
|
/* NOTE: since we are reading a bitmap, we can immediately convert
|
|
* the color table entries to bits. */
|
|
for( i = 0; i<bmpinfo.ncolors; i++ )
|
|
{
|
|
TRY( bmp_readint( f, bmpinfo.ctbits / 8, &c ) );
|
|
c = ( (c >> 16) & 0xff ) + ( (c >> 8) & 0xff ) + (c & 0xff);
|
|
coltable[i] = (c > 3 * threshold * 255 ? 0 : 1);
|
|
|
|
if( i<2 )
|
|
{
|
|
col1[i] = c;
|
|
}
|
|
}
|
|
}
|
|
|
|
/* forward to data */
|
|
if( bmpinfo.InfoSize != 12 ) /* not old OS/2 format */
|
|
{
|
|
TRY( bmp_forward( f, bmpinfo.DataOffset ) );
|
|
}
|
|
|
|
/* allocate bitmap */
|
|
bm = bm_new( bmpinfo.w, bmpinfo.h );
|
|
|
|
if( !bm )
|
|
{
|
|
goto std_error;
|
|
}
|
|
|
|
/* zero it out */
|
|
bm_clear( bm, 0 );
|
|
|
|
switch( bmpinfo.bits + 0x100 * bmpinfo.comp )
|
|
{
|
|
default:
|
|
goto format_error;
|
|
break;
|
|
|
|
case 0x001: /* monochrome palette */
|
|
|
|
if( col1[0] < col1[1] ) /* make the darker color black */
|
|
{
|
|
mask = 0xff;
|
|
}
|
|
else
|
|
{
|
|
mask = 0;
|
|
}
|
|
|
|
/* raster data */
|
|
for( y = 0; y<bmpinfo.h; y++ )
|
|
{
|
|
bmp_pad_reset();
|
|
|
|
for( i = 0; 8 * i<bmpinfo.w; i++ )
|
|
{
|
|
TRY_EOF( bmp_readint( f, 1, &b ) );
|
|
b ^= mask;
|
|
*bm_index( bm, i * 8,
|
|
ycorr( y ) ) |= ( (potrace_word) b ) <<
|
|
( 8 * ( BM_WORDSIZE - 1 - (i % BM_WORDSIZE) ) );
|
|
}
|
|
|
|
TRY( bmp_pad( f ) );
|
|
}
|
|
|
|
break;
|
|
|
|
case 0x002: /* 2-bit to 8-bit palettes */
|
|
case 0x003:
|
|
case 0x004:
|
|
case 0x005:
|
|
case 0x006:
|
|
case 0x007:
|
|
case 0x008:
|
|
|
|
for( y = 0; y<bmpinfo.h; y++ )
|
|
{
|
|
bmp_pad_reset();
|
|
bitbuf = 0; /* bit buffer: bits in buffer are high-aligned */
|
|
n = 0; /* number of bits currently in bitbuffer */
|
|
|
|
for( x = 0; x<bmpinfo.w; x++ )
|
|
{
|
|
if( n < bmpinfo.bits )
|
|
{
|
|
TRY_EOF( bmp_readint( f, 1, &b ) );
|
|
bitbuf |= b << (INTBITS - 8 - n);
|
|
n += 8;
|
|
}
|
|
|
|
b = bitbuf >> (INTBITS - bmpinfo.bits);
|
|
bitbuf <<= bmpinfo.bits;
|
|
n -= bmpinfo.bits;
|
|
BM_UPUT( bm, x, ycorr( y ), COLTABLE( b ) );
|
|
}
|
|
|
|
TRY( bmp_pad( f ) );
|
|
}
|
|
|
|
break;
|
|
|
|
case 0x010: /* 16-bit encoding */
|
|
/* can't do this format because it is not well-documented and I
|
|
* don't have any samples */
|
|
bm_read_error = "cannot handle bmp 16-bit coding";
|
|
goto format_error;
|
|
break;
|
|
|
|
case 0x018: /* 24-bit encoding */
|
|
case 0x020: /* 32-bit encoding */
|
|
|
|
for( y = 0; y<bmpinfo.h; y++ )
|
|
{
|
|
bmp_pad_reset();
|
|
|
|
for( x = 0; x<bmpinfo.w; x++ )
|
|
{
|
|
TRY_EOF( bmp_readint( f, bmpinfo.bits / 8, &c ) );
|
|
c = ( (c >> 16) & 0xff ) + ( (c >> 8) & 0xff ) + (c & 0xff);
|
|
BM_UPUT( bm, x, ycorr( y ), c > 3 * threshold * 255 ? 0 : 1 );
|
|
}
|
|
|
|
TRY( bmp_pad( f ) );
|
|
}
|
|
|
|
break;
|
|
|
|
case 0x320: /* 32-bit encoding with bitfields */
|
|
redshift = lobit( bmpinfo.RedMask );
|
|
greenshift = lobit( bmpinfo.GreenMask );
|
|
blueshift = lobit( bmpinfo.BlueMask );
|
|
|
|
for( y = 0; y<bmpinfo.h; y++ )
|
|
{
|
|
bmp_pad_reset();
|
|
|
|
for( x = 0; x<bmpinfo.w; x++ )
|
|
{
|
|
TRY_EOF( bmp_readint( f, bmpinfo.bits / 8, &c ) );
|
|
c = ( (c & bmpinfo.RedMask) >> redshift ) +
|
|
( (c & bmpinfo.GreenMask) >> greenshift ) +
|
|
( (c & bmpinfo.BlueMask) >> blueshift );
|
|
BM_UPUT( bm, x, ycorr( y ), c > 3 * threshold * 255 ? 0 : 1 );
|
|
}
|
|
|
|
TRY( bmp_pad( f ) );
|
|
}
|
|
|
|
break;
|
|
|
|
case 0x204: /* 4-bit runlength compressed encoding (RLE4) */
|
|
x = 0;
|
|
y = 0;
|
|
|
|
while( 1 )
|
|
{
|
|
TRY_EOF( bmp_readint( f, 1, &b ) ); /* opcode */
|
|
TRY_EOF( bmp_readint( f, 1, &c ) ); /* argument */
|
|
|
|
if( b>0 )
|
|
{
|
|
/* repeat count */
|
|
col[0] = COLTABLE( (c >> 4) & 0xf );
|
|
col[1] = COLTABLE( c & 0xf );
|
|
|
|
for( i = 0; i<b && x<bmpinfo.w; i++ )
|
|
{
|
|
if( x>=bmpinfo.w )
|
|
{
|
|
x = 0;
|
|
y++;
|
|
}
|
|
|
|
if( y>=bmpinfo.h )
|
|
{
|
|
break;
|
|
}
|
|
|
|
BM_UPUT( bm, x, ycorr( y ), col[i & 1] );
|
|
x++;
|
|
}
|
|
}
|
|
else if( c == 0 )
|
|
{
|
|
/* end of line */
|
|
y++;
|
|
x = 0;
|
|
}
|
|
else if( c == 1 )
|
|
{
|
|
/* end of bitmap */
|
|
break;
|
|
}
|
|
else if( c == 2 )
|
|
{
|
|
/* "delta": skip pixels in x and y directions */
|
|
TRY_EOF( bmp_readint( f, 1, &b ) ); /* x offset */
|
|
TRY_EOF( bmp_readint( f, 1, &c ) ); /* y offset */
|
|
x += b;
|
|
y += c;
|
|
}
|
|
else
|
|
{
|
|
/* verbatim segment */
|
|
for( i = 0; i<c; i++ )
|
|
{
|
|
if( (i & 1)==0 )
|
|
{
|
|
TRY_EOF( bmp_readint( f, 1, &b ) );
|
|
}
|
|
|
|
if( x>=bmpinfo.w )
|
|
{
|
|
x = 0;
|
|
y++;
|
|
}
|
|
|
|
if( y>=bmpinfo.h )
|
|
{
|
|
break;
|
|
}
|
|
|
|
BM_PUT( bm, x, ycorr( y ), COLTABLE( ( b >> ( 4 - 4 * (i & 1) ) ) & 0xf ) );
|
|
x++;
|
|
}
|
|
|
|
if( (c + 1) & 2 )
|
|
{
|
|
/* pad to 16-bit boundary */
|
|
TRY_EOF( bmp_readint( f, 1, &b ) );
|
|
}
|
|
}
|
|
}
|
|
|
|
break;
|
|
|
|
case 0x108: /* 8-bit runlength compressed encoding (RLE8) */
|
|
x = 0;
|
|
y = 0;
|
|
|
|
while( 1 )
|
|
{
|
|
TRY_EOF( bmp_readint( f, 1, &b ) ); /* opcode */
|
|
TRY_EOF( bmp_readint( f, 1, &c ) ); /* argument */
|
|
|
|
if( b>0 )
|
|
{
|
|
/* repeat count */
|
|
for( i = 0; i<b; i++ )
|
|
{
|
|
if( x>=bmpinfo.w )
|
|
{
|
|
x = 0;
|
|
y++;
|
|
}
|
|
|
|
if( y>=bmpinfo.h )
|
|
{
|
|
break;
|
|
}
|
|
|
|
BM_UPUT( bm, x, ycorr( y ), COLTABLE( c ) );
|
|
x++;
|
|
}
|
|
}
|
|
else if( c == 0 )
|
|
{
|
|
/* end of line */
|
|
y++;
|
|
x = 0;
|
|
}
|
|
else if( c == 1 )
|
|
{
|
|
/* end of bitmap */
|
|
break;
|
|
}
|
|
else if( c == 2 )
|
|
{
|
|
/* "delta": skip pixels in x and y directions */
|
|
TRY_EOF( bmp_readint( f, 1, &b ) ); /* x offset */
|
|
TRY_EOF( bmp_readint( f, 1, &c ) ); /* y offset */
|
|
x += b;
|
|
y += c;
|
|
}
|
|
else
|
|
{
|
|
/* verbatim segment */
|
|
for( i = 0; i<c; i++ )
|
|
{
|
|
TRY_EOF( bmp_readint( f, 1, &b ) );
|
|
|
|
if( x>=bmpinfo.w )
|
|
{
|
|
x = 0;
|
|
y++;
|
|
}
|
|
|
|
if( y>=bmpinfo.h )
|
|
{
|
|
break;
|
|
}
|
|
|
|
BM_PUT( bm, x, ycorr( y ), COLTABLE( b ) );
|
|
x++;
|
|
}
|
|
|
|
if( c & 1 )
|
|
{
|
|
/* pad input to 16-bit boundary */
|
|
TRY_EOF( bmp_readint( f, 1, &b ) );
|
|
}
|
|
}
|
|
}
|
|
|
|
break;
|
|
} /* switch */
|
|
|
|
/* skip any potential junk after the data section, but don't
|
|
* complain in case EOF is encountered */
|
|
bmp_forward( f, bmpinfo.FileSize );
|
|
|
|
free( coltable );
|
|
*bmp = bm;
|
|
return 0;
|
|
|
|
eof:
|
|
free( coltable );
|
|
*bmp = bm;
|
|
return 1;
|
|
|
|
format_error:
|
|
try_error:
|
|
free( coltable );
|
|
bm_free( bm );
|
|
|
|
if( !bm_read_error )
|
|
{
|
|
bm_read_error = "invalid bmp file";
|
|
}
|
|
|
|
return -2;
|
|
|
|
std_error:
|
|
free( coltable );
|
|
bm_free( bm );
|
|
return -1;
|
|
}
|
|
|
|
|
|
/* ---------------------------------------------------------------------- */
|
|
/* output pbm format */
|
|
|
|
void bm_writepbm( FILE* f, potrace_bitmap_t* bm )
|
|
{
|
|
int w, h, bpr, y, i, c;
|
|
|
|
w = bm->w;
|
|
h = bm->h;
|
|
|
|
bpr = (w + 7) / 8;
|
|
|
|
fprintf( f, "P4\n%d %d\n", w, h );
|
|
|
|
for( y = h - 1; y>=0; y-- )
|
|
{
|
|
for( i = 0; i<bpr; i++ )
|
|
{
|
|
c =
|
|
( *bm_index( bm, i * 8,
|
|
y ) >> ( 8 * ( BM_WORDSIZE - 1 - (i % BM_WORDSIZE) ) ) ) & 0xff;
|
|
fputc( c, f );
|
|
}
|
|
}
|
|
}
|
|
|
|
|
|
/* ---------------------------------------------------------------------- */
|
|
/* output - for primitive debugging purposes only! */
|
|
|
|
/* print bitmap to screen */
|
|
int bm_print( FILE* f, potrace_bitmap_t* bm )
|
|
{
|
|
int x, y;
|
|
int xx, yy;
|
|
int d;
|
|
int sw, sh;
|
|
|
|
sw = bm->w < 79 ? bm->w : 79;
|
|
sh = bm->w < 79 ? bm->h : bm->h * sw * 44 / (79 * bm->w);
|
|
|
|
for( yy = sh - 1; yy>=0; yy-- )
|
|
{
|
|
for( xx = 0; xx<sw; xx++ )
|
|
{
|
|
d = 0;
|
|
|
|
for( x = xx * bm->w / sw; x<(xx + 1) * bm->w / sw; x++ )
|
|
{
|
|
for( y = yy * bm->h / sh; y<(yy + 1) * bm->h / sh; y++ )
|
|
{
|
|
if( BM_GET( bm, x, y ) )
|
|
{
|
|
d++;
|
|
}
|
|
}
|
|
}
|
|
|
|
fputc( d ? '*' : ' ', f );
|
|
}
|
|
|
|
fputc( '\n', f );
|
|
}
|
|
|
|
return 0;
|
|
}
|