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-rw-r--r--potrace/bitmap_io.cpp969
1 files changed, 969 insertions, 0 deletions
diff --git a/potrace/bitmap_io.cpp b/potrace/bitmap_io.cpp
new file mode 100644
index 0000000..3866593
--- /dev/null
+++ b/potrace/bitmap_io.cpp
@@ -0,0 +1,969 @@
+/* Copyright (C) 2001-2007 Peter Selinger.
+ * This file is part of Potrace. It is free software and it is covered
+ * by the GNU General Public License. See the file COPYING for details. */
+
+/* $Id: bitmap_io.c 147 2007-04-09 00:44:09Z selinger $ */
+
+/* Routines for manipulating bitmaps, including reading pbm files. */
+
+#include <stdio.h>
+
+#include <bitmap.h>
+
+#define INTBITS ( 8 * sizeof(int) )
+
+static int bm_readbody_bmp( FILE* f, double threshold, potrace_bitmap_t** bmp );
+static int bm_readbody_pnm( FILE* f, double threshold, potrace_bitmap_t** bmp, int magic );
+
+/* ---------------------------------------------------------------------- */
+/* routines for reading pnm streams */
+
+/* read next character after whitespace and comments. Return EOF on
+ * end of file or error. */
+static int fgetc_ws( FILE* f )
+{
+ int c;
+
+ while( 1 )
+ {
+ c = fgetc( f );
+ if( c=='#' )
+ {
+ while( 1 )
+ {
+ c = fgetc( f );
+ if( c=='\n' || c==EOF )
+ {
+ break;
+ }
+ }
+ }
+ /* space, tab, line feed, carriage return, form-feed */
+ if( c!=' ' && c!='\t' && c!='\r' && c!='\n' && c!=12 )
+ {
+ return c;
+ }
+ }
+}
+
+
+/* skip whitespace and comments, then read a non-negative decimal
+ * number from a stream. Return -1 on EOF. Tolerate other errors (skip
+ * bad characters). Do not the read any characters following the
+ * number (put next character back into the stream) */
+
+static int readnum( FILE* f )
+{
+ int c;
+ int acc;
+
+ /* skip whitespace and comments */
+ while( 1 )
+ {
+ c = fgetc_ws( f );
+ if( c==EOF )
+ {
+ return -1;
+ }
+ if( c>='0' && c<='9' )
+ {
+ break;
+ }
+ }
+
+ /* first digit is already in c */
+ acc = c - '0';
+ while( 1 )
+ {
+ c = fgetc( f );
+ if( c==EOF )
+ {
+ break;
+ }
+ if( c<'0' || c>'9' )
+ {
+ ungetc( c, f );
+ break;
+ }
+ acc *= 10;
+ acc += c - '0';
+ }
+
+ return acc;
+}
+
+
+/* similar to readnum, but read only a single 0 or 1, and do not read
+ * any characters after it. */
+
+static int readbit( FILE* f )
+{
+ int c;
+
+ /* skip whitespace and comments */
+ while( 1 )
+ {
+ c = fgetc_ws( f );
+ if( c==EOF )
+ {
+ return -1;
+ }
+ if( c>='0' && c<='1' )
+ {
+ break;
+ }
+ }
+
+ return c - '0';
+}
+
+
+/* ---------------------------------------------------------------------- */
+
+/* read a PNM stream: P1-P6 format (see pnm(5)), or a BMP stream, and
+ * convert the output to a bitmap. Return bitmap in *bmp. Return 0 on
+ * success, -1 on error with errno set, -2 on bad file format (with
+ * error message in bm_read_error), and 1 on premature end of file, -3
+ * on empty file (including files which contain only whitespace and
+ * comments), -4 if wrong magic number. If the return value is >=0,
+ *bmp is valid. */
+
+const char* bm_read_error = NULL;
+
+int bm_read( FILE* f, double threshold, potrace_bitmap_t** bmp )
+{
+ int magic[2];
+
+ /* read magic number. We ignore whitespace and comments before the
+ * magic, for the benefit of concatenated files in P1-P3 format.
+ * Multiple P1-P3 images in a single file are not formally allowed
+ * by the PNM standard, but there is no harm in being lenient. */
+
+ magic[0] = fgetc_ws( f );
+ if( magic[0] == EOF )
+ {
+ return -3;
+ }
+ magic[1] = fgetc( f );
+ if( magic[0] == 'P' && magic[1] >= '1' && magic[1] <= '6' )
+ {
+ return bm_readbody_pnm( f, threshold, bmp, magic[1] );
+ }
+ if( magic[0] == 'B' && magic[1] == 'M' )
+ {
+ return bm_readbody_bmp( f, threshold, bmp );
+ }
+ return -4;
+}
+
+
+/* ---------------------------------------------------------------------- */
+/* read PNM format */
+
+/* read PNM stream after magic number. Return values as for bm_read */
+static int bm_readbody_pnm( FILE* f, double threshold, potrace_bitmap_t** bmp, int magic )
+{
+ potrace_bitmap_t* bm;
+ int x, y, i, b, b1, sum;
+ int bpr; /* bytes per row (as opposed to 4*bm->c) */
+ int w, h, max;
+
+ bm = NULL;
+
+ w = readnum( f );
+ if( w<0 )
+ {
+ goto format_error;
+ }
+
+ h = readnum( f );
+ if( h<0 )
+ {
+ goto format_error;
+ }
+
+ /* allocate bitmap */
+ bm = bm_new( w, h );
+ if( !bm )
+ {
+ return -1;
+ }
+
+ /* zero it out */
+ bm_clear( bm, 0 );
+
+ switch( magic )
+ {
+ default:
+ /* not reached */
+ goto format_error;
+
+ case '1':
+ /* read P1 format: PBM ascii */
+
+ for( y = h - 1; y>=0; y-- )
+ {
+ for( x = 0; x<w; x++ )
+ {
+ b = readbit( f );
+ if( b<0 )
+ {
+ goto eof;
+ }
+ BM_UPUT( bm, x, y, b );
+ }
+ }
+
+ break;
+
+ case '2':
+ /* read P2 format: PGM ascii */
+
+ max = readnum( f );
+ if( max<1 )
+ {
+ goto format_error;
+ }
+
+ for( y = h - 1; y>=0; y-- )
+ {
+ for( x = 0; x<w; x++ )
+ {
+ b = readnum( f );
+ if( b<0 )
+ {
+ goto eof;
+ }
+ BM_UPUT( bm, x, y, b > threshold * max ? 0 : 1 );
+ }
+ }
+
+ break;
+
+ case '3':
+ /* read P3 format: PPM ascii */
+
+ max = readnum( f );
+ if( max<1 )
+ {
+ goto format_error;
+ }
+
+ for( y = h - 1; y>=0; y-- )
+ {
+ for( x = 0; x<w; x++ )
+ {
+ sum = 0;
+ for( i = 0; i<3; i++ )
+ {
+ b = readnum( f );
+ if( b<0 )
+ {
+ goto eof;
+ }
+ sum += b;
+ }
+
+ BM_UPUT( bm, x, y, sum > 3 * threshold * max ? 0 : 1 );
+ }
+ }
+
+ break;
+
+ case '4':
+ /* read P4 format: PBM raw */
+
+ b = fgetc( f ); /* read single white-space character after height */
+ if( b==EOF )
+ {
+ goto format_error;
+ }
+
+ bpr = (w + 7) / 8;
+
+ for( y = h - 1; y>=0; y-- )
+ {
+ for( i = 0; i<bpr; i++ )
+ {
+ b = fgetc( f );
+ if( b==EOF )
+ {
+ goto eof;
+ }
+ *bm_index( bm, i * 8,
+ y ) |= ( (potrace_word) b ) <<
+ ( 8 * ( BM_WORDSIZE - 1 - (i % BM_WORDSIZE) ) );
+ }
+ }
+
+ break;
+
+ case '5':
+ /* read P5 format: PGM raw */
+
+ max = readnum( f );
+ if( max<1 )
+ {
+ goto format_error;
+ }
+
+ b = fgetc( f ); /* read single white-space character after max */
+ if( b==EOF )
+ {
+ goto format_error;
+ }
+
+ for( y = h - 1; y>=0; y-- )
+ {
+ for( x = 0; x<w; x++ )
+ {
+ b = fgetc( f );
+ if( b==EOF )
+ goto eof;
+ if( max>=256 )
+ {
+ b <<= 8;
+ b1 = fgetc( f );
+ if( b1==EOF )
+ goto eof;
+ b |= b1;
+ }
+ BM_UPUT( bm, x, y, b > threshold * max ? 0 : 1 );
+ }
+ }
+
+ break;
+
+ case '6':
+ /* read P6 format: PPM raw */
+
+ max = readnum( f );
+ if( max<1 )
+ {
+ goto format_error;
+ }
+
+ b = fgetc( f ); /* read single white-space character after max */
+ if( b==EOF )
+ {
+ goto format_error;
+ }
+
+ for( y = h - 1; y>=0; y-- )
+ {
+ for( x = 0; x<w; x++ )
+ {
+ sum = 0;
+ for( i = 0; i<3; i++ )
+ {
+ b = fgetc( f );
+ if( b==EOF )
+ {
+ goto eof;
+ }
+ if( max>=256 )
+ {
+ b <<= 8;
+ b1 = fgetc( f );
+ if( b1==EOF )
+ goto eof;
+ b |= b1;
+ }
+ sum += b;
+ }
+
+ BM_UPUT( bm, x, y, sum > 3 * threshold * max ? 0 : 1 );
+ }
+ }
+
+ break;
+ }
+
+ *bmp = bm;
+ return 0;
+
+eof:
+ *bmp = bm;
+ return 1;
+
+format_error:
+ bm_free( bm );
+ if( magic == '1' || magic == '4' )
+ {
+ bm_read_error = "invalid pbm file";
+ }
+ else if( magic == '2' || magic == '5' )
+ {
+ bm_read_error = "invalid pgm file";
+ }
+ else
+ {
+ bm_read_error = "invalid ppm file";
+ }
+ return -2;
+}
+
+
+/* ---------------------------------------------------------------------- */
+/* read BMP format */
+
+struct bmp_info_s
+{
+ unsigned int FileSize;
+ unsigned int reserved;
+ unsigned int DataOffset;
+ unsigned int InfoSize;
+ unsigned int w; /* width */
+ unsigned int h; /* height */
+ unsigned int Planes;
+ unsigned int bits; /* bits per sample */
+ unsigned int comp; /* compression mode */
+ unsigned int ImageSize;
+ unsigned int XpixelsPerM;
+ unsigned int YpixelsPerM;
+ unsigned int ncolors; /* number of colors in palette */
+ unsigned int ColorsImportant;
+ unsigned int ctbits; /* sample size for color table */
+};
+typedef struct bmp_info_s bmp_info_t;
+
+/* auxiliary */
+
+static int bmp_count = 0; /* counter for byte padding */
+static int bmp_pos = 0; /* counter from start of BMP data */
+
+/* read n-byte little-endian integer. Return 1 on EOF or error, else
+ * 0. Assume n<=4. */
+static int bmp_readint( FILE* f, int n, unsigned int* p )
+{
+ int i;
+ unsigned int sum = 0;
+ int b;
+
+ for( i = 0; i<n; i++ )
+ {
+ b = fgetc( f );
+ if( b==EOF )
+ {
+ return 1;
+ }
+ sum += b << (8 * i);
+ }
+
+ bmp_count += n;
+ bmp_pos += n;
+ *p = sum;
+ return 0;
+}
+
+
+/* reset padding boundary */
+static void bmp_pad_reset( void )
+{
+ bmp_count = 0;
+}
+
+
+/* read padding bytes to 4-byte boundary. Return 1 on EOF or error,
+ * else 0. */
+static int bmp_pad( FILE* f )
+{
+ int c, i, b;
+
+ c = (-bmp_count) & 3;
+ for( i = 0; i<c; i++ )
+ {
+ b = fgetc( f );
+ if( b==EOF )
+ {
+ return 1;
+ }
+ }
+
+ bmp_pos += c;
+ bmp_count = 0;
+ return 0;
+}
+
+
+/* forward to the new file position. Return 1 on EOF or error, else 0 */
+static int bmp_forward( FILE* f, int pos )
+{
+ int b;
+
+ while( bmp_pos < pos )
+ {
+ b = fgetc( f );
+ if( b==EOF )
+ {
+ return 1;
+ }
+ bmp_pos++;
+ bmp_count++;
+ }
+
+ return 0;
+}
+
+
+#define TRY( x ) if( x ) \
+ goto try_error
+#define TRY_EOF( x ) if( x ) \
+ goto eof
+
+/* read BMP stream after magic number. Return values as for bm_read.
+ * We choose to be as permissive as possible, since there are many
+ * programs out there which produce BMP. For instance, ppmtobmp can
+ * 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
+ * read both the old and new OS/2 BMP formats in addition to the
+ * Windows BMP format. */
+static int bm_readbody_bmp( FILE* f, double threshold, potrace_bitmap_t** bmp )
+{
+ bmp_info_t bmpinfo;
+ int* coltable;
+ unsigned int b, c;
+ unsigned int i;
+ potrace_bitmap_t* bm;
+ int mask;
+ unsigned int x, y;
+ int col[2];
+ unsigned int bitbuf;
+ unsigned int n;
+ int col1[2];
+
+ bm_read_error = NULL;
+ bm = NULL;
+ coltable = NULL;
+
+ bmp_pos = 2; /* set file position */
+
+ /* file header (minus magic number) */
+ TRY( bmp_readint( f, 4, &bmpinfo.FileSize ) );
+ TRY( bmp_readint( f, 4, &bmpinfo.reserved ) );
+ TRY( bmp_readint( f, 4, &bmpinfo.DataOffset ) );
+
+ /* info header */
+ TRY( bmp_readint( f, 4, &bmpinfo.InfoSize ) );
+ if( bmpinfo.InfoSize == 40 || bmpinfo.InfoSize == 64 )
+ {
+ /* 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 ) );
+ TRY( bmp_readint( f, 2, &bmpinfo.Planes ) );
+ TRY( bmp_readint( f, 2, &bmpinfo.bits ) );
+ TRY( bmp_readint( f, 4, &bmpinfo.comp ) );
+ 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 ) );
+ }
+ 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;
+ }
+ else
+ {
+ goto format_error;
+ }
+
+ /* forward to color table (i.e., 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*) malloc( 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,
+ 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, 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, 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, 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, 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, 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, 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 );
+ free( bm );
+ if( !bm_read_error )
+ {
+ bm_read_error = "invalid bmp file";
+ }
+ return -2;
+
+std_error:
+ free( coltable );
+ 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 );
+ }
+ }
+
+ return;
+}
+
+
+/* ---------------------------------------------------------------------- */
+/* 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;
+}
generated by cgit (git 2.34.1) at 2024-12-19 10:19:25 +0000