diff options
Diffstat (limited to 'converter/pbm/ybmtopbm.c')
-rw-r--r-- | converter/pbm/ybmtopbm.c | 113 |
1 files changed, 113 insertions, 0 deletions
diff --git a/converter/pbm/ybmtopbm.c b/converter/pbm/ybmtopbm.c new file mode 100644 index 00000000..739e168a --- /dev/null +++ b/converter/pbm/ybmtopbm.c @@ -0,0 +1,113 @@ +/* ybmtopbm.c - read a file from Bennet Yee's 'xbm' program and write a pbm. +** +** Written by Jamie Zawinski based on code (C) 1988 by Jef Poskanzer. +** +** Permission to use, copy, modify, and distribute this software and its +** documentation for any purpose and without fee is hereby granted, provided +** that the above copyright notice appear in all copies and that both that +** copyright notice and this permission notice appear in supporting +** documentation. This software is provided "as is" without express or +** implied warranty. +*/ + +#include <stdio.h> +#include "pbm.h" + +static void getinit ARGS(( FILE* file, short* colsP, short* rowsP, short* depthP, short* padrightP )); +static bit getbit ARGS(( FILE* file )); + +#define YBM_MAGIC ( ( '!' << 8 ) | '!' ) + +int +main( argc, argv ) + int argc; + char* argv[]; + { + FILE* ifp; + bit* bitrow; + register bit* bP; + short rows, cols, padright, row, col; + short depth; + + pbm_init( &argc, argv ); + + if ( argc > 2 ) + pm_usage( "[ybmfile]" ); + + if ( argc == 2 ) + ifp = pm_openr( argv[1] ); + else + ifp = stdin; + + getinit( ifp, &cols, &rows, &depth, &padright ); + if ( depth != 1 ) + pm_error( + "YBM file has depth of %d, must be 1", + (int) depth ); + + pbm_writepbminit( stdout, cols, rows, 0 ); + bitrow = pbm_allocrow( cols ); + + for ( row = 0; row < rows; ++row ) + { + /* Get data. */ + for ( col = 0, bP = bitrow; col < cols; ++col, ++bP ) + *bP = getbit( ifp ); + /* Discard line padding */ + for ( col = 0; col < padright; ++col ) + (void) getbit( ifp ); + pbm_writepbmrow( stdout, bitrow, cols, 0 ); + } + + pm_close( ifp ); + pm_close( stdout ); + + exit( 0 ); + } + +static int item; +static int bitsperitem, bitshift; + +static void +getinit( file, colsP, rowsP, depthP, padrightP ) + FILE* file; + short* colsP; + short* rowsP; + short* depthP; + short* padrightP; + { + short magic; + + if ( pm_readbigshort( file, &magic ) == -1 ) + pm_error( "EOF / read error" ); + if ( magic != YBM_MAGIC ) + pm_error( "bad magic number in YBM file" ); + if ( pm_readbigshort( file, colsP ) == -1 ) + pm_error( "EOF / read error" ); + if ( pm_readbigshort( file, rowsP ) == -1 ) + pm_error( "EOF / read error" ); + + *depthP = 1; + *padrightP = ( ( *colsP + 15 ) / 16 ) * 16 - *colsP; + bitsperitem = 0; + } + +static bit +getbit( file ) + FILE* file; + { + bit b; + + if ( bitsperitem == 0 ) + { + item = getc(file) | getc(file)<<8; + if ( item == EOF ) + pm_error( "EOF / read error" ); + bitsperitem = 16; + bitshift = 0; + } + b = ( ( item >> bitshift) & 1 ) ? PBM_BLACK : PBM_WHITE; + --bitsperitem; + ++bitshift; + return b; + } |