diff options
Diffstat (limited to 'converter/pbm/mgrtopbm.c')
| -rw-r--r-- | converter/pbm/mgrtopbm.c | 145 |
1 files changed, 145 insertions, 0 deletions
diff --git a/converter/pbm/mgrtopbm.c b/converter/pbm/mgrtopbm.c new file mode 100644 index 00000000..cea4be48 --- /dev/null +++ b/converter/pbm/mgrtopbm.c @@ -0,0 +1,145 @@ +/* mgrtopbm.c - read a MGR bitmap and produce a portable bitmap +** +** Copyright (C) 1989 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 <string.h> +#include <errno.h> + +#include "pbm.h" +#include "mgr.h" + + +static unsigned char item; +static int bitsperitem, bitshift; + +static void +getinit(FILE * const file, + int * const colsP, + int * const rowsP, + int * const depthP, + int * const padrightP, + int * const bitsperitemP) { + + struct b_header head; + int pad; + + if (fread(&head, sizeof(struct old_b_header), 1, file ) != 1) + pm_error("Unable to read 1st byte of file. " + "fread() returns errno %d (%s)", + errno, strerror(errno)); + if (head.magic[0] == 'y' && head.magic[1] == 'z') { + /* new style bitmap */ + if (fread(&head.depth, + sizeof(head) - sizeof(struct old_b_header), 1, file) + != 1 ) + pm_error("Unable to read header after 1st byte. " + "fread() returns errno %d (%s)", + errno, strerror(errno)); + *depthP = (int) head.depth - ' '; + pad = 8; + } else if (head.magic[0] == 'x' && head.magic[1] == 'z') { + /* old style bitmap with 32-bit padding */ + *depthP = 1; + pad = 32; + } else if (head.magic[0] == 'z' && head.magic[1] == 'z') { + /* old style bitmap with 16-bit padding */ + *depthP = 1; + pad = 16; + } else if (head.magic[0] == 'z' && head.magic[1] == 'y') { + /* old style 8-bit pixmap with 16-bit padding */ + *depthP = 8; + pad = 16; + } else { + pm_error("bad magic chars in MGR file: '%c%c'", + head.magic[0], head.magic[1] ); + pad = -1; /* should never reach here */ + } + + if (head.h_wide < ' ' || head.l_wide < ' ') + pm_error("Invalid width field in MGR header"); + if (head.h_high < ' ' || head.l_high < ' ') + pm_error("Invalid width field in MGR header"); + + *colsP = (((int)head.h_wide - ' ') << 6) + ((int)head.l_wide - ' '); + *rowsP = (((int)head.h_high - ' ') << 6) + ((int) head.l_high - ' '); + *padrightP = ( ( *colsP + pad - 1 ) / pad ) * pad - *colsP; + + *bitsperitemP = 8; +} + + + +static bit +getbit( file ) + FILE* file; + { + bit b; + + if ( bitsperitem == 8 ) + { + item = getc( file ); + bitsperitem = 0; + bitshift = 7; + } + bitsperitem++; + b = ( ( item >> bitshift) & 1 ) ? PBM_BLACK : PBM_WHITE; + bitshift--; + return b; + } + + + +int +main( argc, argv ) + int argc; + char* argv[]; + { + FILE* ifp; + bit* bitrow; + register bit* bP; + int rows, cols, depth, padright, row, col; + + + pbm_init( &argc, argv ); + + if ( argc > 2 ) + pm_usage( "[mgrfile]" ); + + if ( argc == 2 ) + ifp = pm_openr( argv[1] ); + else + ifp = stdin; + + getinit( ifp, &cols, &rows, &depth, &padright, &bitsperitem ); + if ( depth != 1 ) + pm_error( "MGR file has depth of %d, must be 1", depth ); + + pbm_writepbminit( stdout, cols, rows, 0 ); + bitrow = pbm_allocrow( cols ); + + for ( row = 0; row < rows; row++ ) + { + /* Get data, bit-reversed within each byte. */ + 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 ); + } + + |