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- /* pnmcut.c - cut a rectangle out of a portable anymap
- **
- ** 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 "pnm.h"
-
- int
- main( argc, argv )
- int argc;
- char* argv[];
- {
- FILE* ifp;
- register xel* xelrow;
- xelval maxval;
- int rows, cols, format, x, y, width, height, row;
- char* usage = "x y width height [pnmfile]";
-
- pnm_init( &argc, argv );
-
- if ( argc < 5 || argc > 6 )
- pm_usage( usage );
-
- if ( sscanf( argv[1], "%d", &x ) != 1 )
- pm_usage( usage );
- if ( sscanf( argv[2], "%d", &y ) != 1 )
- pm_usage( usage );
- if ( sscanf( argv[3], "%d", &width ) != 1 )
- pm_usage( usage );
- if ( sscanf( argv[4], "%d", &height ) != 1 )
- pm_usage( usage );
-
- if ( width < 1 )
- pm_error( "width is less than 1" );
- if ( height < 1 )
- pm_error( "height is less than 1" );
-
- if ( argc == 6 )
- ifp = pm_openr( argv[5] );
- else
- ifp = stdin;
-
- pnm_readpnminit( ifp, &cols, &rows, &maxval, &format );
- xelrow = pnm_allocrow( cols );
-
- if ( x <= -cols )
- pm_error(
- "x is too negative -- the anymap has only %d cols", cols );
- else if ( x >= cols )
- pm_error(
- "x is too large -- the anymap has only %d cols", cols );
- if ( y <= -rows )
- pm_error(
- "y is too negative -- the anymap has only %d rows", rows );
- else if ( y >= rows )
- pm_error(
- "y is too large -- the anymap has only %d rows", rows );
-
- if ( x < 0 )
- x += cols;
- if ( y < 0 )
- y += rows;
-
- if ( x + width > cols )
- pm_error(
- "x + width is too large by %d xels", x + width - cols );
- if ( y + height > rows )
- pm_error(
- "y + height is too large by %d xels", y + height - rows );
-
- pnm_writepnminit( stdout, width, height, maxval, format, 0 );
- for ( row = 0; row < y + height; row++ )
- {
- pnm_readpnmrow( ifp, xelrow, cols, maxval, format );
- if ( row >= y )
- pnm_writepnmrow( stdout, &(xelrow[x]), width, maxval, format, 0 );
- }
-
- pm_close( ifp );
- pm_close( stdout );
-
- exit( 0 );
- }
-