/* libpbm3.c - pbm utility library part 3
**
** Copyright (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 "pbm.h"
#include "libpbm.h"

void
pbm_writepbminit( FILE* file, int cols, int rows, int forceplain )
    {
    if ( ! forceplain )
	fprintf( file, "%c%c\n%d %d\n", PBM_MAGIC1, RPBM_MAGIC2, cols, rows );
    else
	fprintf( file, "%c%c\n%d %d\n", PBM_MAGIC1, PBM_MAGIC2, cols, rows );
    }

static void
pbm_writepbmrowraw( FILE* file, bit* bitrow, int cols )
    {
    int col, bitshift;
    unsigned char item;
    bit* bP;

    bitshift = 7;
    item = 0;
    for ( col = 0, bP = bitrow; col < cols; ++col, ++bP )
	{
	if ( *bP )
	    item += 1 << bitshift;
	--bitshift;
	if ( bitshift == -1 )
	    {
	    (void) putc( item, file );
	    bitshift = 7;
	    item = 0;
	    }
	}
    if ( bitshift != 7 )
	(void) putc( item, file );
    }

static void
pbm_writepbmrowplain( FILE* file, bit* bitrow, int cols )
    {
    int col, charcount;
    bit* bP;

    charcount = 0;
    for ( col = 0, bP = bitrow; col < cols; ++col, ++bP )
	{
	if ( charcount >= 70 )
	    {
	    (void) putc( '\n', file );
	    charcount = 0;
	    }
	(void) putc( *bP ? '1' : '0', file );
	++charcount;
	}
    (void) putc( '\n', file );
    }

void
pbm_writepbmrow( FILE* file, bit* bitrow, int cols, int forceplain )
    {
    if ( ! forceplain )
	pbm_writepbmrowraw( file, bitrow, cols );
    else
	pbm_writepbmrowplain( file, bitrow, cols );
    }

void
pbm_writepbm( FILE* file, bit** bits, int cols, int rows, int forceplain )
    {
    int row;

    pbm_writepbminit( file, cols, rows, forceplain );

    for ( row = 0; row < rows; ++row )
	pbm_writepbmrow( file, bits[row], cols, forceplain );
    }