/*
    This file is part of MacPaint Format, a File Format plugin for Adobe Photoshop
    Copyright (C) 2003-6 Toby Thain, toby@telegraphics.com.au

    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by  
    the Free Software Foundation; either version 2 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License  
    along with this program; if not, write to the Free Software
    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
*/

//#include <stdio.h>

#include <string.h>
#include <stdlib.h>

#include "macpaint.h"
#include "file_io.h"
#include "bufio.h"
#include "packbits.h"

char *outdata;

/*
See:
	http://developer.apple.com/technotes/tn/tn1023.html (Understanding PackBits)
	http://developer.apple.com/technotes/pt/pt_24.html (MacPaint Document Format)
*/

OSErr write_start(FormatRecordPtr pb,long *data){
	OSErr e;
	char header[PNTG_HEADERSIZE-4];
	long count;
	
	if( !(e = write4B((FILEREF)pb->dataFork,PNTG_VERSION)) ){
		count = PNTG_HEADERSIZE-4;
		memset(header,0,count);
		if( !(e = FSWrite((FILEREF)pb->dataFork,&count,header)) ){
			pb->theRect.left = pb->theRect.top = 0;
			pb->theRect.right = pb->imageSize.h;
			pb->theRect.bottom = pb->imageSize.v;
			pb->loPlane = pb->hiPlane = 0;
			pb->colBytes = 1;
			pb->rowBytes = PNTG_ROWBYTES;
			if(!(pb->data = outdata = malloc((long)PNTG_ROWS*PNTG_ROWBYTES)))
				e = memFullErr;
		}
	}
	return e;
}

OSErr write_continue(FormatRecordPtr pb,long *data){
	OSErr e = noErr;
	char outrow[PNTG_ROWBYTES+1],temp[PNTG_ROWBYTES],*inrow;
	int n,j,mask = ~(0xff >> (pb->imageSize.h & 7));

	for(j = 0,inrow = outdata ; j < pb->imageSize.v ; ++j,inrow += PNTG_ROWBYTES ){
//		sprintf(s,"row %d",j);dbg(s);

		n = (pb->imageSize.h+7)/8; // bytes of image data
		
		// blank out rightmost bits of last image byte
		if(pb->imageSize.h & 7)
			inrow[n-1] &= mask; 
		
		// blank out remainder of row
		memset(inrow+n,0,PNTG_ROWBYTES-n); 

		n = packbits(inrow,outrow,PNTG_ROWBYTES);
		if( (e = bufputbytes((FILEREF)pb->dataFork,n,outrow)) )
			break;
	}

	// output blank rows to fill image depth
	memset(temp,0,PNTG_ROWBYTES);
	n = packbits(temp,outrow,PNTG_ROWBYTES);

	for( ; !e && j < PNTG_ROWS ; ++j )
		e = bufputbytes((FILEREF)pb->dataFork,n,outrow);

	pb->data = 0;
//	pb->theRect.left = pb->theRect.top = pb->theRect.right = pb->theRect.bottom = 0;
	return e;
}

OSErr write_finish(FormatRecordPtr pb,long *data){
	free(outdata);
	flushbuffer((FILEREF)pb->dataFork);
	return noErr;
}