/*
    This file is part of Netpbm Formats, a File Format plugin for Adobe Photoshop
    Copyright (C) 2004-6 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 "file_io.h"
#include "pbm.h"

extern int chunk;

char *outdata;
int top;

unsigned fix16(unsigned x);

void nextchunk(FormatRecordPtr pb){
	if(top+chunk > pb->imageSize.v)
		chunk = pb->imageSize.v - top;

	pb->theRect.left = 0;
	pb->theRect.right = pb->imageSize.h;
	pb->theRect.top = top;
	pb->theRect.bottom = top+chunk;
	pb->data = outdata;
}

OSErr write_start(FormatRecordPtr pb){
	OSErr e;
	char s[32];
	int n,subformat,rb;
	long m;
	
	switch(pb->imageMode){
	case plugInModeBitmap:
		subformat = PBM_KEY;
		break;
	case plugInModeGrayScale: 
	case plugInModeGray16:
		subformat = PGM_KEY;
		break;
	case plugInModeRGBColor: 
	case plugInModeRGB48:
		subformat = PPM_KEY;
		break;
	default: 
		return formatBadParameters;
	}

	n = sprintf(s,"P%c %d %d",subformat,pb->imageSize.h,pb->imageSize.v);
	if( !(e = bufputbytes(F,n,s)) ){
	
		m = (1L << pb->depth)-1;
		n = sprintf(s," %ld",m);
		/* unless it's a bitmap, we need to write a third number in the header,
		   denoting highest pixel value: 255 for 8 bit images, 65535 for 16 bit ones */
		if( pb->depth == 1 || !(e = bufputbytes(F,n,s)) ){
			bufputc(F,'\n');
	
			pb->loPlane = 0;
			pb->hiPlane = pb->planes-1;
			pb->colBytes = pb->planes*pb->depth/8;
			pb->rowBytes = rb = ((long)pb->planes*pb->imageSize.h*pb->depth + 7)/8;
			pb->planeBytes = pb->depth/8;

			if( (outdata = malloc((long)chunk*rb)) ){
				top = 0;
				nextchunk(pb);
			}else
				e = memFullErr;
		}
	}
	return e;
}

OSErr write_continue(FormatRecordPtr pb){
	OSErr e = noErr;
	char *p;
	int i,j,mask;
	long count;
	
	if(top < pb->imageSize.v){

		if(pb->depth == 1){
			mask = ~(0xff >> (pb->imageSize.h & 7));
			for(j = 0,p = pb->data ; j < chunk ; ++j,p += pb->rowBytes ){
		
				// blank out rightmost (padding) bits of last image byte
				if(pb->imageSize.h & 7)
					p[pb->rowBytes-1] &= mask; 
					
				if( (e = bufputbytes(F,pb->rowBytes,p)) )
					break;
			}
		}else{
			count = (long)pb->rowBytes*chunk;
			if( pb->depth == 16 ){
				for( i = count/2, p = pb->data ; i-- ; ){
					unsigned v = fix16( *(unsigned short*)p );
					*p++ = v>>8;
					*p++ = v;
				}
			}
			e = bufputbytes(F,count,pb->data);
		}
		
		top += chunk;
		nextchunk(pb);
	
	}else
		pb->data = 0;

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

OSErr write_finish(FormatRecordPtr pb){
	free(outdata);
	flushbuffer(F);
	return noErr;
}