/*
    This file is part of Netpbm Formats, a File Format plugin for Adobe Photoshop
    Copyright (C) 2004-2010 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 "entry.h" // must come after Photoshop includes

#include "pbm.h"

DLLEXPORT MACPASCAL
void PluginMain(short selector,FormatRecordPtr pb,intptr_t *data,short *result);

int chunk; /* can process this many rows at a time (depends on available memory) */

#define MAXDATA_LIMIT (1L<<20) /* don't ask Photoshop for more than 1MB */
#define SLOP 16384

DLLEXPORT MACPASCAL
void PluginMain(short selector,FormatRecordPtr pb,intptr_t *data,short *result){
	OSErr e = noErr;
	long rb;
	FILECOUNT count;
	char sig[2];

	EnterCodeResource();

	if(selector == formatSelectorAbout)
		DoAbout((AboutRecordPtr)pb);
	else{
		rb = ((long)pb->planes*pb->depth*pb->imageSize.h + 7)/8;

		switch (selector){
		case formatSelectorReadPrepare:
	#ifdef USEMALLOC
			/* split memory with Photoshop, but don't ask for a ridiculous amount */
			pb->maxData /= 2;
			if(pb->maxData > MAXDATA_LIMIT)
				pb->maxData = MAXDATA_LIMIT;
	#else
			pb->maxData = 0; // memory will be allocated via Photoshop callback
	#endif
			break;
		case formatSelectorWritePrepare:
			/* split memory with Photoshop, but don't ask for more than
			 * the entire image would need */
			chunk = (pb->maxData/2 - SLOP)/rb;
			if(chunk > pb->imageSize.v)
				chunk = pb->imageSize.v;
			else if(chunk < 1)
				chunk = 1;
			pb->maxData = rb*chunk + SLOP;
			break;
		case formatSelectorEstimatePrepare:
		case formatSelectorOptionsPrepare:
			pb->maxData = 0;
			break;

		case formatSelectorReadStart:    e = read_start(pb); break;
		case formatSelectorReadContinue: e = read_continue(pb); break;
		case formatSelectorReadFinish:   e = read_finish(pb); break;

		case formatSelectorEstimateStart:
			pb->minDataBytes = pb->maxDataBytes = 3+6+6+6+pb->imageSize.v*rb;
		case formatSelectorOptionsStart:
		case formatSelectorEstimateContinue:
		case formatSelectorOptionsContinue:
			pb->data = 0;
		case formatSelectorEstimateFinish:
		case formatSelectorOptionsFinish:
			break;

		case formatSelectorWriteStart:    e = write_start(pb); break;
		case formatSelectorWriteContinue: e = write_continue(pb); break;
		case formatSelectorWriteFinish:   e = write_finish(pb); break;

		case formatSelectorFilterFile:
			count = 2;
			e = !FSREAD(F,&count,sig) && sig[0]=='P' && sig[1]>='1' && sig[1]<='6'
			? noErr : formatCannotRead;
			break;

		default:
			e = formatBadParameters;
		}
	}

	*result = e;

	ExitCodeResource();
}