//
//  Filename         : GridDensityProvider.h
//  Author(s)        : Alexander Beels
//  Purpose          : Class to define a cell grid surrounding
//                     the projected image of a scene
//  Date of creation : 2011-2-5
//
///////////////////////////////////////////////////////////////////////////////


//
//  Copyright (C) : Please refer to the COPYRIGHT file distributed 
//   with this source distribution. 
//
//  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.
//
///////////////////////////////////////////////////////////////////////////////

#ifndef GRIDDENSITYPROVIDER_H
#define GRIDDENSITYPROVIDER_H

#include <stdexcept>
#include <memory>
#include "OccluderSource.h"
#include "../geometry/BBox.h"

class GridDensityProvider {
	// Disallow copying and assignment
	GridDensityProvider (const GridDensityProvider& other);
	GridDensityProvider& operator= (const GridDensityProvider& other);

public:
	GridDensityProvider (OccluderSource& source)
		: source(source) {
	}

	virtual ~GridDensityProvider() {};

	float cellSize() {
		return _cellSize;
	}

	unsigned cellsX() {
		return _cellsX;
	}

	unsigned cellsY() {
		return _cellsY;
	}

	float cellOrigin(int index) {
		if ( index < 2 ) {
			return _cellOrigin[index];
		} else {
			throw new out_of_range("GridDensityProvider::cellOrigin can take only indexes of 0 or 1.");
		}
	}

	static void calculateOptimalProscenium(OccluderSource& source, real proscenium[4]) {
		source.begin();
		if ( source.isValid() ) {
			const Vec3r& initialPoint = source.getGridSpacePolygon().getVertices()[0];
			proscenium[0] = proscenium[1] = initialPoint[0];
			proscenium[2] = proscenium[3] = initialPoint[1];
			while ( source.isValid() ) {
				GridHelpers::expandProscenium (proscenium, source.getGridSpacePolygon());
				source.next();
			}
		}
		cout << "Proscenium: (" << proscenium[0] << ", " << proscenium[1] << ", " << proscenium[2] << ", " << proscenium[3] << ")" << endl;
	}

	static void calculateQuickProscenium(const GridHelpers::Transform& transform, const BBox<Vec3r>& bbox, real proscenium[4]) {
		real z;
		// We want to use the z-coordinate closest to the camera to determine the proscenium face
		if ( ::fabs(bbox.getMin()[2]) < ::fabs(bbox.getMax()[2]) ) {
			z = bbox.getMin()[2];
		} else {
			z = bbox.getMax()[2];
		}
		// Now calculate the proscenium according to the min and max values of the x and y coordinates
		Vec3r minPoint = transform(Vec3r(bbox.getMin()[0], bbox.getMin()[1], z));
		Vec3r maxPoint = transform(Vec3r(bbox.getMax()[0], bbox.getMax()[1], z));
		cout << "Bounding box: " << minPoint << " to " << maxPoint << endl;
		proscenium[0] = std::min(minPoint[0], maxPoint[0]);
		proscenium[1] = std::max(minPoint[0], maxPoint[0]);
		proscenium[2] = std::min(minPoint[1], maxPoint[1]);
		proscenium[3] = std::max(minPoint[1], maxPoint[1]);
		cout << "Proscenium  : " << proscenium[0] << ", " << proscenium[1] << ", " << proscenium[2] << ", " << proscenium[3] << endl;
	}

protected:
	OccluderSource& source;
	unsigned _cellsX, _cellsY;
	float _cellSize;
	float _cellOrigin[2];
};

class GridDensityProviderFactory {
	// Disallow copying and assignment
	GridDensityProviderFactory (const GridDensityProviderFactory& other);
	GridDensityProviderFactory& operator= (const GridDensityProviderFactory& other);

public:
	GridDensityProviderFactory() 
	{
	}

	virtual auto_ptr<GridDensityProvider> newGridDensityProvider(OccluderSource& source, const real proscenium[4]) =0;

	virtual auto_ptr<GridDensityProvider> newGridDensityProvider(OccluderSource& source, const BBox<Vec3r>& bbox, const GridHelpers::Transform& transform) =0;

	virtual auto_ptr<GridDensityProvider> newGridDensityProvider(OccluderSource& source) =0;

	virtual ~GridDensityProviderFactory () {}
};

#endif // GRIDDENSITYPROVIDER_H