/*

 * sampler.h: screen sample generation and image reconstruction

 *

 * This file is part of Pyrit Ray Tracer.

 *

 * Copyright 2008  Radek Brich

 *

 * Permission is hereby granted, free of charge, to any person obtaining a copy

 * of this software and associated documentation files (the "Software"), to deal

 * in the Software without restriction, including without limitation the rights

 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell

 * copies of the Software, and to permit persons to whom the Software is

 * furnished to do so, subject to the following conditions:

 *

 * The above copyright notice and this permission notice shall be included in

 * all copies or substantial portions of the Software.

 *

 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR

 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,

 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE

 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER

 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,

 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN

 * THE SOFTWARE.

 */

#ifndef SAMPLER_H

#define SAMPLER_H

#include "common.h"

#include "vector.h"

using namespace std;

/**

 * sample

 */

class Sample

{

	friend class Sampler;

public:

	Float x,y;

	int sx,sy,osa_samp;

};

/**

 * A abstract sampler.

 * It generates screen samples in coordinates between [-1..1] for height

 * and [-w/h..w/h] for width. It works in phases: initSampleSet returns

 * number of samples for each phase, then samples can be generated using

 * nextSample method. The resulting colour of each sample should be returned

 * via saveSample method. The sampler should save the results to given buffer

 * and decide if other phase is needed. When the picture is complete,

 * initSampleSet returns zero and picture can be read from buffer.

 */

class Sampler

{

public:

	Float *buffer;

	int w,h;

	Sampler(Float *abuffer, int &aw, int &ah): buffer(abuffer), w(aw), h(ah) {};

	virtual ~Sampler() {};

	void resetBuffer(Float *abuffer, int &aw, int &ah) { buffer = abuffer; w = aw; h = ah; };

	virtual void init() = 0;

	virtual int initSampleSet() = 0;

	virtual bool nextSample(Sample *s) = 0;

	virtual void saveSample(Sample &samp, Colour &col) = 0;

};

/**

 * Default sampler.

 * Implements basic adaptive subsampling and oversampling.

 */

class DefaultSampler: public Sampler

{

	int phase;

	int subsample;

	int oversample; // 0 = no, 1 = 5x, 2 = 9x, 3 = 16x

	int sx,sy,osa_samp; // current sample properties

public:

	DefaultSampler(Float *abuffer, int &aw, int &ah):

		Sampler(abuffer, aw, ah), phase(-1), subsample(8), oversample(0) {};

	void init();

	int initSampleSet();

	bool nextSample(Sample *s);

	void saveSample(Sample &samp, Colour &col);

	void setSubsample(int sub) { subsample = sub; };

	int getSubsample() { return subsample; };

	void setOversample(int osa) { oversample = osa; };

	int getOversample() { return oversample; };

};

#endif