/*

 * material.h: material and texture classes

 *

 * This file is part of Pyrit Ray Tracer.

 *

 * Copyright 2006, 2007, 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 MATERIAL_H

#define MATERIAL_H

#include "common.h"

#include "vector.h"

/**

 * perlin noise

 */

Float perlin(Float x, Float y, Float z);

/**

 * general texture

 */

class Texture

{

public:

	virtual ~Texture() {};

	virtual Colour evaluate(const Vector3 &point) = 0;

};

/**

 * general colour map

 */

class ColourMap

{

public:

	virtual Colour map(const Float &val) = 0;

};

/**

 * linear colour map

 * maps value lineary between two colours

 */

class LinearColourMap: public ColourMap

{

	Colour col,cdiff;

public:

	LinearColourMap(const Colour &clow, const Colour &chigh):

		col(clow), cdiff(chigh-clow) {};

	Colour map(const Float &val) { return col + cdiff*val; };

};

/**

 * bound colour map

 * initialize with two arrays, bounds and colours, of same size

 * bounds must contain numbers between 0 and 1 in rising order,

 * last number should be larger than max 'val'

 * colours are mapped to slices between bounds (with zero being

 * implicit bottom bound)

 */

class BoundColourMap: public ColourMap

{

	Float *bounds;

	Colour *colours;

public:

	BoundColourMap(Float *abounds, Colour *acolours):

		bounds(abounds), colours(acolours) {};

	Colour map(const Float &val)

	{

		Float *b = bounds;

		Colour *c = colours;

		while (val > *b)

		{

			b++;

			c++;

		}

		return *c;

	};

};

/**

 * general texture mapping

 */

class TextureMap

{

protected:

	Vector3 center;

	Float invsize;

public:

	TextureMap(const Vector3 &acenter, const Float &size):

		center(acenter), invsize(1./size) {};

	virtual void map(const Vector3 &point, Float &u, Float &v) = 0;

};

/**

 * planar mapping

 */

class PlanarMap: public TextureMap

{

public:

	PlanarMap(const Vector3 &acenter, const Float &size):

		TextureMap(acenter, size) {};

	void map(const Vector3 &point, Float &u, Float &v)

	{

		const Vector3 p = point - center;

		u = p.x*invsize;

		v = p.y*invsize;

	};

};

/**

 * cubic mapping

 */

class CubicMap: public TextureMap

{

public:

	CubicMap(const Vector3 &acenter, const Float &size):

		TextureMap(acenter, size) {};

	void map(const Vector3 &point, Float &u, Float &v)

	{

		const Vector3 p = point - center;

		if (fabs(p.x) > fabs(p.y))

		{

			if (fabs(p.x) > fabs(p.z))

			{

				if (p.x < 0)

					u = -p.y;

				else

					u = p.y;

				v = p.z;

			}

			else

			{

				if (p.z < 0)

					u = -p.x;

				else

					u = p.x;

				v = p.y;

			}

		}

		else

		{

			if (fabs(p.y) > fabs(p.z))

			{

				if (p.y < 0)

					u = -p.x;

				else

					u = p.x;

				v = p.z;

			}

			else

			{

				if (p.z < 0)

					u = -p.x;

				else

					u = p.x;

				v = p.y;

			}

		}

		u = u*invsize;

		v = v*invsize;

	};

};

/**

 * cylindrical mapping

 */

class CylinderMap: public TextureMap

{

public:

	CylinderMap(const Vector3 &acenter, const Float &size):

		TextureMap(acenter, size) {};

	void map(const Vector3 &point, Float &u, Float &v)

	{

		const Vector3 p = point - center;

		u = ( M_PI + atan2(p.z, p.x) ) * invsize;

		v = p.y * invsize;

	};

};

/**

 * spherical mapping

 */

class SphereMap: public TextureMap

{

public:

	SphereMap(const Vector3 &acenter, const Float &size):

		TextureMap(acenter, size) {};

	void map(const Vector3 &point, Float &u, Float &v)

	{

		const Vector3 p = point - center;

		u = ( M_PI + atan2(p.z, p.x) ) * invsize;

		v = acos(p.y / p.mag()) * invsize;

	};

};

/**

 * general 2D texture

 */

class Texture2D: public Texture

{

protected:

	TextureMap *map;

public:

	Texture2D(TextureMap *amap): map(amap) {};

};

/**

 * 2D checkers texture

 */

class CheckersTexture: public Texture2D

{

	ColourMap *colourmap;

public:

	CheckersTexture(TextureMap *tmap, ColourMap *cmap):

		Texture2D(tmap), colourmap(cmap) {};

	Colour evaluate(const Vector3 &point)

	{

		Float u,v, val;

		map->map(point, u,v);

		val = 0.5*(round(u - floor(u)) + round(v - floor(v)));

		return colourmap->map(val);

	};

};

/**

 * 3D perlin cloud texture

 */

class CloudTexture: public Texture

{

	Float detail;

	ColourMap *colourmap;

public:

	CloudTexture(const Float &adetail, ColourMap *cmap):

		detail(adetail), colourmap(cmap) {};

	Colour evaluate(const Vector3 &point)

	{

		Float sum = 0.0;

		for (int i = 1; i < detail; i++)

			sum += fabs(perlin(point.x*i, point.y*i, point.z*i))/i;

		//Float value = sinf(point.x + sum)/2 + 0.5;

		return colourmap->map(sum);

	};

};

/**

 * material

 */

class Material

{

public:

	Colour colour;

	Texture *texture;

	Float ambient, diffuse, specular, shininess; // Phong constants

	Float reflectivity; // how much reflective is the surface

	Float transmissivity, refract_index; // part of light which can be refracted; index of refraction

	bool smooth; // triangle smoothing

	Material(const Colour &acolour): colour(acolour), texture(NULL), smooth(false)

	{

		ambient = 0.2;

		diffuse = 0.8;

		specular = 0.2;

		shininess = 0.5;

		reflectivity = 0.2;

		transmissivity = 0.0;

		refract_index = 1.3;

	}

	void setPhong(const Float amb, const Float dif, const Float spec, const Float shin)

		{ ambient = amb; diffuse = dif; specular = spec; shininess = shin; };

	void setReflectivity(const Float refl) { reflectivity = refl; };

	void setTransmissivity(const Float trans, const Float rindex)

		{ transmissivity = trans; refract_index = rindex; };

	void setSmooth(bool sm) { smooth = sm; };

};

#endif