/*
 * ***** BEGIN GPL LICENSE BLOCK *****
 *
 * 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 *
 * Copyright (c) 2007 The Zdeno Ash Miklas
 *
 * This source file is part of blendTex library
 *
 * Contributor(s):
 *
 * ***** END GPL LICENSE BLOCK *****
 */

/** \file FilterBlueScreen.h
 *  \ingroup bgevideotex
 */

#ifndef __FILTERBLUESCREEN_H__
#define __FILTERBLUESCREEN_H__

#include "Common.h"

#include "FilterBase.h"


/// pixel filter for blue screen
class FilterBlueScreen : public FilterBase
{
public:
	/// constructor
	FilterBlueScreen (void);
	/// destructor
	virtual ~FilterBlueScreen (void) {}

	/// get color
	unsigned char * getColor (void) { return m_color; }
	/// set color
	void setColor (unsigned char red, unsigned char green, unsigned char blue);

	/// get limits for color variation
	unsigned short * getLimits (void) { return m_limits; }
	/// set limits for color variation
	void setLimits (unsigned short minLimit, unsigned short maxLimit);

protected:
	///  blue screen color (red component first)
	unsigned char m_color[3];
	/// limits for color variation - first defines, where ends fully transparent
	/// color, second defines, where begins fully opaque color
	unsigned short m_limits[2];
	/// squared limits for color variation
	unsigned int m_squareLimits[2];
	/// distance between squared limits
	unsigned int m_limitDist;

	/// filter pixel template, source int buffer
	template <class SRC> unsigned int tFilter (SRC src, short x, short y,
		short * size, unsigned int pixSize, unsigned int val)
	{
		// calculate differences
		int difRed = int(VT_R(val)) - int(m_color[0]);
		int difGreen = int(VT_G(val)) - int(m_color[1]);
		int difBlue = int(VT_B(val)) - int(m_color[2]);
		// calc distance from "blue screen" color
		unsigned int dist = (unsigned int)(difRed * difRed + difGreen * difGreen
			+ difBlue * difBlue);
		// condition for fully transparent color
		if (m_squareLimits[0] >= dist) 
			// return color with zero alpha
			VT_A(val) = 0;
		// condition for fully opaque color
		else if (m_squareLimits[1] <= dist)
			// return normal color
			VT_A(val) = 0xFF;
		// otherwise calc alpha
		else
			VT_A(val) = (((dist - m_squareLimits[0]) << 8) / m_limitDist);
		return val;
	}

	/// virtual filtering function for byte source
	virtual unsigned int filter (unsigned char *src, short x, short y,
	                             short * size, unsigned int pixSize, unsigned int val = 0)
	{ return tFilter(src, x, y, size, pixSize, val); }
	/// virtual filtering function for unsigned int source
	virtual unsigned int filter (unsigned int *src, short x, short y,
	                             short * size, unsigned int pixSize, unsigned int val = 0)
	{ return tFilter(src, x, y, size, pixSize, val); }
};


#endif
