/** 
 * @file v3color.cpp
 * @brief LLColor3 class implementation.
 *
 * Copyright (c) 2000-$CurrentYear$, Linden Research, Inc.
 * $License$
 */

#include "linden_common.h"

#include "v3color.h"
#include "v4color.h"

LLColor3 LLColor3::white(1.0f, 1.0f, 1.0f);
LLColor3 LLColor3::black(0.0f, 0.0f, 0.0f);
LLColor3 LLColor3::grey (0.5f, 0.5f, 0.5f);

LLColor3::LLColor3(const LLColor4 &a)
{
	mV[0] = a.mV[0];
	mV[1] = a.mV[1];
	mV[2] = a.mV[2];
}

LLColor3::LLColor3(const LLSD &sd)
{
	mV[0] = (F32) sd[0].asReal();
	mV[1] = (F32) sd[1].asReal();
	mV[2] = (F32) sd[2].asReal();
}

const LLColor3& LLColor3::operator=(const LLColor4 &a) 
{
	mV[0] = a.mV[0];
	mV[1] = a.mV[1];
	mV[2] = a.mV[2];
	return (*this);
}

std::ostream& operator<<(std::ostream& s, const LLColor3 &a) 
{
	s << "{ " << a.mV[VX] << ", " << a.mV[VY] << ", " << a.mV[VZ] << " }";
	return s;
}

void LLColor3::calcHSL(F32* hue, F32* saturation, F32* luminance) const
{
	F32 var_R = mV[VRED];
	F32 var_G = mV[VGREEN];
	F32 var_B = mV[VBLUE];

	F32 var_Min = ( var_R < ( var_G < var_B ? var_G : var_B ) ? var_R : ( var_G < var_B ? var_G : var_B ) );
	F32 var_Max = ( var_R > ( var_G > var_B ? var_G : var_B ) ? var_R : ( var_G > var_B ? var_G : var_B ) );

	F32 del_Max = var_Max - var_Min;

	F32 L = ( var_Max + var_Min ) / 2.0f;
	F32 H = 0.0f;
	F32 S = 0.0f;

	if ( del_Max == 0.0f )
	{
	   H = 0.0f;
	   S = 0.0f;
	}
	else
	{
		if ( L < 0.5 )
			S = del_Max / ( var_Max + var_Min );
		else
			S = del_Max / ( 2.0f - var_Max - var_Min );

		F32 del_R = ( ( ( var_Max - var_R ) / 6.0f ) + ( del_Max / 2.0f ) ) / del_Max;
		F32 del_G = ( ( ( var_Max - var_G ) / 6.0f ) + ( del_Max / 2.0f ) ) / del_Max;
		F32 del_B = ( ( ( var_Max - var_B ) / 6.0f ) + ( del_Max / 2.0f ) ) / del_Max;

		if ( var_R >= var_Max )
			H = del_B - del_G;
		else
		if ( var_G >= var_Max )
			H = ( 1.0f / 3.0f ) + del_R - del_B;
		else
		if ( var_B >= var_Max )
			H = ( 2.0f / 3.0f ) + del_G - del_R;

		if ( H < 0.0f ) H += 1.0f;
		if ( H > 1.0f ) H -= 1.0f;
	}

	if (hue) *hue = H;
	if (saturation) *saturation = S;
	if (luminance) *luminance = L;
}