/*
-----------------------------------------------------------------------------
This source file is part of OGRE
    (Object-oriented Graphics Rendering Engine)
For the latest info, see http://www.ogre3d.org/

Copyright (c) 2000-2011 Torus Knot Software Ltd

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.
-----------------------------------------------------------------------------
*/

#include "OgreColourValue.h"
#include "OgreMath.h"

namespace Ogre {

    const ColourValue ColourValue::ZERO = ColourValue(0.0,0.0,0.0,0.0);
    const ColourValue ColourValue::Black = ColourValue(0.0,0.0,0.0);
    const ColourValue ColourValue::White = ColourValue(1.0,1.0,1.0);
    const ColourValue ColourValue::Red = ColourValue(1.0,0.0,0.0);
    const ColourValue ColourValue::Green = ColourValue(0.0,1.0,0.0);
    const ColourValue ColourValue::Blue = ColourValue(0.0,0.0,1.0);

    //---------------------------------------------------------------------
#if OGRE_ENDIAN == OGRE_ENDIAN_BIG
    ABGR ColourValue::getAsABGR(void) const
#else
    RGBA ColourValue::getAsRGBA(void) const
#endif
    {
        uint8 val8;
        uint32 val32 = 0;

        // Convert to 32bit pattern
        // (RGBA = 8888)

        // Red
        val8 = static_cast<uint8>(r * 255);
        val32 = val8 << 24;

        // Green
        val8 = static_cast<uint8>(g * 255);
        val32 += val8 << 16;

        // Blue
        val8 = static_cast<uint8>(b * 255);
        val32 += val8 << 8;

        // Alpha
        val8 = static_cast<uint8>(a * 255);
        val32 += val8;

        return val32;
    }
    //---------------------------------------------------------------------
#if OGRE_ENDIAN == OGRE_ENDIAN_BIG
    BGRA ColourValue::getAsBGRA(void) const
#else
    ARGB ColourValue::getAsARGB(void) const
#endif
    {
        uint8 val8;
        uint32 val32 = 0;

        // Convert to 32bit pattern
        // (ARGB = 8888)

        // Alpha
        val8 = static_cast<uint8>(a * 255);
        val32 = val8 << 24;

        // Red
        val8 = static_cast<uint8>(r * 255);
        val32 += val8 << 16;

        // Green
        val8 = static_cast<uint8>(g * 255);
        val32 += val8 << 8;

        // Blue
        val8 = static_cast<uint8>(b * 255);
        val32 += val8;


        return val32;
    }
	//---------------------------------------------------------------------
#if OGRE_ENDIAN == OGRE_ENDIAN_BIG
	ARGB ColourValue::getAsARGB(void) const
#else
	BGRA ColourValue::getAsBGRA(void) const
#endif
	{
		uint8 val8;
		uint32 val32 = 0;

		// Convert to 32bit pattern
		// (ARGB = 8888)

		// Blue
		val8 = static_cast<uint8>(b * 255);
		val32 = val8 << 24;

		// Green
		val8 = static_cast<uint8>(g * 255);
		val32 += val8 << 16;

		// Red
		val8 = static_cast<uint8>(r * 255);
		val32 += val8 << 8;

		// Alpha
		val8 = static_cast<uint8>(a * 255);
		val32 += val8;


		return val32;
	}
    //---------------------------------------------------------------------
#if OGRE_ENDIAN == OGRE_ENDIAN_BIG
    RGBA ColourValue::getAsRGBA(void) const
#else
    ABGR ColourValue::getAsABGR(void) const
#endif
    {
        uint8 val8;
        uint32 val32 = 0;

        // Convert to 32bit pattern
        // (ABRG = 8888)

        // Alpha
        val8 = static_cast<uint8>(a * 255);
        val32 = val8 << 24;

        // Blue
        val8 = static_cast<uint8>(b * 255);
        val32 += val8 << 16;

        // Green
        val8 = static_cast<uint8>(g * 255);
        val32 += val8 << 8;

        // Red
        val8 = static_cast<uint8>(r * 255);
        val32 += val8;


        return val32;
    }
    //---------------------------------------------------------------------
#if OGRE_ENDIAN == OGRE_ENDIAN_BIG
    void ColourValue::setAsABGR(const ABGR val)
#else
    void ColourValue::setAsRGBA(const RGBA val)
#endif
    {
        uint32 val32 = val;

        // Convert from 32bit pattern
        // (RGBA = 8888)

        // Red
        r = ((val32 >> 24) & 0xFF) / 255.0f;

        // Green
        g = ((val32 >> 16) & 0xFF) / 255.0f;

        // Blue
        b = ((val32 >> 8) & 0xFF) / 255.0f;

        // Alpha
        a = (val32 & 0xFF) / 255.0f;
    }
    //---------------------------------------------------------------------
#if OGRE_ENDIAN == OGRE_ENDIAN_BIG
    void ColourValue::setAsBGRA(const BGRA val)
#else
    void ColourValue::setAsARGB(const ARGB val)
#endif
    {
        uint32 val32 = val;

        // Convert from 32bit pattern
        // (ARGB = 8888)

        // Alpha
        a = ((val32 >> 24) & 0xFF) / 255.0f;

        // Red
        r = ((val32 >> 16) & 0xFF) / 255.0f;

        // Green
        g = ((val32 >> 8) & 0xFF) / 255.0f;

        // Blue
        b = (val32 & 0xFF) / 255.0f;
    }
	//---------------------------------------------------------------------
#if OGRE_ENDIAN == OGRE_ENDIAN_BIG
	void ColourValue::setAsARGB(const ARGB val)
#else
	void ColourValue::setAsBGRA(const BGRA val)
#endif
	{
		uint32 val32 = val;

		// Convert from 32bit pattern
		// (ARGB = 8888)

		// Blue
		b = ((val32 >> 24) & 0xFF) / 255.0f;

		// Green
		g = ((val32 >> 16) & 0xFF) / 255.0f;

		// Red
		r = ((val32 >> 8) & 0xFF) / 255.0f;

		// Alpha
		a = (val32 & 0xFF) / 255.0f;
	}
    //---------------------------------------------------------------------
#if OGRE_ENDIAN == OGRE_ENDIAN_BIG
    void ColourValue::setAsRGBA(const RGBA val)
#else
    void ColourValue::setAsABGR(const ABGR val)
#endif
    {
        uint32 val32 = val;

        // Convert from 32bit pattern
        // (ABGR = 8888)

        // Alpha
        a = ((val32 >> 24) & 0xFF) / 255.0f;

        // Blue
        b = ((val32 >> 16) & 0xFF) / 255.0f;

        // Green
        g = ((val32 >> 8) & 0xFF) / 255.0f;

        // Red
        r = (val32 & 0xFF) / 255.0f;
    }
    //---------------------------------------------------------------------
    bool ColourValue::operator==(const ColourValue& rhs) const
    {
        return (r == rhs.r &&
            g == rhs.g &&
            b == rhs.b &&
            a == rhs.a);
    }
    //---------------------------------------------------------------------
    bool ColourValue::operator!=(const ColourValue& rhs) const
    {
        return !(*this == rhs);
    }
	//---------------------------------------------------------------------
	void ColourValue::setHSB(Real hue, Real saturation, Real brightness)
	{
		// wrap hue
		if (hue > 1.0f)
		{
			hue -= (int)hue;
		}
		else if (hue < 0.0f)
		{
			hue += (int)hue + 1;
		}
		// clamp saturation / brightness
		saturation = std::min(saturation, (Real)1.0);
		saturation = std::max(saturation, (Real)0.0);
		brightness = std::min(brightness, (Real)1.0);
		brightness = std::max(brightness, (Real)0.0);

		if (brightness == 0.0f)
		{   
			// early exit, this has to be black
			r = g = b = 0.0f;
			return;
		}

		if (saturation == 0.0f)
		{   
			// early exit, this has to be grey

			r = g = b = brightness;
			return;
		}


		Real hueDomain  = hue * 6.0f;
		if (hueDomain >= 6.0f)
		{
			// wrap around, and allow mathematical errors
			hueDomain = 0.0f;
		}
		unsigned short domain = (unsigned short)hueDomain;
		Real f1 = brightness * (1 - saturation);
		Real f2 = brightness * (1 - saturation * (hueDomain - domain));
		Real f3 = brightness * (1 - saturation * (1 - (hueDomain - domain)));

		switch (domain)
		{
		case 0:
			// red domain; green ascends
			r = brightness;
			g = f3;
			b = f1;
			break;
		case 1:
			// yellow domain; red descends
			r = f2;
			g = brightness;
			b = f1;
			break;
		case 2:
			// green domain; blue ascends
			r = f1;
			g = brightness;
			b = f3;
			break;
		case 3:
			// cyan domain; green descends
			r = f1;
			g = f2;
			b = brightness;
			break;
		case 4:
			// blue domain; red ascends
			r = f3;
			g = f1;
			b = brightness;
			break;
		case 5:
			// magenta domain; blue descends
			r = brightness;
			g = f1;
			b = f2;
			break;
		}


	}
	//---------------------------------------------------------------------
	void ColourValue::getHSB(Real* hue, Real* saturation, Real* brightness) const
	{

		Real vMin = std::min(r, std::min(g, b));
		Real vMax = std::max(r, std::max(g, b));
		Real delta = vMax - vMin;

		*brightness = vMax;

		if (Math::RealEqual(delta, 0.0f, 1e-6f))
		{
			// grey
			*hue = 0;
			*saturation = 0;
		}
		else                                    
		{
			// a colour
			*saturation = delta / vMax;

			Real deltaR = (((vMax - r) / 6.0f) + (delta / 2.0f)) / delta;
			Real deltaG = (((vMax - g) / 6.0f) + (delta / 2.0f)) / delta;
			Real deltaB = (((vMax - b) / 6.0f) + (delta / 2.0f)) / delta;

			if (Math::RealEqual(r, vMax))
				*hue = deltaB - deltaG;
			else if (Math::RealEqual(g, vMax))
				*hue = 0.3333333f + deltaR - deltaB;
			else if (Math::RealEqual(b, vMax)) 
				*hue = 0.6666667f + deltaG - deltaR;

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

		
	}

}