/*
-----------------------------------------------------------------------------
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 "CmColor.h"
#include "CmMath.h"

namespace CamelotEngine {

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

    //---------------------------------------------------------------------
#if CM_ENDIAN == CM_ENDIAN_BIG
    ABGR Color::getAsABGR(void) const
#else
    RGBA Color::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 CM_ENDIAN == CM_ENDIAN_BIG
    BGRA Color::getAsBGRA(void) const
#else
    ARGB Color::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 CM_ENDIAN == CM_ENDIAN_BIG
	ARGB Color::getAsARGB(void) const
#else
	BGRA Color::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 CM_ENDIAN == CM_ENDIAN_BIG
    RGBA Color::getAsRGBA(void) const
#else
    ABGR Color::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 CM_ENDIAN == CM_ENDIAN_BIG
    void Color::setAsABGR(const ABGR val)
#else
    void Color::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 CM_ENDIAN == CM_ENDIAN_BIG
    void Color::setAsBGRA(const BGRA val)
#else
    void Color::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 CM_ENDIAN == CM_ENDIAN_BIG
	void Color::setAsARGB(const ARGB val)
#else
	void Color::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 CM_ENDIAN == CM_ENDIAN_BIG
    void Color::setAsRGBA(const RGBA val)
#else
    void Color::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 Color::operator==(const Color& rhs) const
    {
        return (r == rhs.r &&
            g == rhs.g &&
            b == rhs.b &&
            a == rhs.a);
    }
    //---------------------------------------------------------------------
    bool Color::operator!=(const Color& rhs) const
    {
        return !(*this == rhs);
    }
	//---------------------------------------------------------------------
	void Color::setHSB(float hue, float saturation, float 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, (float)1.0);
		saturation = std::max(saturation, (float)0.0);
		brightness = std::min(brightness, (float)1.0);
		brightness = std::max(brightness, (float)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;
		}


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

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

		*brightness = vMax;

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

			float deltaR = (((vMax - r) / 6.0f) + (delta / 2.0f)) / delta;
			float deltaG = (((vMax - g) / 6.0f) + (delta / 2.0f)) / delta;
			float 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;
		}

		
	}

}

