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

Copyright (c) 2000-2006 Torus Knot Software Ltd
Also see acknowledgements in Readme.html

This program is free software; you can redistribute it and/or modify it under 
the terms of the GNU Lesser 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 Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public License along with 
this program; if not, write to the Free Software Foundation, Inc., 59 Temple 
Place - Suite 330, Boston, MA 02111-1307, USA, or go to 
http://www.gnu.org/copyleft/lesser.txt.

You may alternatively use this source under the terms of a specific version of
the OGRE Unrestricted License provided you have obtained such a license from
Torus Knot Software Ltd.
-----------------------------------------------------------------------------
*/
#include "OgreColourInterpolatorAffector.h"
#include "OgreParticleSystem.h"
#include "OgreStringConverter.h"
#include "OgreParticle.h"


namespace Ogre {
    
    // init statics
    ColourInterpolatorAffector::CmdColourAdjust		ColourInterpolatorAffector::msColourCmd[MAX_STAGES];
    ColourInterpolatorAffector::CmdTimeAdjust		ColourInterpolatorAffector::msTimeCmd[MAX_STAGES];

    //-----------------------------------------------------------------------
    ColourInterpolatorAffector::ColourInterpolatorAffector(ParticleSystem* psys)
        : ParticleAffector(psys)
    {
		for (int i=0;i<MAX_STAGES;i++)
		{
			// set default colour to transparent grey, transparent since we might not want to display the particle here
			// grey because when a colour component is 0.5f the maximum difference to another colour component is 0.5f
			mColourAdj[i]	= ColourValue(0.5f, 0.5f, 0.5f, 0.0f);
			mTimeAdj[i]		= 1.0f;
		}

        mType = "ColourInterpolator";

        // Init parameters
        if (createParamDictionary("ColourInterpolatorAffector"))
        {
            ParamDictionary* dict = getParamDictionary();

			for (int i=0;i<MAX_STAGES;i++)
			{
				msColourCmd[i].mIndex	= i;
				msTimeCmd[i].mIndex		= i;

				StringUtil::StrStreamType stage;
				stage << i;
				String	colour_title	= String("colour") + stage.str();
				String	time_title		= String("time") + stage.str();
				String	colour_descr	= String("Stage ") + stage.str() + String(" colour.");
				String	time_descr		= String("Stage ") + stage.str() + String(" time.");

				dict->addParameter(ParameterDef(colour_title, colour_descr, PT_COLOURVALUE), &msColourCmd[i]);
				dict->addParameter(ParameterDef(time_title,   time_descr,   PT_REAL),		 &msTimeCmd[i]);
			}
        }
    }
    //-----------------------------------------------------------------------
    void ColourInterpolatorAffector::_affectParticles(ParticleSystem* pSystem, Real timeElapsed)
    {
        Particle*			p;
		ParticleIterator	pi				= pSystem->_getIterator();


		while (!pi.end())
        {
            p = pi.getNext();
			const Real		life_time		= p->totalTimeToLive;
			Real			particle_time	= 1.0f - (p->timeToLive / life_time); 

			if (particle_time <= mTimeAdj[0])
			{
				p->colour = mColourAdj[0];
			} else
			if (particle_time >= mTimeAdj[MAX_STAGES - 1])
			{
				p->colour = mColourAdj[MAX_STAGES-1];
			} else
			{
				for (int i=0;i<MAX_STAGES-1;i++)
				{
					if (particle_time >= mTimeAdj[i] && particle_time < mTimeAdj[i + 1])
					{
						particle_time -= mTimeAdj[i];
						particle_time /= (mTimeAdj[i+1]-mTimeAdj[i]);
						p->colour.r = ((mColourAdj[i+1].r * particle_time) + (mColourAdj[i].r * (1.0f - particle_time)));
						p->colour.g = ((mColourAdj[i+1].g * particle_time) + (mColourAdj[i].g * (1.0f - particle_time)));
						p->colour.b = ((mColourAdj[i+1].b * particle_time) + (mColourAdj[i].b * (1.0f - particle_time)));
						p->colour.a = ((mColourAdj[i+1].a * particle_time) + (mColourAdj[i].a * (1.0f - particle_time)));
						break;
					}
				}
			}
		}
    }
    
	//-----------------------------------------------------------------------
    void ColourInterpolatorAffector::setColourAdjust(size_t index, ColourValue colour)
    {
        mColourAdj[index] = colour;
    }
    //-----------------------------------------------------------------------
    ColourValue ColourInterpolatorAffector::getColourAdjust(size_t index) const
    {
        return mColourAdj[index];
    }


    //-----------------------------------------------------------------------
    void ColourInterpolatorAffector::setTimeAdjust(size_t index, Real time)
    {
        mTimeAdj[index] = time;
    }
    //-----------------------------------------------------------------------
    Real ColourInterpolatorAffector::getTimeAdjust(size_t index) const
    {
        return mTimeAdj[index];
    }
    
	
	//-----------------------------------------------------------------------
    //-----------------------------------------------------------------------
    //-----------------------------------------------------------------------
    // Command objects
    //-----------------------------------------------------------------------
    //-----------------------------------------------------------------------
    String ColourInterpolatorAffector::CmdColourAdjust::doGet(const void* target) const
    {
        return StringConverter::toString(
            static_cast<const ColourInterpolatorAffector*>(target)->getColourAdjust(mIndex) );
    }
    void ColourInterpolatorAffector::CmdColourAdjust::doSet(void* target, const String& val)
    {
        static_cast<ColourInterpolatorAffector*>(target)->setColourAdjust(mIndex,
            StringConverter::parseColourValue(val));
    }
	//-----------------------------------------------------------------------
    String ColourInterpolatorAffector::CmdTimeAdjust::doGet(const void* target) const
    {
        return StringConverter::toString(
            static_cast<const ColourInterpolatorAffector*>(target)->getTimeAdjust(mIndex) );
    }
    void ColourInterpolatorAffector::CmdTimeAdjust::doSet(void* target, const String& val)
    {
        static_cast<ColourInterpolatorAffector*>(target)->setTimeAdjust(mIndex,
            StringConverter::parseReal(val));
    }

}