// NeL - MMORPG Framework <http://dev.ryzom.com/projects/nel/>
// Copyright (C) 2010  Winch Gate Property Limited
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU Affero General Public License as
// published by the Free Software Foundation, either version 3 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 Affero General Public License for more details.
//
// You should have received a copy of the GNU Affero General Public License
// along with this program.  If not, see <http://www.gnu.org/licenses/>.

#include "std3d.h"

#include "nel/3d/ps_fan_light.h"
#include "nel/3d/ps_macro.h"
#include "nel/3d/ps_attrib_maker.h"
#include "nel/3d/ps_iterator.h"
#include "nel/3d/particle_system.h"
#include "nel/3d/driver.h"



namespace NL3D
{



//////////////////////////////
// fan light implementation //
//////////////////////////////


uint8 CPSFanLight::_RandomPhaseTab[32][128];
bool CPSFanLight::_RandomPhaseTabInitialized = false;

CPSFanLight::TVBMap				CPSFanLight::_VBMap; // fanlight, no texture
CPSFanLight::TVBMap				CPSFanLight::_TexVBMap; // fanlight, textured
CPSFanLight::TVBMap				CPSFanLight::_ColoredVBMap; // fanlight, no texture, varying color
CPSFanLight::TVBMap				CPSFanLight::_ColoredTexVBMap; // fanlight, textured, varying color
CPSFanLight::TIBMap				CPSFanLight::_IBMap;


static const uint FanLightBufSize  = 128; // the size of a buffer of particle to deal with at a time
static const uint NumVertsInBuffer = 4 * FanLightBufSize;





///====================================================================================

/** Well, we could have put a method template in CPSFanLight, but some compilers
  * want the definition of the methods in the header, and some compilers
  * don't want friend with function template, so we use a static method template of a friend class instead,
  * which gives us the same result :)
  */
class CPSFanLightHelper
{
public:
	template <class T, class U>
	static void drawFanLight(T posIt, U timeIt, CPSFanLight &f, uint size, uint32 srcStep)
	{
		NL_PS_FUNC(CPSFanLightHelper_drawFanLight)
		PARTICLES_CHECK_MEM;
		nlassert(f._RandomPhaseTabInitialized);
		//
		f.setupDriverModelMatrix();
		const CVector I = f.computeI();
		const CVector K = f.computeK();
		//
		CVertexBuffer *vb;
		CIndexBuffer  *ib;
		// get (and build if necessary) the vb and the ib
		f.getVBnIB(vb, ib);
		// tmp
		vb->setPreferredMemory(CVertexBuffer::AGPVolatile, true);
		IDriver *driver = f.getDriver();
		const uint maxNumFanLightToDealWith = std::min(FanLightBufSize, f.getNumFanlightsInVB());
		uint8 *randomPhaseTab = &f._RandomPhaseTab[f._PhaseSmoothness][0];
		f._Owner->incrementNbDrawnParticles(size); // for benchmark purpose
		float pSizes[FanLightBufSize];
		float pAngles[FanLightBufSize];
		T endPosIt;

		sint32 k; // helps to count the fans


		 // if so, we need to deal process separatly group of particles
		const uint32 stride = vb->getVertexSize();

		float currentAngle;
		const float angleStep = 256.0f / f._NbFans;


		float *currentSizePt; // it points either the particle constant size, or a size in a table
		float *currentAnglePt; // it points either the particle constant angle, or an angle in a table


		const uint32 currentSizePtIncrement = f._SizeScheme ? 1 : 0; // increment to get the next size for the size pointer. It is 0 if the size is constant
		const uint32 currentAnglePtIncrement = f._Angle2DScheme ? 1 : 0; // increment to get the next angle for the angle pointer. It is 0 if the size is constant


		uint leftToDo = size;
		if (f._ColorScheme)
		{
			// we change the color at each fan light center
			f._ColorScheme->setColorType(driver->getVertexColorFormat());
		}
		do
		{
			uint toProcess = std::min(leftToDo, maxNumFanLightToDealWith);
			vb->setNumVertices(toProcess * f._NbFans * 3);
			{
				CVertexBufferReadWrite vba;
				vb->lock (vba);

				uint8 *ptVect = (uint8 *) vba.getVertexCoordPointer();
				// compute individual colors if needed
				if (f._ColorScheme)
				{
					// we change the color at each fan light center
					f._ColorScheme->make(f._Owner, size - leftToDo, vba.getColorPointer(), vb->getVertexSize() * (f._NbFans + 2), toProcess, false, srcStep);
				}
				if (f._SizeScheme)
				{
					currentSizePt  = (float *) (f._SizeScheme->make(f._Owner, size - leftToDo, pSizes, sizeof(float), toProcess, true, srcStep));
					currentSizePt = pSizes;
				}
				else
				{
					currentSizePt = &f._ParticleSize;
				}
				if (f._Angle2DScheme)
				{
					currentAnglePt = (float *) (f._Angle2DScheme->make(f._Owner, size - leftToDo, pAngles, sizeof(float), toProcess, true, srcStep));
				}
				else
				{
					currentAnglePt = &f._Angle2D;
				}
				//
				float fSize, firstSize, sizeStepBase=0.0, sizeStep;
				if (f._PhaseSmoothness)
				{
					sizeStepBase = 1.f / f._PhaseSmoothness;
				}
				endPosIt = posIt + toProcess;
				for (;posIt != endPosIt; ++posIt, ++timeIt)
				{

					CHECK_VERTEX_BUFFER(*vb, ptVect);
					*(CVector *) ptVect = *posIt;
					// the start angle
					currentAngle = *currentAnglePt;
					const uint8 phaseAdd = (uint8) (f._PhaseSpeed * (*timeIt));
					ptVect += stride;
					const float fanSize = *currentSizePt * 0.5f;
					const float moveIntensity = f._MoveIntensity * fanSize;
					// compute radius & vect for first fan
					firstSize  = fanSize + (moveIntensity * CPSUtil::getCos(randomPhaseTab[0] + phaseAdd));
					*(CVector *) ptVect = (*posIt) + I * firstSize * (CPSUtil::getCos((sint32) currentAngle))
										  + K * firstSize * (CPSUtil::getSin((sint32) currentAngle));
					currentAngle += angleStep;
					ptVect += stride;
					fSize = firstSize;
					// computes other fans
					const sint32 upperBound = (sint32) (f._NbFans - f._PhaseSmoothness - 1);
					for (k = 1; k <= upperBound; ++k)
					{
						fSize  = fanSize + (moveIntensity * CPSUtil::getCos(randomPhaseTab[k] + phaseAdd));
						*(CVector *) ptVect = (*posIt) + I * fSize * (CPSUtil::getCos((sint32) currentAngle))
											  + K * fSize * (CPSUtil::getSin((sint32) currentAngle));
						currentAngle += angleStep;
						ptVect += stride;
					}

					// interpolate radius, so that the fanlight loops correctly
					sizeStep = sizeStepBase * (firstSize - fSize);
					for (; k <= (sint32) (f._NbFans - 1); ++k)
					{
						*(CVector *) ptVect = (*posIt) + I * fSize * (CPSUtil::getCos((sint32) currentAngle))
											  + K * fSize * (CPSUtil::getSin((sint32) currentAngle));
						currentAngle += angleStep;
						ptVect += stride;
						fSize  += sizeStep;
					}
					// last fan
					*(CVector *) ptVect = (*posIt) + I * firstSize * (CPSUtil::getCos((sint32) *currentAnglePt))
											  + K * firstSize * (CPSUtil::getSin((sint32) *currentAnglePt));
					ptVect += stride;
					currentSizePt += currentSizePtIncrement;
					currentAnglePt += currentAnglePtIncrement;
				}
			}
			driver->activeIndexBuffer(*ib);
			driver->activeVertexBuffer(*vb);
			driver->renderTriangles(f._Mat, 0, toProcess * f._NbFans);
			leftToDo -= toProcess;
		}
		while (leftToDo != 0);
		PARTICLES_CHECK_MEM;
	}
};


///====================================================================================
// this blur a tab of bytes once
static void BlurBytesTab(const uint8 *src, uint8 *dest, uint size)
{
	NL_PS_FUNC(BlurBytesTab)
	std::vector<uint8> b(src, src + size);
	for (sint k = 1 ; k < (sint) (size - 1); ++k)
	{
		dest[k] = (uint8) (((uint16) b[k - 1] + (uint16) b[k + 1])>>1);
	}
}

///====================================================================================
void CPSFanLight::initFanLightPrecalc(void)
{
	NL_PS_FUNC(CPSFanLight_initFanLightPrecalc)
	// build several random tab, and linearly interpolate between l values
	float currPhase, nextPhase, phaseStep;
	for (uint l = 0; l < 32 ; l++)
	{
		nextPhase = (float) (uint8) (rand()&0xFF);
		uint32 k = 0;
		while (k < 128)
		{
			currPhase = nextPhase;
			nextPhase = (float) (uint8) (rand()&0xFF);
			phaseStep = (nextPhase - currPhase) / (l + 1);

			for (uint32 m = 0; m <= l; ++m)
			{
				_RandomPhaseTab[l][k] = (uint8) currPhase;
				currPhase += phaseStep;
				++k;
				if (k >= 128) break;
			}
		}
		for (uint m = 0; m < 2 * l; ++m)
			BlurBytesTab(&_RandomPhaseTab[l][0], &_RandomPhaseTab[l][0], 128);
	}
	//#ifdef NL_DEBUG
		_RandomPhaseTabInitialized = true;
	//#endif
}

///====================================================================================
uint32 CPSFanLight::getNumWantedTris() const
{
	NL_PS_FUNC(CPSFanLight_getNumWantedTris)
	nlassert(_Owner);
	//return _Owner->getMaxSize() * _NbFans;
	return _Owner->getSize() * _NbFans;
}

///====================================================================================
bool CPSFanLight::hasTransparentFaces(void)
{
	NL_PS_FUNC(CPSFanLight_hasTransparentFaces)
	return getBlendingMode() != CPSMaterial::alphaTest ;
}

///====================================================================================
bool CPSFanLight::hasOpaqueFaces(void)
{
	NL_PS_FUNC(CPSFanLight_hasOpaqueFaces)
	return !hasTransparentFaces();
}

///====================================================================================
void CPSFanLight::newElement(const CPSEmitterInfo &info)
{
	NL_PS_FUNC(CPSFanLight_newElement)
	newColorElement(info);
	newSizeElement(info);
	newAngle2DElement(info);
}

///====================================================================================
void CPSFanLight::deleteElement(uint32 index)
{
	NL_PS_FUNC(CPSFanLight_deleteElement)
	deleteColorElement(index);
	deleteSizeElement(index);
	deleteAngle2DElement(index);
}

///====================================================================================
void CPSFanLight::setPhaseSpeed(float multiplier)
{
	NL_PS_FUNC(CPSFanLight_setPhaseSpeed)
	_PhaseSpeed = 256.0f * multiplier;
}

///====================================================================================
inline void CPSFanLight::setupMaterial()
{
	NL_PS_FUNC(CPSFanLight_setupMaterial)
	CParticleSystem &ps = *(_Owner->getOwner());
	/// update material color
	if (_Tex == NULL)
	{
		forceTexturedMaterialStages(1);
		SetupModulatedStage(_Mat, 0, CMaterial::Diffuse, CMaterial::Constant);
	}
	else
	{
		_Mat.setTexture(0, _Tex);
		forceTexturedMaterialStages(2);
		SetupModulatedStage(_Mat, 0, CMaterial::Texture, CMaterial::Constant);
		SetupModulatedStage(_Mat, 1, CMaterial::Diffuse, CMaterial::Previous);
	}

	// always setup global colors
	if (_ColorScheme)
	{
		if (ps.getForceGlobalColorLightingFlag() || usesGlobalColorLighting())
		{
			_Mat.texConstantColor(0, ps.getGlobalColorLighted());
		}
		else
		{
			_Mat.texConstantColor(0, ps.getGlobalColor());
		}
	}
	else
	{
		NLMISC::CRGBA col;
		if (ps.getForceGlobalColorLightingFlag() || usesGlobalColorLighting())
		{
			col.modulateFromColor(ps.getGlobalColorLighted(), _Color);
		}
		else if (ps.getColorAttenuationScheme() != NULL || ps.isUserColorUsed())
		{
			col.modulateFromColor(ps.getGlobalColor(), _Color);
		}
		else
		{
			col = _Color;
		}
		_Mat.texConstantColor(0, col);
	}
}


///====================================================================================
void CPSFanLight::draw(bool opaque)
{
//	if (!FilterPS[3]) return;
	NL_PS_FUNC(CPSFanLight_draw)
	PARTICLES_CHECK_MEM;
	if (!_Owner->getSize()) return;

	uint32 step;
	uint   numToProcess;
	computeSrcStep(step, numToProcess);
	if (!numToProcess) return;

	setupMaterial();

	if (step == (1 << 16))
	{
		CPSFanLightHelper::drawFanLight(_Owner->getPos().begin(),
									    _Owner->getTime().begin(),
									   *this,
										numToProcess,
										step
									   );
	}
	else
	{
		CPSFanLightHelper::drawFanLight(TIteratorVectStep1616(_Owner->getPos().begin(), 0, step),
										TIteratorTimeStep1616(_Owner->getTime().begin(), 0, step),
									    *this,
									    numToProcess,
									    step
									   );
	}

	PARTICLES_CHECK_MEM;
}

///====================================================================================
void CPSFanLight::serial(NLMISC::IStream &f) throw(NLMISC::EStream)
{
	NL_PS_FUNC(CPSFanLight_serial)
	sint ver = f.serialVersion(2);
	CPSParticle::serial(f);
	CPSColoredParticle::serialColorScheme(f);
	CPSSizedParticle::serialSizeScheme(f);
	CPSRotated2DParticle::serialAngle2DScheme(f);
	f.serial(_NbFans);
	serialMaterial(f);
	if (ver > 1)
	{
		f.serial(_PhaseSmoothness, _MoveIntensity);
		ITexture *tex = _Tex;
		f.serialPolyPtr(tex);
		if (f.isReading()) _Tex = tex ;
	}
	if (f.isReading())
	{
		init();
	}
}

///====================================================================================
bool CPSFanLight::completeBBox(NLMISC::CAABBox &box) const
{
	NL_PS_FUNC(CPSFanLight_completeBBox)
	// TODO

	return false;
}

///====================================================================================
CPSFanLight::CPSFanLight(uint32 nbFans) : _NbFans(nbFans),
										  _PhaseSmoothness(0),
										  _MoveIntensity(1.5f),
										  _Tex(NULL),
										  _PhaseSpeed(256)
{
	NL_PS_FUNC(CPSFanLight_CPSFanLight)
	nlassert(nbFans >= 3);


	init();
	if (CParticleSystem::getSerializeIdentifierFlag()) _Name = std::string("FanLight");
}


///====================================================================================
CPSFanLight::~CPSFanLight()
{
	NL_PS_FUNC(CPSFanLight_CPSFanLight)
}


///====================================================================================
void CPSFanLight::setNbFans(uint32 nbFans)
{
	NL_PS_FUNC(CPSFanLight_setNbFans)
	_NbFans = nbFans;
	resize(_Owner->getMaxSize());
	//notifyOwnerMaxNumFacesChanged();
}

///====================================================================================
void CPSFanLight::resize(uint32 size)
{
	NL_PS_FUNC(CPSFanLight_resize)
	nlassert(size < (1 << 16));
	resizeColor(size);
	resizeAngle2D(size);
	resizeSize(size);

}

///====================================================================================
void CPSFanLight::init(void)
{
	NL_PS_FUNC(CPSFanLight_init)
	_Mat.setLighting(false);
	_Mat.setZFunc(CMaterial::less);
	_Mat.setDoubleSided(true);
	_Mat.setColor(NLMISC::CRGBA::White);

	updateMatAndVbForColor();
}

///====================================================================================
void CPSFanLight::updateMatAndVbForColor(void)
{
	NL_PS_FUNC(CPSFanLight_updateMatAndVbForColor)
	//touch();
}

///====================================================================================
void CPSFanLight::getVBnIB(CVertexBuffer *&retVb, CIndexBuffer *&retIb)
{
	NL_PS_FUNC(CPSFanLight_getVBnIB)
	TVBMap &vbMap = _ColorScheme ? (_Tex == NULL  ? _ColoredVBMap : _ColoredTexVBMap)
								 : (_Tex == NULL  ? _VBMap : _TexVBMap);
	#ifdef NL_NAMED_INDEX_BUFFER
		const char *ibName = _ColorScheme ? (_Tex == NULL  ? "_ColoredVBMap" : "_ColoredTexVBMap")
					                    : (_Tex == NULL  ? "_VBMap" : "_TexVBMap");
	#endif
	TVBMap::iterator vbIt = vbMap.find(_NbFans);
	if (vbIt != vbMap.end())
	{
		retVb = &(vbIt->second);
		TIBMap::iterator pbIt = _IBMap.find(_NbFans);
		nlassert(pbIt != _IBMap.end());
		#ifdef NL_NAMED_INDEX_BUFFER
			if (pbIt->second.getName().empty()) NL_SET_IB_NAME(pbIt->second, ibName);
		#endif
		retIb = &(pbIt->second);
	}
	else // we need to create the vb
	{
		// create an entry (we setup the primitive block at the same time, this could be avoided, but doesn't make much difference)
		CVertexBuffer &vb = vbMap[_NbFans]; // create a vb
		CIndexBuffer &ib = _IBMap[_NbFans]; // eventually create a pb
		const uint32 size = getNumFanlightsInVB();
		vb.setVertexFormat(CVertexBuffer::PositionFlag |
						   CVertexBuffer::PrimaryColorFlag |
						   (_Tex != NULL ?  CVertexBuffer::TexCoord0Flag : 0)
						  );
		vb.setNumVertices(size * (2 + _NbFans));
		vb.setPreferredMemory(CVertexBuffer::AGPVolatile, true); // keep local memory because of interleaved format
		vb.setName("CPSFanLight");
		ib.setFormat(NL_DEFAULT_INDEX_BUFFER_FORMAT);
		ib.setNumIndexes(size * _NbFans * 3);
		// pointer on the current index to fill
		CIndexBufferReadWrite iba;
		ib.lock (iba);
		TIndexType *ptIndex = (TIndexType *) iba.getPtr();

		CVertexBufferReadWrite vba;
		vb.lock (vba);

		// index of the first vertex of the current fanFilght
		uint currVertFan = 0;

		uint l; // the current fan in the current fanlight
		uint k; // the current fan light

		for (k = 0; k < size; ++k)
		{
			for (l = 0; l < _NbFans; ++l)
			{
				*ptIndex++ = (TIndexType) currVertFan;
				*ptIndex++ = (TIndexType) (currVertFan + (l + 1));
				*ptIndex++ = (TIndexType) (currVertFan + (l + 2));
			}
			currVertFan += 2 + _NbFans;
		}

		for (k = 0; k < size; ++k)
		{
			if (_Tex)
			{
				vba.setTexCoord(k * (_NbFans + 2), 0, NLMISC::CUV(0, 0));
			}
			if (!_ColorScheme)
			{
				vba.setColor(k * (_NbFans + 2), CRGBA::White);
			}
			if (!_Tex)
			{
				for(l = 1; l <= _NbFans + 1; ++l)
				{
					vba.setColor(l + k * (_NbFans + 2), CRGBA(0, 0, 0));
				}
			}
			else
			{
				for(l = 1; l <= _NbFans + 1; ++l)
				{
					vba.setColor(l + k * (_NbFans + 2), CRGBA(0, 0, 0));
					vba.setTexCoord(l + k * (_NbFans + 2), 0, NLMISC::CUV((l - 1) / (float) _NbFans, 1));
				}
			}
		}

		retVb = &vb;
		retIb = &ib;
	}
}

///====================================================================================
uint CPSFanLight::getNumFanlightsInVB() const
{
	NL_PS_FUNC(CPSFanLight_getNumFanlightsInVB)
	const uint numRib = NumVertsInBuffer / (2 + _NbFans);
	return std::max(1u, numRib);
}

///====================================================================================
void CPSFanLight::enumTexs(std::vector<NLMISC::CSmartPtr<ITexture> > &dest, IDriver &drv)
{
	NL_PS_FUNC(CPSFanLight_enumTexs)
	if (_Tex)
	{
		dest.push_back(_Tex);
	}
}

} // NL3D