// 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_ribbon.h"
#include "nel/3d/ps_macro.h"
#include "nel/3d/particle_system.h"
#include "nel/3d/driver.h"
#include "nel/3d/ps_util.h"
#include "nel/3d/texture_mem.h"
#include "nel/misc/matrix.h"

namespace NL3D
{

static NLMISC::CRGBA GradientB2W[] = {NLMISC::CRGBA(0, 0, 0, 0), NLMISC::CRGBA(255, 255, 255, 255) };

CPSRibbon::TVBMap CPSRibbon::_VBMaps[16];


/// private use : this create a gradient texture that goew from black to white
static ITexture *CreateGradientTexture()
{
	NL_PS_FUNC(CreateGradientTexture)
	std::auto_ptr<CTextureMem> tex(new CTextureMem((uint8 *) &GradientB2W,
												   sizeof(GradientB2W),
												   false, /* dont delete */
												   false, /* not a file */
												   2, 1)
								  );
	//tex->setWrapS(ITexture::Clamp);
	tex->setShareName("#GradBW");
	return tex.release();
}


///////////////////////////
// ribbon implementation //
///////////////////////////

// predifined shapes
const NLMISC::CVector CPSRibbon::Triangle[] =
{
	NLMISC::CVector(0, 1, 0),
	NLMISC::CVector(1, -1, 0),
	NLMISC::CVector(-1, -1, 0),
};

const NLMISC::CVector CPSRibbon::Losange[] =
{
	NLMISC::CVector(0, 1.f, 0),
	NLMISC::CVector(1.f, 0, 0),
	NLMISC::CVector(0, -1.f, 0),
	NLMISC::CVector(-1.f, 0, 0)
};

const NLMISC::CVector  CPSRibbon::HeightSides[] =
{
	NLMISC::CVector(-0.5f, 1, 0),
	NLMISC::CVector(0.5f, 1, 0),
	NLMISC::CVector(1, 0.5f, 0),
	NLMISC::CVector(1, -0.5f, 0),
	NLMISC::CVector(0.5f, -1, 0),
	NLMISC::CVector(-0.5f, -1, 0),
	NLMISC::CVector(-1, -0.5f, 0),
	NLMISC::CVector(-1, 0.5f, 0)
};


const NLMISC::CVector CPSRibbon::Pentagram[] =
{
	NLMISC::CVector(0, 1, 0),
	NLMISC::CVector(1, -1, 0),
	NLMISC::CVector(-1, 0, 0),
	NLMISC::CVector(1, 0, 0),
	NLMISC::CVector(-1, -1, 0)
};

const NLMISC::CVector CPSRibbon::SimpleSegmentX[] =
{
	NLMISC::CVector(1, 0, 0),
	NLMISC::CVector(-1, 0, 0),
};
const uint CPSRibbon::NbVerticesInSimpleSegmentX = sizeof(CPSRibbon::SimpleSegmentX) / sizeof(CVector);

const NLMISC::CVector CPSRibbon::SimpleSegmentY[] =
{
	NLMISC::CVector(0, 1, 0),
	NLMISC::CVector(0, -1, 0),
};
const uint CPSRibbon::NbVerticesInSimpleSegmentY = sizeof(CPSRibbon::SimpleSegmentY) / sizeof(CVector);

const NLMISC::CVector CPSRibbon::SimpleSegmentZ[] =
{
	NLMISC::CVector(0, 0, 1),
	NLMISC::CVector(0, 0, -1),
};
const uint CPSRibbon::NbVerticesInSimpleSegmentZ = sizeof(CPSRibbon::SimpleSegmentZ) / sizeof(CVector);

const NLMISC::CVector CPSRibbon::SimpleBrace[] =
{
	NLMISC::CVector(1, 0, 0),
	NLMISC::CVector(-1, 0, 0),
	NLMISC::CVector(0, 1, 0),
	NLMISC::CVector(0, -1, 0)
};
const uint CPSRibbon::NbVerticesInSimpleBrace = sizeof(CPSRibbon::SimpleBrace) / sizeof(CVector);

const uint CPSRibbon::NbVerticesInTriangle = sizeof(CPSRibbon::Triangle) / sizeof(CVector);
const uint CPSRibbon::NbVerticesInLosange = sizeof(Losange) / sizeof(CVector);
const uint CPSRibbon::NbVerticesInHeightSide = sizeof(CPSRibbon::HeightSides) / sizeof(CVector);
const uint CPSRibbon::NbVerticesInPentagram = sizeof(CPSRibbon::Pentagram) / sizeof(CVector);


struct CDummy2DAngle : CPSRotated2DParticle
{
	CPSLocated *getAngle2DOwner(void) { return NULL; }
};

///==================================================================================================================
void CPSRibbon::serial(NLMISC::IStream &f) throw(NLMISC::EStream)
{
	NL_PS_FUNC(CPSRibbon_serial)
	// Version 3 : - added brace mode
	//             - added orientation enum
	sint ver = f.serialVersion(3);
	if (ver == 1)
	{
		nlassert(f.isReading());

		/// we had CPSParticle::serial(f), but this is not the base class anymore, so we emulate this...
		/// version 2 : auto-lod saved
		sint ver2 = f.serialVersion(2);

		// here is CPSLocatedBindable::serial(f)
		sint ver3 = f.serialVersion(4);
		f.serialPtr(_Owner);
		if (ver3 > 1) f.serialEnum(_LOD);
		if (ver3 > 2) f.serial(_Name);
		if (ver3 > 3)
		{
			if (f.isReading())
			{
				uint32 id;
				f.serial(id);
				setExternID(id);
			}
			else
			{
				f.serial(_ExternID);
			}
		}

		if (ver2 >= 2)
		{
			bool bDisableAutoLOD;
			f.serial(bDisableAutoLOD);
			disableAutoLOD(bDisableAutoLOD);
		}

		uint32 tailNbSegs;
		bool   colorFading;
		bool   systemBasisEnabled;
		bool   drEnabled; // dying ribbons, not supported in this version

		CPSColoredParticle::serialColorScheme(f);
		CPSSizedParticle::serialSizeScheme(f);

		// we dont use the 2d angle anymore...serial a dummy one
		{
			 CDummy2DAngle _Dummy2DAngle;
			_Dummy2DAngle.serialAngle2DScheme(f);
		}

		f.serial(colorFading, systemBasisEnabled);
		serialMaterial(f);

		f.serial(drEnabled);
		f.serial(tailNbSegs);
		ITexture *tex = NULL;
		f.serialPolyPtr(tex);
		_Tex = tex;
		if (_Tex != NULL)
		{
			f.serial(_UFactor, _VFactor) ;
		}

		// shape serialization
		f.serialCont(_Shape);


		_NbSegs = tailNbSegs >> 1;
		if (_NbSegs < 1) _NbSegs = 2;
		setInterpolationMode(Linear);

		nlassert(_Owner);
		resize(_Owner->getMaxSize());
		initDateVect();
		resetFromOwner();
	}


	if (ver >= 2)
	{
		CPSRibbonBase::serial(f);
		CPSColoredParticle::serialColorScheme(f);
		CPSSizedParticle::serialSizeScheme(f);
		CPSMaterial::serialMaterial(f);
		f.serialCont(_Shape);
		bool colorFading = _ColorFading;
		f.serial(colorFading);
		_ColorFading = colorFading;
		uint32 tailNbSegs = _NbSegs;
		f.serial(tailNbSegs);
		if (f.isReading())
		{
			setTailNbSeg(_NbSegs);
			touch();
		}
		ITexture *tex = _Tex;
		f.serialPolyPtr(tex);
		_Tex = tex;
		if (_Tex != NULL)
		{
			f.serial(_UFactor, _VFactor) ;
		}
	}

	if (ver >= 3)
	{
		bool braceMode = _BraceMode;
		f.serial(braceMode);
		_BraceMode = braceMode;
		f.serialEnum(_Orientation);
	}

	if (f.isReading())
	{
		touch();
	}
}


//=======================================================
CPSRibbon::CPSRibbon() : _UFactor(1.f),
						 _VFactor(1.f),
						 _Orientation(FollowPath),
						 _BraceMode(true),
						 _ColorFading(true),
						 _GlobalColor(false),
						 _Lighted(false),
						 _ForceLighted(false),
						 _Touch(true)
{
	NL_PS_FUNC(CPSRibbon_CPSRibbon)
	setInterpolationMode(Linear);
	setSegDuration(0.06f);
	if (CParticleSystem::getSerializeIdentifierFlag()) _Name = std::string("Ribbon");
	setShape(Triangle, NbVerticesInTriangle);
	_Mat.setDoubleSided(true);
}


//=======================================================
CPSRibbon::~CPSRibbon()
{
	NL_PS_FUNC(CPSRibbon_CPSRibbonDtor)
}


//==========================================================================
inline uint CPSRibbon::getNumVerticesInSlice() const
{
	NL_PS_FUNC(CPSRibbon_getNumVerticesInSlice)
	if (_BraceMode)
	{
		return (uint)_Shape.size();
	}
	else
	{
		return (uint)_Shape.size() + (_Tex == NULL ? 0 : 1);
	}
}





//=======================================================
void CPSRibbon::step(TPSProcessPass pass)
{
	NL_PS_FUNC(CPSRibbon_step)
	if (pass == PSMotion)
	{
		if (!_Parametric)
		{
			updateGlobals();
		}
	}
	else
	if (
		(pass == PSBlendRender && hasTransparentFaces())
		|| (pass == PSSolidRender && hasOpaqueFaces())
		)
	{
		uint32 step;
		uint   numToProcess;
		computeSrcStep(step, numToProcess);
		if (!numToProcess) return;

		/// update the material color
		CParticleSystem &ps = *(_Owner->getOwner());
		if (ps.getForceGlobalColorLightingFlag() || usesGlobalColorLighting())
		{
			_Mat.setColor(ps.getGlobalColorLighted());
		}
		else
		{
			_Mat.setColor(ps.getGlobalColor());
		}

		/** We support Auto-LOD for ribbons, although there is a built-in LOD (that change the geometry rather than the number of ribbons)
		  * that gives better result (both can be used simultaneously)
		  */

		displayRibbons(numToProcess, step);

	}
	else
	if (pass == PSToolRender) // edition mode only
	{
		//showTool();
	}
}


//=======================================================
void CPSRibbon::newElement(const CPSEmitterInfo &info)
{
	NL_PS_FUNC(CPSRibbon_newElement)
	CPSRibbonBase::newElement(info);
	newColorElement(info);
	newSizeElement(info);
}


//=======================================================
void CPSRibbon::deleteElement(uint32 index)
{
	NL_PS_FUNC(CPSRibbon_deleteElement)
	CPSRibbonBase::deleteElement(index);
	deleteColorElement(index);
	deleteSizeElement(index);
}


//=======================================================
void CPSRibbon::resize(uint32 size)
{
	NL_PS_FUNC(CPSRibbon_resize)
	nlassert(size < (1 << 16));
	CPSRibbonBase::resize(size);
	resizeColor(size);
	resizeSize(size);
}

//=======================================================
void CPSRibbon::updateMatAndVbForColor(void)
{
	NL_PS_FUNC(CPSRibbon_updateMatAndVbForColor)
	touch();
}


///=========================================================================
// Create the start slice of a ribbon (all vertices at the same pos)
static inline uint8 *BuildRibbonFirstSlice(const NLMISC::CVector &pos,
										   uint  numVerts,
										   uint8 *dest,
										   uint  vertexSize
									      )
{
	NL_PS_FUNC(BuildRibbonFirstSlice)
	do
	{
		* (NLMISC::CVector *) dest = pos;
		dest += vertexSize;
	}
	while (--numVerts);
	return dest;
}


///=========================================================================
// This compute one slice of a ribbon, and return the next vertex to be filled
static inline uint8 *ComputeRibbonSliceFollowPath(const NLMISC::CVector &prev,
									    const NLMISC::CVector &next,
									    const NLMISC::CVector *shape,
									    uint  numVerts,
									    uint8 *dest,
									    uint  vertexSize,
										float size,
										NLMISC::CMatrix &basis
									   )
{
	NL_PS_FUNC(ComputeRibbonSliceFollowPath)
	// compute a basis from the next and previous position.
	// (not optimized for now, but not widely used, either...)
	const float epsilon = 10E-5f;
	if (fabsf(next.x - prev.x) > epsilon
		|| fabsf(next.y - prev.y) > epsilon
		|| fabsf(next.z - prev.z) > epsilon)
	{
		// build a new basis, or use the previous one otherwise
		CPSUtil::buildSchmidtBasis(next - prev, basis);
	}
	basis.setPos(next);

	const NLMISC::CVector *shapeEnd = shape + numVerts;
	do
	{
		*(NLMISC::CVector *) dest = basis * (size * (*shape));
		++shape;
		dest += vertexSize;
	}
	while (shape != shapeEnd);
	return dest;
}

///=========================================================================
// This compute one slice of a ribbon, and return the next vertex to be filled
static inline uint8 *ComputeRibbonSliceIdentity(const NLMISC::CVector &prev,
											   const NLMISC::CVector &next,
											   const NLMISC::CVector *shape,
											   uint  numVerts,
											   uint8 *dest,
											   uint  vertexSize,
											   float size
											  )
{
	NL_PS_FUNC(ComputeRibbonSliceIdentity)
	const NLMISC::CVector *shapeEnd = shape + numVerts;
	do
	{
		((NLMISC::CVector *) dest)->set(size * shape->x + next.x,
			                            size * shape->y + next.y,
										size * shape->z + next.z);
		++shape;
		dest += vertexSize;
	}
	while (shape != shapeEnd);
	return dest;
}

///=========================================================================
static inline uint8 *ComputeRibbonSliceFollowPathXY(const NLMISC::CVector &prev,
												  const NLMISC::CVector &next,
												  const NLMISC::CVector *shape,
												  uint  numVerts,
												  uint8 *dest,
												  uint  vertexSize,
												  float size,
												  NLMISC::CMatrix &basis
												  )
{
	NL_PS_FUNC(ComputeRibbonSliceFollowPathXY)
	float deltaX = next.x - prev.x;
	float deltaY = next.y - prev.y;
	const float epsilon = 10E-5f;
	if (fabsf(deltaX) > epsilon
		|| fabsf(deltaY) > epsilon)
	{
		float norm = sqrtf(NLMISC::sqr(deltaX) + NLMISC::sqr(deltaY));
		float invNorm = (norm != 0.f) ? 1.f / norm : 0.f;
		NLMISC::CVector I, J;
		J.set(deltaX * invNorm, deltaY * invNorm, 0.f);
		I.set(-J.y, J.x, 0.f);
		basis.setRot(I, CVector::K, J, true);
	}
	basis.setPos(next);
	const NLMISC::CVector *shapeEnd = shape + numVerts;
	do
	{
		*(NLMISC::CVector *) dest = basis * (size * (*shape));
		++shape;
		dest += vertexSize;
	}
	while (shape != shapeEnd);
	return dest;
}




///=========================================================================
// This is used to compute a ribbon mesh from its curve and its base shape.
// This is for untextured versions (no need to duplicate the last vertex of each slice)
static inline uint8 *ComputeUntexturedRibbonMesh(uint8 *destVb,
											     uint  vertexSize,
											     const NLMISC::CVector *curve,
											     const NLMISC::CVector *shape,
											     uint  numSegs,
												 uint  numVerticesInShape,
												 float sizeIncrement,
												 float size,
												 CPSRibbon::TOrientation orientation
												)
{
	NL_PS_FUNC(ComputeUntexturedRibbonMesh)
	CMatrix basis;
	basis.scale(0);
	switch(orientation)
	{
		case CPSRibbon::FollowPath:
			do
			{
				destVb = ComputeRibbonSliceFollowPath(curve[1],
											         curve[0],
											         shape,
											         numVerticesInShape,
											         destVb,
											         vertexSize,
											         size,
											         basis);
				++ curve;
				size -= sizeIncrement;
			}
			while (--numSegs);
		break;
		case CPSRibbon::FollowPathXY:
			do
			{
				destVb = ComputeRibbonSliceFollowPathXY(curve[1],
											         curve[0],
													 shape,
													 numVerticesInShape,
													 destVb,
													 vertexSize,
													 size,
													 basis);
				++ curve;
				size -= sizeIncrement;
			}
			while (--numSegs);
		break;
		case CPSRibbon::Identity:
			do
			{
				destVb = ComputeRibbonSliceIdentity(curve[1],
											        curve[0],
													shape,
													numVerticesInShape,
													destVb,
													vertexSize,
													size
												   );
				++ curve;
				size -= sizeIncrement;
			}
			while (--numSegs);
		break;
		default:
			nlassert(0);
		break;
	}
	return BuildRibbonFirstSlice(curve[0], numVerticesInShape, destVb, vertexSize);
}

///=========================================================================
// This is used to compute a ribbon mesh from its curve and its base shape.
// (Textured Version)
static inline uint8 *ComputeTexturedRibbonMesh(uint8 *destVb,
											   uint  vertexSize,
											   const NLMISC::CVector *curve,
											   const NLMISC::CVector *shape,
											   uint  numSegs,
											   uint  numVerticesInShape,
											   float sizeIncrement,
											   float size,
											   CPSRibbon::TOrientation orientation
											  )
{
	NL_PS_FUNC(ComputeTexturedRibbonMesh)
	CMatrix basis;
	basis.scale(0);
	switch(orientation)
	{
		case CPSRibbon::FollowPath:
			do
			{
				uint8 *nextDestVb = ComputeRibbonSliceFollowPath(curve[1],
													   curve[0],
													   shape,
													   numVerticesInShape,
													   destVb,
													   vertexSize,
													   size,
													   basis
													  );
				// duplicate last vertex ( equal first)
				* (NLMISC::CVector *) nextDestVb = * (NLMISC::CVector *) destVb;
				destVb = nextDestVb + vertexSize;
				//
				++ curve;
				size -= sizeIncrement;
			}
			while (--numSegs);
		break;
		case CPSRibbon::FollowPathXY:
			do
			{
				uint8 *nextDestVb = ComputeRibbonSliceFollowPathXY(curve[1],
					curve[0],
					shape,
					numVerticesInShape,
					destVb,
					vertexSize,
					size,
					basis
					);
				// duplicate last vertex ( equal first)
				* (NLMISC::CVector *) nextDestVb = * (NLMISC::CVector *) destVb;
				destVb = nextDestVb + vertexSize;
				//
				++ curve;
				size -= sizeIncrement;
			}
			while (--numSegs);
		break;
		case CPSRibbon::Identity:
			do
			{
				uint8 *nextDestVb = ComputeRibbonSliceIdentity(curve[1],
					curve[0],
					shape,
					numVerticesInShape,
					destVb,
					vertexSize,
					size
					);
				// duplicate last vertex ( equal first)
				* (NLMISC::CVector *) nextDestVb = * (NLMISC::CVector *) destVb;
				destVb = nextDestVb + vertexSize;
				//
				++ curve;
				size -= sizeIncrement;
			}
			while (--numSegs);
		break;
		default:
			nlassert(0);
		break;
	}
	return BuildRibbonFirstSlice(curve[0], numVerticesInShape + 1, destVb, vertexSize);
}

//==========================================================================
void CPSRibbon::displayRibbons(uint32 nbRibbons, uint32 srcStep)
{
//	if (!FilterPS[5]) return;
	NL_PS_FUNC(CPSRibbon_displayRibbons)
	if (!nbRibbons) return;
	nlassert(_Owner);
	CPSRibbonBase::updateLOD();
	if (_UsedNbSegs < 2) return;
	const float date = _Owner->getOwner()->getSystemDate();
	uint8						*currVert;
	CVBnPB						&VBnPB = getVBnPB(); // get the appropriate vb (built it if needed)
	CVertexBuffer				&VB = VBnPB.VB;
	CIndexBuffer				&PB = VBnPB.PB;
	const uint32				vertexSize  = VB.getVertexSize();
	uint						colorOffset=0;

	IDriver *drv = this->getDriver();
	#ifdef NL_DEBUG
		nlassert(drv);
	#endif
	drv->setupModelMatrix(getLocalToWorldTrailMatrix());
	_Owner->incrementNbDrawnParticles(nbRibbons); // for benchmark purpose
	const uint numRibbonBatch = getNumRibbonsInVB(); // number of ribons to process at once
	if (_UsedNbSegs == 0) return;
	////////////////////
	// Material setup //
	////////////////////
		CParticleSystem &ps = *(_Owner->getOwner());
		bool useGlobalColor = ps.getColorAttenuationScheme() != NULL || ps.isUserColorUsed();
		if (useGlobalColor != _GlobalColor)
		{
			_GlobalColor = useGlobalColor;
			touch();
		}
		if (usesGlobalColorLighting() != _Lighted)
		{
			_Lighted = usesGlobalColorLighting();
			touch();
		}
		if (ps.getForceGlobalColorLightingFlag() != _ForceLighted)
		{
			_ForceLighted = ps.getForceGlobalColorLightingFlag();
			touch();
		}
		updateMaterial();
		setupGlobalColor();
		//
		if (_ColorScheme)
		{
			colorOffset = VB.getColorOff();
		}
	/////////////////////
	// Compute ribbons //
	/////////////////////
		const uint numVerticesInSlice = getNumVerticesInSlice();
		const uint numVerticesInShape = (uint)_Shape.size();
		//
		static std::vector<float> sizes;
		static std::vector<NLMISC::CVector> ribbonPos;  // this is where the position of each ribbon slice center i stored
		ribbonPos.resize(_UsedNbSegs + 1); // make sure we have enough room
		sizes.resize(numRibbonBatch);

		//
		uint toProcess;
		uint ribbonIndex = 0; // index of the first ribbon in the batch being processed
		uint32 fpRibbonIndex = 0; // fixed point index in source
		if (_ColorScheme)
		{
			_ColorScheme->setColorType(drv->getVertexColorFormat());
		}
		do
		{
			toProcess = std::min((uint) (nbRibbons - ribbonIndex) , numRibbonBatch);
			VB.setNumVertices((_UsedNbSegs + 1) * toProcess * numVerticesInSlice);
			{
				CVertexBufferReadWrite vba;
				VB.lock(vba);
				currVert = (uint8 *) vba.getVertexCoordPointer();
				/// setup sizes
				const float	*ptCurrSize;
				uint32  ptCurrSizeIncrement;
				if (_SizeScheme)
				{
					ptCurrSize = (float *) _SizeScheme->make(this->_Owner, ribbonIndex, &sizes[0], sizeof(float), toProcess, true, srcStep);
					ptCurrSizeIncrement = 1;
				}
				else
				{
					ptCurrSize = &_ParticleSize;
					ptCurrSizeIncrement = 0;
				}

				/// compute colors
				if (_ColorScheme)
				{
					_ColorScheme->makeN(this->_Owner, ribbonIndex, currVert + colorOffset, vertexSize, toProcess, numVerticesInSlice * (_UsedNbSegs + 1), srcStep);
				}
				uint k = toProcess;
				//////////////////////////////////////////////////////////////////////////////////////
				// interpolate and project points the result is directly setup in the vertex buffer //
				//////////////////////////////////////////////////////////////////////////////////////
				if (!_Parametric)
				{
					//////////////////////
					// INCREMENTAL CASE //
					//////////////////////
					if (_Tex != NULL && !_BraceMode) // textured case : must duplicate last vertex, unless in brace mod
					{
						do
						{
							const float ribbonSizeIncrement = *ptCurrSize / (float) _UsedNbSegs;
							ptCurrSize += ptCurrSizeIncrement;
							// the parent class has a method to get the ribbons positions
							computeRibbon((uint) (fpRibbonIndex >> 16), &ribbonPos[0], sizeof(NLMISC::CVector));
							currVert = ComputeTexturedRibbonMesh(currVert,
																 vertexSize,
																 &ribbonPos[0],
																 &_Shape[0],
																 _UsedNbSegs,
																 numVerticesInShape,
																 ribbonSizeIncrement,
																 *ptCurrSize,
																 _Orientation
																);
							fpRibbonIndex += srcStep;
						}
						while (--k);
					}
					else // untextured case
					{
						do
						{
							const float ribbonSizeIncrement = *ptCurrSize / (float) _UsedNbSegs;
							ptCurrSize += ptCurrSizeIncrement;
							// the parent class has a method to get the ribbons positions
							computeRibbon((uint) (fpRibbonIndex >> 16), &ribbonPos[0], sizeof(NLMISC::CVector));
							currVert = ComputeUntexturedRibbonMesh(currVert,
																   vertexSize,
																   &ribbonPos[0],
																   &_Shape[0],
																   _UsedNbSegs,
																   numVerticesInShape,
																   ribbonSizeIncrement,
																   *ptCurrSize,
																   _Orientation
																  );
							fpRibbonIndex += srcStep;
						}
						while (--k);
					}
				}
				else
				{
					//////////////////////
					// PARAMETRIC  CASE //
					//////////////////////
					if (_Tex != NULL) // textured case
					{
						do
						{
							const float ribbonSizeIncrement = *ptCurrSize / (float) _UsedNbSegs;
							ptCurrSize += ptCurrSizeIncrement;
							_Owner->integrateSingle(date - _UsedSegDuration * (_UsedNbSegs + 1),
													_UsedSegDuration,
													_UsedNbSegs + 1,
													(uint) (fpRibbonIndex >> 16),
													&ribbonPos[0]);

							currVert = ComputeTexturedRibbonMesh(currVert,
																 vertexSize,
																 &ribbonPos[0],
																 &_Shape[0],
																 _UsedNbSegs,
																 numVerticesInShape,
																 ribbonSizeIncrement,
																 *ptCurrSize,
																 _Orientation
																);
							fpRibbonIndex += srcStep;
						}
						while (--k);
					}
					else // untextured case
					{
						do
						{
							const float ribbonSizeIncrement = *ptCurrSize / (float) _UsedNbSegs;
							ptCurrSize += ptCurrSizeIncrement;
							_Owner->integrateSingle(date - _UsedSegDuration * (_UsedNbSegs + 1),
													_UsedSegDuration,
													_UsedNbSegs + 1,
													(uint) (fpRibbonIndex >> 16),
													&ribbonPos[0]);

							currVert = ComputeUntexturedRibbonMesh(currVert,
																   vertexSize,
																   &ribbonPos[0],
																   &_Shape[0],
																   _UsedNbSegs,
																   numVerticesInShape,
																   ribbonSizeIncrement,
																   *ptCurrSize,
																   _Orientation
																  );
							fpRibbonIndex += srcStep;
						}
						while (--k);
					}
				}
			}
			// display the result
			uint numTri = numVerticesInShape * _UsedNbSegs * toProcess;
			if (!_BraceMode)
			{
				numTri <<= 1;
			}
			PB.setNumIndexes(3 * numTri);
			drv->activeIndexBuffer(PB);
			drv->activeVertexBuffer(VB);
			drv->renderTriangles(_Mat, 0, numTri);
			ribbonIndex += toProcess;
		}
		while (ribbonIndex != nbRibbons);

}

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


//==========================================================================
bool CPSRibbon::hasOpaqueFaces(void)
{
	NL_PS_FUNC(CPSRibbon_hasOpaqueFaces)
	return !hasTransparentFaces();
}

//==========================================================================
uint32 CPSRibbon::getNumWantedTris() const
{
	NL_PS_FUNC(CPSRibbon_getNumWantedTris)
	nlassert(_Owner);
	//return _Owner->getMaxSize() * _NbSegs;
	return _Owner->getSize() * _NbSegs;
}

//==========================================================================
// Set a tri in ribbon with check added
static inline void setTri(CIndexBufferReadWrite &ibrw, const CVertexBuffer &vb, uint32 triIndex, uint32 i0, uint32 i1, uint32 i2)
{
	nlassert(i0 < vb.getNumVertices());
	nlassert(i1 < vb.getNumVertices());
	nlassert(i2 < vb.getNumVertices());
	ibrw.setTri(triIndex, i0, i1, i2);
}

//==========================================================================
CPSRibbon::CVBnPB &CPSRibbon::getVBnPB()
{
	NL_PS_FUNC(CPSRibbon_getVBnPB)
	// TODO : vb pointer caching ?
	// TODO : better vb reuse ?
	/// choose the right vb by building an index for lookup into 'vbMaps' defined above
	TVBMap &map = _VBMaps[ (_BraceMode		         ? 8 : 0)  | // set bit 3 if brace mode
						   (_Tex != NULL			 ? 4 : 0)  | // set bit 2 if textured
						   (_ColorScheme != NULL     ? 2 : 0)  | // set bit 1 if per ribbon color
						   (_ColorFading			 ? 1 : 0)		    // set bit 0 if color fading
						 ];

	const uint numVerticesInSlice = getNumVerticesInSlice(); /// 1 vertex added for textured ribbon (to avoid texture stretching)
	const uint numVerticesInShape = (uint)_Shape.size();


	// The number of slice is encoded in the upper word of the vb index
	// The number of vertices per slices is encoded in the lower word
	uint VBnPDIndex = ((_UsedNbSegs + 1) << 16) | numVerticesInSlice;
	TVBMap::iterator it = map.find(VBnPDIndex);
	if (it != map.end())
	{
		return it->second;
	}
	else	// must create this vb, with few different size, it is still interseting, though they are only destroyed at exit
	{
		const uint numRibbonInVB = getNumRibbonsInVB();
		CVBnPB &VBnPB = map[VBnPDIndex]; // make an entry
		CIndexBuffer &pb = VBnPB.PB;
		CVertexBuffer &vb = VBnPB.VB;
		vb.setPreferredMemory(CVertexBuffer::AGPVolatile, true); // keep local memory because of interleaved format
		/// set the vb format & size
		/// In the case of a ribbon with color and fading, we encode the fading in a texture
		/// If the ribbon has fading, but only a global color, we encode it in the primary color
		vb.setVertexFormat(CVertexBuffer::PositionFlag	| /* alway need position */
						   (_ColorScheme || _ColorFading ? CVertexBuffer::PrimaryColorFlag : 0) | /* need a color ? */
						   ((_ColorScheme && _ColorFading) ||  _Tex != NULL ? CVertexBuffer::TexCoord0Flag : 0) | /* need texture coordinates ? */
						   (_Tex != NULL && _ColorScheme && _ColorFading ? CVertexBuffer::TexCoord1Flag : 0) /* need 2nd texture coordinates ? */
						  );
		vb.setNumVertices((_UsedNbSegs + 1) * numRibbonInVB * numVerticesInSlice); // 1 seg = 1 line + terminal vertices
		pb.setFormat(NL_DEFAULT_INDEX_BUFFER_FORMAT);
		pb.setPreferredMemory(CIndexBuffer::AGPVolatile, false);
		// set the primitive block size
		if (_BraceMode)
		{
			pb.setNumIndexes(6 * _UsedNbSegs * numRibbonInVB * (uint32)(_Shape.size() / 2));
		}
		else
		{
			pb.setNumIndexes(6 * _UsedNbSegs * numRibbonInVB * (uint32)_Shape.size());
		}
		//
		CIndexBufferReadWrite ibaWrite;
		pb.lock (ibaWrite);
		CVertexBufferReadWrite vba;
		vb.lock(vba);
		/// Setup the pb and vb parts. Not very fast but executed only once
		uint vbIndex = 0;
		uint pbIndex = 0;
		uint i, k, l;
		for (i = 0; i < numRibbonInVB; ++i)
		{
			for (k = 0; k < (_UsedNbSegs + 1); ++k)
			{

				/// setup primitive block
				if (k != _UsedNbSegs) /// there are alway one more slice than segments in the ribbon...
				{
					if (_BraceMode)
					{
						uint vIndex = vbIndex;
						for (l = 0; l < numVerticesInShape / 2; ++l) /// deals with segment
						{
							setTri(ibaWrite, vb, pbIndex, vIndex, vIndex + numVerticesInSlice, vIndex + numVerticesInSlice + 1);
							pbIndex+=3;
							setTri(ibaWrite, vb, pbIndex, vIndex, vIndex + numVerticesInSlice + 1, vIndex + 1);
							pbIndex+=3;
							vIndex += 2;
						}
					}
					else
					{
						uint vIndex = vbIndex;
						for (l = 0; l < (numVerticesInShape - 1); ++l) /// deals with each ribbon vertices
						{
							setTri(ibaWrite, vb, pbIndex, vIndex, vIndex + numVerticesInSlice, vIndex + numVerticesInSlice + 1);
							pbIndex+=3;
							setTri(ibaWrite, vb, pbIndex, vIndex, vIndex + numVerticesInSlice + 1, vIndex + 1);
							pbIndex+=3;
							++ vIndex;
						}

						/// the last 2 index don't loop if there's a texture
						uint nextVertexIndex = (numVerticesInShape == numVerticesInSlice) ?	vIndex + 1 - numVerticesInShape // no texture -> we loop
											   : vIndex + 1; // a texture is used : use onemore vertex
						setTri(ibaWrite, vb, pbIndex, vIndex, vIndex + numVerticesInSlice, nextVertexIndex + numVerticesInSlice);
						pbIndex+=3;
						setTri(ibaWrite, vb, pbIndex, vIndex, nextVertexIndex + numVerticesInSlice, nextVertexIndex);
						pbIndex+=3;
					}
				}

				/// setup vb
				if (_BraceMode)
				{
					for (l = 0; l < numVerticesInSlice / 2; ++l) /// deals with each ribbon vertices
					{
						nlassert(vbIndex < vb.getNumVertices());
						/// setup texture (if any)
						if (_Tex != NULL)
						{
							vba.setTexCoord(vbIndex,
											_ColorScheme && _ColorFading ? 1 : 0,		// must we use the second texture coord ? (when 1st one used by the gradient texture : we can't encode it in the diffuse as it encodes each ribbon color)
											(float) k / _UsedNbSegs,				    // u
											0.f											// v
										   );
							vba.setTexCoord(vbIndex + 1,
								            _ColorScheme && _ColorFading ? 1 : 0,
								            (float) k / _UsedNbSegs,
								            1.f
								           );
						}
						/// setup gradient
						if (_ColorFading)
						{
							// If not per ribbon color, we can encode it in the diffuse
							if (_ColorScheme == NULL)
							{
								uint8 intensity = (uint8) (255 * (1.f - ((float) k / _UsedNbSegs)));
								NLMISC::CRGBA col(intensity, intensity, intensity, intensity);
								vba.setColor(vbIndex, col);
								vba.setColor(vbIndex + 1, col);
							}
							else // encode it in the first texture
							{
								vba.setTexCoord(vbIndex, 0, 0.5f - 0.5f * ((float) k / _UsedNbSegs), 0);
								vba.setTexCoord(vbIndex + 1, 0, 0.5f - 0.5f * ((float) k / _UsedNbSegs), 0);
							}
						}
						vbIndex += 2;
					}
				}
				else
				{
					for (l = 0; l < numVerticesInSlice; ++l) /// deals with each ribbon vertices
					{
						nlassert(vbIndex < vb.getNumVertices());
						/// setup texture (if any)
						if (_Tex != NULL)
						{
							vba.setTexCoord(vbIndex,
										   _ColorScheme && _ColorFading ? 1 : 0,		// must we use the second texture coord ? (when 1st one used by the gradient texture : we can't encode it in the diffuse as it encodes each ribbon color)
										   (float) k / _UsedNbSegs,				  // u
										   1.f - (l / (float) numVerticesInShape) // v
										  );
						}
						/// setup gradient
						if (_ColorFading)
						{
							// If not per ribbon color, we can encode it in the diffuse
							if (_ColorScheme == NULL)
							{
								uint8 intensity = (uint8) (255 * (1.f - ((float) k / _UsedNbSegs)));
								NLMISC::CRGBA col(intensity, intensity, intensity, intensity);
								vba.setColor(vbIndex, col);
							}
							else // encode it in the first texture
							{
								vba.setTexCoord(vbIndex, 0, 0.5f - 0.5f * ((float) k / _UsedNbSegs), 0);
							}
						}
						++ vbIndex;
					}
				}
			}
		}
		return VBnPB;
	}
}

//==========================================================================
uint	CPSRibbon::getNumRibbonsInVB() const
{
	NL_PS_FUNC(CPSRibbon_getNumRibbonsInVB)
	const uint numVerticesInSlice = getNumVerticesInSlice(); /// 1 vertex added for textured ribbon (to avoid texture stretching)
	const uint vertexInVB = 512;
	return std::max(1u, (uint) (vertexInVB / (numVerticesInSlice * (_UsedNbSegs + 1))));
}


//==========================================================================
inline void	CPSRibbon::updateUntexturedMaterial()
{
	NL_PS_FUNC(CPSRibbon_updateUntexturedMaterial)
	///////////////////////
	// UNTEXTURED RIBBON //
	///////////////////////

	static NLMISC::CRefPtr<ITexture> ptGradTexture;

	CParticleSystem &ps = *(_Owner->getOwner());
	if (_ColorScheme)
	{	// PER RIBBON COLOR
		if (ps.getForceGlobalColorLightingFlag() || usesGlobalColorLighting() || ps.getColorAttenuationScheme() || ps.isUserColorUsed())
		{
			if (_ColorFading) // global color + fading + per ribbon color
			{
				// the first stage is used to get fading * global color
				// the second stage multiply the result by the diffuse colot
				if (ptGradTexture == NULL) // have we got a gradient texture ?
				{
					ptGradTexture = CreateGradientTexture();
				}
				_Mat.setTexture(0, ptGradTexture);
				CPSMaterial::forceTexturedMaterialStages(2); // use constant color 0 * diffuse, 1 stage needed
				SetupModulatedStage(_Mat, 0, CMaterial::Texture, CMaterial::Constant);
				SetupModulatedStage(_Mat, 1, CMaterial::Previous, CMaterial::Diffuse);
			}
			else // per ribbon color with global color
			{
				CPSMaterial::forceTexturedMaterialStages(1); // use constant color 0 * diffuse, 1 stage needed
				SetupModulatedStage(_Mat, 0, CMaterial::Diffuse, CMaterial::Constant);
			}
		}
		else
		{
			if (_ColorFading) // per ribbon color, no fading
			{
				if (ptGradTexture == NULL) // have we got a gradient texture ?
				{
					ptGradTexture = CreateGradientTexture();
				}
				_Mat.setTexture(0, ptGradTexture);
				ptGradTexture->setWrapS(ITexture::Clamp);
				ptGradTexture->setWrapT(ITexture::Clamp);
				CPSMaterial::forceTexturedMaterialStages(1);
				SetupModulatedStage(_Mat, 0, CMaterial::Texture, CMaterial::Diffuse);
			}
			else // per color ribbon with no fading, and no global color
			{
				CPSMaterial::forceTexturedMaterialStages(0); // no texture use constant diffuse only
			}
		}
	}
	else // GLOBAL COLOR
	{
		if (_ColorFading)
		{
			CPSMaterial::forceTexturedMaterialStages(1); // use constant color 0 * diffuse, 1 stage needed
			SetupModulatedStage(_Mat, 0, CMaterial::Diffuse, CMaterial::Constant);
		}
		else // color attenuation, no fading :
		{
			CPSMaterial::forceTexturedMaterialStages(0); // no texture use constant diffuse only
		}
	}
	_Touch = false;
}

//==========================================================================
inline void	CPSRibbon::updateTexturedMaterial()
{
	NL_PS_FUNC(CPSRibbon_updateTexturedMaterial)
	/////////////////////
	// TEXTURED RIBBON //
	/////////////////////
	if (_Tex)
	{
		//_Tex->setWrapS(ITexture::Clamp);
		//_Tex->setWrapT(ITexture::Clamp);
	}
	static NLMISC::CRefPtr<ITexture> ptGradTexture;
	CParticleSystem &ps = *(_Owner->getOwner());
	if (_ColorScheme)
	{	// PER RIBBON COLOR
		if (ps.getForceGlobalColorLightingFlag() || usesGlobalColorLighting() || ps.getColorAttenuationScheme() || ps.isUserColorUsed())
		{
			if (_ColorFading) // global color + fading + per ribbon color
			{
				if (ptGradTexture == NULL) // have we got a gradient texture ?
				{
					ptGradTexture = CreateGradientTexture(); // create it
				}
				/// fading is stored in last stage (work only with 3 stages...)
				_Mat.setTexture(0, ptGradTexture);
				ptGradTexture->setWrapS(ITexture::Clamp);
				ptGradTexture->setWrapT(ITexture::Clamp);
				_Mat.setTexture(1, _Tex);
				CPSMaterial::forceTexturedMaterialStages(3); // use constant color 0 * diffuse, 1 stage needed
				SetupModulatedStage(_Mat, 0, CMaterial::Texture, CMaterial::Diffuse);
				SetupModulatedStage(_Mat, 1, CMaterial::Texture, CMaterial::Previous);
				SetupModulatedStage(_Mat, 2, CMaterial::Previous, CMaterial::Constant);
			}
			else // per ribbon color with global color
			{
				_Mat.setTexture(0, _Tex);

				CPSMaterial::forceTexturedMaterialStages(2); // use constant color 0 * diffuse, 1 stage needed
				SetupModulatedStage(_Mat, 0, CMaterial::Texture, CMaterial::Diffuse);
				SetupModulatedStage(_Mat, 1, CMaterial::Previous, CMaterial::Constant);
			}
		}
		else
		{
			if (_ColorFading) // per ribbon color, fading : 2 textures needed
			{
				if (ptGradTexture == NULL) // have we got a gradient texture ?
				{
					ptGradTexture = CreateGradientTexture(); // create it
				}
				_Mat.setTexture(0, ptGradTexture);
				ptGradTexture->setWrapS(ITexture::Clamp);
				ptGradTexture->setWrapT(ITexture::Clamp);
				_Mat.setTexture(1, _Tex);
				CPSMaterial::forceTexturedMaterialStages(2);
				SetupModulatedStage(_Mat, 0, CMaterial::Texture, CMaterial::Diffuse); // texture * ribbon color
				SetupModulatedStage(_Mat, 1, CMaterial::Texture, CMaterial::Previous);	// * gradient
			}
			else // per color ribbon with no fading, and no global color
			{
				_Mat.setTexture(0, _Tex);
				CPSMaterial::forceTexturedMaterialStages(1); // no texture use constant diffuse only
				SetupModulatedStage(_Mat, 0, CMaterial::Texture, CMaterial::Diffuse);
			}
		}
	}
	else // GLOBAL COLOR
	{

		if (_ColorFading) // gradient is encoded in diffuse
		{
			_Mat.setTexture(0, _Tex);
			CPSMaterial::forceTexturedMaterialStages(2); // use constant color 0 * diffuse, 1 stage needed
			SetupModulatedStage(_Mat, 0, CMaterial::Texture, CMaterial::Diffuse);
			SetupModulatedStage(_Mat, 1, CMaterial::Previous, CMaterial::Constant);
		}
		else // constant color
		{
			_Mat.setTexture(0, _Tex);
			CPSMaterial::forceTexturedMaterialStages(1); // no texture use constant diffuse only
			SetupModulatedStage(_Mat, 0, CMaterial::Texture, CMaterial::Diffuse);
		}
	}
	_Touch = false;
}

//==========================================================================
void	CPSRibbon::updateMaterial()
{
	NL_PS_FUNC(CPSRibbon_updateMaterial)
	if (!_Touch) return;
	if (_Tex != NULL)
	{
		updateTexturedMaterial();
		setupTextureMatrix();
	}
	else
	{
		updateUntexturedMaterial();
	}
}



//==========================================================================
inline void	CPSRibbon::setupUntexturedGlobalColor()
{
	NL_PS_FUNC(CPSRibbon_setupUntexturedGlobalColor)
	/// setup the global color if it is used
	CParticleSystem &ps = *(_Owner->getOwner());
	if (_ColorScheme)
	{
		if (ps.getForceGlobalColorLightingFlag() || usesGlobalColorLighting())
		{
			_Mat.texConstantColor(0, ps.getGlobalColorLighted());
		}
		else
		{
			_Mat.texConstantColor(0, ps.getGlobalColor());
		}
	}
	else // GLOBAL COLOR with / without fading
	{
		NLMISC::CRGBA col;
		if (ps.getForceGlobalColorLightingFlag() || usesGlobalColorLighting())
		{
			col.modulateFromColor(ps.getGlobalColorLighted(), _Color);
		}
		else if (ps.getColorAttenuationScheme() || ps.isUserColorUsed())
		{
			col.modulateFromColor(ps.getGlobalColor(), _Color);
		}
		else
		{
			col = _Color;
		}
		if (_ColorFading)
		{
			_Mat.texConstantColor(0, col);
		}
		else // color attenuation, no fading :
		{
			_Mat.setColor(col);
		}
	}
}

//==========================================================================
inline void	CPSRibbon::setupTexturedGlobalColor()
{
	NL_PS_FUNC(CPSRibbon_setupTexturedGlobalColor)
	/// setup the global color if it is used
	CParticleSystem &ps = *(_Owner->getOwner());
	if (_ColorScheme)
	{
		if (ps.getForceGlobalColorLightingFlag() || usesGlobalColorLighting())
		{
			if (_ColorFading)
			{
				_Mat.texConstantColor(2, ps.getGlobalColorLighted());
			}
			else
			{
				_Mat.texConstantColor(1, ps.getGlobalColorLighted());
			}
		}
		else
		{
			if (_ColorFading)
			{
				_Mat.texConstantColor(2, ps.getGlobalColor());
			}
			else
			{
				_Mat.texConstantColor(1, ps.getGlobalColor());
			}
		}
	}
	else // GLOBAL COLOR with / without fading
	{
		if (ps.getForceGlobalColorLightingFlag() || usesGlobalColorLighting())
		{
			NLMISC::CRGBA col;
			col.modulateFromColor(ps.getGlobalColorLighted(), _Color);
			if (_ColorFading)
			{
				_Mat.texConstantColor(1, col);
			}
			else // color attenuation, no fading :
			{
				_Mat.setColor(col);
			}
		}
		else
		if (ps.getColorAttenuationScheme() || ps.isUserColorUsed())
		{
			NLMISC::CRGBA col;
			col.modulateFromColor(ps.getGlobalColor(), _Color);
			if (_ColorFading)
			{
				_Mat.texConstantColor(1, col);
			}
			else // color attenuation, no fading :
			{
				_Mat.setColor(col);
			}
		}
		else
		{
			if (_ColorFading)
			{
				_Mat.texConstantColor(1, _Color);
			}
			else // constant color
			{
				_Mat.setColor(_Color);
			}
		}
	}
}


//==========================================================================
void	CPSRibbon::setupGlobalColor()
{
	NL_PS_FUNC(CPSRibbon_setupGlobalColor)
	if (_Tex != NULL) setupTexturedGlobalColor();
		else setupUntexturedGlobalColor();
}

//==========================================================================
void CPSRibbon::setupTextureMatrix()
{
	NL_PS_FUNC(CPSRibbon_setupTextureMatrix)
	uint stage = (_ColorScheme != NULL && _ColorFading == true) ? 1 : 0;
	if (_UFactor != 1.f || _VFactor != 1.f)
	{
		_Mat.enableUserTexMat(stage);
		CMatrix texMat;
		texMat.setRot(_UFactor  * NLMISC::CVector::I,
					  _VFactor  * NLMISC::CVector::J,
					  NLMISC::CVector::K
					 );
		_Mat.setUserTexMat(stage, texMat);
	}
	else
	{
		_Mat.enableUserTexMat(stage, false);
	}
	_Mat.enableUserTexMat(1 - stage, false);
}

//==========================================================================
///==================================================================================================================
void CPSRibbon::setShape(const CVector *shape, uint32 nbPointsInShape, bool braceMode)
{
	NL_PS_FUNC(CPSRibbon_setShape)
	if (!braceMode)
	{
		nlassert(nbPointsInShape >= 3);
	}
	else
	{
		nlassert(nbPointsInShape >= 2);
		nlassert(!(nbPointsInShape & 1)); // must be even
	}
	_Shape.resize(nbPointsInShape);
	std::copy(shape, shape + nbPointsInShape, _Shape.begin());
	_BraceMode = braceMode;
}

///==================================================================================================================
void CPSRibbon::getShape(CVector *shape) const
{
	NL_PS_FUNC(CPSRibbon_getShape)
	std::copy(_Shape.begin(), _Shape.end(), shape);
}

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


} // NL3D