/*
---------------------------------------------------------------------------
Free Asset Import Library (ASSIMP)
---------------------------------------------------------------------------

Copyright (c) 2006-2008, ASSIMP Development Team

All rights reserved.

Redistribution and use of this software in source and binary forms, 
with or without modification, are permitted provided that the following 
conditions are met:

* Redistributions of source code must retain the above
  copyright notice, this list of conditions and the
  following disclaimer.

* Redistributions in binary form must reproduce the above
  copyright notice, this list of conditions and the
  following disclaimer in the documentation and/or other
  materials provided with the distribution.

* Neither the name of the ASSIMP team, nor the names of its
  contributors may be used to endorse or promote products
  derived from this software without specific prior
  written permission of the ASSIMP Development Team.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 
"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 
LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 
OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 
LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 
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OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
---------------------------------------------------------------------------
*/

/** @file Implementation of the 3ds importer class */
#include "3DSLoader.h"
#include "MaterialSystem.h"

#include "../include/IOStream.h"
#include "../include/IOSystem.h"
#include "../include/aiMesh.h"
#include "../include/aiScene.h"
#include "../include/aiAssert.h"

#include <boost/scoped_ptr.hpp>

using namespace Assimp;


// ------------------------------------------------------------------------------------------------
void Dot3DSImporter::ReplaceDefaultMaterial()
{
	// try to find an existing material that matches the
	// typical default material setting:
	// - no textures
	// - diffuse color (in grey!)
	// NOTE: This is here to workaround the fact that some
	// exporters are writing a default material, too.
	unsigned int iIndex = 0xcdcdcdcd;
	for (unsigned int i = 0; i < this->mScene->mMaterials.size();++i)
	{
	if (std::string::npos == this->mScene->mMaterials[i].mName.find("default") &&
		std::string::npos == this->mScene->mMaterials[i].mName.find("DEFAULT"))continue;

	if (this->mScene->mMaterials[i].mDiffuse.r !=
		this->mScene->mMaterials[i].mDiffuse.g ||
		this->mScene->mMaterials[i].mDiffuse.r !=
		this->mScene->mMaterials[i].mDiffuse.b)continue;

	if (this->mScene->mMaterials[i].sTexDiffuse.mMapName.length() != 0	||
		this->mScene->mMaterials[i].sTexBump.mMapName.length()!= 0		|| 
		this->mScene->mMaterials[i].sTexOpacity.mMapName.length() != 0	||
		this->mScene->mMaterials[i].sTexEmissive.mMapName.length() != 0	||
		this->mScene->mMaterials[i].sTexSpecular.mMapName.length() != 0	||
		this->mScene->mMaterials[i].sTexShininess.mMapName.length() != 0 )continue;

	iIndex = i;
	}
	if (0xcdcdcdcd == iIndex)iIndex = this->mScene->mMaterials.size();

	// now iterate through all meshes and through all faces and
	// find all faces that are using the default material
	unsigned int iCnt = 0;
	for (std::vector<Dot3DS::Mesh>::iterator
		i =  this->mScene->mMeshes.begin();
		i != this->mScene->mMeshes.end();++i)
	{
		for (std::vector<unsigned int>::iterator
			a =  (*i).mFaceMaterials.begin();
			a != (*i).mFaceMaterials.end();++a)
		{
			// NOTE: The additional check seems to be necessary,
			// some exporters seem to generate invalid data here
			if (0xcdcdcdcd == (*a) || (*a) >= this->mScene->mMaterials.size())
			{
				(*a) = iIndex;
				++iCnt;
			}
		}
	}
	if (0 != iCnt && iIndex == this->mScene->mMaterials.size())
	{
		// we need to create our own default material
		Dot3DS::Material sMat;
		sMat.mDiffuse = aiColor3D(0.3f,0.3f,0.3f);
		sMat.mName = "%%%DEFAULT";
		this->mScene->mMaterials.push_back(sMat);
	}
	return;
}
// ------------------------------------------------------------------------------------------------
void Dot3DSImporter::CheckIndices(Dot3DS::Mesh* sMesh)
{
	for (std::vector< Dot3DS::Face >::iterator
		 i =  sMesh->mFaces.begin();
		 i != sMesh->mFaces.end();++i)
	{
		// check whether all indices are in range
		if ((*i).i1 >= sMesh->mPositions.size())
		{
			(*i).i1 = sMesh->mPositions.size()-1;
		}
		if ((*i).i2 >= sMesh->mPositions.size())
		{
			(*i).i2 = sMesh->mPositions.size()-1;
		}
		if ((*i).i3 >= sMesh->mPositions.size())
		{
			(*i).i3 = sMesh->mPositions.size()-1;
		}
	}
	return;
}
// ------------------------------------------------------------------------------------------------
void Dot3DSImporter::MakeUnique(Dot3DS::Mesh* sMesh)
{
	std::vector<aiVector3D> vNew;
	vNew.resize(sMesh->mFaces.size() * 3);

	std::vector<aiVector2D> vNew2;

	// TODO: Remove this step. By maintaining a small LUT it
	// would be possible to do this directly in the parsing step
	unsigned int iBase = 0;

	if (0 != sMesh->mTexCoords.size())
	{
		vNew2.resize(sMesh->mFaces.size() * 3);
		for (unsigned int i = 0; i < sMesh->mFaces.size();++i)
		{
			// position and texture coordinates
			vNew[iBase]   = sMesh->mPositions[sMesh->mFaces[i].i1];
			vNew2[iBase]   = sMesh->mTexCoords[sMesh->mFaces[i].i1];
			sMesh->mFaces[i].i1 = iBase++;

			vNew[iBase]   = sMesh->mPositions[sMesh->mFaces[i].i2];
			vNew2[iBase]   = sMesh->mTexCoords[sMesh->mFaces[i].i2];
			sMesh->mFaces[i].i2 = iBase++;

			vNew[iBase]   = sMesh->mPositions[sMesh->mFaces[i].i3];
			vNew2[iBase]   = sMesh->mTexCoords[sMesh->mFaces[i].i3];
			sMesh->mFaces[i].i3 = iBase++;
		}
	}
	else
	{
		for (unsigned int i = 0; i < sMesh->mFaces.size();++i)
		{
			// position only
			vNew[iBase]   = sMesh->mPositions[sMesh->mFaces[i].i1];
			sMesh->mFaces[i].i1 = iBase++;
			vNew[iBase]   = sMesh->mPositions[sMesh->mFaces[i].i2];
			sMesh->mFaces[i].i2 = iBase++;
			vNew[iBase]   = sMesh->mPositions[sMesh->mFaces[i].i3];
			sMesh->mFaces[i].i3 = iBase++;
		}
	}
	sMesh->mPositions = vNew;
	sMesh->mTexCoords = vNew2;
	return;
}
// ------------------------------------------------------------------------------------------------
void Dot3DSImporter::ConvertMaterial(Dot3DS::Material& oldMat,
	MaterialHelper& mat)
{
	// NOTE: Pass the background image to the viewer by bypassing the
	// material system. This is an evil hack, never do it  again!
	if (0 != this->mBackgroundImage.length() && this->bHasBG)
		{
		aiString tex;
		tex.Set( this->mBackgroundImage);
		mat.AddProperty( &tex, AI_MATKEY_GLOBAL_BACKGROUND_IMAGE);

		// be sure this is only done for the first material
		this->mBackgroundImage = std::string("");
		}

	// At first add the base ambient color of the
	// scene to	the material
	oldMat.mAmbient.r += this->mClrAmbient.r;
	oldMat.mAmbient.g += this->mClrAmbient.g;
	oldMat.mAmbient.b += this->mClrAmbient.b;

	aiString name;
	name.Set( oldMat.mName);
	mat.AddProperty( &name, AI_MATKEY_NAME);

	// material colors
	mat.AddProperty( &oldMat.mAmbient, 1, AI_MATKEY_COLOR_AMBIENT);
	mat.AddProperty( &oldMat.mDiffuse, 1, AI_MATKEY_COLOR_DIFFUSE);
	mat.AddProperty( &oldMat.mSpecular, 1, AI_MATKEY_COLOR_SPECULAR);
	mat.AddProperty( &oldMat.mSpecularExponent, 1, AI_MATKEY_SHININESS);
	mat.AddProperty( &oldMat.mEmissive, 1, AI_MATKEY_COLOR_EMISSIVE);

	// opacity
	mat.AddProperty<float>( &oldMat.mTransparency,1,AI_MATKEY_OPACITY);

	// bump height scaling
	mat.AddProperty<float>( &oldMat.mBumpHeight,1,AI_MATKEY_BUMPSCALING);

	// shading mode
	aiShadingMode eShading = aiShadingMode_NoShading;
	switch (oldMat.mShading)
	{
		case Dot3DS::Dot3DSFile::Flat:
			eShading = aiShadingMode_Flat; break;
		case Dot3DS::Dot3DSFile::Phong :
			eShading = aiShadingMode_Phong; break;

		// I don't know what "Wire" shading should be,
		// assume it is simple lambertian diffuse (L dot N) shading
		case Dot3DS::Dot3DSFile::Wire:
		case Dot3DS::Dot3DSFile::Gouraud:
			eShading = aiShadingMode_Gouraud; break;

		// assume cook-torrance shading for metals.
		// NOTE: I assume the real shader inside 3ds max is an anisotropic
		// Phong-Blinn shader, but this is a good approximation too
		case Dot3DS::Dot3DSFile::Metal :
			eShading = aiShadingMode_CookTorrance; break;
	}
	mat.AddProperty<int>( (int*)&eShading,1,AI_MATKEY_SHADING_MODEL);

	if (Dot3DS::Dot3DSFile::Wire == oldMat.mShading)
	{
		// set the wireframe flag
		unsigned int iWire = 1;
		mat.AddProperty<int>( (int*)&iWire,1,AI_MATKEY_ENABLE_WIREFRAME);
	}

	// texture, if there is one
	if( oldMat.sTexDiffuse.mMapName.length() > 0)
	{
		aiString tex;
		tex.Set( oldMat.sTexDiffuse.mMapName);
		mat.AddProperty( &tex, AI_MATKEY_TEXTURE_DIFFUSE(0));

		if (is_not_qnan(oldMat.sTexDiffuse.mTextureBlend))
			mat.AddProperty<float>( &oldMat.sTexDiffuse.mTextureBlend, 1, AI_MATKEY_TEXBLEND_DIFFUSE(0));
	}
	if( oldMat.sTexSpecular.mMapName.length() > 0)
	{
		aiString tex;
		tex.Set( oldMat.sTexSpecular.mMapName);
		mat.AddProperty( &tex, AI_MATKEY_TEXTURE_SPECULAR(0));

		if (is_not_qnan(oldMat.sTexSpecular.mTextureBlend))
			mat.AddProperty<float>( &oldMat.sTexSpecular.mTextureBlend, 1, AI_MATKEY_TEXBLEND_SPECULAR(0));
	}
	if( oldMat.sTexOpacity.mMapName.length() > 0)
	{
		aiString tex;
		tex.Set( oldMat.sTexOpacity.mMapName);
		mat.AddProperty( &tex, AI_MATKEY_TEXTURE_OPACITY(0));

		if (is_not_qnan(oldMat.sTexOpacity.mTextureBlend))
			mat.AddProperty<float>( &oldMat.sTexOpacity.mTextureBlend, 1,AI_MATKEY_TEXBLEND_OPACITY(0));
	}
	if( oldMat.sTexEmissive.mMapName.length() > 0)
	{
		aiString tex;
		tex.Set( oldMat.sTexEmissive.mMapName);
		mat.AddProperty( &tex, AI_MATKEY_TEXTURE_EMISSIVE(0));

		if (is_not_qnan(oldMat.sTexEmissive.mTextureBlend))
			mat.AddProperty<float>( &oldMat.sTexEmissive.mTextureBlend, 1, AI_MATKEY_TEXBLEND_EMISSIVE(0));
	}
	if( oldMat.sTexBump.mMapName.length() > 0)
	{
		aiString tex;
		tex.Set( oldMat.sTexBump.mMapName);
		mat.AddProperty( &tex, AI_MATKEY_TEXTURE_HEIGHT(0));

		if (is_not_qnan(oldMat.sTexBump.mTextureBlend))
			mat.AddProperty<float>( &oldMat.sTexBump.mTextureBlend, 1, AI_MATKEY_TEXBLEND_HEIGHT(0));
	}
	if( oldMat.sTexShininess.mMapName.length() > 0)
	{
		aiString tex;
		tex.Set( oldMat.sTexShininess.mMapName);
		mat.AddProperty( &tex, AI_MATKEY_TEXTURE_SHININESS(0));

		if (is_not_qnan(oldMat.sTexShininess.mTextureBlend))
			mat.AddProperty<float>( &oldMat.sTexShininess.mTextureBlend, 1, AI_MATKEY_TEXBLEND_SHININESS(0));
	}

	// store the name of the material itself, too
	if( oldMat.mName.length() > 0)
	{
		aiString tex;
		tex.Set( oldMat.mName);
		mat.AddProperty( &tex, AI_MATKEY_NAME);
	}
	return;
}
// ------------------------------------------------------------------------------------------------
void SetupMatUVSrc (aiMaterial* pcMat, const Dot3DS::Material* pcMatIn)
	{
	MaterialHelper* pcHelper = (MaterialHelper*)pcMat;
	pcHelper->AddProperty<int>(&pcMatIn->sTexDiffuse.iUVSrc,1,AI_MATKEY_UVWSRC_DIFFUSE(0));
	pcHelper->AddProperty<int>(&pcMatIn->sTexSpecular.iUVSrc,1,AI_MATKEY_UVWSRC_SPECULAR(0));
	pcHelper->AddProperty<int>(&pcMatIn->sTexEmissive.iUVSrc,1,AI_MATKEY_UVWSRC_EMISSIVE(0));
	pcHelper->AddProperty<int>(&pcMatIn->sTexBump.iUVSrc,1,AI_MATKEY_UVWSRC_HEIGHT(0));
	pcHelper->AddProperty<int>(&pcMatIn->sTexShininess.iUVSrc,1,AI_MATKEY_UVWSRC_SHININESS(0));
	pcHelper->AddProperty<int>(&pcMatIn->sTexOpacity.iUVSrc,1,AI_MATKEY_UVWSRC_OPACITY(0));
	}
// ------------------------------------------------------------------------------------------------
void Dot3DSImporter::ConvertMeshes(aiScene* pcOut)
{
	std::vector<aiMesh*> avOutMeshes;
	avOutMeshes.reserve(this->mScene->mMeshes.size() * 2);

	unsigned int iFaceCnt = 0;

	// we need to split all meshes by their materials
	for (std::vector<Dot3DS::Mesh>::iterator
		i =  this->mScene->mMeshes.begin();
		i != this->mScene->mMeshes.end();++i)
	{
		std::vector<unsigned int>* aiSplit = new std::vector<unsigned int>[
			this->mScene->mMaterials.size()];

		unsigned int iNum = 0;
		for (std::vector<unsigned int>::const_iterator
			a =  (*i).mFaceMaterials.begin();
			a != (*i).mFaceMaterials.end();++a,++iNum)
		{
		// check range
		if ((*a) >= this->mScene->mMaterials.size())
			{
			// use the last material instead
			aiSplit[this->mScene->mMaterials.size()-1].push_back(iNum);
			}
		else aiSplit[*a].push_back(iNum);
		}
		// now generate submeshes
#if 0
		bool bFirst = true;
#endif
		for (unsigned int p = 0; p < this->mScene->mMaterials.size();++p)
		{
			if (aiSplit[p].size() != 0)
			{
				aiMesh* p_pcOut = new aiMesh();

				// be sure to setup the correct material index
				p_pcOut->mMaterialIndex = p;

				// use the color data as temporary storage
				p_pcOut->mColors[0] = (aiColor4D*)new std::string((*i).mName);
				avOutMeshes.push_back(p_pcOut);

#if 0
				if (bFirst)
				{
					p_pcOut->mColors[1] = (aiColor4D*)new aiMatrix4x4();

					*((aiMatrix4x4*)p_pcOut->mColors[1]) = (*i).mMat;
					bFirst = false;
				}
#endif

				// convert vertices
				p_pcOut->mNumVertices = aiSplit[p].size()*3;
				p_pcOut->mNumFaces = aiSplit[p].size();

				// allocate enough storage for faces
				p_pcOut->mFaces = new aiFace[p_pcOut->mNumFaces];
				iFaceCnt += p_pcOut->mNumFaces;

				if (p_pcOut->mNumVertices != 0)
				{
					p_pcOut->mVertices = new aiVector3D[p_pcOut->mNumVertices];
					p_pcOut->mNormals = new aiVector3D[p_pcOut->mNumVertices];
					unsigned int iBase = 0;

					for (unsigned int q = 0; q < aiSplit[p].size();++q)
					{
						unsigned int iIndex = aiSplit[p][q];

						p_pcOut->mFaces[q].mIndices = new unsigned int[3];
						p_pcOut->mFaces[q].mNumIndices = 3;

						p_pcOut->mFaces[q].mIndices[0] = iBase;
						p_pcOut->mVertices[iBase] = (*i).mPositions[(*i).mFaces[iIndex].i1];
						p_pcOut->mNormals[iBase++] = (*i).mNormals[(*i).mFaces[iIndex].i1];

						p_pcOut->mFaces[q].mIndices[1] = iBase;
						p_pcOut->mVertices[iBase] = (*i).mPositions[(*i).mFaces[iIndex].i2];
						p_pcOut->mNormals[iBase++] = (*i).mNormals[(*i).mFaces[iIndex].i2];

						p_pcOut->mFaces[q].mIndices[2] = iBase;
						p_pcOut->mVertices[iBase] = (*i).mPositions[(*i).mFaces[iIndex].i3];
						p_pcOut->mNormals[iBase++] = (*i).mNormals[(*i).mFaces[iIndex].i3];
					}
				}
				// convert texture coordinates
				if ((*i).mTexCoords.size() != 0)
				{
					p_pcOut->mTextureCoords[0] = new aiVector3D[p_pcOut->mNumVertices];

					unsigned int iBase = 0;
					for (unsigned int q = 0; q < aiSplit[p].size();++q)
					{
						unsigned int iIndex2 = aiSplit[p][q];

						unsigned int iIndex = (*i).mFaces[iIndex2].i1;
						aiVector2D& pc = (*i).mTexCoords[iIndex];
						p_pcOut->mTextureCoords[0][iBase++] = aiVector3D(pc.x,pc.y,0.0f);

						iIndex = (*i).mFaces[iIndex2].i2;
						pc = (*i).mTexCoords[iIndex];
						p_pcOut->mTextureCoords[0][iBase++] = aiVector3D(pc.x,pc.y,0.0f);

						iIndex = (*i).mFaces[iIndex2].i3;
						pc = (*i).mTexCoords[iIndex];
						p_pcOut->mTextureCoords[0][iBase++] = aiVector3D(pc.x,pc.y,0.0f);
					}
					// apply texture coordinate scalings
					this->BakeScaleNOffset ( p_pcOut, &this->mScene->mMaterials[
						p_pcOut->mMaterialIndex] );
					
					// setup bitflags to indicate which texture coordinate
					// channels are used
					p_pcOut->mNumUVComponents[0] = 2;
					if (p_pcOut->HasTextureCoords(1))
						p_pcOut->mNumUVComponents[1] = 2;
					if (p_pcOut->HasTextureCoords(2))
						p_pcOut->mNumUVComponents[2] = 2;
					if (p_pcOut->HasTextureCoords(3))
						p_pcOut->mNumUVComponents[3] = 2;
				}
			}
		}
		delete[] aiSplit;
	}
	pcOut->mNumMeshes = avOutMeshes.size();
	pcOut->mMeshes = new aiMesh*[pcOut->mNumMeshes]();
	for (unsigned int a = 0; a < pcOut->mNumMeshes;++a)
	{
		pcOut->mMeshes[a] = avOutMeshes[a];
	}

	if (0 == iFaceCnt)
	{
		throw new ImportErrorException("No faces loaded. The mesh is empty");
	}

	// for each material in the scene we need to setup the UV source
	// set for each texture
	for (unsigned int a = 0; a < pcOut->mNumMaterials;++a)
	{
		SetupMatUVSrc( pcOut->mMaterials[a], &this->mScene->mMaterials[a] );
	}
	return;
}
// ------------------------------------------------------------------------------------------------
void Dot3DSImporter::AddNodeToGraph(aiScene* pcSOut,aiNode* pcOut,Dot3DS::Node* pcIn)
{
	// find the corresponding mesh indices
	std::vector<unsigned int> iArray;

	if (pcIn->mName != "$$$DUMMY")
	{		
		for (unsigned int a = 0; a < pcSOut->mNumMeshes;++a)
		{
			if (0 == ASSIMP_stricmp(pcIn->mName.c_str(),
				((std::string*)pcSOut->mMeshes[a]->mColors[0])->c_str()))
			{
				iArray.push_back(a);
			}
		}
	}
	pcOut->mName.Set(pcIn->mName);
	pcOut->mNumMeshes = iArray.size();
	pcOut->mMeshes = new unsigned int[iArray.size()];
	
	for (unsigned int i = 0;i < iArray.size();++i)
	{
		const unsigned int iIndex = iArray[i];
#if 0
		if (NULL != pcSOut->mMeshes[iIndex]->mColors[1])
		{
			pcOut->mTransformation = *((aiMatrix4x4*)
				(pcSOut->mMeshes[iIndex]->mColors[1]));

			delete (aiMatrix4x4*)pcSOut->mMeshes[iIndex]->mColors[1];
			pcSOut->mMeshes[iIndex]->mColors[1] = NULL;
		}
#endif
		pcOut->mMeshes[i] = iIndex;
	}

	// NOTE: Not necessary. We can use the given transformation matrix.
	// However, we'd need it if we wanted to implement keyframe animation

#if 0
	// build the scaling matrix. Toggle y and z axis
	aiMatrix4x4 mS;
	mS.a1 = pcIn->vScaling.x;
	mS.b2 = pcIn->vScaling.z;
	mS.c3 = pcIn->vScaling.y;

	// build the translation matrix. Toggle y and z axis
	aiMatrix4x4 mT;
	mT.a4 = pcIn->vPosition.x;
	mT.b4 = pcIn->vPosition.z;
	mT.c4 = pcIn->vPosition.y;

	// build the pivot matrix. Toggle y and z axis
	aiMatrix4x4 mP;
	mP.a4 = pcIn->vPivot.x;
	mP.b4 = pcIn->vPivot.z;
	mP.c4 = pcIn->vPivot.y;
#endif
	pcOut->mTransformation = aiMatrix4x4(); //  mT * pcIn->mRotation * mS * mP * pcOut->mTransformation.Inverse(); 

	pcOut->mNumChildren = pcIn->mChildren.size();
	pcOut->mChildren = new aiNode*[pcIn->mChildren.size()];
	for (unsigned int i = 0; i < pcIn->mChildren.size();++i)
	{
		pcOut->mChildren[i] = new aiNode();
		pcOut->mChildren[i]->mParent = pcOut;
		AddNodeToGraph(pcSOut,pcOut->mChildren[i],
			pcIn->mChildren[i]);
	}
	return;
}
// ------------------------------------------------------------------------------------------------
inline bool HasUVTransform(const Dot3DS::Texture& rcIn)
	{
	return (0.0f != rcIn.mOffsetU ||
			0.0f != rcIn.mOffsetV ||
			1.0f != rcIn.mScaleU  ||
			1.0f != rcIn.mScaleV  ||
			0.0f != rcIn.mRotation);
	}
// ------------------------------------------------------------------------------------------------
void Dot3DSImporter::ApplyScaleNOffset()
	{
	unsigned int iNum = 0;
	for (std::vector<Dot3DS::Material>::iterator
		i =  this->mScene->mMaterials.begin();
		i != this->mScene->mMaterials.end();++i,++iNum)
		{
		unsigned int iCnt = 0;
		Dot3DS::Texture* pcTexture = NULL;
		if (HasUVTransform((*i).sTexDiffuse))
			{
			(*i).sTexDiffuse.bPrivate = true;
			pcTexture = &(*i).sTexDiffuse;
			++iCnt;
			}
		if (HasUVTransform((*i).sTexSpecular))
			{
			(*i).sTexSpecular.bPrivate = true;
			pcTexture = &(*i).sTexSpecular;
			++iCnt;
			}
		if (HasUVTransform((*i).sTexOpacity))
			{
			(*i).sTexOpacity.bPrivate = true;
			pcTexture = &(*i).sTexOpacity;
			++iCnt;
			}
		if (HasUVTransform((*i).sTexEmissive))
			{
			(*i).sTexEmissive.bPrivate = true;
			pcTexture = &(*i).sTexEmissive;
			++iCnt;
			}
		if (HasUVTransform((*i).sTexBump))
			{
			(*i).sTexBump.bPrivate = true;
			pcTexture = &(*i).sTexBump;
			++iCnt;
			}
		if (HasUVTransform((*i).sTexShininess))
			{
			(*i).sTexShininess.bPrivate = true;
			pcTexture = &(*i).sTexShininess;
			++iCnt;
			}
		if (0 != iCnt)
			{
			// if only one texture needs scaling/offset operations
			// we can apply them directly to the first texture
			// coordinate sets of all meshes referencing *this* material
			// However, we can't do it  now. We need to wait until
			// everything is sorted by materials.
			if (1 == iCnt)
				{
				(*i).iBakeUVTransform = 1;
				(*i).pcSingleTexture = pcTexture;
				}
			// we will need to generate a separate new texture channel
			// for each texture. 
			// However, we can't do it  now. We need to wait until
			// everything is sorted by materials.
			else (*i).iBakeUVTransform = 2;
			}
		}
	}
// ------------------------------------------------------------------------------------------------
struct STransformVecInfo 
	{
	float fScaleU;
	float fScaleV;
	float fOffsetU;
	float fOffsetV;
	float fRotation;

	std::vector<Dot3DS::Texture*> pcTextures; 
	};
// ------------------------------------------------------------------------------------------------
void AddToList(std::vector<STransformVecInfo>& rasVec,Dot3DS::Texture* pcTex)
	{
	if (0 == pcTex->mMapName.length())return;

	for (std::vector<STransformVecInfo>::iterator
		i =  rasVec.begin();
		i != rasVec.end();++i)
		{
		if ((*i).fOffsetU == pcTex->mOffsetU &&
			(*i).fOffsetV == pcTex->mOffsetV && 
			(*i).fScaleU  == pcTex->mScaleU  &&
			(*i).fScaleV  == pcTex->mScaleV  &&
			(*i).fRotation == pcTex->mRotation)
			{
			(*i).pcTextures.push_back(pcTex);
			return;
			}
		}
	STransformVecInfo sInfo;
	sInfo.fScaleU = pcTex->mScaleU;
	sInfo.fScaleV = pcTex->mScaleV;
	sInfo.fOffsetU = pcTex->mOffsetU;
	sInfo.fOffsetV = pcTex->mOffsetV;
	sInfo.fRotation = pcTex->mRotation;
	sInfo.pcTextures.push_back(pcTex);

	rasVec.push_back(sInfo);
	}
// ------------------------------------------------------------------------------------------------
void Dot3DSImporter::BakeScaleNOffset(
	aiMesh* pcMesh, Dot3DS::Material* pcSrc)
	{
	if (!pcMesh->mTextureCoords[0])return;
	if (1 == pcSrc->iBakeUVTransform)
		{
		if (0.0f == pcSrc->pcSingleTexture->mRotation)
			{
			for (unsigned int i = 0; i < pcMesh->mNumVertices;++i)
				{
				pcMesh->mTextureCoords[0][i].x /= pcSrc->pcSingleTexture->mScaleU;
				pcMesh->mTextureCoords[0][i].y /= pcSrc->pcSingleTexture->mScaleV;

				pcMesh->mTextureCoords[0][i].x += pcSrc->pcSingleTexture->mOffsetU;
				pcMesh->mTextureCoords[0][i].y += pcSrc->pcSingleTexture->mOffsetV;
				}
			}
		else
			{
			const float fSin = sinf(pcSrc->pcSingleTexture->mRotation);
			const float fCos = cosf(pcSrc->pcSingleTexture->mRotation);
			for (unsigned int i = 0; i < pcMesh->mNumVertices;++i)
				{
				pcMesh->mTextureCoords[0][i].x /= pcSrc->pcSingleTexture->mScaleU;
				pcMesh->mTextureCoords[0][i].y /= pcSrc->pcSingleTexture->mScaleV;

				pcMesh->mTextureCoords[0][i].x *= fCos;
				pcMesh->mTextureCoords[0][i].y *= fSin;

				pcMesh->mTextureCoords[0][i].x += pcSrc->pcSingleTexture->mOffsetU;
				pcMesh->mTextureCoords[0][i].y += pcSrc->pcSingleTexture->mOffsetV;
				}
			}
		}
	else if (2 == pcSrc->iBakeUVTransform)
		{
		// now we need to find all textures in the material
		// which require scaling/offset operations
		std::vector<STransformVecInfo> sOps;
		AddToList(sOps,&pcSrc->sTexDiffuse);
		AddToList(sOps,&pcSrc->sTexSpecular);
		AddToList(sOps,&pcSrc->sTexEmissive);
		AddToList(sOps,&pcSrc->sTexOpacity);
		AddToList(sOps,&pcSrc->sTexBump);
		AddToList(sOps,&pcSrc->sTexShininess);

		const aiVector3D* _pvBase;
		if (0.0f == sOps[0].fOffsetU && 0.0f == sOps[0].fOffsetV &&
			1.0f == sOps[0].fScaleU  && 1.0f == sOps[0].fScaleV &&
			0.0f == sOps[0].fRotation)
			{
			// we'll have an unmodified set, so we can use *this* one
			_pvBase = pcMesh->mTextureCoords[0];
			}
		else
			{
			_pvBase = new aiVector3D[pcMesh->mNumVertices];
			memcpy(const_cast<aiVector3D*>(_pvBase),pcMesh->mTextureCoords[0],
				pcMesh->mNumVertices * sizeof(aiVector3D));
			}

		unsigned int iCnt = 0;
		for (std::vector<STransformVecInfo>::iterator
			i =  sOps.begin();
			i != sOps.end();++i,++iCnt)
			{
			if (!pcMesh->mTextureCoords[iCnt])
				{
				pcMesh->mTextureCoords[iCnt] = new aiVector3D[pcMesh->mNumVertices];
				}
			// more than 4 UV texture channels are not available
			if (iCnt > 3)
				{
				for (std::vector<Dot3DS::Texture*>::iterator
					a =  (*i).pcTextures.begin();
					a != (*i).pcTextures.end();++a)
					{
					(*a)->iUVSrc = 0;
					}
				continue;
				}
			const aiVector3D* pvBase = _pvBase;

			if (0.0f == (*i).fRotation)
				{
				for (unsigned int n = 0; n < pcMesh->mNumVertices;++n)
					{
					pcMesh->mTextureCoords[iCnt][n].x = pvBase->x / (*i).fScaleU;
					pcMesh->mTextureCoords[iCnt][n].y = pvBase->y / (*i).fScaleV;

					pcMesh->mTextureCoords[iCnt][n].x += (*i).fOffsetU;
					pcMesh->mTextureCoords[iCnt][n].y += (*i).fOffsetV;

					pvBase++;
					}
				}
			else
				{
				const float fSin = sinf((*i).fRotation);
				const float fCos = cosf((*i).fRotation);
				for (unsigned int n = 0; n < pcMesh->mNumVertices;++n)
					{
					pcMesh->mTextureCoords[iCnt][n].x = pvBase->x / (*i).fScaleU;
					pcMesh->mTextureCoords[iCnt][n].y = pvBase->y / (*i).fScaleV;

					pcMesh->mTextureCoords[iCnt][n].x *= fCos;
					pcMesh->mTextureCoords[iCnt][n].y *= fSin;

					pcMesh->mTextureCoords[iCnt][n].x += (*i).fOffsetU;
					pcMesh->mTextureCoords[iCnt][n].y += (*i).fOffsetV;

					pvBase++;
					}
				}
			// setup UV source
			for (std::vector<Dot3DS::Texture*>::iterator
				a =  (*i).pcTextures.begin();
				a != (*i).pcTextures.end();++a)
				{
				(*a)->iUVSrc = iCnt;
				}
			}

		// release temporary storage
		if (_pvBase != pcMesh->mTextureCoords[0])
			delete[] _pvBase;
		}
	}
// ------------------------------------------------------------------------------------------------
void Dot3DSImporter::GenerateNodeGraph(aiScene* pcOut)
{
	pcOut->mRootNode = new aiNode();

	if (0 == this->mRootNode->mChildren.size())
		{
		// seems the file has not even a hierarchy.
		// generate a flat hiearachy which looks like this:
		//
		//                ROOT_NODE
		//                   |
		//   ----------------------------------------
		//   |       |       |            |
		// MESH_0  MESH_1  MESH_2  ...  MESH_N
		//
		unsigned int iCnt = 0;

		pcOut->mRootNode->mNumChildren = pcOut->mNumMeshes;
		pcOut->mRootNode->mChildren = new aiNode* [ pcOut->mNumMeshes ];

		for (unsigned int i = 0; i < pcOut->mNumMeshes;++i)
			{
			aiNode* pcNode = new aiNode();
			pcNode->mParent = pcOut->mRootNode;
			pcNode->mNumChildren = 0;
			pcNode->mChildren = 0;
			pcNode->mMeshes = new unsigned int[1];
			pcNode->mMeshes[0] = i;
			pcNode->mNumMeshes = 1;
			pcNode->mName.Set("UNNAMED");

			// add the new child to the parent node
			pcOut->mRootNode->mChildren[i] = pcNode;
			}
		}
	else this->AddNodeToGraph(pcOut,  pcOut->mRootNode, this->mRootNode);

	for (unsigned int a = 0; a < pcOut->mNumMeshes;++a)
	{
		delete (std::string*)pcOut->mMeshes[a]->mColors[0];
		pcOut->mMeshes[a]->mColors[0] = NULL;

		// may be NULL
		delete (aiMatrix4x4*)pcOut->mMeshes[a]->mColors[1];
		pcOut->mMeshes[a]->mColors[1] = NULL;
	}
}
// ------------------------------------------------------------------------------------------------
void Dot3DSImporter::ConvertScene(aiScene* pcOut)
{
	pcOut->mNumMaterials = this->mScene->mMaterials.size();
	pcOut->mMaterials = new aiMaterial*[pcOut->mNumMaterials];

	for (unsigned int i = 0; i < pcOut->mNumMaterials;++i)
	{
		MaterialHelper* pcNew = new MaterialHelper();
		this->ConvertMaterial(this->mScene->mMaterials[i],*pcNew);
		pcOut->mMaterials[i] = pcNew;
	}
	this->ConvertMeshes(pcOut);
	return;
}
// ------------------------------------------------------------------------------------------------
void Dot3DSImporter::GenTexCoord (Dot3DS::Texture* pcTexture,
	const std::vector<aiVector2D>& p_vIn,
	std::vector<aiVector2D>& p_vOut)
{
	p_vOut.resize(p_vIn.size());

	std::vector<aiVector2D>::const_iterator i =  p_vIn.begin();
	std::vector<aiVector2D>::iterator		a =  p_vOut.begin();
	for(;i != p_vOut.end();++i,++a)
	{
		// TODO: Find out in which order 3ds max is performing
		// scaling and translation. However it seems reasonable to
		// scale first.
		//
		// TODO: http://www.jalix.org/ressources/graphics/3DS/_specifications/3ds-0.1.htm
		// says it is not u and v scale but 1/u and 1/v scale. Other sources
		// tell different things. Believe this one, the author seems to be funny
		// or drunken or both ;-)
		(*a) = (*i);
		(*a).x /= pcTexture->mScaleU;
		(*a).y /= pcTexture->mScaleV;
		(*a).x += pcTexture->mOffsetU;
		(*a).y += pcTexture->mOffsetV;
	}
	return;
}