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/// \file AMFImporter_Postprocess.cpp
/// \brief Convert built scenegraph and objects to Assimp scenegraph.
/// \date 2016
/// \author smal.root@gmail.com

#ifndef ASSIMP_BUILD_NO_AMF_IMPORTER

#include "AMFImporter.hpp"

// Header files, Assimp.
#include "SceneCombiner.h"
#include "StandardShapes.h"
#include "StringUtils.h"

// Header files, stdlib.
#include <algorithm>
#include <iterator>

namespace Assimp
{

aiColor4D AMFImporter::SPP_Material::GetColor(const float pX, const float pY, const float pZ) const
{
aiColor4D tcol;

	// Check if stored data are supported.
	if(Composition.size() != 0)
	{
		throw DeadlyImportError("IME. GetColor for composition");
	}
	else if(Color->Composed)
	{
		throw DeadlyImportError("IME. GetColor, composed color");
	}
	else
	{
		tcol = Color->Color;
	}

	// Check if default color must be used
	if((tcol.r == 0) && (tcol.g == 0) && (tcol.b == 0) && (tcol.a == 0))
	{
		tcol.r = 0.5f;
		tcol.g = 0.5f;
		tcol.b = 0.5f;
		tcol.a = 1;
	}

	return tcol;
}

void AMFImporter::PostprocessHelper_CreateMeshDataArray(const CAMFImporter_NodeElement_Mesh& pNodeElement, std::vector<aiVector3D>& pVertexCoordinateArray,
														std::vector<CAMFImporter_NodeElement_Color*>& pVertexColorArray) const
{
CAMFImporter_NodeElement_Vertices* vn = nullptr;
size_t col_idx;

	// All data stored in "vertices", search for it.
	for(CAMFImporter_NodeElement* ne_child: pNodeElement.Child)
	{
		if(ne_child->Type == CAMFImporter_NodeElement::ENET_Vertices) vn = (CAMFImporter_NodeElement_Vertices*)ne_child;
	}

	// If "vertices" not found then no work for us.
	if(vn == nullptr) return;

	pVertexCoordinateArray.reserve(vn->Child.size());// all coordinates stored as child and we need to reserve space for future push_back's.
	pVertexColorArray.resize(vn->Child.size());// colors count equal vertices count.
	col_idx = 0;
	// Inside vertices collect all data and place to arrays
	for(CAMFImporter_NodeElement* vn_child: vn->Child)
	{
		// vertices, colors
		if(vn_child->Type == CAMFImporter_NodeElement::ENET_Vertex)
		{
			// by default clear color for current vertex
			pVertexColorArray[col_idx] = nullptr;

			for(CAMFImporter_NodeElement* vtx: vn_child->Child)
			{
				if(vtx->Type == CAMFImporter_NodeElement::ENET_Coordinates)
				{
					pVertexCoordinateArray.push_back(((CAMFImporter_NodeElement_Coordinates*)vtx)->Coordinate);

					continue;
				}

				if(vtx->Type == CAMFImporter_NodeElement::ENET_Color)
				{
					pVertexColorArray[col_idx] = (CAMFImporter_NodeElement_Color*)vtx;

					continue;
				}
			}// for(CAMFImporter_NodeElement* vtx: vn_child->Child)

			col_idx++;
		}// if(vn_child->Type == CAMFImporter_NodeElement::ENET_Vertex)
	}// for(CAMFImporter_NodeElement* vn_child: vn->Child)
}

size_t AMFImporter::PostprocessHelper_GetTextureID_Or_Create(const std::string& pID_R, const std::string& pID_G, const std::string& pID_B,
																const std::string& pID_A)
{
size_t TextureConverted_Index;
std::string TextureConverted_ID;

	// check input data
	if(pID_R.empty() && pID_G.empty() && pID_B.empty() && pID_A.empty())
		throw DeadlyImportError("PostprocessHelper_GetTextureID_Or_Create. At least one texture ID must be defined.");

	// Create ID
	TextureConverted_ID = pID_R + "_" + pID_G + "_" + pID_B + "_" + pID_A;
	// Check if texture specified by set of IDs is converted already.
	TextureConverted_Index = 0;
	for(const SPP_Texture& tex_convd: mTexture_Converted)
	{
		if(tex_convd.ID == TextureConverted_ID)
			return TextureConverted_Index;
		else
			TextureConverted_Index++;
	}

	//
	// Converted texture not found, create it.
	//
	CAMFImporter_NodeElement_Texture* src_texture[4]{nullptr};
	std::vector<CAMFImporter_NodeElement_Texture*> src_texture_4check;
	SPP_Texture converted_texture;

	{// find all specified source textures
		CAMFImporter_NodeElement* t_tex;

		// R
		if(!pID_R.empty())
		{
			if(!Find_NodeElement(pID_R, CAMFImporter_NodeElement::ENET_Texture, &t_tex)) Throw_ID_NotFound(pID_R);

			src_texture[0] = (CAMFImporter_NodeElement_Texture*)t_tex;
			src_texture_4check.push_back((CAMFImporter_NodeElement_Texture*)t_tex);
		}
		else
		{
			src_texture[0] = nullptr;
		}

		// G
		if(!pID_G.empty())
		{
			if(!Find_NodeElement(pID_G, CAMFImporter_NodeElement::ENET_Texture, &t_tex)) Throw_ID_NotFound(pID_G);

			src_texture[1] = (CAMFImporter_NodeElement_Texture*)t_tex;
			src_texture_4check.push_back((CAMFImporter_NodeElement_Texture*)t_tex);
		}
		else
		{
			src_texture[1] = nullptr;
		}

		// B
		if(!pID_B.empty())
		{
			if(!Find_NodeElement(pID_B, CAMFImporter_NodeElement::ENET_Texture, &t_tex)) Throw_ID_NotFound(pID_B);

			src_texture[2] = (CAMFImporter_NodeElement_Texture*)t_tex;
			src_texture_4check.push_back((CAMFImporter_NodeElement_Texture*)t_tex);
		}
		else
		{
			src_texture[2] = nullptr;
		}

		// A
		if(!pID_A.empty())
		{
			if(!Find_NodeElement(pID_A, CAMFImporter_NodeElement::ENET_Texture, &t_tex)) Throw_ID_NotFound(pID_A);

			src_texture[3] = (CAMFImporter_NodeElement_Texture*)t_tex;
			src_texture_4check.push_back((CAMFImporter_NodeElement_Texture*)t_tex);
		}
		else
		{
			src_texture[3] = nullptr;
		}
	}// END: find all specified source textures

	// check that all textures has same size
	if(src_texture_4check.size() > 1)
	{
		for (size_t i = 0, i_e = (src_texture_4check.size() - 1); i < i_e; i++)
		{
			if((src_texture_4check[i]->Width != src_texture_4check[i + 1]->Width) || (src_texture_4check[i]->Height != src_texture_4check[i + 1]->Height) ||
				(src_texture_4check[i]->Depth != src_texture_4check[i + 1]->Depth))
			{
				throw DeadlyImportError("PostprocessHelper_GetTextureID_Or_Create. Source texture must has the same size.");
			}
		}
	}// if(src_texture_4check.size() > 1)

	// set texture attributes
	converted_texture.Width = src_texture_4check[0]->Width;
	converted_texture.Height = src_texture_4check[0]->Height;
	converted_texture.Depth = src_texture_4check[0]->Depth;
	// if one of source texture is tiled then converted texture is tiled too.
	converted_texture.Tiled = false;
	for(uint8_t i = 0; i < src_texture_4check.size(); i++) converted_texture.Tiled |= src_texture_4check[i]->Tiled;

	// Create format hint.
	strcpy(converted_texture.FormatHint, "rgba0000");// copy initial string.
	if(!pID_R.empty()) converted_texture.FormatHint[4] = '8';
	if(!pID_G.empty()) converted_texture.FormatHint[5] = '8';
	if(!pID_B.empty()) converted_texture.FormatHint[6] = '8';
	if(!pID_A.empty()) converted_texture.FormatHint[7] = '8';

	//
	// Сopy data of textures.
	//
	size_t tex_size = 0;
	size_t step = 0;
	size_t off_g = 0;
	size_t off_b = 0;

	// Calculate size of the target array and rule how data will be copied.
	if(!pID_R.empty()) { tex_size += src_texture[0]->Data.size(); step++, off_g++, off_b++; }
	if(!pID_G.empty()) { tex_size += src_texture[1]->Data.size(); step++, off_b++; }
	if(!pID_B.empty()) { tex_size += src_texture[2]->Data.size(); step++; }
	if(!pID_A.empty()) { tex_size += src_texture[3]->Data.size(); step++; }

	// Create target array.
	converted_texture.Data = new uint8_t[tex_size];
	// And copy data
	auto CopyTextureData = [&](const std::string& pID, const size_t pOffset, const size_t pStep, const uint8_t pSrcTexNum) -> void
	{
		if(!pID.empty())
		{
			for(size_t idx_target = pOffset, idx_src = 0; idx_target < tex_size; idx_target += pStep, idx_src++)
				converted_texture.Data[idx_target] = src_texture[pSrcTexNum]->Data.at(idx_src);
		}
	};// auto CopyTextureData = [&](const size_t pOffset, const size_t pStep, const uint8_t pSrcTexNum) -> void

	CopyTextureData(pID_R, 0, step, 0);
	CopyTextureData(pID_G, off_g, step, 1);
	CopyTextureData(pID_B, off_b, step, 2);
	CopyTextureData(pID_A, step - 1, step, 3);

	// Store new converted texture ID
	converted_texture.ID = TextureConverted_ID;
	// Store new converted texture
	mTexture_Converted.push_back(converted_texture);

	return TextureConverted_Index;
}

void AMFImporter::PostprocessHelper_SplitFacesByTextureID(std::list<SComplexFace>& pInputList, std::list<std::list<SComplexFace> >& pOutputList_Separated)
{
auto texmap_is_equal = [](const CAMFImporter_NodeElement_TexMap* pTexMap1, const CAMFImporter_NodeElement_TexMap* pTexMap2) -> bool
{
	if((pTexMap1 == nullptr) && (pTexMap2 == nullptr)) return true;
	if(pTexMap1 == nullptr) return false;
	if(pTexMap2 == nullptr) return false;

	if(pTexMap1->TextureID_R != pTexMap2->TextureID_R) return false;
	if(pTexMap1->TextureID_G != pTexMap2->TextureID_G) return false;
	if(pTexMap1->TextureID_B != pTexMap2->TextureID_B) return false;
	if(pTexMap1->TextureID_A != pTexMap2->TextureID_A) return false;

	return true;
};

	pOutputList_Separated.clear();
	if(pInputList.size() == 0) return;

	do
	{
		SComplexFace face_start = pInputList.front();
		std::list<SComplexFace> face_list_cur;

		for(std::list<SComplexFace>::iterator it = pInputList.begin(), it_end = pInputList.end(); it != it_end;)
		{
			if(texmap_is_equal(face_start.TexMap, it->TexMap))
			{
				auto it_old = it;

				it++;
				face_list_cur.push_back(*it_old);
				pInputList.erase(it_old);
			}
			else
			{
				it++;
			}
		}

		if(face_list_cur.size() > 0) pOutputList_Separated.push_back(face_list_cur);

	} while(pInputList.size() > 0);
}

void AMFImporter::Postprocess_AddMetadata(const std::list<CAMFImporter_NodeElement_Metadata*>& metadataList, aiNode& sceneNode) const
{
	if ( !metadataList.empty() )
	{
		if(sceneNode.mMetaData != nullptr) throw DeadlyImportError("Postprocess. MetaData member in node are not nullptr. Something went wrong.");

		// copy collected metadata to output node.
        sceneNode.mMetaData = aiMetadata::Alloc( static_cast<unsigned int>(metadataList.size()) );
		size_t meta_idx( 0 );

		for(const CAMFImporter_NodeElement_Metadata& metadata: metadataList)
		{
			sceneNode.mMetaData->Set(static_cast<unsigned int>(meta_idx++), metadata.Type, aiString(metadata.Value));
		}
	}// if(!metadataList.empty())
}

void AMFImporter::Postprocess_BuildNodeAndObject(const CAMFImporter_NodeElement_Object& pNodeElement, std::list<aiMesh*>& pMeshList, aiNode** pSceneNode)
{
CAMFImporter_NodeElement_Color* object_color = nullptr;

	// create new aiNode and set name as <object> has.
	*pSceneNode = new aiNode;
	(*pSceneNode)->mName = pNodeElement.ID;
	// read mesh and color
	for(const CAMFImporter_NodeElement* ne_child: pNodeElement.Child)
	{
		std::vector<aiVector3D> vertex_arr;
		std::vector<CAMFImporter_NodeElement_Color*> color_arr;

		// color for object
		if(ne_child->Type == CAMFImporter_NodeElement::ENET_Color) object_color = (CAMFImporter_NodeElement_Color*)ne_child;

		if(ne_child->Type == CAMFImporter_NodeElement::ENET_Mesh)
		{
			// Create arrays from children of mesh: vertices.
			PostprocessHelper_CreateMeshDataArray(*((CAMFImporter_NodeElement_Mesh*)ne_child), vertex_arr, color_arr);
			// Use this arrays as a source when creating every aiMesh
			Postprocess_BuildMeshSet(*((CAMFImporter_NodeElement_Mesh*)ne_child), vertex_arr, color_arr, object_color, pMeshList, **pSceneNode);
		}
	}// for(const CAMFImporter_NodeElement* ne_child: pNodeElement)
}

void AMFImporter::Postprocess_BuildMeshSet(const CAMFImporter_NodeElement_Mesh& pNodeElement, const std::vector<aiVector3D>& pVertexCoordinateArray,
											const std::vector<CAMFImporter_NodeElement_Color*>& pVertexColorArray,
											const CAMFImporter_NodeElement_Color* pObjectColor, std::list<aiMesh*>& pMeshList, aiNode& pSceneNode)
{
std::list<unsigned int> mesh_idx;

	// all data stored in "volume", search for it.
	for(const CAMFImporter_NodeElement* ne_child: pNodeElement.Child)
	{
		const CAMFImporter_NodeElement_Color* ne_volume_color = nullptr;
		const SPP_Material* cur_mat = nullptr;

		if(ne_child->Type == CAMFImporter_NodeElement::ENET_Volume)
		{
			/******************* Get faces *******************/
			const CAMFImporter_NodeElement_Volume* ne_volume = reinterpret_cast<const CAMFImporter_NodeElement_Volume*>(ne_child);

			std::list<SComplexFace> complex_faces_list;// List of the faces of the volume.
			std::list<std::list<SComplexFace> > complex_faces_toplist;// List of the face list for every mesh.

			// check if volume use material
			if(!ne_volume->MaterialID.empty())
			{
				if(!Find_ConvertedMaterial(ne_volume->MaterialID, &cur_mat)) Throw_ID_NotFound(ne_volume->MaterialID);
			}

			// inside "volume" collect all data and place to arrays or create new objects
			for(const CAMFImporter_NodeElement* ne_volume_child: ne_volume->Child)
			{
				// color for volume
				if(ne_volume_child->Type == CAMFImporter_NodeElement::ENET_Color)
				{
					ne_volume_color = reinterpret_cast<const CAMFImporter_NodeElement_Color*>(ne_volume_child);
				}
				else if(ne_volume_child->Type == CAMFImporter_NodeElement::ENET_Triangle)// triangles, triangles colors
				{
					const CAMFImporter_NodeElement_Triangle& tri_al = *reinterpret_cast<const CAMFImporter_NodeElement_Triangle*>(ne_volume_child);

					SComplexFace complex_face;

					// initialize pointers
					complex_face.Color = nullptr;
					complex_face.TexMap = nullptr;
					// get data from triangle children: color, texture coordinates.
					if(tri_al.Child.size())
					{
						for(const CAMFImporter_NodeElement* ne_triangle_child: tri_al.Child)
						{
							if(ne_triangle_child->Type == CAMFImporter_NodeElement::ENET_Color)
								complex_face.Color = reinterpret_cast<const CAMFImporter_NodeElement_Color*>(ne_triangle_child);
							else if(ne_triangle_child->Type == CAMFImporter_NodeElement::ENET_TexMap)
								complex_face.TexMap = reinterpret_cast<const CAMFImporter_NodeElement_TexMap*>(ne_triangle_child);
						}
					}// if(tri_al.Child.size())

					// create new face and store it.
					complex_face.Face.mNumIndices = 3;
					complex_face.Face.mIndices = new unsigned int[3];
					complex_face.Face.mIndices[0] = static_cast<unsigned int>(tri_al.V[0]);
					complex_face.Face.mIndices[1] = static_cast<unsigned int>(tri_al.V[1]);
					complex_face.Face.mIndices[2] = static_cast<unsigned int>(tri_al.V[2]);
					complex_faces_list.push_back(complex_face);
				}
			}// for(const CAMFImporter_NodeElement* ne_volume_child: ne_volume->Child)

			/**** Split faces list: one list per mesh ****/
			PostprocessHelper_SplitFacesByTextureID(complex_faces_list, complex_faces_toplist);

			/***** Create mesh for every faces list ******/
			for(std::list<SComplexFace>& face_list_cur: complex_faces_toplist)
			{
				auto VertexIndex_GetMinimal = [](const std::list<SComplexFace>& pFaceList, const size_t* pBiggerThan) -> size_t
				{
					size_t rv;

					if(pBiggerThan != nullptr)
					{
						bool found = false;

						for(const SComplexFace& face: pFaceList)
						{
							for(size_t idx_vert = 0; idx_vert < face.Face.mNumIndices; idx_vert++)
							{
								if(face.Face.mIndices[idx_vert] > *pBiggerThan)
								{
									rv = face.Face.mIndices[idx_vert];
									found = true;

									break;
								}
							}

							if(found) break;
						}

						if(!found) return *pBiggerThan;
					}
					else
					{
						rv = pFaceList.front().Face.mIndices[0];
					}// if(pBiggerThan != nullptr) else

					for(const SComplexFace& face: pFaceList)
					{
						for(size_t vi = 0; vi < face.Face.mNumIndices; vi++)
						{
							if(face.Face.mIndices[vi] < rv)
							{
								if(pBiggerThan != nullptr)
								{
									if(face.Face.mIndices[vi] > *pBiggerThan) rv = face.Face.mIndices[vi];
								}
								else
								{
									rv = face.Face.mIndices[vi];
								}
							}
						}
					}// for(const SComplexFace& face: pFaceList)

					return rv;
				};// auto VertexIndex_GetMinimal = [](const std::list<SComplexFace>& pFaceList, const size_t* pBiggerThan) -> size_t

				auto VertexIndex_Replace = [](std::list<SComplexFace>& pFaceList, const size_t pIdx_From, const size_t pIdx_To) -> void
				{
					for(const SComplexFace& face: pFaceList)
					{
						for(size_t vi = 0; vi < face.Face.mNumIndices; vi++)
						{
							if(face.Face.mIndices[vi] == pIdx_From) face.Face.mIndices[vi] = static_cast<unsigned int>(pIdx_To);
						}
					}
				};// auto VertexIndex_Replace = [](std::list<SComplexFace>& pFaceList, const size_t pIdx_From, const size_t pIdx_To) -> void

				auto Vertex_CalculateColor = [&](const size_t pIdx) -> aiColor4D
				{
					// Color priorities(In descending order):
					// 1. triangle color;
					// 2. vertex color;
					// 3. volume color;
					// 4. object color;
					// 5. material;
					// 6. default - invisible coat.
					//
					// Fill vertices colors in color priority list above that's points from 1 to 6.
					if((pIdx < pVertexColorArray.size()) && (pVertexColorArray[pIdx] != nullptr))// check for vertex color
					{
						if(pVertexColorArray[pIdx]->Composed)
							throw DeadlyImportError("IME: vertex color composed");
						else
							return pVertexColorArray[pIdx]->Color;
					}
					else if(ne_volume_color != nullptr)// check for volume color
					{
						if(ne_volume_color->Composed)
							throw DeadlyImportError("IME: volume color composed");
						else
							return ne_volume_color->Color;
					}
					else if(pObjectColor != nullptr)// check for object color
					{
						if(pObjectColor->Composed)
							throw DeadlyImportError("IME: object color composed");
						else
							return pObjectColor->Color;
					}
					else if(cur_mat != nullptr)// check for material
					{
						return cur_mat->GetColor(pVertexCoordinateArray.at(pIdx).x, pVertexCoordinateArray.at(pIdx).y, pVertexCoordinateArray.at(pIdx).z);
					}
					else// set default color.
					{
						return {0, 0, 0, 0};
					}// if((vi < pVertexColorArray.size()) && (pVertexColorArray[vi] != nullptr)) else

				};// auto Vertex_CalculateColor = [&](const size_t pIdx) -> aiColor4D

				aiMesh* tmesh = new aiMesh;

				tmesh->mPrimitiveTypes = aiPrimitiveType_TRIANGLE;// Only triangles is supported by AMF.
				//
				// set geometry and colors (vertices)
				//
				// copy faces/triangles
				tmesh->mNumFaces = static_cast<unsigned int>(face_list_cur.size());
				tmesh->mFaces = new aiFace[tmesh->mNumFaces];

				// Create vertices list and optimize indices. Optimisation mean following.In AMF all volumes use one big list of vertices. And one volume
				// can use only part of vertices list, for example: vertices list contain few thousands of vertices and volume use vertices 1, 3, 10.
				// Do you need all this thousands of garbage? Of course no. So, optimisation step transformate sparse indices set to continuous.
				size_t VertexCount_Max = tmesh->mNumFaces * 3;// 3 - triangles.
				std::vector<aiVector3D> vert_arr, texcoord_arr;
				std::vector<aiColor4D> col_arr;

				vert_arr.reserve(VertexCount_Max * 2);// "* 2" - see below TODO.
				col_arr.reserve(VertexCount_Max * 2);

				{// fill arrays
					size_t vert_idx_from, vert_idx_to;

					// first iteration.
					vert_idx_to = 0;
					vert_idx_from = VertexIndex_GetMinimal(face_list_cur, nullptr);
					vert_arr.push_back(pVertexCoordinateArray.at(vert_idx_from));
					col_arr.push_back(Vertex_CalculateColor(vert_idx_from));
					if(vert_idx_from != vert_idx_to) VertexIndex_Replace(face_list_cur, vert_idx_from, vert_idx_to);

					// rest iterations
					do
					{
						vert_idx_from = VertexIndex_GetMinimal(face_list_cur, &vert_idx_to);
						if(vert_idx_from == vert_idx_to) break;// all indices are transferred,

						vert_arr.push_back(pVertexCoordinateArray.at(vert_idx_from));
						col_arr.push_back(Vertex_CalculateColor(vert_idx_from));
						vert_idx_to++;
						if(vert_idx_from != vert_idx_to) VertexIndex_Replace(face_list_cur, vert_idx_from, vert_idx_to);

					} while(true);
				}// fill arrays. END.

				//
				// check if triangle colors are used and create additional faces if needed.
				//
				for(const SComplexFace& face_cur: face_list_cur)
				{
					if(face_cur.Color != nullptr)
					{
						aiColor4D face_color;
						size_t vert_idx_new = vert_arr.size();

						if(face_cur.Color->Composed)
							throw DeadlyImportError("IME: face color composed");
						else
							face_color = face_cur.Color->Color;

						for(size_t idx_ind = 0; idx_ind < face_cur.Face.mNumIndices; idx_ind++)
						{
							vert_arr.push_back(vert_arr.at(face_cur.Face.mIndices[idx_ind]));
							col_arr.push_back(face_color);
							face_cur.Face.mIndices[idx_ind] = static_cast<unsigned int>(vert_idx_new++);
						}
					}// if(face_cur.Color != nullptr)
				}// for(const SComplexFace& face_cur: face_list_cur)

				//
				// if texture is used then copy texture coordinates too.
				//
				if(face_list_cur.front().TexMap != nullptr)
				{
					size_t idx_vert_new = vert_arr.size();
					///TODO: clean unused vertices. "* 2": in certain cases - mesh full of triangle colors - vert_arr will contain duplicated vertices for
					/// colored triangles and initial vertices (for colored vertices) which in real became unused. This part need more thinking about
					/// optimisation.
					bool* idx_vert_used;

					idx_vert_used = new bool[VertexCount_Max * 2];
					for(size_t i = 0, i_e = VertexCount_Max * 2; i < i_e; i++) idx_vert_used[i] = false;

					// This ID's will be used when set materials ID in scene.
					tmesh->mMaterialIndex = static_cast<unsigned int>(PostprocessHelper_GetTextureID_Or_Create(face_list_cur.front().TexMap->TextureID_R,
																						face_list_cur.front().TexMap->TextureID_G,
																						face_list_cur.front().TexMap->TextureID_B,
																						face_list_cur.front().TexMap->TextureID_A));
					texcoord_arr.resize(VertexCount_Max * 2);
					for(const SComplexFace& face_cur: face_list_cur)
					{
						for(size_t idx_ind = 0; idx_ind < face_cur.Face.mNumIndices; idx_ind++)
						{
							const size_t idx_vert = face_cur.Face.mIndices[idx_ind];

							if(!idx_vert_used[idx_vert])
							{
								texcoord_arr.at(idx_vert) = face_cur.TexMap->TextureCoordinate[idx_ind];
								idx_vert_used[idx_vert] = true;
							}
							else if(texcoord_arr.at(idx_vert) != face_cur.TexMap->TextureCoordinate[idx_ind])
							{
								// in that case one vertex is shared with many texture coordinates. We need to duplicate vertex with another texture
								// coordinates.
								vert_arr.push_back(vert_arr.at(idx_vert));
								col_arr.push_back(col_arr.at(idx_vert));
								texcoord_arr.at(idx_vert_new) = face_cur.TexMap->TextureCoordinate[idx_ind];
								face_cur.Face.mIndices[idx_ind] = static_cast<unsigned int>(idx_vert_new++);
							}
						}// for(size_t idx_ind = 0; idx_ind < face_cur.Face.mNumIndices; idx_ind++)
					}// for(const SComplexFace& face_cur: face_list_cur)

					delete [] idx_vert_used;
					// shrink array
					texcoord_arr.resize(idx_vert_new);
				}// if(face_list_cur.front().TexMap != nullptr)

				//
				// copy collected data to mesh
				//
				tmesh->mNumVertices = static_cast<unsigned int>(vert_arr.size());
				tmesh->mVertices = new aiVector3D[tmesh->mNumVertices];
				tmesh->mColors[0] = new aiColor4D[tmesh->mNumVertices];
				tmesh->mFaces = new aiFace[face_list_cur.size()];

				memcpy(tmesh->mVertices, vert_arr.data(), tmesh->mNumVertices * sizeof(aiVector3D));
				memcpy(tmesh->mColors[0], col_arr.data(), tmesh->mNumVertices * sizeof(aiColor4D));
				if(texcoord_arr.size() > 0)
				{
					tmesh->mTextureCoords[0] = new aiVector3D[tmesh->mNumVertices];
					memcpy(tmesh->mTextureCoords[0], texcoord_arr.data(), tmesh->mNumVertices * sizeof(aiVector3D));
					tmesh->mNumUVComponents[0] = 2;// U and V stored in "x", "y" of aiVector3D.
				}

				size_t idx_face = 0;
				for(const SComplexFace& face_cur: face_list_cur) tmesh->mFaces[idx_face++] = face_cur.Face;

				// store new aiMesh
				mesh_idx.push_back(static_cast<unsigned int>(pMeshList.size()));
				pMeshList.push_back(tmesh);
			}// for(const std::list<SComplexFace>& face_list_cur: complex_faces_toplist)
		}// if(ne_child->Type == CAMFImporter_NodeElement::ENET_Volume)
	}// for(const CAMFImporter_NodeElement* ne_child: pNodeElement.Child)

	// if meshes was created then assign new indices with current aiNode
	if(mesh_idx.size() > 0)
	{
		std::list<unsigned int>::const_iterator mit = mesh_idx.begin();

		pSceneNode.mNumMeshes = static_cast<unsigned int>(mesh_idx.size());
		pSceneNode.mMeshes = new unsigned int[pSceneNode.mNumMeshes];
		for(size_t i = 0; i < pSceneNode.mNumMeshes; i++) pSceneNode.mMeshes[i] = *mit++;
	}// if(mesh_idx.size() > 0)
}

void AMFImporter::Postprocess_BuildMaterial(const CAMFImporter_NodeElement_Material& pMaterial)
{
SPP_Material new_mat;

	new_mat.ID = pMaterial.ID;
	for(const CAMFImporter_NodeElement* mat_child: pMaterial.Child)
	{
		if(mat_child->Type == CAMFImporter_NodeElement::ENET_Color)
		{
			new_mat.Color = (CAMFImporter_NodeElement_Color*)mat_child;
		}
		else if(mat_child->Type == CAMFImporter_NodeElement::ENET_Metadata)
		{
			new_mat.Metadata.push_back((CAMFImporter_NodeElement_Metadata*)mat_child);
		}
	}// for(const CAMFImporter_NodeElement* mat_child; pMaterial.Child)

	// place converted material to special list
	mMaterial_Converted.push_back(new_mat);
}

void AMFImporter::Postprocess_BuildConstellation(CAMFImporter_NodeElement_Constellation& pConstellation, std::list<aiNode*>& pNodeList) const
{
aiNode* con_node;
std::list<aiNode*> ch_node;

	// We will build next hierarchy:
	// aiNode as parent (<constellation>) for set of nodes as a children
	//  |- aiNode for transformation (<instance> -> <delta...>, <r...>) - aiNode for pointing to object ("objectid")
	//  ...
	//  \_ aiNode for transformation (<instance> -> <delta...>, <r...>) - aiNode for pointing to object ("objectid")
	con_node = new aiNode;
	con_node->mName = pConstellation.ID;
	// Walk through children and search for instances of another objects, constellations.
	for(const CAMFImporter_NodeElement* ne: pConstellation.Child)
	{
		aiMatrix4x4 tmat;
		aiNode* t_node;
		aiNode* found_node;

		if(ne->Type == CAMFImporter_NodeElement::ENET_Metadata) continue;
		if(ne->Type != CAMFImporter_NodeElement::ENET_Instance) throw DeadlyImportError("Only <instance> nodes can be in <constellation>.");

		// create alias for conveniance
		CAMFImporter_NodeElement_Instance& als = *((CAMFImporter_NodeElement_Instance*)ne);
		// find referenced object
		if(!Find_ConvertedNode(als.ObjectID, pNodeList, &found_node)) Throw_ID_NotFound(als.ObjectID);

		// create node for apllying transformation
		t_node = new aiNode;
		t_node->mParent = con_node;
		// apply transformation
		aiMatrix4x4::Translation(als.Delta, tmat), t_node->mTransformation *= tmat;
		aiMatrix4x4::RotationX(als.Rotation.x, tmat), t_node->mTransformation *= tmat;
		aiMatrix4x4::RotationY(als.Rotation.y, tmat), t_node->mTransformation *= tmat;
		aiMatrix4x4::RotationZ(als.Rotation.z, tmat), t_node->mTransformation *= tmat;
		// create array for one child node
		t_node->mNumChildren = 1;
		t_node->mChildren = new aiNode*[t_node->mNumChildren];
		SceneCombiner::Copy(&t_node->mChildren[0], found_node);
		t_node->mChildren[0]->mParent = t_node;
		ch_node.push_back(t_node);
	}// for(const CAMFImporter_NodeElement* ne: pConstellation.Child)

	// copy found aiNode's as children
	if(ch_node.size() == 0) throw DeadlyImportError("<constellation> must have at least one <instance>.");

	size_t ch_idx = 0;

	con_node->mNumChildren = static_cast<unsigned int>(ch_node.size());
	con_node->mChildren = new aiNode*[con_node->mNumChildren];
	for(aiNode* node: ch_node) con_node->mChildren[ch_idx++] = node;

	// and place "root" of <constellation> node to node list
	pNodeList.push_back(con_node);
}

void AMFImporter::Postprocess_BuildScene(aiScene* pScene)
{
std::list<aiNode*> node_list;
std::list<aiMesh*> mesh_list;
std::list<CAMFImporter_NodeElement_Metadata*> meta_list;

	//
	// Because for AMF "material" is just complex colors mixing so aiMaterial will not be used.
	// For building aiScene we are must to do few steps:
	// at first creating root node for aiScene.
	pScene->mRootNode = new aiNode;
	pScene->mRootNode->mParent = nullptr;
	pScene->mFlags |= AI_SCENE_FLAGS_ALLOW_SHARED;
	// search for root(<amf>) element
	CAMFImporter_NodeElement* root_el = nullptr;

	for(CAMFImporter_NodeElement* ne: mNodeElement_List)
	{
		if(ne->Type != CAMFImporter_NodeElement::ENET_Root) continue;

		root_el = ne;

		break;
	}// for(const CAMFImporter_NodeElement* ne: mNodeElement_List)

	// Check if root element are found.
	if(root_el == nullptr) throw DeadlyImportError("Root(<amf>) element not found.");

	// after that walk through children of root and collect data. Five types of nodes can be placed at top level - in <amf>: <object>, <material>, <texture>,
	// <constellation> and <metadata>. But at first we must read <material> and <texture> because they will be used in <object>. <metadata> can be read
	// at any moment.
	//
	// 1. <material>
	// 2. <texture> will be converted later when processing triangles list. \sa Postprocess_BuildMeshSet
	for(const CAMFImporter_NodeElement* root_child: root_el->Child)
	{
		if(root_child->Type == CAMFImporter_NodeElement::ENET_Material) Postprocess_BuildMaterial(*((CAMFImporter_NodeElement_Material*)root_child));
	}

	// After "appearance" nodes we must read <object> because it will be used in <constellation> -> <instance>.
	//
	// 3. <object>
	for(const CAMFImporter_NodeElement* root_child: root_el->Child)
	{
		if(root_child->Type == CAMFImporter_NodeElement::ENET_Object)
		{
			aiNode* tnode = nullptr;

			// for <object> mesh and node must be built: object ID assigned to aiNode name and will be used in future for <instance>
			Postprocess_BuildNodeAndObject(*((CAMFImporter_NodeElement_Object*)root_child), mesh_list, &tnode);
			if(tnode != nullptr) node_list.push_back(tnode);

		}
	}// for(const CAMFImporter_NodeElement* root_child: root_el->Child)

	// And finally read rest of nodes.
	//
	for(const CAMFImporter_NodeElement* root_child: root_el->Child)
	{
		// 4. <constellation>
		if(root_child->Type == CAMFImporter_NodeElement::ENET_Constellation)
		{
			// <object> and <constellation> at top of self abstraction use aiNode. So we can use only aiNode list for creating new aiNode's.
			Postprocess_BuildConstellation(*((CAMFImporter_NodeElement_Constellation*)root_child), node_list);
		}

		// 5, <metadata>
		if(root_child->Type == CAMFImporter_NodeElement::ENET_Metadata) meta_list.push_back((CAMFImporter_NodeElement_Metadata*)root_child);
	}// for(const CAMFImporter_NodeElement* root_child: root_el->Child)

	// at now we can add collected metadata to root node
	Postprocess_AddMetadata(meta_list, *pScene->mRootNode);
	//
	// Check constellation children
	//
	// As said in specification:
	// "When multiple objects and constellations are defined in a single file, only the top level objects and constellations are available for printing."
	// What that means? For example: if some object is used in constellation then you must show only constellation but not original object.
	// And at this step we are checking that relations.
nl_clean_loop:

	if(node_list.size() > 1)
	{
		// walk through all nodes
		for(std::list<aiNode*>::iterator nl_it = node_list.begin(); nl_it != node_list.end(); nl_it++)
		{
			// and try to find them in another top nodes.
			std::list<aiNode*>::const_iterator next_it = nl_it;

			next_it++;
			for(; next_it != node_list.end(); next_it++)
			{
				if((*next_it)->FindNode((*nl_it)->mName) != nullptr)
				{
					// if current top node(nl_it) found in another top node then erase it from node_list and restart search loop.
					node_list.erase(nl_it);

					goto nl_clean_loop;
				}
			}// for(; next_it != node_list.end(); next_it++)
		}// for(std::list<aiNode*>::const_iterator nl_it = node_list.begin(); nl_it != node_list.end(); nl_it++)
	}

	//
	// move created objects to aiScene
	//
	//
	// Nodes
	if(node_list.size() > 0)
	{
		std::list<aiNode*>::const_iterator nl_it = node_list.begin();

		pScene->mRootNode->mNumChildren = static_cast<unsigned int>(node_list.size());
		pScene->mRootNode->mChildren = new aiNode*[pScene->mRootNode->mNumChildren];
		for(size_t i = 0; i < pScene->mRootNode->mNumChildren; i++)
		{
			// Objects and constellation that must be showed placed at top of hierarchy in <amf> node. So all aiNode's in node_list must have
			// mRootNode only as parent.
			(*nl_it)->mParent = pScene->mRootNode;
			pScene->mRootNode->mChildren[i] = *nl_it++;
		}
	}// if(node_list.size() > 0)

	//
	// Meshes
	if(mesh_list.size() > 0)
	{
		std::list<aiMesh*>::const_iterator ml_it = mesh_list.begin();

		pScene->mNumMeshes = static_cast<unsigned int>(mesh_list.size());
		pScene->mMeshes = new aiMesh*[pScene->mNumMeshes];
		for(size_t i = 0; i < pScene->mNumMeshes; i++) pScene->mMeshes[i] = *ml_it++;
	}// if(mesh_list.size() > 0)

	//
	// Textures
	pScene->mNumTextures = static_cast<unsigned int>(mTexture_Converted.size());
	if(pScene->mNumTextures > 0)
	{
		size_t idx;

		idx = 0;
		pScene->mTextures = new aiTexture*[pScene->mNumTextures];
		for(const SPP_Texture& tex_convd: mTexture_Converted)
		{
			pScene->mTextures[idx] = new aiTexture;
			pScene->mTextures[idx]->mWidth = static_cast<unsigned int>(tex_convd.Width);
			pScene->mTextures[idx]->mHeight = static_cast<unsigned int>(tex_convd.Height);
			pScene->mTextures[idx]->pcData = (aiTexel*)tex_convd.Data;
			// texture format description.
			strcpy(pScene->mTextures[idx]->achFormatHint, tex_convd.FormatHint);
			idx++;
		}// for(const SPP_Texture& tex_convd: mTexture_Converted)

		// Create materials for embedded textures.
		idx = 0;
		pScene->mNumMaterials = static_cast<unsigned int>(mTexture_Converted.size());
		pScene->mMaterials = new aiMaterial*[pScene->mNumMaterials];
		for(const SPP_Texture& tex_convd: mTexture_Converted)
		{
			const aiString texture_id(AI_EMBEDDED_TEXNAME_PREFIX + to_string(idx));
			const int mode = aiTextureOp_Multiply;
			const int repeat = tex_convd.Tiled ? 1 : 0;

			pScene->mMaterials[idx] = new aiMaterial;
			pScene->mMaterials[idx]->AddProperty(&texture_id, AI_MATKEY_TEXTURE_DIFFUSE(0));
			pScene->mMaterials[idx]->AddProperty(&mode, 1, AI_MATKEY_TEXOP_DIFFUSE(0));
			pScene->mMaterials[idx]->AddProperty(&repeat, 1, AI_MATKEY_MAPPINGMODE_U_DIFFUSE(0));
			pScene->mMaterials[idx]->AddProperty(&repeat, 1, AI_MATKEY_MAPPINGMODE_V_DIFFUSE(0));
			idx++;
		}
	}// if(pScene->mNumTextures > 0)
}// END: after that walk through children of root and collect data

}// namespace Assimp

#endif // !ASSIMP_BUILD_NO_AMF_IMPORTER