binaries/assimp-3.1.1/code/DXFLoader.cpp

/*
---------------------------------------------------------------------------
Open Asset Import Library (assimp)
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All rights reserved.

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  following disclaimer.

* Redistributions in binary form must reproduce the above
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*/

/** @file  DXFLoader.cpp
 *  @brief Implementation of the DXF importer class
 */

#include "AssimpPCH.h"
#ifndef ASSIMP_BUILD_NO_DXF_IMPORTER

#include "DXFLoader.h"
#include "ParsingUtils.h"
#include "ConvertToLHProcess.h"
#include "fast_atof.h"

#include "DXFHelper.h"

using namespace Assimp;

// AutoCAD Binary DXF<CR><LF><SUB><NULL> 
#define AI_DXF_BINARY_IDENT ("AutoCAD Binary DXF\r\n\x1a\0")
#define AI_DXF_BINARY_IDENT_LEN (24)

// default vertex color that all uncolored vertices will receive
#define AI_DXF_DEFAULT_COLOR aiColor4D(0.6f,0.6f,0.6f,0.6f)

// color indices for DXF - 16 are supported, the table is 
// taken directly from the DXF spec.
static aiColor4D g_aclrDxfIndexColors[] =
{
	aiColor4D (0.6f, 0.6f, 0.6f, 1.0f),
	aiColor4D (1.0f, 0.0f, 0.0f, 1.0f), // red
	aiColor4D (0.0f, 1.0f, 0.0f, 1.0f), // green
	aiColor4D (0.0f, 0.0f, 1.0f, 1.0f), // blue
	aiColor4D (0.3f, 1.0f, 0.3f, 1.0f), // light green
	aiColor4D (0.3f, 0.3f, 1.0f, 1.0f), // light blue
	aiColor4D (1.0f, 0.3f, 0.3f, 1.0f), // light red
	aiColor4D (1.0f, 0.0f, 1.0f, 1.0f), // pink
	aiColor4D (1.0f, 0.6f, 0.0f, 1.0f), // orange
	aiColor4D (0.6f, 0.3f, 0.0f, 1.0f), // dark orange
	aiColor4D (1.0f, 1.0f, 0.0f, 1.0f), // yellow
	aiColor4D (0.3f, 0.3f, 0.3f, 1.0f), // dark gray
	aiColor4D (0.8f, 0.8f, 0.8f, 1.0f), // light gray
	aiColor4D (0.0f, 00.f, 0.0f, 1.0f), // black
	aiColor4D (1.0f, 1.0f, 1.0f, 1.0f), // white
	aiColor4D (0.6f, 0.0f, 1.0f, 1.0f)  // violet
};
#define AI_DXF_NUM_INDEX_COLORS (sizeof(g_aclrDxfIndexColors)/sizeof(g_aclrDxfIndexColors[0]))
#define AI_DXF_ENTITIES_MAGIC_BLOCK "$ASSIMP_ENTITIES_MAGIC"


static const aiImporterDesc desc = {
	"Drawing Interchange Format (DXF) Importer",
	"",
	"",
	"",
	aiImporterFlags_SupportTextFlavour | aiImporterFlags_LimitedSupport,
	0,
	0,
	0,
	0,
	"dxf" 
};

// ------------------------------------------------------------------------------------------------
// Constructor to be privately used by Importer
DXFImporter::DXFImporter()
{}

// ------------------------------------------------------------------------------------------------
// Destructor, private as well 
DXFImporter::~DXFImporter()
{}

// ------------------------------------------------------------------------------------------------
// Returns whether the class can handle the format of the given file. 
bool DXFImporter::CanRead( const std::string& pFile, IOSystem* /*pIOHandler*/, bool /*checkSig*/) const
{
	return SimpleExtensionCheck(pFile,"dxf");
}

// ------------------------------------------------------------------------------------------------
// Get a list of all supported file extensions
const aiImporterDesc* DXFImporter::GetInfo () const
{
	return &desc;
}

// ------------------------------------------------------------------------------------------------
// Imports the given file into the given scene structure. 
void DXFImporter::InternReadFile( const std::string& pFile, 
	aiScene* pScene, 
	IOSystem* pIOHandler)
{
	boost::shared_ptr<IOStream> file = boost::shared_ptr<IOStream>( pIOHandler->Open( pFile) );
	
	// Check whether we can read the file
	if( file.get() == NULL) {
		throw DeadlyImportError( "Failed to open DXF file " + pFile + "");
	}

	// check whether this is a binaray DXF file - we can't read binary DXF files :-(
	char buff[AI_DXF_BINARY_IDENT_LEN+1] = {0};
	file->Read(buff,AI_DXF_BINARY_IDENT_LEN,1);

	if (!strncmp(AI_DXF_BINARY_IDENT,buff,AI_DXF_BINARY_IDENT_LEN)) {
		throw DeadlyImportError("DXF: Binary files are not supported at the moment");
	}

	// DXF files can grow very large, so read them via the StreamReader,
	// which will choose a suitable strategy.
	file->Seek(0,aiOrigin_SET);
	StreamReaderLE stream( file );
	
	DXF::LineReader reader (stream);
	DXF::FileData output;

	// now get all lines of the file and process top-level sections
	bool eof = false;
	while(!reader.End()) {

		// blocks table - these 'build blocks' are later (in ENTITIES)
		// referenced an included via INSERT statements.
		if (reader.Is(2,"BLOCKS")) {
			ParseBlocks(reader,output);
			continue;
		}
	
		// primary entity table
		if (reader.Is(2,"ENTITIES")) {
			ParseEntities(reader,output);
			continue;
		}

		// skip unneeded sections entirely to avoid any problems with them 
		// alltogether.
		else if (reader.Is(2,"CLASSES") || reader.Is(2,"TABLES")) {
			SkipSection(reader);
			continue;
		}

		else if (reader.Is(2,"HEADER")) {
			ParseHeader(reader,output);
			continue;
		}

		// comments
		else if (reader.Is(999)) {
			DefaultLogger::get()->info("DXF Comment: " + reader.Value());
		}

		// don't read past the official EOF sign
		else if (reader.Is(0,"EOF")) {
			eof = true;
			break;
		}

		++reader;
	}
	if (!eof) {
		DefaultLogger::get()->warn("DXF: EOF reached, but did not encounter DXF EOF marker");
	}

	ConvertMeshes(pScene,output);

	// Now rotate the whole scene by 90 degrees around the x axis to convert from AutoCAD's to Assimp's coordinate system
	pScene->mRootNode->mTransformation = aiMatrix4x4(
		1.f,0.f,0.f,0.f,
		0.f,0.f,1.f,0.f,
		0.f,-1.f,0.f,0.f,
		0.f,0.f,0.f,1.f) * pScene->mRootNode->mTransformation;
}

// ------------------------------------------------------------------------------------------------
void DXFImporter::ConvertMeshes(aiScene* pScene, DXF::FileData& output)
{
	// the process of resolving all the INSERT statements can grow the
	// polycount excessively, so log the original number.
	// XXX Option to import blocks as separate nodes?
	if (!DefaultLogger::isNullLogger()) {

		unsigned int vcount = 0, icount = 0;
		BOOST_FOREACH (const DXF::Block& bl, output.blocks) {
			BOOST_FOREACH (boost::shared_ptr<const DXF::PolyLine> pl, bl.lines) {
				vcount += pl->positions.size();
				icount += pl->counts.size();
			}
		}

		DefaultLogger::get()->debug((Formatter::format("DXF: Unexpanded polycount is "),
			icount,", vertex count is ",vcount
		));
	}

	if (! output.blocks.size()  ) {
		throw DeadlyImportError("DXF: no data blocks loaded");
	}

	DXF::Block* entities = 0;
	
	// index blocks by name
	DXF::BlockMap blocks_by_name;
	BOOST_FOREACH (DXF::Block& bl, output.blocks) {
		blocks_by_name[bl.name] = &bl;
		if ( !entities && bl.name == AI_DXF_ENTITIES_MAGIC_BLOCK ) {
			entities = &bl;
		}
	}

	if (!entities) {
		throw DeadlyImportError("DXF: no ENTITIES data block loaded");
	}

	typedef std::map<std::string, unsigned int> LayerMap;

	LayerMap layers;
	std::vector< std::vector< const DXF::PolyLine*> > corr;

	// now expand all block references in the primary ENTITIES block
	// XXX this involves heavy memory copying, consider a faster solution for future versions.
	ExpandBlockReferences(*entities,blocks_by_name);

	unsigned int cur = 0;
	BOOST_FOREACH (boost::shared_ptr<const DXF::PolyLine> pl, entities->lines) {
		if (pl->positions.size()) {

			std::map<std::string, unsigned int>::iterator it = layers.find(pl->layer);
			if (it == layers.end()) {
				++pScene->mNumMeshes;

				layers[pl->layer] = cur++;

				std::vector< const DXF::PolyLine* > pv;
				pv.push_back(&*pl);

				corr.push_back(pv);
			}
			else {
				corr[(*it).second].push_back(&*pl);
			}
		}
	}

	if (!pScene->mNumMeshes) {
		throw DeadlyImportError("DXF: this file contains no 3d data");
	}

	pScene->mMeshes = new aiMesh*[ pScene->mNumMeshes ] ();

	BOOST_FOREACH(const LayerMap::value_type& elem, layers){
		aiMesh* const mesh =  pScene->mMeshes[elem.second] = new aiMesh();
		mesh->mName.Set(elem.first);

		unsigned int cvert = 0,cface = 0;
		BOOST_FOREACH(const DXF::PolyLine* pl, corr[elem.second]){
			// sum over all faces since we need to 'verbosify' them.
			cvert += std::accumulate(pl->counts.begin(),pl->counts.end(),0); 
			cface += pl->counts.size();
		}

		aiVector3D* verts = mesh->mVertices = new aiVector3D[cvert];
		aiColor4D* colors = mesh->mColors[0] = new aiColor4D[cvert];
		aiFace* faces = mesh->mFaces = new aiFace[cface];

		mesh->mNumVertices = cvert;
		mesh->mNumFaces = cface;

		unsigned int prims = 0;
		unsigned int overall_indices = 0;
		BOOST_FOREACH(const DXF::PolyLine* pl, corr[elem.second]){

			std::vector<unsigned int>::const_iterator it = pl->indices.begin();
			BOOST_FOREACH(unsigned int facenumv,pl->counts) {
				aiFace& face = *faces++;
				face.mIndices = new unsigned int[face.mNumIndices = facenumv];

				for (unsigned int i = 0; i < facenumv; ++i) {
					face.mIndices[i] = overall_indices++;

					ai_assert(pl->positions.size() == pl->colors.size());
					if (*it >= pl->positions.size()) {
						throw DeadlyImportError("DXF: vertex index out of bounds");
					}

					*verts++ = pl->positions[*it];
					*colors++ = pl->colors[*it++];
				}

				// set primitive flags now, this saves the extra pass in ScenePreprocessor.
				switch(face.mNumIndices) {
					case 1:
						prims |= aiPrimitiveType_POINT;
						break;
					case 2:
						prims |= aiPrimitiveType_LINE;
						break;
					case 3:
						prims |= aiPrimitiveType_TRIANGLE;
						break;
					default:
						prims |= aiPrimitiveType_POLYGON;
						break;
				}
			}
		}

		mesh->mPrimitiveTypes = prims;
		mesh->mMaterialIndex = 0;
	}

	GenerateHierarchy(pScene,output);
	GenerateMaterials(pScene,output);
}


// ------------------------------------------------------------------------------------------------
void DXFImporter::ExpandBlockReferences(DXF::Block& bl,const DXF::BlockMap& blocks_by_name)
{
	BOOST_FOREACH (const DXF::InsertBlock& insert, bl.insertions) {

		// first check if the referenced blocks exists ...
		const DXF::BlockMap::const_iterator it = blocks_by_name.find(insert.name);
		if (it == blocks_by_name.end()) {
			DefaultLogger::get()->error((Formatter::format("DXF: Failed to resolve block reference: "),
				insert.name,"; skipping"
			));
			continue;
		}

		// XXX this would be the place to implement recursive expansion if needed.
		const DXF::Block& bl_src = *(*it).second;
		
		BOOST_FOREACH (boost::shared_ptr<const DXF::PolyLine> pl_in, bl_src.lines) {
			boost::shared_ptr<DXF::PolyLine> pl_out = boost::shared_ptr<DXF::PolyLine>(new DXF::PolyLine(*pl_in));

			if (bl_src.base.Length() || insert.scale.x!=1.f || insert.scale.y!=1.f || insert.scale.z!=1.f || insert.angle || insert.pos.Length()) {
				// manual coordinate system transformation
				// XXX order
				aiMatrix4x4 trafo, tmp;
				aiMatrix4x4::Translation(-bl_src.base,trafo);
				trafo *= aiMatrix4x4::Scaling(insert.scale,tmp);
				trafo *= aiMatrix4x4::Translation(insert.pos,tmp);

				// XXX rotation currently ignored - I didn't find an appropriate sample model.
				if (insert.angle != 0.f) {
					DefaultLogger::get()->warn("DXF: BLOCK rotation not currently implemented");
				}

				BOOST_FOREACH (aiVector3D& v, pl_out->positions) {
					v *= trafo;
				}
			}

			bl.lines.push_back(pl_out);
		}
	}
}


// ------------------------------------------------------------------------------------------------
void DXFImporter::GenerateMaterials(aiScene* pScene, DXF::FileData& /*output*/)
{
	// generate an almost-white default material. Reason:
	// the default vertex color is GREY, so we are
	// already at Assimp's usual default color.
	// generate a default material
	aiMaterial* pcMat = new aiMaterial();
	aiString s;
	s.Set(AI_DEFAULT_MATERIAL_NAME);
	pcMat->AddProperty(&s, AI_MATKEY_NAME);

	aiColor4D clrDiffuse(0.9f,0.9f,0.9f,1.0f);
	pcMat->AddProperty(&clrDiffuse,1,AI_MATKEY_COLOR_DIFFUSE);

	clrDiffuse = aiColor4D(1.0f,1.0f,1.0f,1.0f);
	pcMat->AddProperty(&clrDiffuse,1,AI_MATKEY_COLOR_SPECULAR);

	clrDiffuse = aiColor4D(0.05f,0.05f,0.05f,1.0f);
	pcMat->AddProperty(&clrDiffuse,1,AI_MATKEY_COLOR_AMBIENT);

	pScene->mNumMaterials = 1;
	pScene->mMaterials = new aiMaterial*[1];
	pScene->mMaterials[0] = pcMat;
}


// ------------------------------------------------------------------------------------------------
void DXFImporter::GenerateHierarchy(aiScene* pScene, DXF::FileData& /*output*/)
{
	// generate the output scene graph, which is just the root node with a single child for each layer.
	pScene->mRootNode = new aiNode();
	pScene->mRootNode->mName.Set("<DXF_ROOT>");

	if (1 == pScene->mNumMeshes)	{
		pScene->mRootNode->mMeshes = new unsigned int[ pScene->mRootNode->mNumMeshes = 1 ];
		pScene->mRootNode->mMeshes[0] = 0;
	}
	else
	{
		pScene->mRootNode->mChildren = new aiNode*[ pScene->mRootNode->mNumChildren = pScene->mNumMeshes ];
		for (unsigned int m = 0; m < pScene->mRootNode->mNumChildren;++m)	{
			aiNode* p = pScene->mRootNode->mChildren[m] = new aiNode();
			p->mName = pScene->mMeshes[m]->mName;

			p->mMeshes = new unsigned int[p->mNumMeshes = 1];
			p->mMeshes[0] = m;
			p->mParent = pScene->mRootNode;
		}
	}
}


// ------------------------------------------------------------------------------------------------
void DXFImporter::SkipSection(DXF::LineReader& reader)
{	
	for( ;!reader.End() && !reader.Is(0,"ENDSEC"); reader++);
}


// ------------------------------------------------------------------------------------------------
void DXFImporter::ParseHeader(DXF::LineReader& reader, DXF::FileData& /*output*/)
{	
	for( ;!reader.End() && !reader.Is(0,"ENDSEC"); reader++);
}


// ------------------------------------------------------------------------------------------------
void DXFImporter::ParseBlocks(DXF::LineReader& reader, DXF::FileData& output)
{	
	while( !reader.End() && !reader.Is(0,"ENDSEC")) {
		if (reader.Is(0,"BLOCK")) {
			ParseBlock(++reader,output);
			continue;
		}
		++reader;
	}

	DefaultLogger::get()->debug((Formatter::format("DXF: got "),
		output.blocks.size()," entries in BLOCKS"
	));
}


// ------------------------------------------------------------------------------------------------
void DXFImporter::ParseBlock(DXF::LineReader& reader, DXF::FileData& output)
{	
	// push a new block onto the stack.
	output.blocks.push_back( DXF::Block() );
	DXF::Block& block = output.blocks.back();

	while( !reader.End() && !reader.Is(0,"ENDBLK")) {

		switch(reader.GroupCode()) {
			case 2:
				block.name = reader.Value();
				break;

			case 10:
				block.base.x = reader.ValueAsFloat();
				break;
			case 20:
				block.base.y = reader.ValueAsFloat();
				break;
			case 30:
				block.base.z = reader.ValueAsFloat();
				break;
		}

		if (reader.Is(0,"POLYLINE")) {
			ParsePolyLine(++reader,output);
			continue;
		}

		// XXX is this a valid case?
		if (reader.Is(0,"INSERT")) {
			DefaultLogger::get()->warn("DXF: INSERT within a BLOCK not currently supported; skipping");
			for( ;!reader.End() && !reader.Is(0,"ENDBLK"); ++reader);
			break;
		}

		else if (reader.Is(0,"3DFACE") || reader.Is(0,"LINE") || reader.Is(0,"3DLINE")) {
			//http://sourceforge.net/tracker/index.php?func=detail&aid=2970566&group_id=226462&atid=1067632
			Parse3DFace(++reader, output);
			continue;
		}
		++reader;
	}
}


// ------------------------------------------------------------------------------------------------
void DXFImporter::ParseEntities(DXF::LineReader& reader, DXF::FileData& output)
{	
	// push a new block onto the stack.
	output.blocks.push_back( DXF::Block() );
	DXF::Block& block = output.blocks.back();

	block.name = AI_DXF_ENTITIES_MAGIC_BLOCK;

	while( !reader.End() && !reader.Is(0,"ENDSEC")) {
		if (reader.Is(0,"POLYLINE")) {
			ParsePolyLine(++reader,output);
			continue;
		}

		else if (reader.Is(0,"INSERT")) {
			ParseInsertion(++reader,output);
			continue;
		}

		else if (reader.Is(0,"3DFACE") || reader.Is(0,"LINE") || reader.Is(0,"3DLINE")) {
			//http://sourceforge.net/tracker/index.php?func=detail&aid=2970566&group_id=226462&atid=1067632
			Parse3DFace(++reader, output);
			continue;
		}

		++reader;
	}

	DefaultLogger::get()->debug((Formatter::format("DXF: got "),
		block.lines.size()," polylines and ", block.insertions.size() ," inserted blocks in ENTITIES"
	));
}


void DXFImporter::ParseInsertion(DXF::LineReader& reader, DXF::FileData& output)
{	
	output.blocks.back().insertions.push_back( DXF::InsertBlock() );
	DXF::InsertBlock& bl = output.blocks.back().insertions.back();

	while( !reader.End() && !reader.Is(0)) {

		switch(reader.GroupCode()) 
		{
			// name of referenced block
		case 2:
			bl.name = reader.Value();
			break;

			// translation
		case 10:
			bl.pos.x = reader.ValueAsFloat();
			break;
		case 20:
			bl.pos.y = reader.ValueAsFloat();
			break;
		case 30:
			bl.pos.z = reader.ValueAsFloat();
			break;

			// scaling
		case 41:
			bl.scale.x = reader.ValueAsFloat();
			break;
		case 42:
			bl.scale.y = reader.ValueAsFloat();
			break;
		case 43:
			bl.scale.z = reader.ValueAsFloat();
			break;

			// rotation angle
		case 50:
			bl.angle = reader.ValueAsFloat();
			break;
		}
		reader++;
	}
}

#define DXF_POLYLINE_FLAG_CLOSED		0x1
#define DXF_POLYLINE_FLAG_3D_POLYLINE	0x8
#define DXF_POLYLINE_FLAG_3D_POLYMESH	0x10
#define DXF_POLYLINE_FLAG_POLYFACEMESH	0x40

// ------------------------------------------------------------------------------------------------
void DXFImporter::ParsePolyLine(DXF::LineReader& reader, DXF::FileData& output)
{
	output.blocks.back().lines.push_back( boost::shared_ptr<DXF::PolyLine>( new DXF::PolyLine() ) );
	DXF::PolyLine& line = *output.blocks.back().lines.back();

	unsigned int iguess = 0, vguess = 0;
	while( !reader.End() && !reader.Is(0,"ENDSEC")) {
	
		if (reader.Is(0,"VERTEX")) {
			ParsePolyLineVertex(++reader,line);
			if (reader.Is(0,"SEQEND")) {
				break;
			}
			continue;
		}

		switch(reader.GroupCode())	
		{
		// flags --- important that we know whether it is a 
		// polyface mesh or 'just' a line.
		case 70:
			if (!line.flags)	{
				line.flags = reader.ValueAsSignedInt();
			}
			break;

		// optional number of vertices
		case 71:
			vguess = reader.ValueAsSignedInt();
			line.positions.reserve(vguess);
			break;

		// optional number of faces
		case 72:
			iguess = reader.ValueAsSignedInt();
			line.indices.reserve(iguess);
			break;

		// 8 specifies the layer on which this line is placed on
		case 8:
			line.layer = reader.Value();
			break;
		}

		reader++;
	}

	//if (!(line.flags & DXF_POLYLINE_FLAG_POLYFACEMESH))	{
	//	DefaultLogger::get()->warn((Formatter::format("DXF: polyline not currently supported: "),line.flags));
	//	output.blocks.back().lines.pop_back();
	//	return;
	//}

	if (vguess && line.positions.size() != vguess) {
		DefaultLogger::get()->warn((Formatter::format("DXF: unexpected vertex count in polymesh: "),
			line.positions.size(),", expected ", vguess
		));
	}

	if (line.flags & DXF_POLYLINE_FLAG_POLYFACEMESH ) {
		if (line.positions.size() < 3 || line.indices.size() < 3)	{
				DefaultLogger::get()->warn("DXF: not enough vertices for polymesh; ignoring");
				output.blocks.back().lines.pop_back();
				return;
		}

		// if these numbers are wrong, parsing might have gone wild. 
		// however, the docs state that applications are not required
		// to set the 71 and 72 fields, respectively, to valid values.
		// So just fire a warning.
		if (iguess && line.counts.size() != iguess) {
			DefaultLogger::get()->warn((Formatter::format("DXF: unexpected face count in polymesh: "),
				line.counts.size(),", expected ", iguess
			));
		}
	}
	else if (!line.indices.size() && !line.counts.size()) {
		// a polyline - so there are no indices yet.
		size_t guess = line.positions.size() + (line.flags & DXF_POLYLINE_FLAG_CLOSED ? 1 : 0);
		line.indices.reserve(guess);

		line.counts.reserve(guess/2);
		for (unsigned int i = 0; i < line.positions.size()/2; ++i) {
			line.indices.push_back(i*2);
			line.indices.push_back(i*2+1);
			line.counts.push_back(2);
		}

		// closed polyline?
		if (line.flags & DXF_POLYLINE_FLAG_CLOSED) {
			line.indices.push_back(line.positions.size()-1);
			line.indices.push_back(0);
			line.counts.push_back(2);
		}
	}
}

#define DXF_VERTEX_FLAG_PART_OF_POLYFACE 0x80
#define DXF_VERTEX_FLAG_HAS_POSITIONS 0x40

// ------------------------------------------------------------------------------------------------
void DXFImporter::ParsePolyLineVertex(DXF::LineReader& reader, DXF::PolyLine& line)
{
	unsigned int cnti = 0, flags = 0;
	unsigned int indices[4];

	aiVector3D out;
	aiColor4D clr = AI_DXF_DEFAULT_COLOR;

	while( !reader.End() ) {

		if (reader.Is(0)) { // SEQEND or another VERTEX
			break;
		}

		switch (reader.GroupCode())
		{
		case 8:
				// layer to which the vertex belongs to - assume that
				// this is always the layer the top-level polyline
				// entity resides on as well.
				if(reader.Value() != line.layer) {
					DefaultLogger::get()->warn("DXF: expected vertex to be part of a polyface but the 0x128 flag isn't set");
				}
				break;

		case 70:
				flags = reader.ValueAsUnsignedInt();
				break;

		// VERTEX COORDINATES
		case 10: out.x = reader.ValueAsFloat();break;
		case 20: out.y = reader.ValueAsFloat();break;
		case 30: out.z = reader.ValueAsFloat();break;

		// POLYFACE vertex indices
		case 71: 
		case 72:
		case 73:
		case 74: 
			if (cnti == 4) {
				DefaultLogger::get()->warn("DXF: more than 4 indices per face not supported; ignoring");
				break;
			}
			indices[cnti++] = reader.ValueAsUnsignedInt();
			break;

		// color
		case 62: 
			clr = g_aclrDxfIndexColors[reader.ValueAsUnsignedInt() % AI_DXF_NUM_INDEX_COLORS]; 
			break;
		};
	
		reader++;
	}
	
	if (line.flags & DXF_POLYLINE_FLAG_POLYFACEMESH && !(flags & DXF_VERTEX_FLAG_PART_OF_POLYFACE)) {
		DefaultLogger::get()->warn("DXF: expected vertex to be part of a polyface but the 0x128 flag isn't set");
	}

	if (cnti) {
		line.counts.push_back(cnti);
		for (unsigned int i = 0; i < cnti; ++i) {
			// IMPORTANT NOTE: POLYMESH indices are ONE-BASED
			if (indices[i] == 0) {
				DefaultLogger::get()->warn("DXF: invalid vertex index, indices are one-based.");
				--line.counts.back();
				continue;
			}
			line.indices.push_back(indices[i]-1);
		}
	}
	else {
		line.positions.push_back(out);
		line.colors.push_back(clr);
	}
}

// ------------------------------------------------------------------------------------------------
void DXFImporter::Parse3DFace(DXF::LineReader& reader, DXF::FileData& output)
{
	// (note) this is also used for for parsing line entities, so we
	// must handle the vertex_count == 2 case as well.

	output.blocks.back().lines.push_back( boost::shared_ptr<DXF::PolyLine>( new DXF::PolyLine() )  );
	DXF::PolyLine& line = *output.blocks.back().lines.back();

	aiVector3D vip[4];
	aiColor4D  clr = AI_DXF_DEFAULT_COLOR;
	
	bool b[4] = {false,false,false,false};
	while( !reader.End() ) {

		// next entity with a groupcode == 0 is probably already the next vertex or polymesh entity
		if (reader.GroupCode() == 0) {
			break;
		}
		switch (reader.GroupCode())	
		{

		// 8 specifies the layer
		case 8:	
			line.layer = reader.Value();
			break;

		// x position of the first corner
		case 10: vip[0].x = reader.ValueAsFloat();
			b[2] = true;
			break;

		// y position of the first corner
		case 20: vip[0].y = reader.ValueAsFloat();
			b[2] = true;
			break;

		// z position of the first corner
		case 30: vip[0].z = reader.ValueAsFloat();
			b[2] = true;
			break;

		// x position of the second corner
		case 11: vip[1].x = reader.ValueAsFloat();
			b[3] = true;
			break;

		// y position of the second corner
		case 21: vip[1].y = reader.ValueAsFloat();
			b[3] = true;
			break;

		// z position of the second corner
		case 31: vip[1].z = reader.ValueAsFloat();
			b[3] = true;
			break;

		// x position of the third corner
		case 12: vip[2].x = reader.ValueAsFloat();
			b[0] = true;
			break;

		// y position of the third corner
		case 22: vip[2].y = reader.ValueAsFloat();
			b[0] = true;
			break;

		// z position of the third corner
		case 32: vip[2].z = reader.ValueAsFloat();
			b[0] = true;
			break;

		// x position of the fourth corner
		case 13: vip[3].x = reader.ValueAsFloat();
			b[1] = true;
			break;

		// y position of the fourth corner
		case 23: vip[3].y = reader.ValueAsFloat();
			b[1] = true;
			break;

		// z position of the fourth corner
		case 33: vip[3].z = reader.ValueAsFloat();
			b[1] = true;
			break;

		// color
		case 62: 
			clr = g_aclrDxfIndexColors[reader.ValueAsUnsignedInt() % AI_DXF_NUM_INDEX_COLORS]; 
			break;
		};

		++reader;
	}

	// the fourth corner may even be identical to the third,
	// in this case we treat it as if it didn't exist.
	if (vip[3] == vip[2]) {
		b[1] = false;
	}
	
	// sanity checks to see if we got something meaningful
	if ((b[1] && !b[0]) || !b[2] || !b[3]) {
		DefaultLogger::get()->warn("DXF: unexpected vertex setup in 3DFACE/LINE/FACE entity; ignoring");
		output.blocks.back().lines.pop_back();
		return;
	}

	const unsigned int cnt = (2+(b[0]?1:0)+(b[1]?1:0));
	line.counts.push_back(cnt);

	for (unsigned int i = 0; i < cnt; ++i) {
		line.indices.push_back(line.positions.size());
		line.positions.push_back(vip[i]);
		line.colors.push_back(clr);
	}
}

#endif // !! ASSIMP_BUILD_NO_DXF_IMPORTER