assimp/code/BaseImporter.cpp

/*
---------------------------------------------------------------------------
Open Asset Import Library (ASSIMP)
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Copyright (c) 2006-2010, ASSIMP Development Team

All rights reserved.

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* Redistributions of source code must retain the above
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  following disclaimer.

* Redistributions in binary form must reproduce the above
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  derived from this software without specific prior
  written permission of the ASSIMP Development Team.

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*/

/** @file  BaseImporter.cpp
 *  @brief Implementation of BaseImporter 
 */

#include "AssimpPCH.h"
#include "BaseImporter.h"
#include "FileSystemFilter.h"

using namespace Assimp;

// ------------------------------------------------------------------------------------------------
// Constructor to be privately used by Importer
BaseImporter::BaseImporter()
{
	// nothing to do here
}

// ------------------------------------------------------------------------------------------------
// Destructor, private as well
BaseImporter::~BaseImporter()
{
	// nothing to do here
}

template <typename T>
struct tinyguard
{
	tinyguard(T* obj) : obj(obj), mdismiss() {}
	~tinyguard () throw() {if (!mdismiss) {delete obj;} obj = NULL;} 

	void dismiss() {
		mdismiss=true;
	}

	operator T*() {
		return obj;
	}

private:
	T* obj;
	bool mdismiss;
};

// ------------------------------------------------------------------------------------------------
// Imports the given file and returns the imported data.
aiScene* BaseImporter::ReadFile( const std::string& pFile, IOSystem* pIOHandler)
{
	// Construct a file system filter to improve our success ratio reading external files
	FileSystemFilter filter(pFile,pIOHandler);

	// create a scene object to hold the data
	tinyguard<aiScene> sc(new aiScene());

	// dispatch importing
	try
	{
		InternReadFile( pFile, sc, &filter);

	} catch( const std::exception& err )	{
		// extract error description
		mErrorText = err.what();
		DefaultLogger::get()->error(mErrorText);
		return NULL;
	}

	// return what we gathered from the import. 
	sc.dismiss();
	return sc;
}

// ------------------------------------------------------------------------------------------------
void BaseImporter::SetupProperties(const Importer* pImp)
{
	// the default implementation does nothing
}

// ------------------------------------------------------------------------------------------------
/*static*/ bool BaseImporter::SearchFileHeaderForToken(IOSystem* pIOHandler,
	const std::string&	pFile,
	const char**		tokens, 
	unsigned int		numTokens,
	unsigned int		searchBytes /* = 200 */)
{
	ai_assert(NULL != tokens && 0 != numTokens && 0 != searchBytes);
	if (!pIOHandler)
		return false;

	boost::scoped_ptr<IOStream> pStream (pIOHandler->Open(pFile));
	if (pStream.get() )	{
		// read 200 characters from the file
		boost::scoped_array<char> _buffer (new char[searchBytes+1 /* for the '\0' */]);
		char* buffer = _buffer.get();

		unsigned int read = (unsigned int)pStream->Read(buffer,1,searchBytes);
		if (!read)return false;

		for (unsigned int i = 0; i < read;++i)
			buffer[i] = ::tolower(buffer[i]);

		// It is not a proper handling of unicode files here ...
		// ehm ... but it works in most cases.
		char* cur = buffer,*cur2 = buffer,*end = &buffer[read];
		while (cur != end)	{
			if (*cur)
				*cur2++ = *cur;
			++cur;
		}
		*cur2 = '\0';

		for (unsigned int i = 0; i < numTokens;++i)	{
			ai_assert(NULL != tokens[i]);

			if (::strstr(buffer,tokens[i]))	{
				DefaultLogger::get()->debug(std::string("Found positive match for header keyword: ") + tokens[i]);
				return true;
			}
		}
	}
	return false;
}

// ------------------------------------------------------------------------------------------------
// Simple check for file extension
/*static*/ bool BaseImporter::SimpleExtensionCheck (const std::string& pFile, 
	const char* ext0,
	const char* ext1,
	const char* ext2)
{
	std::string::size_type pos = pFile.find_last_of('.');

	// no file extension - can't read
	if( pos == std::string::npos)
		return false;
	
	const char* ext_real = & pFile[ pos+1 ];
	if( !ASSIMP_stricmp(ext_real,ext0) )
		return true;

	// check for other, optional, file extensions
	if (ext1 && !ASSIMP_stricmp(ext_real,ext1))
		return true;

	if (ext2 && !ASSIMP_stricmp(ext_real,ext2))
		return true;

	return false;
}

// ------------------------------------------------------------------------------------------------
// Get file extension from path
/*static*/ std::string BaseImporter::GetExtension (const std::string& pFile)
{
	std::string::size_type pos = pFile.find_last_of('.');

	// no file extension at all
	if( pos == std::string::npos)
		return "";

	std::string ret = pFile.substr(pos+1);
	std::transform(ret.begin(),ret.end(),ret.begin(),::tolower); // thanks to Andy Maloney for the hint
	return ret;
}

// ------------------------------------------------------------------------------------------------
// Check for magic bytes at the beginning of the file.
/* static */ bool BaseImporter::CheckMagicToken(IOSystem* pIOHandler, const std::string& pFile, 
	const void* _magic, unsigned int num, unsigned int offset, unsigned int size)
{
	ai_assert(size <= 16 && _magic);

	if (!pIOHandler) {
		return false;
	}
	union {
		const char* magic;
		const uint16_t* magic_u16;
		const uint32_t* magic_u32;
	};
	magic = reinterpret_cast<const char*>(_magic);
	boost::scoped_ptr<IOStream> pStream (pIOHandler->Open(pFile));
	if (pStream.get() )	{

		// skip to offset
		pStream->Seek(offset,aiOrigin_SET);

		// read 'size' characters from the file
		union {
			char data[16];
			uint16_t data_u16[8];
			uint32_t data_u32[4];
		};
		if(size != pStream->Read(data,1,size)) {
			return false;
		}

		for (unsigned int i = 0; i < num; ++i) {
			// also check against big endian versions of tokens with size 2,4
			// that's just for convinience, the chance that we cause conflicts
			// is quite low and it can save some lines and prevent nasty bugs
			if (2 == size) {
				uint16_t rev = *magic_u16; 
				ByteSwap::Swap(&rev);
				if (data_u16[0] == *magic_u16 || data_u16[0] == rev) {
					return true;
				}
			}
			else if (4 == size) {
				uint32_t rev = *magic_u32;
				ByteSwap::Swap(&rev);
				if (data_u32[0] == *magic_u32 || data_u32[0] == rev) {
					return true;
				}
			}
			else {
				// any length ... just compare
				if(!memcmp(magic,data,size)) {
					return true;
				}
			}
			magic += size;
		}
	}
	return false;
}

#include "../contrib/ConvertUTF/ConvertUTF.h"

// ------------------------------------------------------------------------------------------------
void ReportResult(ConversionResult res)
{
	if(res == sourceExhausted) {
		DefaultLogger::get()->error("Source ends with incomplete character sequence, transformation to UTF-8 fails");
	}
	else if(res == sourceIllegal) {
		DefaultLogger::get()->error("Source contains illegal character sequence, transformation to UTF-8 fails");
	}
}

// ------------------------------------------------------------------------------------------------
// Convert to UTF8 data
void BaseImporter::ConvertToUTF8(std::vector<char>& data)
{
	ConversionResult result;
	if(data.size() < 8) {
		throw DeadlyImportError("File is too small");
	}

	// UTF 8 with BOM
	if((uint8_t)data[0] == 0xEF && (uint8_t)data[1] == 0xBB && (uint8_t)data[2] == 0xBF) {
		DefaultLogger::get()->debug("Found UTF-8 BOM ...");

		std::copy(data.begin()+3,data.end(),data.begin());
		data.resize(data.size()-3);
		return;
	}

	// UTF 32 BE with BOM
	if(*((uint32_t*)&data.front()) == 0xFFFE0000) {
	
		// swap the endianess ..
		for(uint32_t* p = (uint32_t*)&data.front(), *end = (uint32_t*)&data.back(); p <= end; ++p) {
			AI_SWAP4P(p);
		}
	}
	
	// UTF 32 LE with BOM
	if(*((uint32_t*)&data.front()) == 0x0000FFFE) {
		DefaultLogger::get()->debug("Found UTF-32 BOM ...");

		const uint32_t* sstart = (uint32_t*)&data.front()+1, *send = (uint32_t*)&data.back()+1;
		char* dstart,*dend;
		std::vector<char> output;
		do {
			output.resize(output.size()?output.size()*3/2:data.size()/2);
			dstart = &output.front(),dend = &output.back()+1;

			result = ConvertUTF32toUTF8((const UTF32**)&sstart,(const UTF32*)send,(UTF8**)&dstart,(UTF8*)dend,lenientConversion);
		} while(result == targetExhausted);

		ReportResult(result);

		// copy to output buffer. 
		const size_t outlen = (size_t)(dstart-&output.front());
		data.assign(output.begin(),output.begin()+outlen);
		return;
	}

	// UTF 16 BE with BOM
	if(*((uint16_t*)&data.front()) == 0xFFFE) {
	
		// swap the endianess ..
		for(uint16_t* p = (uint16_t*)&data.front(), *end = (uint16_t*)&data.back(); p <= end; ++p) {
			ByteSwap::Swap2(p);
		}
	}
	
	// UTF 16 LE with BOM
	if(*((uint16_t*)&data.front()) == 0xFEFF) {
		DefaultLogger::get()->debug("Found UTF-16 BOM ...");

		const uint16_t* sstart = (uint16_t*)&data.front()+1, *send = (uint16_t*)&data.back()+1;
		char* dstart,*dend;
		std::vector<char> output;
		do {
			output.resize(output.size()?output.size()*3/2:data.size()*3/4);
			dstart = &output.front(),dend = &output.back()+1;

			result = ConvertUTF16toUTF8((const UTF16**)&sstart,(const UTF16*)send,(UTF8**)&dstart,(UTF8*)dend,lenientConversion);
		} while(result == targetExhausted);

		ReportResult(result);

		// copy to output buffer.
		const size_t outlen = (size_t)(dstart-&output.front());
		data.assign(output.begin(),output.begin()+outlen);
		return;
	}
}

// ------------------------------------------------------------------------------------------------
void BaseImporter::TextFileToBuffer(IOStream* stream,
	std::vector<char>& data)
{
	ai_assert(NULL != stream);

	const size_t fileSize = stream->FileSize();
	if(!fileSize) {
		throw DeadlyImportError("File is empty");
	}

	data.reserve(fileSize+1); 
	data.resize(fileSize); 
	if(fileSize != stream->Read( &data[0], 1, fileSize)) {
		throw DeadlyImportError("File read error");
	}

	ConvertToUTF8(data);

	// append a binary zero to simplify string parsing
	data.push_back(0);
}

// ------------------------------------------------------------------------------------------------
namespace Assimp
{
	// Represents an import request
	struct LoadRequest
	{
		LoadRequest(const std::string& _file, unsigned int _flags,const BatchLoader::PropertyMap* _map, unsigned int _id)
			: file(_file), flags(_flags), refCnt(1),scene(NULL), loaded(false), id(_id)
		{
			if (_map)
				map = *_map;
		}

		const std::string file;
		unsigned int flags;
		unsigned int refCnt;
		aiScene* scene;
		bool loaded;
		BatchLoader::PropertyMap map;
		unsigned int id;

		bool operator== (const std::string& f) {
			return file == f;
		}
	};
}

// ------------------------------------------------------------------------------------------------
// BatchLoader::pimpl data structure
struct Assimp::BatchData
{
	BatchData()
		:	next_id(0xffff)
	{}

	// IO system to be used for all imports
	IOSystem* pIOSystem;

	// Importer used to load all meshes
	Importer* pImporter;

	// List of all imports
	std::list<LoadRequest> requests;

	// Base path
	std::string pathBase;

	// Id for next item
	unsigned int next_id;
};

// ------------------------------------------------------------------------------------------------
BatchLoader::BatchLoader(IOSystem* pIO)
{
	ai_assert(NULL != pIO);

	data = new BatchData();
	data->pIOSystem = pIO;

	data->pImporter = new Importer();
	data->pImporter->SetIOHandler(data->pIOSystem);
}

// ------------------------------------------------------------------------------------------------
BatchLoader::~BatchLoader()
{
	// delete all scenes wthat have not been polled by the user
	for (std::list<LoadRequest>::iterator it = data->requests.begin();it != data->requests.end(); ++it)	{

		delete (*it).scene;
	}
	data->pImporter->SetIOHandler(NULL); /* get pointer back into our posession */
	delete data->pImporter;
	delete data;
}


// ------------------------------------------------------------------------------------------------
unsigned int BatchLoader::AddLoadRequest	(const std::string& file,
	unsigned int steps /*= 0*/, const PropertyMap* map /*= NULL*/)
{
	ai_assert(!file.empty());
	
	// check whether we have this loading request already
	std::list<LoadRequest>::iterator it;
	for (it = data->requests.begin();it != data->requests.end(); ++it)	{

		// Call IOSystem's path comparison function here
		if (data->pIOSystem->ComparePaths((*it).file,file))	{

			if (map) {
				if (!((*it).map == *map))
					continue;
			}
			else if (!(*it).map.empty())
				continue;

			(*it).refCnt++;
			return (*it).id;
		}
	}

	// no, we don't have it. So add it to the queue ...
	data->requests.push_back(LoadRequest(file,steps,map,data->next_id));
	return data->next_id++;
}

// ------------------------------------------------------------------------------------------------
aiScene* BatchLoader::GetImport		(unsigned int which)
{
	for (std::list<LoadRequest>::iterator it = data->requests.begin();it != data->requests.end(); ++it)	{

		if ((*it).id == which && (*it).loaded)	{

			aiScene* sc = (*it).scene;
			if (!(--(*it).refCnt))	{
				data->requests.erase(it);
			}
			return sc;
		}
	}
	return NULL;
}

// ------------------------------------------------------------------------------------------------
void BatchLoader::LoadAll()
{
	// no threaded implementation for the moment
	for (std::list<LoadRequest>::iterator it = data->requests.begin();it != data->requests.end(); ++it)	{
		// force validation in debug builds
		unsigned int pp = (*it).flags;
#ifdef _DEBUG
		pp |= aiProcess_ValidateDataStructure;
#endif
		// setup config properties if necessary
		data->pImporter->pimpl->mFloatProperties  = (*it).map.floats;
		data->pImporter->pimpl->mIntProperties    = (*it).map.ints;
		data->pImporter->pimpl->mStringProperties = (*it).map.strings;

		if (!DefaultLogger::isNullLogger())
		{
			DefaultLogger::get()->info("%%% BEGIN EXTERNAL FILE %%%");
			DefaultLogger::get()->info("File: " + (*it).file);
		}
		data->pImporter->ReadFile((*it).file,pp);
		(*it).scene = const_cast<aiScene*>(data->pImporter->GetOrphanedScene());
		(*it).loaded = true;

		DefaultLogger::get()->info("%%% END EXTERNAL FILE %%%");
	}
}