assimp/code/BaseImporter.cpp

/*
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Open Asset Import Library (ASSIMP)
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Copyright (c) 2006-2008, ASSIMP Development Team

All rights reserved.

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  following disclaimer.

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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
}

// ------------------------------------------------------------------------------------------------
// 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
	aiScene* scene = new aiScene();

	// dispatch importing
	try
	{
		InternReadFile( pFile, scene, &filter);
	} catch( ImportErrorException* exception)
	{
		// extract error description
		mErrorText = exception->GetErrorText();

		DefaultLogger::get()->error(mErrorText);

		delete exception;

		// and kill the partially imported data
		delete scene;
		scene = NULL;
	}

	// return what we gathered from the import. 
	return scene;
}

// ------------------------------------------------------------------------------------------------
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;

	const char* magic = (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
		char data[16];
		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) {
				int16_t rev = *((int16_t*)magic);
				ByteSwap::Swap(&rev);
				if (*((int16_t*)data) == ((int16_t*)magic)[i] || *((int16_t*)data) == rev)
					return true;
			}
			else if (4 == size) {
				int32_t rev = *((int32_t*)magic);
				ByteSwap::Swap(&rev);
				if (*((int32_t*)data) == ((int32_t*)magic)[i] || *((int32_t*)data) == rev)
					return true;
			}
			else {
				// any length ... just compare
				if(!::memcmp(magic,data,size))
					return true;
			}
			magic += size;
		}
	}
	return false;
}

// ------------------------------------------------------------------------------------------------
// 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 %%%");
	}
}