assimp/code/irrXMLWrapper.h

/*
Open Asset Import Library (assimp)
----------------------------------------------------------------------

Copyright (c) 2006-2016, assimp team
All rights reserved.

Redistribution and use of this software in source and binary forms,
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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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following disclaimer in the documentation and/or other
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* Neither the name of the assimp team, nor the names of its
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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.

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*/

#ifndef INCLUDED_AI_IRRXML_WRAPPER
#define INCLUDED_AI_IRRXML_WRAPPER

// some long includes ....
#include "./../contrib/irrXML/irrXML.h"
#include "./../include/assimp/IOStream.hpp"
#include "BaseImporter.h"
#include <vector>

namespace Assimp    {

// ---------------------------------------------------------------------------------
/** @brief Utility class to make IrrXML work together with our custom IO system
 *  See the IrrXML docs for more details.
 *
 *  Construct IrrXML-Reader in BaseImporter::InternReadFile():
 *  @code
 * // open the file
 * std::unique_ptr<IOStream> file( pIOHandler->Open( pFile));
 * if( file.get() == NULL) {
 *    throw DeadlyImportError( "Failed to open file " + pFile + ".");
 * }
 *
 * // generate a XML reader for it
 * std::unique_ptr<CIrrXML_IOStreamReader> mIOWrapper( new CIrrXML_IOStreamReader( file.get()));
 * mReader = irr::io::createIrrXMLReader( mIOWrapper.get());
 * if( !mReader) {
 *    ThrowException( "xxxx: Unable to open file.");
 * }
 * @endcode
 **/
class CIrrXML_IOStreamReader
    : public irr::io::IFileReadCallBack
{
public:

    // ----------------------------------------------------------------------------------
    //! Construction from an existing IOStream
    explicit CIrrXML_IOStreamReader(IOStream* _stream)
        : stream (_stream)
        , t (0)
    {

        // Map the buffer into memory and convert it to UTF8. IrrXML provides its
        // own conversion, which is merely a cast from uintNN_t to uint8_t. Thus,
        // it is not suitable for our purposes and we have to do it BEFORE IrrXML
        // gets the buffer. Sadly, this forces us to map the whole file into
        // memory.

        data.resize(stream->FileSize());
        stream->Read(&data[0],data.size(),1);

        // Remove null characters from the input sequence otherwise the parsing will utterly fail
        unsigned int size = 0;
        unsigned int size_max = static_cast<unsigned int>(data.size());
        for(unsigned int i = 0; i < size_max; i++) {
            if(data[i] != '\0') {
                data[size++] = data[i];
            }
        }
        data.resize(size);

        BaseImporter::ConvertToUTF8(data);
    }

    // ----------------------------------------------------------------------------------
    //! Virtual destructor
    virtual ~CIrrXML_IOStreamReader() {}

    // ----------------------------------------------------------------------------------
    //!   Reads an amount of bytes from the file.
    /**  @param buffer:       Pointer to output buffer.
     *   @param sizeToRead:   Amount of bytes to read
     *   @return              Returns how much bytes were read.  */
    virtual int read(void* buffer, int sizeToRead)  {
        if(sizeToRead<0) {
            return 0;
        }
        if(t+sizeToRead>data.size()) {
            sizeToRead = static_cast<int>(data.size()-t);
        }

        memcpy(buffer,&data.front()+t,sizeToRead);

        t += sizeToRead;
        return sizeToRead;
    }

    // ----------------------------------------------------------------------------------
    //! Returns size of file in bytes
    virtual int getSize()   {
        return (int)data.size();
    }

private:
    IOStream* stream;
    std::vector<char> data;
    size_t t;

}; // ! class CIrrXML_IOStreamReader

} // ! Assimp

#endif // !! INCLUDED_AI_IRRXML_WRAPPER