///////////////////////////////////////////////////////////////////////////
//
// Copyright (c) 2004, Industrial Light & Magic, a division of Lucas
// Digital Ltd. LLC
//
// All rights reserved.
//
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// modification, are permitted provided that the following conditions are
// met:
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// copyright notice, this list of conditions and the following disclaimer
// in the documentation and/or other materials provided with the
// distribution.
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// its contributors may be used to endorse or promote products derived
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///////////////////////////////////////////////////////////////////////////

//-----------------------------------------------------------------------------
//
//	Utility routines to test quickly if a given
//	file is an OpenEXR file, and whether the
//	file is scanline-based or tiled.
//
//-----------------------------------------------------------------------------


#include <ImfTestFile.h>
#include <ImfStdIO.h>
#include <ImfXdr.h>
#include <ImfVersion.h>

namespace Imf {


bool
isOpenExrFile (const char fileName[], bool &tiled)
{
    try
    {
    StdIFStream is (fileName);

    int magic, version;
    Xdr::read <StreamIO> (is, magic);
    Xdr::read <StreamIO> (is, version);

    tiled = isTiled (version);
    return magic == MAGIC;
    }
    catch (...)
    {
    tiled = false;
    return false;
    }
}


bool
isOpenExrFile (const char fileName[])
{
    bool tiled;
    return isOpenExrFile (fileName, tiled);
}


bool
isTiledOpenExrFile (const char fileName[])
{
    bool exr, tiled;
    exr = isOpenExrFile (fileName, tiled);
    return exr && tiled;
}


bool
isOpenExrFile (IStream &is, bool &tiled)
{
    try
    {
    Int64 pos = is.tellg();

    if (pos != 0)
        is.seekg (0);

    int magic, version;
    Xdr::read <StreamIO> (is, magic);
    Xdr::read <StreamIO> (is, version);

    is.seekg (pos);

    tiled = isTiled (version);
    return magic == MAGIC;
    }
    catch (...)
    {
    is.clear();
    tiled = false;
    return false;
    }
}


bool
isOpenExrFile (IStream &is)
{
    bool tiled;
    return isOpenExrFile (is, tiled);
}


bool
isTiledOpenExrFile (IStream &is)
{
    bool exr, tiled;
    exr = isOpenExrFile (is, tiled);
    return exr && tiled;
}

} // namespace Imf
