OpenEXR.cpp

//-
// ==========================================================================
// Copyright 1995,2006,2008 Autodesk, Inc. All rights reserved.
//
// Use of this software is subject to the terms of the Autodesk
// license agreement provided at the time of installation or download,
// or which otherwise accompanies this software in either electronic
// or hard copy form.
// ==========================================================================
//+

// DESCRIPTION: 
//  OpenEXR Image File plugin.
//

#include <maya/MPxImageFile.h>
#include <maya/MImageFileInfo.h>
#include <maya/MImage.h>
#include <maya/MFnPlugin.h>
#include <maya/MStringArray.h>
#include <maya/MIOStream.h>

#if _WIN32   
#pragma warning( disable : 4290 )       // Disable STL warnings.
#pragma warning( disable : 4244 )       // Disable conversion from unsigned int to unsigned short 
#endif

#undef min
#undef max

#include <maya/cxx17_enter_legacy_scope.hpp>
#include <ImfRgbaFile.h>
#include <ImfArray.h>
#include <half.h>
#include <maya/cxx17_exit_legacy_scope.hpp>

#define INVALID_PIXEL_TYPE Imf::NUM_PIXELTYPES
MString kImagePluginName( "OpenEXR");

class OpenEXRImageFile : public MPxImageFile
{
public:
                    OpenEXRImageFile();
    virtual         ~OpenEXRImageFile();
    static void*    creator();
    virtual MStatus open( MString pathname, MImageFileInfo* info);
    virtual MStatus load( MImage& image, unsigned int idx);

protected:
    int             fWidth;
    int             fHeight;
    int             fChannels;
    int             fLayers;
    Imf::PixelType  fPixelType;
    Imf::RgbaInputFile* fInputFile;
};

//
// DESCRIPTION:
OpenEXRImageFile::OpenEXRImageFile()
: fInputFile( NULL), fChannels( 0), fLayers( 0), fPixelType( INVALID_PIXEL_TYPE)
{

}

//
// DESCRIPTION:
OpenEXRImageFile::~OpenEXRImageFile()
{
    if( fInputFile)
        delete fInputFile;
}

//
// DESCRIPTION:
void * OpenEXRImageFile::creator()
{
    return new OpenEXRImageFile();
}

//
// DESCRIPTION:
MStatus OpenEXRImageFile::open( MString pathname, MImageFileInfo* info)
{
    if( fInputFile) 
        delete fInputFile;

    try
    {
        fInputFile = new Imf::RgbaInputFile( pathname.asChar());
    }
    catch( ... )
    {
    }

    if( !fInputFile)
        return MS::kFailure;

    if( info)
    {
        const Imf::Header& header = fInputFile->header();
        fWidth = header.dataWindow().max.x - header.dataWindow().min.x + 1;
        fHeight = header.dataWindow().max.y - header.dataWindow().min.y + 1;
        info->width( fWidth);
        info->height( fHeight);
        const Imf::RgbaChannels channels = fInputFile->channels();
        //printf( "Found rgbaChannels %d\n", (int)channels);
        fChannels = channels & Imf::WRITE_A ? 4 : 3;

        info->channels( fChannels);
        info->numberOfImages( fLayers);
        info->pixelType( MImage::kFloat);
        //printf( "Successfully opened EXR image with %d channels of type %d\n", fChannels, (int)fPixelType);
    }
    return MS::kSuccess;
}


//
// DESCRIPTION:
MStatus OpenEXRImageFile::load( MImage& image, unsigned int imageNumber)
{
    MStatus rval = MS::kFailure;
    Imf::Array<Imf::Rgba> pixels;
    try
    {
        // Setup a frame buffer to hold the image
        int dw = fWidth;
        int dh = fHeight;
        int dx = fInputFile->dataWindow().min.x;
        int dy = fInputFile->dataWindow().min.y;
        pixels.resizeErase (dw * dh);
        fInputFile->setFrameBuffer (pixels - dx - dy * dw, 1, dw);
        fInputFile->readPixels( fInputFile->dataWindow().min.y, fInputFile->dataWindow().max.y);

        // Configure our Maya image to hold the result
        image.create( fWidth, fHeight, fChannels, MImage::kFloat);

        // Now transfer the channels in
        bool flipVertically = true;
        float* dest = image.floatPixels();
        if( flipVertically)
        {
            Imf::Rgba* src = pixels + (fHeight - 1) * fWidth;
            for( int y = 0; y < fHeight; y++)
            {
                for( int x = 0; x < fWidth; x++)
                {
                    *dest++ = src->r;
                    *dest++ = src->g;
                    *dest++ = src->b;
                    if( fChannels == 4)
                        *dest++ = src->a;
                    *src++;
                }
                src -= fWidth * 2;
            }
        }
        else
        {
//          half* src = pixels;
//          for( int y = 0; y < fHeight; y++)
//              for( int x = 0; x < fWidth; x++)
//                  for( int c = 0; c < fChannels; c++)
//                      *dest++ = *src++;
        }

        rval = MS::kSuccess;
    }
    catch (...)
    {
        //
        // If some of the pixels in the file cannot be read,
        // print an error message, and return a partial image
        // to the caller.
        //

        cerr << "OpenEXRImageFile::load() failed to load image." << endl;
    }

    return rval;
}


MStatus initializePlugin( MObject obj )
{
    MFnPlugin plugin( obj, PLUGIN_COMPANY, "8.0", "Any" );
    MStringArray extensions;
    extensions.append( "exr");
    CHECK_MSTATUS( plugin.registerImageFile( 
                    kImagePluginName,
                    OpenEXRImageFile::creator, 
                    extensions));
    
    return MS::kSuccess;
}

// DESCRIPTION:
MStatus uninitializePlugin( MObject obj )
{
    MFnPlugin plugin( obj );
    CHECK_MSTATUS( plugin.deregisterImageFile( kImagePluginName ) );

    return MS::kSuccess;
}