ImfDeepScanLineOutputFile.h

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//
// SPDX-License-Identifier: BSD-3-Clause
// Copyright (c) Contributors to the OpenEXR Project.
//

#ifndef INCLUDED_IMF_DEEP_SCAN_LINE_OUTPUT_FILE_H
#define INCLUDED_IMF_DEEP_SCAN_LINE_OUTPUT_FILE_H

//-----------------------------------------------------------------------------
//
//      class DeepScanLineOutputFile
//
//-----------------------------------------------------------------------------

#include "ImfExport.h"
#include "ImfForward.h"
#include "ImfFrameBuffer.h"
#include "ImfGenericOutputFile.h"
#include "ImfHeader.h"
#include "ImfNamespace.h"
#include "ImfThreading.h"

OPENEXR_IMF_INTERNAL_NAMESPACE_HEADER_ENTER

struct PreviewRgba;

class DeepScanLineOutputFile : public GenericOutputFile
{
public:
    //-----------------------------------------------------------
    // Constructor -- opens the file and writes the file header.
    // The file header is also copied into the DeepScanLineOutputFile
    // object, and can later be accessed via the header() method.
    // Destroying this DeepScanLineOutputFile object automatically closes
    // the file.
    //
    // numThreads determines the number of threads that will be
    // used to write the file (see ImfThreading.h).
    //-----------------------------------------------------------

    IMF_EXPORT
    DeepScanLineOutputFile (
        const char    fileName[],
        const Header& header,
        int           numThreads = globalThreadCount ());

    //------------------------------------------------------------
    // Constructor -- attaches the new DeepScanLineOutputFile object
    // to a file that has already been opened, and writes the file header.
    // The file header is also copied into the DeepScanLineOutputFile
    // object, and can later be accessed via the header() method.
    // Destroying this DeepScanLineOutputFile object does not automatically
    // close the file.
    //
    // numThreads determines the number of threads that will be
    // used to write the file (see ImfThreading.h).
    //------------------------------------------------------------

    IMF_EXPORT
    DeepScanLineOutputFile (
        OPENEXR_IMF_INTERNAL_NAMESPACE::OStream& os,
        const Header&                            header,
        int numThreads = globalThreadCount ());

    //-------------------------------------------------
    // Destructor
    //
    // Destroying the DeepScanLineOutputFile object
    // before writing all scan lines within the data
    // window results in an incomplete file.
    //-------------------------------------------------

    IMF_EXPORT
    virtual ~DeepScanLineOutputFile ();

    //------------------------
    // Access to the file name
    //------------------------

    IMF_EXPORT
    const char* fileName () const;

    //--------------------------
    // Access to the file header
    //--------------------------

    IMF_EXPORT
    const Header& header () const;

    //-------------------------------------------------------
    // Set the current frame buffer -- copies the FrameBuffer
    // object into the OutputFile object.
    //
    // The current frame buffer is the source of the pixel
    // data written to the file.  The current frame buffer
    // must be set at least once before writePixels() is
    // called.  The current frame buffer can be changed
    // after each call to writePixels.
    //-------------------------------------------------------

    IMF_EXPORT
    void setFrameBuffer (const DeepFrameBuffer& frameBuffer);

    //-----------------------------------
    // Access to the current frame buffer
    //-----------------------------------

    IMF_EXPORT
    const DeepFrameBuffer& frameBuffer () const;

    //-------------------------------------------------------------------
    // Write pixel data:
    //
    // writePixels(n) retrieves the next n scan lines worth of data from
    // the current frame buffer, starting with the scan line indicated by
    // currentScanLine(), and stores the data in the output file, and
    // progressing in the direction indicated by header.lineOrder().
    //
    // To produce a complete and correct file, exactly m scan lines must
    // be written, where m is equal to
    // header().dataWindow().max.y - header().dataWindow().min.y + 1.
    //-------------------------------------------------------------------

    IMF_EXPORT
    void writePixels (int numScanLines = 1);

    //------------------------------------------------------------------
    // Access to the current scan line:
    //
    // currentScanLine() returns the y coordinate of the first scan line
    // that will be read from the current frame buffer during the next
    // call to writePixels().
    //
    // If header.lineOrder() == INCREASING_Y:
    //
    //  The current scan line before the first call to writePixels()
    //  is header().dataWindow().min.y.  After writing each scan line,
    //  the current scan line is incremented by 1.
    //
    // If header.lineOrder() == DECREASING_Y:
    //
    //  The current scan line before the first call to writePixels()
    //  is header().dataWindow().max.y.  After writing each scan line,
    //  the current scan line is decremented by 1.
    //
    //------------------------------------------------------------------

    IMF_EXPORT
    int currentScanLine () const;

    //--------------------------------------------------------------
    // Shortcut to copy all pixels from an InputFile into this file,
    // without uncompressing and then recompressing the pixel data.
    // This file's header must be compatible with the InputFile's
    // header:  The two header's "dataWindow", "compression",
    // "lineOrder" and "channels" attributes must be the same.
    //--------------------------------------------------------------

    IMF_EXPORT
    void copyPixels (DeepScanLineInputFile& in);

    // --------------------------------------------------------------
    // Shortcut to copy pixels from a given part of a multipart file
    // --------------------------------------------------------------
    IMF_EXPORT
    void copyPixels (DeepScanLineInputPart& in);

    //--------------------------------------------------------------
    // Updating the preview image:
    //
    // updatePreviewImage() supplies a new set of pixels for the
    // preview image attribute in the file's header.  If the header
    // does not contain a preview image, updatePreviewImage() throws
    // an IEX_NAMESPACE::LogicExc.
    //
    // Note: updatePreviewImage() is necessary because images are
    // often stored in a file incrementally, a few scan lines at a
    // time, while the image is being generated.  Since the preview
    // image is an attribute in the file's header, it gets stored in
    // the file as soon as the file is opened, but we may not know
    // what the preview image should look like until we have written
    // the last scan line of the main image.
    //
    //--------------------------------------------------------------

    IMF_EXPORT
    void updatePreviewImage (const PreviewRgba newPixels[]);

    struct Data;

private:
    //------------------------------------------------------------
    // Constructor -- attaches the OutputStreamMutex to the
    // given one from MultiPartOutputFile. Set the previewPosition
    // and lineOffsetsPosition which have been acquired from
    // the constructor of MultiPartOutputFile as well.
    //------------------------------------------------------------
    DeepScanLineOutputFile (const OutputPartData* part);

    DeepScanLineOutputFile (const DeepScanLineOutputFile&)            = delete;
    DeepScanLineOutputFile& operator= (const DeepScanLineOutputFile&) = delete;
    DeepScanLineOutputFile (DeepScanLineOutputFile&&)                 = delete;
    DeepScanLineOutputFile& operator= (DeepScanLineOutputFile&&)      = delete;

    void initialize (const Header& header);
    void initializeLineBuffer ();

    Data* _data;

    friend class MultiPartOutputFile;
};

OPENEXR_IMF_INTERNAL_NAMESPACE_HEADER_EXIT

#endif