//

// SPDX-License-Identifier: BSD-3-Clause

// Copyright (c) Contributors to the OpenEXR Project.

//

#ifndef INCLUDED_IMF_FRAME_BUFFER_H

#define INCLUDED_IMF_FRAME_BUFFER_H

//-----------------------------------------------------------------------------

//

//      class Slice

//      class FrameBuffer

//

//-----------------------------------------------------------------------------

#include "ImfForward.h"

#include "ImfName.h"

#include "ImfPixelType.h"

#include <ImathBox.h>

#include <cstdint>

#include <map>

#include <string>

OPENEXR_IMF_INTERNAL_NAMESPACE_HEADER_ENTER

//-------------------------------------------------------

// Description of a single slice of the frame buffer:

//

// Note -- terminology: as part of a file, a component of

// an image (e.g. red, green, blue, depth etc.) is called

// a "channel".  As part of a frame buffer, an image

// component is called a "slice".

//-------------------------------------------------------

struct IMF_EXPORT_TYPE Slice

{

    //------------------------------

    // Data type; see ImfPixelType.h

    //------------------------------

    PixelType type;

    //---------------------------------------------------------------------

    // Memory layout:  The address of pixel (x, y) is

    //

    //  base + (xp / xSampling) * xStride + (yp / ySampling) * yStride

    //

    // where xp and yp are computed as follows:

    //

    //  * If we are reading or writing a scanline-based file:

    //

    //      xp = x

    //      yp = y

    //

    //  * If we are reading a tile whose upper left coorner is at (xt, yt):

    //

    //      if xTileCoords is true then xp = x - xt, else xp = x

    //      if yTileCoords is true then yp = y - yt, else yp = y

    //

    //---------------------------------------------------------------------

    char*  base;

    size_t xStride;

    size_t yStride;

    //--------------------------------------------

    // Subsampling: pixel (x, y) is present in the

    // slice only if

    //

    //  x % xSampling == 0 && y % ySampling == 0

    //

    //--------------------------------------------

    int xSampling;

    int ySampling;

    //----------------------------------------------------------

    // Default value, used to fill the slice when a file without

    // a channel that corresponds to this slice is read.

    //----------------------------------------------------------

    double fillValue;

    //-------------------------------------------------------

    // For tiled files, the xTileCoords and yTileCoords flags

    // determine whether pixel addressing is performed using

    // absolute coordinates or coordinates relative to a

    // tile's upper left corner.  (See the comment on base,

    // xStride and yStride, above.)

    //

    // For scanline-based files these flags have no effect;

    // pixel addressing is always done using absolute

    // coordinates.

    //-------------------------------------------------------

    bool xTileCoords;

    bool yTileCoords;

    //------------

    // Constructor

    //------------

    IMF_EXPORT

    Slice (

        PixelType type        = HALF,

        char*     base        = 0,

        size_t    xStride     = 0,

        size_t    yStride     = 0,

        int       xSampling   = 1,

        int       ySampling   = 1,

        double    fillValue   = 0.0,

        bool      xTileCoords = false,

        bool      yTileCoords = false);

    // Does the heavy lifting of computing the base pointer for a slice,

    // avoiding overflow issues with large origin offsets

    //

    // if xStride == 0, assumes sizeof(pixeltype)

    // if yStride == 0, assumes xStride * ( w / xSampling )

    IMF_EXPORT

    static Slice Make (

        PixelType                   type,

        const void*                 ptr,

        const IMATH_NAMESPACE::V2i& origin,

        int64_t                     w,

        int64_t                     h,

        size_t                      xStride     = 0,

        size_t                      yStride     = 0,

        int                         xSampling   = 1,

        int                         ySampling   = 1,

        double                      fillValue   = 0.0,

        bool                        xTileCoords = false,

        bool                        yTileCoords = false);

    // same as above, just computes w and h for you

    // from a data window

    IMF_EXPORT

    static Slice Make (

        PixelType                     type,

        const void*                   ptr,

        const IMATH_NAMESPACE::Box2i& dataWindow,

        size_t                        xStride     = 0,

        size_t                        yStride     = 0,

        int                           xSampling   = 1,

        int                           ySampling   = 1,

        double                        fillValue   = 0.0,

        bool                          xTileCoords = false,

        bool                          yTileCoords = false);

};

class IMF_EXPORT_TYPE FrameBuffer

{

public:

    //------------

    // Add a slice

    //------------

    IMF_EXPORT

    void insert (const char name[], const Slice& slice);

    IMF_EXPORT

    void insert (const std::string& name, const Slice& slice);

    //----------------------------------------------------------------

    // Access to existing slices:

    //

    // [n]              Returns a reference to the slice with name n.

    //                  If no slice with name n exists, an IEX_NAMESPACE::ArgExc

    //                  is thrown.

    //

    // findSlice(n)     Returns a pointer to the slice with name n,

    //                  or 0 if no slice with name n exists.

    //

    //----------------------------------------------------------------

    IMF_EXPORT

    Slice& operator[] (const char name[]);

    IMF_EXPORT

    const Slice& operator[] (const char name[]) const;

    IMF_EXPORT

    Slice& operator[] (const std::string& name);

    IMF_EXPORT

    const Slice& operator[] (const std::string& name) const;

    IMF_EXPORT

    Slice* findSlice (const char name[]);

    IMF_EXPORT

    const Slice* findSlice (const char name[]) const;

    IMF_EXPORT

    Slice* findSlice (const std::string& name);

    IMF_EXPORT

    const Slice* findSlice (const std::string& name) const;

    //-----------------------------------------

    // Iterator-style access to existing slices

    //-----------------------------------------

    typedef std::map<Name, Slice> SliceMap;

    class Iterator;

    class ConstIterator;

    IMF_EXPORT

    Iterator begin ();

    IMF_EXPORT

    ConstIterator begin () const;

    IMF_EXPORT

    Iterator end ();

    IMF_EXPORT

    ConstIterator end () const;

    IMF_EXPORT

    Iterator find (const char name[]);

    IMF_EXPORT

    ConstIterator find (const char name[]) const;

    IMF_EXPORT

    Iterator find (const std::string& name);

    IMF_EXPORT

    ConstIterator find (const std::string& name) const;

private:

    SliceMap _map;

};

//----------

// Iterators

//----------

class IMF_EXPORT_TYPE FrameBuffer::Iterator

{

public:

    IMF_EXPORT

    Iterator ();

    IMF_EXPORT

    Iterator (const FrameBuffer::SliceMap::iterator& i);

    IMF_EXPORT

    Iterator& operator++ ();

    IMF_EXPORT

    Iterator operator++ (int);

    IMF_EXPORT

    const char* name () const;

    IMF_EXPORT

    Slice& slice () const;

private:

    friend class FrameBuffer::ConstIterator;

    FrameBuffer::SliceMap::iterator _i;

};

class IMF_EXPORT_TYPE FrameBuffer::ConstIterator

{

public:

    IMF_EXPORT

    ConstIterator ();

    IMF_EXPORT

    ConstIterator (const FrameBuffer::SliceMap::const_iterator& i);

    IMF_EXPORT

    ConstIterator (const FrameBuffer::Iterator& other);

    IMF_EXPORT

    ConstIterator& operator++ ();

    IMF_EXPORT

    ConstIterator operator++ (int);

    IMF_EXPORT

    const char* name () const;

    IMF_EXPORT

    const Slice& slice () const;

private:

    friend bool operator== (const ConstIterator&, const ConstIterator&);

    friend bool operator!= (const ConstIterator&, const ConstIterator&);

    FrameBuffer::SliceMap::const_iterator _i;

};

//-----------------

// Inline Functions

//-----------------

inline FrameBuffer::Iterator::Iterator () : _i ()

{

    // empty

}

inline FrameBuffer::Iterator::Iterator (

    const FrameBuffer::SliceMap::iterator& i)

    : _i (i)

{

    // empty

}

inline FrameBuffer::Iterator&

FrameBuffer::Iterator::operator++ ()

{

    ++_i;

    return *this;

}

inline FrameBuffer::Iterator

FrameBuffer::Iterator::operator++ (int)

{

    Iterator tmp = *this;

    ++_i;

    return tmp;

}

inline const char*

FrameBuffer::Iterator::name () const

{

    return *_i->first;

}

inline Slice&

FrameBuffer::Iterator::slice () const

{

    return _i->second;

}

inline FrameBuffer::ConstIterator::ConstIterator () : _i ()

{

    // empty

}

inline FrameBuffer::ConstIterator::ConstIterator (

    const FrameBuffer::SliceMap::const_iterator& i)

    : _i (i)

{

    // empty

}

inline FrameBuffer::ConstIterator::ConstIterator (

    const FrameBuffer::Iterator& other)

    : _i (other._i)

{

    // empty

}

inline FrameBuffer::ConstIterator&

FrameBuffer::ConstIterator::operator++ ()

{

    ++_i;

    return *this;

}

inline FrameBuffer::ConstIterator

FrameBuffer::ConstIterator::operator++ (int)

{

    ConstIterator tmp = *this;

    ++_i;

    return tmp;

}

inline const char*

FrameBuffer::ConstIterator::name () const

{

    return *_i->first;

}

inline const Slice&

FrameBuffer::ConstIterator::slice () const

{

    return _i->second;

}

inline bool

operator== (

    const FrameBuffer::ConstIterator& x, const FrameBuffer::ConstIterator& y)

{

    return x._i == y._i;

}

inline bool

operator!= (

    const FrameBuffer::ConstIterator& x, const FrameBuffer::ConstIterator& y)

{

    return !(x == y);

}

OPENEXR_IMF_INTERNAL_NAMESPACE_HEADER_EXIT

#endif