/*

 * Copyright 2017 Google Inc.

 *

 * Use of this source code is governed by a BSD-style license that can be

 * found in the LICENSE file.

 */

#ifndef SkPngEncoder_DEFINED

#define SkPngEncoder_DEFINED

#include "include/core/SkDataTable.h"

#include "include/core/SkRefCnt.h"

#include "include/private/base/SkAPI.h"

// TODO(kjlubick) update clients to directly include this

#include "include/encode/SkEncoder.h"  // IWYU pragma: keep

#include <memory>

class GrDirectContext;

class SkData;

class SkImage;

class SkPixmap;

class SkWStream;

struct skcms_ICCProfile;

namespace SkPngEncoder {

enum class FilterFlag : int {

    kZero = 0x00,

    kNone = 0x08,

    kSub = 0x10,

    kUp = 0x20,

    kAvg = 0x40,

    kPaeth = 0x80,

    kAll = kNone | kSub | kUp | kAvg | kPaeth,

};

inline FilterFlag operator|(FilterFlag x, FilterFlag y) { return (FilterFlag)((int)x | (int)y); }

struct Options {

    /**

     *  Selects which filtering strategies to use.

     *

     *  If a single filter is chosen, libpng will use that filter for every row.

     *

     *  If multiple filters are chosen, libpng will use a heuristic to guess which filter

     *  will encode smallest, then apply that filter.  This happens on a per row basis,

     *  different rows can use different filters.

     *

     *  Using a single filter (or less filters) is typically faster.  Trying all of the

     *  filters may help minimize the output file size.

     *

     *  Our default value matches libpng's default.

     */

    FilterFlag fFilterFlags = FilterFlag::kAll;

    /**

     *  Must be in [0, 9] where 9 corresponds to maximal compression.  This value is passed

     *  directly to zlib.  0 is a special case to skip zlib entirely, creating dramatically

     *  larger pngs.

     *

     *  Our default value matches libpng's default.

     */

    int fZLibLevel = 6;

    /**

     *  Represents comments in the tEXt ancillary chunk of the png.

     *  The 2i-th entry is the keyword for the i-th comment,

     *  and the (2i + 1)-th entry is the text for the i-th comment.

     */

    sk_sp<SkDataTable> fComments;

    /**

     * An optional ICC profile to override the default behavior.

     *

     * The default behavior is to generate an ICC profile using a primary matrix and

     * analytic transfer function. If the color space of |src| cannot be represented

     * in this way (e.g, it is HLG or PQ), then no profile will be embedded.

     */

    const skcms_ICCProfile* fICCProfile = nullptr;

    const char* fICCProfileDescription = nullptr;

};

/**

 *  Encode the |src| pixels to the |dst| stream.

 *  |options| may be used to control the encoding behavior.

 *

 *  Returns true on success.  Returns false on an invalid or unsupported |src|.

 */

SK_API bool Encode(SkWStream* dst, const SkPixmap& src, const Options& options);

/**

*  Encode the provided image and return the resulting bytes. If the image was created as

*  a texture-backed image on a GPU context, that |ctx| must be provided so the pixels

*  can be read before being encoded. For raster-backed images, |ctx| can be nullptr.

*  |options| may be used to control the encoding behavior.

*

*  Returns nullptr if the pixels could not be read or encoding otherwise fails.

*/

SK_API sk_sp<SkData> Encode(GrDirectContext* ctx, const SkImage* img, const Options& options);

/**

 *  Create a png encoder that will encode the |src| pixels to the |dst| stream.

 *  |options| may be used to control the encoding behavior.

 *

 *  The primary use of this is incremental encoding of the pixels.

 *

 *  |dst| is unowned but must remain valid for the lifetime of the object.

 *

 *  This returns nullptr on an invalid or unsupported |src|.

 */

SK_API std::unique_ptr<SkEncoder> Make(SkWStream* dst, const SkPixmap& src, const Options& options);

}  // namespace SkPngEncoder

#endif