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/*
* Copyright 2024 Google LLC.
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#ifndef SkPngRustEncoder_DEFINED
#define SkPngRustEncoder_DEFINED
#include <cstdint>
#include <memory>
#include "include/core/SkDataTable.h"
#include "include/core/SkRefCnt.h"
#include "include/private/base/SkAPI.h"
class GrDirectContext;
class SkData;
class SkEncoder;
class SkImage;
class SkPixmap;
class SkWStream;
namespace SkPngRustEncoder {
/*
* Compression level.
*/
enum class CompressionLevel : uint8_t {
// Low compression level - fast, but may result in bigger PNG files.
kLow,
// Medium compression level - somewhere in-between `kLow` and `kHigh`.
kMedium,
// High compression level - slow, but should results in smaller PNG files.
kHigh,
};
/*
* PNG encoding options.
*
* TODO(https://crbug.com/379312510): Add support for `SkPngEncoder::Options`
* like:
* - Comments - `tEXt` chunks.
* - Color profile - `iCCP` chunk.
*/
struct Options {
CompressionLevel fCompressionLevel = CompressionLevel::kMedium;
/**
* Represents comments to be written into tEXt chunks 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.
*
* All entries are treated as strings encoded as Latin-1 (i.e.
* ISO-8859-1). The strings may, but don't have to be NUL-terminated
* (trailing NUL characters will be stripped). Encoding will fail if
* keyword or text don't meet the requirements of the PNG spec - text may
* have any length and contain any of the 191 Latin-1 characters (and/or
* the linefeed character), but keyword's length is restricted to at most
* 79 characters and it can't contain a non-breaking space character.
*/
sk_sp<SkDataTable> fComments;
};
/**
* 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);
/**
* Returns the encoded data for the pixmap, or nullptr on failure.
*/
SK_API sk_sp<SkData> Encode(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 SkPngRustEncoder
#endif // SkPngRustEncoder_DEFINED
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