107 lines
3.3 KiB
C++
107 lines
3.3 KiB
C++
/*
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* Copyright 2024 Google LLC
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*
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* Use of this source code is governed by a BSD-style license that can be
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* found in the LICENSE file.
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*/
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#ifndef SkPngRustEncoder_DEFINED
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#define SkPngRustEncoder_DEFINED
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#include <cstdint>
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#include <memory>
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#include "include/core/SkDataTable.h"
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#include "include/core/SkRefCnt.h"
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#include "include/private/base/SkAPI.h"
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class GrDirectContext;
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class SkData;
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class SkEncoder;
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class SkImage;
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class SkPixmap;
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class SkWStream;
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namespace SkPngRustEncoder {
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/*
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* Compression level.
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*/
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enum class CompressionLevel : uint8_t {
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// Low compression level - fast, but may result in bigger PNG files.
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kLow,
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// Medium compression level - somewhere in-between `kLow` and `kHigh`.
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kMedium,
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// High compression level - slow, but should results in smaller PNG files.
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kHigh,
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};
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/*
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* PNG encoding options.
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*
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* TODO(https://crbug.com/379312510): Add support for `SkPngEncoder::Options`
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* like:
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* - Comments - `tEXt` chunks.
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* - Color profile - `iCCP` chunk.
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*/
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struct Options {
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CompressionLevel fCompressionLevel = CompressionLevel::kMedium;
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/**
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* Represents comments to be written into tEXt chunks of the png.
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*
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* The 2i-th entry is the keyword for the i-th comment,
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* and the (2i + 1)-th entry is the text for the i-th comment.
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*
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* All entries are treated as strings encoded as Latin-1 (i.e.
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* ISO-8859-1). The strings may, but don't have to be NUL-terminated
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* (trailing NUL characters will be stripped). Encoding will fail if
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* keyword or text don't meet the requirements of the PNG spec - text may
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* have any length and contain any of the 191 Latin-1 characters (and/or
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* the linefeed character), but keyword's length is restricted to at most
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* 79 characters and it can't contain a non-breaking space character.
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*/
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sk_sp<SkDataTable> fComments;
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};
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/**
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* Encode the |src| pixels to the |dst| stream.
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* |options| may be used to control the encoding behavior.
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*
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* Returns true on success. Returns false on an invalid or unsupported |src|.
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*
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*/
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SK_API bool Encode(SkWStream* dst, const SkPixmap& src, const Options& options);
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/**
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* Returns the encoded data for the pixmap, or nullptr on failure.
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*/
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SK_API sk_sp<SkData> Encode(const SkPixmap& src, const Options& options);
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/**
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* Encode the provided image and return the resulting bytes. If the image was created as
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* a texture-backed image on a GPU context, that |ctx| must be provided so the pixels
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* can be read before being encoded. For raster-backed images, |ctx| can be nullptr.
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* |options| may be used to control the encoding behavior.
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*
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* Returns nullptr if the pixels could not be read or encoding otherwise fails.
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*/
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SK_API sk_sp<SkData> Encode(GrDirectContext* ctx, const SkImage* img, const Options& options);
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/**
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* Create a png encoder that will encode the |src| pixels to the |dst| stream.
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* |options| may be used to control the encoding behavior.
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*
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* The primary use of this is incremental encoding of the pixels.
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*
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* |dst| is unowned but must remain valid for the lifetime of the object.
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*
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* This returns nullptr on an invalid or unsupported |src|.
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*/
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SK_API std::unique_ptr<SkEncoder> Make(SkWStream* dst, const SkPixmap& src, const Options& options);
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} // namespace SkPngRustEncoder
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#endif // SkPngRustEncoder_DEFINED
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