/*
* Copyright 2023 Google Inc.
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#ifndef SkExif_DEFINED
#define SkExif_DEFINED
#include "include/codec/SkEncodedOrigin.h"
#include "include/core/SkRefCnt.h"
#include "include/private/base/SkAPI.h"
#include <cstdint>
#include <optional>
class SkData;
namespace SkExif {
// Tag values that are parsed by Parse and stored in Metadata.
static constexpr uint16_t kOriginTag = 0x112;
static constexpr uint16_t kResolutionUnitTag = 0x0128;
static constexpr uint16_t kXResolutionTag = 0x011a;
static constexpr uint16_t kYResolutionTag = 0x011b;
static constexpr uint16_t kPixelXDimensionTag = 0xa002;
static constexpr uint16_t kPixelYDimensionTag = 0xa003;
struct Metadata {
// The image orientation.
std::optional<SkEncodedOrigin> fOrigin;
// The HDR headroom property.
// https://developer.apple.com/documentation/appkit/images_and_pdf/applying_apple_hdr_effect_to_your_photos
std::optional<
float> fHdrHeadroom;
// Resolution.
std::optional<uint16_t> fResolutionUnit;
std::optional<
float> fXResolution;
std::optional<
float> fYResolution;
// Size in pixels.
std::optional<uint32_t> fPixelXDimension;
std::optional<uint32_t> fPixelYDimension;
};
/*
* Parse the metadata specified in |data| and write them to |metadata|. Stop only at an
* unrecoverable error (allow truncated input).
*/
void SK_API Parse(Metadata& metadata,
const SkData* data);
/*
* Write exif data that includes the values in |metadata| and returns it as SkData
* untruncated. Return nullptr if a write to the data stream fails or if
* |metadata.fHdrHeadroom| has value.
* This function cannot write an IFD entry based on the HdrHeadroom value because
* the information of maker33 and maker48 are lost in decoding.
* For metadata that belongs in a subIFD the function will write it to one and
* store it after the root IFD.
* Data that does not fit within kSizeEntry, is appended to the end of the data,
* after the subIFD if it exists.
*/
sk_sp<SkData> WriteExif(Metadata& metadata);
}
// namespace SkExif
#endif
