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//
// fiv-io.h: image operations
//
// Copyright (c) 2021, Přemysl Eric Janouch <p@janouch.name>
//
// Permission to use, copy, modify, and/or distribute this software for any
// purpose with or without fee is hereby granted.
//
// THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
// WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
// MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
// SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
// WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
// OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
// CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
//
#pragma once
#include <cairo.h>
#include <gio/gio.h>
#include <glib.h>
// --- Colour management -------------------------------------------------------
// TODO(p): Make it possible to use Skia's skcms,
// which also supports premultiplied alpha.
// NOTE: Little CMS will probably start supporting premultiplied alpha in 2022.
typedef void *FivIoProfile;
FivIoProfile fiv_io_profile_new(const void *data, size_t len);
FivIoProfile fiv_io_profile_new_sRGB(void);
void fiv_io_profile_free(FivIoProfile self);
// From libwebp, verified to exactly match [x * a / 255].
#define PREMULTIPLY8(a, x) (((uint32_t) (x) * (uint32_t) (a) * 32897U) >> 23)
// --- Loading -----------------------------------------------------------------
extern const char *fiv_io_supported_media_types[];
char **fiv_io_all_supported_media_types(void);
// Userdata are typically attached to all Cairo surfaces in an animation.
/// GBytes with plain Exif/TIFF data.
extern cairo_user_data_key_t fiv_io_key_exif;
/// FivIoOrientation, as a uintptr_t.
extern cairo_user_data_key_t fiv_io_key_orientation;
/// GBytes with plain ICC profile data.
extern cairo_user_data_key_t fiv_io_key_icc;
/// GBytes with plain XMP data.
extern cairo_user_data_key_t fiv_io_key_xmp;
/// GBytes with a WebP's THUM chunk, used for our thumbnails.
extern cairo_user_data_key_t fiv_io_key_thum;
/// The next frame in a sequence, as a surface, in a chain, pre-composited.
/// There is no wrap-around.
extern cairo_user_data_key_t fiv_io_key_frame_next;
/// The previous frame in a sequence, as a surface, in a chain, pre-composited.
/// This is a weak pointer that wraps around, and needn't be present
/// for static images.
extern cairo_user_data_key_t fiv_io_key_frame_previous;
/// Frame duration in milliseconds as an intptr_t.
extern cairo_user_data_key_t fiv_io_key_frame_duration;
/// How many times to repeat the animation, or zero for +inf, as a uintptr_t.
extern cairo_user_data_key_t fiv_io_key_loops;
/// The first frame of the next page, as a surface, in a chain.
/// There is no wrap-around.
extern cairo_user_data_key_t fiv_io_key_page_next;
/// The first frame of the previous page, as a surface, in a chain.
/// There is no wrap-around. This is a weak pointer.
extern cairo_user_data_key_t fiv_io_key_page_previous;
cairo_surface_t *fiv_io_open(
const gchar *path, FivIoProfile profile, gboolean enhance, GError **error);
cairo_surface_t *fiv_io_open_from_data(const char *data, size_t len,
const gchar *path, FivIoProfile profile, gboolean enhance, GError **error);
int fiv_io_filecmp(GFile *f1, GFile *f2);
// --- Export ------------------------------------------------------------------
typedef struct WebPConfig WebPConfig;
/// Encodes a Cairo surface as a WebP bitstream, following the configuration.
/// The result needs to be freed using WebPFree/WebPDataClear().
unsigned char *fiv_io_encode_webp(
cairo_surface_t *surface, const WebPConfig *config, size_t *len);
/// Saves the page as a lossless WebP still picture or animation.
/// If no exact frame is specified, this potentially creates an animation.
gboolean fiv_io_save(cairo_surface_t *page, cairo_surface_t *frame,
FivIoProfile target, const gchar *path, GError **error);
// --- Metadata ----------------------------------------------------------------
// https://www.cipa.jp/std/documents/e/DC-008-2012_E.pdf Table 6
typedef enum _FivIoOrientation {
FivIoOrientationUnknown = 0,
FivIoOrientation0 = 1,
FivIoOrientationMirror0 = 2,
FivIoOrientation180 = 3,
FivIoOrientationMirror180 = 4,
FivIoOrientationMirror270 = 5,
FivIoOrientation90 = 6,
FivIoOrientationMirror90 = 7,
FivIoOrientation270 = 8
} FivIoOrientation;
/// Returns whether dimensions need to be swapped for rendering.
gboolean fiv_io_orientation_is_sideways(FivIoOrientation orientation);
/// Returns a rendering matrix for a surface. Dimensions need to be pre-swapped.
cairo_matrix_t fiv_io_orientation_matrix(
FivIoOrientation orientation, double width, double height);
/// Extracts the orientation field from Exif, if there's any.
FivIoOrientation fiv_io_exif_orientation(const guint8 *exif, gsize len);
/// Save metadata attached by this module in Exiv2 format.
gboolean fiv_io_save_metadata(
cairo_surface_t *page, const gchar *path, GError **error);
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