Fix colour management in animations

Bug introduced in d6e79cf.

fiv-io.h

@@ -39,50 +39,93 @@ extern const char *fiv_io_supported_media_types[];
 
 gchar **fiv_io_all_supported_media_types(void);
 
-// Userdata are typically attached to all Cairo surfaces in an animation.
+typedef enum _FivIoOrientation FivIoOrientation;
+typedef struct _FivIoRenderClosure FivIoRenderClosure;
+typedef struct _FivIoImage FivIoImage;
 
-/// 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;
-/// GHashTable with key-value pairs from PNG's tEXt, zTXt, iTXt chunks.
-/// Currently only read by fiv_io_open_png_thumbnail().
-extern cairo_user_data_key_t fiv_io_key_text;
+// https://www.cipa.jp/std/documents/e/DC-008-2012_E.pdf Table 6
+enum _FivIoOrientation {
+	FivIoOrientationUnknown   = 0,
+	FivIoOrientation0         = 1,
+	FivIoOrientationMirror0   = 2,
+	FivIoOrientation180       = 3,
+	FivIoOrientationMirror180 = 4,
+	FivIoOrientationMirror270 = 5,
+	FivIoOrientation90        = 6,
+	FivIoOrientationMirror90  = 7,
+	FivIoOrientation270       = 8
+};
 
-/// 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;
-
-typedef struct _FivIoRenderClosure {
+struct _FivIoRenderClosure {
 	/// The rendering is allowed to fail, returning NULL.
-	cairo_surface_t *(*render)(struct _FivIoRenderClosure *, double scale);
-} FivIoRenderClosure;
+	FivIoImage *(*render)(FivIoRenderClosure *, double scale);
+	void (*destroy)(FivIoRenderClosure *);
+};
 
-/// A FivIoRenderClosure for parametrized re-rendering of vector formats.
-/// This is attached at the page level.
-/// The rendered image will not have this key.
-extern cairo_user_data_key_t fiv_io_key_render;
+// Metadata are typically attached to all Cairo surfaces in an animation.
+
+struct _FivIoImage {
+	uint8_t *data;                      ///< Raw image data
+	cairo_format_t format;              ///< Data format
+	uint32_t width;                     ///< Width of the image in pixels
+	uint32_t stride;                    ///< Row stride in bytes
+	uint32_t height;                    ///< Height of the image in pixels
+
+	FivIoOrientation orientation;       ///< Orientation to use for display
+
+	GBytes *exif;                       ///< Raw Exif/TIFF segment
+	GBytes *icc;                        ///< Raw ICC profile data
+	GBytes *xmp;                        ///< Raw XMP data
+	GBytes *thum;                       ///< WebP THUM chunk, for our thumbnails
+
+	/// GHashTable with key-value pairs from PNG's tEXt, zTXt, iTXt chunks.
+	/// Currently only read by fiv_io_open_png_thumbnail().
+	GHashTable *text;
+
+	/// A FivIoRenderClosure for parametrized re-rendering of vector formats.
+	/// This is attached at the page level.
+	FivIoRenderClosure *render;
+
+	/// The first frame of the next page, in a chain.
+	/// There is no wrap-around.
+	FivIoImage *page_next;
+
+	/// The first frame of the previous page, in a chain.
+	/// There is no wrap-around. This is a weak pointer.
+	FivIoImage *page_previous;
+
+	/// The next frame in a sequence, in a chain, pre-composited.
+	/// There is no wrap-around.
+	FivIoImage *frame_next;
+
+	/// The previous frame in a sequence, in a chain, pre-composited.
+	/// This is a weak pointer that wraps around,
+	/// and needn't be present for static images.
+	FivIoImage *frame_previous;
+
+	/// Frame duration in milliseconds.
+	int64_t frame_duration;
+
+	/// How many times to repeat the animation, or zero for +inf.
+	uint64_t loops;
+};
+
+FivIoImage *fiv_io_image_ref(FivIoImage *image);
+void fiv_io_image_unref(FivIoImage *image);
+
+/// Analogous to cairo_image_surface_create(). May return NULL.
+FivIoImage *fiv_io_image_new(
+	cairo_format_t format, uint32_t width, uint32_t height);
+
+/// Return a new Cairo image surface referencing the same data as the image,
+/// eating the reference to it.
+cairo_surface_t *fiv_io_image_to_surface(FivIoImage *image);
+
+/// Return a new Cairo image surface referencing the same data as the image,
+/// without eating the image's reference.
+cairo_surface_t *fiv_io_image_to_surface_noref(const FivIoImage *image);
+
+// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 
 typedef struct {
 	const char *uri;                    ///< Source URI
@@ -93,10 +136,27 @@ typedef struct {
 	GPtrArray *warnings;                ///< String vector for non-fatal errors
 } FivIoOpenContext;
 
-cairo_surface_t *fiv_io_open(const FivIoOpenContext *ctx, GError **error);
-cairo_surface_t *fiv_io_open_from_data(
+FivIoImage *fiv_io_open(const FivIoOpenContext *ctx, GError **error);
+FivIoImage *fiv_io_open_from_data(
 	const char *data, size_t len, const FivIoOpenContext *ctx, GError **error);
-cairo_surface_t *fiv_io_open_png_thumbnail(const char *path, GError **error);
+
+FivIoImage *fiv_io_open_png_thumbnail(const char *path, GError **error);
+
+// --- Metadata ----------------------------------------------------------------
+
+/// Returns a rendering matrix for an image (user space to pattern space),
+/// and its target dimensions.
+cairo_matrix_t fiv_io_orientation_apply(const FivIoImage *image,
+	FivIoOrientation orientation, double *width, double *height);
+void fiv_io_orientation_dimensions(const FivIoImage *image,
+	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(
+	const FivIoImage *page, const char *path, GError **error);
 
 // --- Thumbnail passing utilities ---------------------------------------------
 
@@ -109,41 +169,12 @@ GBytes *fiv_io_serialize_for_search(cairo_surface_t *surface, GError **error);
 
 // --- Export ------------------------------------------------------------------
 
-/// Encodes a Cairo surface as a WebP bitstream, following the configuration.
+/// Encodes an image 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);
+	FivIoImage *image, 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,
+gboolean fiv_io_save(FivIoImage *page, FivIoImage *frame,
 	FivIoProfile target, const char *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 a rendering matrix for a surface (user space to pattern space),
-/// and its target dimensions.
-cairo_matrix_t fiv_io_orientation_apply(cairo_surface_t *surface,
-	FivIoOrientation orientation, double *width, double *height);
-void fiv_io_orientation_dimensions(cairo_surface_t *surface,
-	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 char *path, GError **error);

fiv-thumbnail.c

@@ -125,7 +125,7 @@ might_be_a_thumbnail(const char *path_or_uri)
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 
-static cairo_surface_t *
+static FivIoImage *
 render(GFile *target, GBytes *data, gboolean *color_managed, GError **error)
 {
 	FivIoOpenContext ctx = {
@@ -137,23 +137,22 @@ render(GFile *target, GBytes *data, gboolean *color_managed, GError **error)
 		.warnings = g_ptr_array_new_with_free_func(g_free),
 	};
 
-	cairo_surface_t *surface = fiv_io_open_from_data(
+	FivIoImage *image = fiv_io_open_from_data(
 		g_bytes_get_data(data, NULL), g_bytes_get_size(data), &ctx, error);
 	g_free((gchar *) ctx.uri);
 	g_ptr_array_free(ctx.warnings, TRUE);
 	if ((*color_managed = !!ctx.screen_profile))
 		fiv_io_profile_free(ctx.screen_profile);
 	g_bytes_unref(data);
-	return surface;
+	return image;
 }
 
 // In principle similar to rescale_thumbnail() from fiv-browser.c.
-static cairo_surface_t *
-adjust_thumbnail(cairo_surface_t *thumbnail, double row_height)
+static FivIoImage *
+adjust_thumbnail(FivIoImage *thumbnail, double row_height)
 {
 	// Hardcode orientation.
-	FivIoOrientation orientation = (uintptr_t) cairo_surface_get_user_data(
-		thumbnail, &fiv_io_key_orientation);
+	FivIoOrientation orientation = thumbnail->orientation;
 
 	double w = 0, h = 0;
 	cairo_matrix_t matrix =
@@ -170,33 +169,40 @@ adjust_thumbnail(cairo_surface_t *thumbnail, double row_height)
 	}
 
 	// Vector images should not have orientation, this should handle them all.
-	FivIoRenderClosure *closure =
-		cairo_surface_get_user_data(thumbnail, &fiv_io_key_render);
+	FivIoRenderClosure *closure = thumbnail->render;
 	if (closure && orientation <= FivIoOrientation0) {
 		// This API doesn't accept non-uniform scaling; prefer a vertical fit.
-		cairo_surface_t *scaled = closure->render(closure, scale_y);
+		FivIoImage *scaled = closure->render(closure, scale_y);
 		if (scaled)
 			return scaled;
 	}
 
-	// This will be CAIRO_FORMAT_INVALID with non-image surfaces, which is fine.
-	cairo_format_t format = cairo_image_surface_get_format(thumbnail);
-	if (format != CAIRO_FORMAT_INVALID &&
-		orientation <= FivIoOrientation0 && scale_x == 1 && scale_y == 1)
-		return cairo_surface_reference(thumbnail);
+	if (orientation <= FivIoOrientation0 && scale_x == 1 && scale_y == 1)
+		return fiv_io_image_ref(thumbnail);
 
+	cairo_format_t format = thumbnail->format;
 	int projected_width = round(scale_x * w);
 	int projected_height = round(scale_y * h);
-	cairo_surface_t *scaled = cairo_image_surface_create(
+	FivIoImage *scaled = fiv_io_image_new(
 		(format == CAIRO_FORMAT_RGB24 || format == CAIRO_FORMAT_RGB30)
 			? CAIRO_FORMAT_RGB24
 			: CAIRO_FORMAT_ARGB32,
 		projected_width, projected_height);
+	if (!scaled) {
+		g_warning("image allocation failure");
+		return fiv_io_image_ref(thumbnail);
+	}
+
+	cairo_surface_t *surface = fiv_io_image_to_surface_noref(scaled);
+	cairo_t *cr = cairo_create(surface);
+	cairo_surface_destroy(surface);
 
-	cairo_t *cr = cairo_create(scaled);
 	cairo_scale(cr, scale_x, scale_y);
 
-	cairo_set_source_surface(cr, thumbnail, 0, 0);
+	surface = fiv_io_image_to_surface_noref(thumbnail);
+	cairo_set_source_surface(cr, surface, 0, 0);
+	cairo_surface_destroy(surface);
+
 	cairo_pattern_t *pattern = cairo_get_source(cr);
 	// CAIRO_FILTER_BEST, for some reason, works bad with CAIRO_FORMAT_RGB30.
 	cairo_pattern_set_filter(pattern, CAIRO_FILTER_GOOD);
@@ -208,9 +214,7 @@ adjust_thumbnail(cairo_surface_t *thumbnail, double row_height)
 
 	// Note that this doesn't get triggered with oversize input surfaces,
 	// even though nothing will be rendered.
-	if (cairo_surface_status(thumbnail) != CAIRO_STATUS_SUCCESS ||
-		cairo_surface_status(scaled) != CAIRO_STATUS_SUCCESS ||
-		cairo_pattern_status(pattern) != CAIRO_STATUS_SUCCESS ||
+	if (cairo_pattern_status(pattern) != CAIRO_STATUS_SUCCESS ||
 		cairo_status(cr) != CAIRO_STATUS_SUCCESS)
 		g_warning("thumbnail scaling failed");
 
@@ -218,27 +222,32 @@ adjust_thumbnail(cairo_surface_t *thumbnail, double row_height)
 	return scaled;
 }
 
-static cairo_surface_t *
-orient_thumbnail(cairo_surface_t *surface)
+static FivIoImage *
+orient_thumbnail(FivIoImage *image)
 {
-	int orientation = (intptr_t) cairo_surface_get_user_data(
-		surface, &fiv_io_key_orientation);
-	if (orientation <= FivIoOrientation0)
-		return surface;
+	if (image->orientation <= FivIoOrientation0)
+		return image;
 
 	double w = 0, h = 0;
 	cairo_matrix_t matrix =
-		fiv_io_orientation_apply(surface, orientation, &w, &h);
-	cairo_surface_t *oriented =
-		cairo_image_surface_create(CAIRO_FORMAT_RGB24, w, h);
+		fiv_io_orientation_apply(image, image->orientation, &w, &h);
+	FivIoImage *oriented = fiv_io_image_new(image->format, w, h);
+	if (!oriented) {
+		g_warning("image allocation failure");
+		return image;
+	}
 
-	cairo_t *cr = cairo_create(oriented);
+	cairo_surface_t *surface = fiv_io_image_to_surface_noref(oriented);
+	cairo_t *cr = cairo_create(surface);
+	cairo_surface_destroy(surface);
+
+	surface = fiv_io_image_to_surface(image);
 	cairo_set_source_surface(cr, surface, 0, 0);
+	cairo_surface_destroy(surface);
 	cairo_pattern_set_matrix(cairo_get_source(cr), &matrix);
 	cairo_set_operator(cr, CAIRO_OPERATOR_SOURCE);
 	cairo_paint(cr);
 	cairo_destroy(cr);
-	cairo_surface_destroy(surface);
 	return oriented;
 }
 
@@ -390,7 +399,7 @@ extract_libraw_unflip(int flip)
 	}
 }
 
-static cairo_surface_t *
+static FivIoImage *
 extract_libraw_bitmap(libraw_processed_image_t *image, int flip, GError **error)
 {
 	// Anything else is extremely rare.
@@ -399,24 +408,26 @@ extract_libraw_bitmap(libraw_processed_image_t *image, int flip, GError **error)
 		return NULL;
 	}
 
-	cairo_surface_t *surface = cairo_image_surface_create(
+	FivIoImage *I = fiv_io_image_new(
 		CAIRO_FORMAT_RGB24, image->width, image->height);
-	guint32 *out = (guint32 *) cairo_image_surface_get_data(surface);
+	if (!I) {
+		set_error(error, "image allocation failure");
+		return NULL;
+	}
+
+	guint32 *out = (guint32 *) I->data;
 	const unsigned char *in = image->data;
 	for (guint64 i = 0; i < image->width * image->height; in += 3)
 		out[i++] = in[0] << 16 | in[1] << 8 | in[2];
-	cairo_surface_mark_dirty(surface);
 
-	FivIoOrientation orient = extract_libraw_unflip(flip);
-	cairo_surface_set_user_data(
-		surface, &fiv_io_key_orientation, (void *) (intptr_t) orient, NULL);
-	return surface;
+	I->orientation = extract_libraw_unflip(flip);
+	return I;
 }
 
-static cairo_surface_t *
+static FivIoImage *
 extract_libraw(GFile *target, GMappedFile *mf, GError **error)
 {
-	cairo_surface_t *surface = NULL;
+	FivIoImage *I = NULL;
 	libraw_data_t *iprc = libraw_init(
 		LIBRAW_OPIONS_NO_MEMERR_CALLBACK | LIBRAW_OPIONS_NO_DATAERR_CALLBACK);
 	if (!iprc) {
@@ -467,11 +478,11 @@ extract_libraw(GFile *target, GMappedFile *mf, GError **error)
 	switch (image->type) {
 		gboolean dummy;
 	case LIBRAW_IMAGE_JPEG:
-		surface = render(
+		I = render(
 			target, g_bytes_new(image->data, image->data_size), &dummy, error);
 		break;
 	case LIBRAW_IMAGE_BITMAP:
-		surface = extract_libraw_bitmap(image, flip, error);
+		I = extract_libraw_bitmap(image, flip, error);
 		break;
 	default:
 		set_error(error, "unsupported embedded thumbnail");
@@ -480,7 +491,7 @@ extract_libraw(GFile *target, GMappedFile *mf, GError **error)
 	libraw_dcraw_clear_mem(image);
 fail:
 	libraw_close(iprc);
-	return surface;
+	return I;
 }
 
 #endif  // HAVE_LIBRAW
@@ -506,30 +517,30 @@ fiv_thumbnail_extract(GFile *target, FivThumbnailSize max_size, GError **error)
 		return NULL;
 	}
 
-	cairo_surface_t *surface = NULL;
+	FivIoImage *image = NULL;
 #ifdef HAVE_LIBRAW
-	surface = extract_libraw(target, mf, error);
+	image = extract_libraw(target, mf, error);
 #else  // ! HAVE_LIBRAW
 	// TODO(p): Implement our own thumbnail extractors.
 	set_error(error, "unsupported file");
 #endif  // ! HAVE_LIBRAW
 	g_mapped_file_unref(mf);
 
-	if (!surface)
+	if (!image)
 		return NULL;
 	if (max_size < FIV_THUMBNAIL_SIZE_MIN || max_size > FIV_THUMBNAIL_SIZE_MAX)
-		return orient_thumbnail(surface);
+		return fiv_io_image_to_surface(orient_thumbnail(image));
 
-	cairo_surface_t *result =
-		adjust_thumbnail(surface, fiv_thumbnail_sizes[max_size].size);
-	cairo_surface_destroy(surface);
-	return result;
+	FivIoImage *result =
+		adjust_thumbnail(image, fiv_thumbnail_sizes[max_size].size);
+	fiv_io_image_unref(image);
+	return fiv_io_image_to_surface(result);
 }
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 
 static WebPData
-encode_thumbnail(cairo_surface_t *surface)
+encode_thumbnail(FivIoImage *image)
 {
 	WebPData bitstream = {};
 	WebPConfig config = {};
@@ -541,12 +552,12 @@ encode_thumbnail(cairo_surface_t *surface)
 	if (!WebPValidateConfig(&config))
 		return bitstream;
 
-	bitstream.bytes = fiv_io_encode_webp(surface, &config, &bitstream.size);
+	bitstream.bytes = fiv_io_encode_webp(image, &config, &bitstream.size);
 	return bitstream;
 }
 
 static void
-save_thumbnail(cairo_surface_t *thumbnail, const char *path, GString *thum)
+save_thumbnail(FivIoImage *thumbnail, const char *path, GString *thum)
 {
 	WebPMux *mux = WebPMuxNew();
 	WebPData bitstream = encode_thumbnail(thumbnail);
@@ -602,15 +613,15 @@ fiv_thumbnail_produce_for_search(
 		return NULL;
 
 	gboolean color_managed = FALSE;
-	cairo_surface_t *surface = render(target, data, &color_managed, error);
-	if (!surface)
+	FivIoImage *image = render(target, data, &color_managed, error);
+	if (!image)
 		return NULL;
 
 	// TODO(p): Might want to keep this a square.
-	cairo_surface_t *result =
-		adjust_thumbnail(surface, fiv_thumbnail_sizes[max_size].size);
-	cairo_surface_destroy(surface);
-	return result;
+	FivIoImage *result =
+		adjust_thumbnail(image, fiv_thumbnail_sizes[max_size].size);
+	fiv_io_image_unref(image);
+	return fiv_io_image_to_surface(result);
 }
 
 static cairo_surface_t *
@@ -638,14 +649,14 @@ produce_fallback(GFile *target, FivThumbnailSize size, GError **error)
 		return NULL;
 
 	gboolean color_managed = FALSE;
-	cairo_surface_t *surface = render(target, data, &color_managed, error);
-	if (!surface)
+	FivIoImage *image = render(target, data, &color_managed, error);
+	if (!image)
 		return NULL;
 
-	cairo_surface_t *result =
-		adjust_thumbnail(surface, fiv_thumbnail_sizes[size].size);
-	cairo_surface_destroy(surface);
-	return result;
+	FivIoImage *result =
+		adjust_thumbnail(image, fiv_thumbnail_sizes[size].size);
+	fiv_io_image_unref(image);
+	return fiv_io_image_to_surface(result);
 }
 
 cairo_surface_t *
@@ -690,10 +701,10 @@ fiv_thumbnail_produce(GFile *target, FivThumbnailSize max_size, GError **error)
 	}
 
 	gboolean color_managed = FALSE;
-	cairo_surface_t *surface =
+	FivIoImage *image =
 		render(target, g_mapped_file_get_bytes(mf), &color_managed, error);
 	g_mapped_file_unref(mf);
-	if (!surface)
+	if (!image)
 		return NULL;
 
 	// Boilerplate copied from fiv_thumbnail_lookup().
@@ -709,12 +720,10 @@ fiv_thumbnail_produce(GFile *target, FivThumbnailSize max_size, GError **error)
 	g_string_append_printf(
 		thum, "%s%c%llu%c", THUMB_SIZE, 0, (unsigned long long) filesize, 0);
 
-	if (cairo_surface_get_type(surface) == CAIRO_SURFACE_TYPE_IMAGE) {
-		g_string_append_printf(thum, "%s%c%d%c", THUMB_IMAGE_WIDTH, 0,
-			cairo_image_surface_get_width(surface), 0);
-		g_string_append_printf(thum, "%s%c%d%c", THUMB_IMAGE_HEIGHT, 0,
-			cairo_image_surface_get_height(surface), 0);
-	}
+	g_string_append_printf(thum, "%s%c%u%c", THUMB_IMAGE_WIDTH, 0,
+		(unsigned) image->width, 0);
+	g_string_append_printf(thum, "%s%c%u%c", THUMB_IMAGE_HEIGHT, 0,
+		(unsigned) image->height, 0);
 
 	// Without a CMM, no conversion is attempted.
 	if (color_managed) {
@@ -722,19 +731,19 @@ fiv_thumbnail_produce(GFile *target, FivThumbnailSize max_size, GError **error)
 			thum, "%s%c%s%c", THUMB_COLORSPACE, 0, THUMB_COLORSPACE_SRGB, 0);
 	}
 
-	cairo_surface_t *max_size_surface = NULL;
+	FivIoImage *max_size_image = NULL;
 	for (int use = max_size; use >= FIV_THUMBNAIL_SIZE_MIN; use--) {
-		cairo_surface_t *scaled =
-			adjust_thumbnail(surface, fiv_thumbnail_sizes[use].size);
+		FivIoImage *scaled =
+			adjust_thumbnail(image, fiv_thumbnail_sizes[use].size);
 		gchar *path = g_strdup_printf("%s/wide-%s/%s.webp", thumbnails_dir,
 			fiv_thumbnail_sizes[use].thumbnail_spec_name, sum);
 		save_thumbnail(scaled, path, thum);
 		g_free(path);
 
-		if (!max_size_surface)
-			max_size_surface = scaled;
+		if (!max_size_image)
+			max_size_image = scaled;
 		else
-			cairo_surface_destroy(scaled);
+			fiv_io_image_unref(scaled);
 	}
 
 	g_string_free(thum, TRUE);
@@ -742,8 +751,8 @@ fiv_thumbnail_produce(GFile *target, FivThumbnailSize max_size, GError **error)
 	g_free(thumbnails_dir);
 	g_free(sum);
 	g_free(uri);
-	cairo_surface_destroy(surface);
-	return max_size_surface;
+	fiv_io_image_unref(image);
+	return fiv_io_image_to_surface(max_size_image);
 }
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
@@ -793,23 +802,23 @@ read_wide_thumbnail(const char *path, const Stat *st, GError **error)
 	if (!thumbnail_uri)
 		return NULL;
 
-	cairo_surface_t *surface =
+	FivIoImage *image =
 		fiv_io_open(&(FivIoOpenContext){.uri = thumbnail_uri}, error);
 	g_free(thumbnail_uri);
-	if (!surface)
+	if (!image)
 		return NULL;
 
 	bool sRGB = false;
-	GBytes *thum = cairo_surface_get_user_data(surface, &fiv_io_key_thum);
-	if (!thum) {
+	if (!image->thum) {
 		g_clear_error(error);
 		set_error(error, "not a thumbnail");
-	} else if (!check_wide_thumbnail_texts(thum, st, &sRGB)) {
+	} else if (!check_wide_thumbnail_texts(image->thum, st, &sRGB)) {
 		g_clear_error(error);
 		set_error(error, "mismatch");
 	} else {
 		// TODO(p): Add a function or a non-valueless define to check
 		// for CMM presence, then remove this ifdef.
+		cairo_surface_t *surface = fiv_io_image_to_surface(image);
 #ifdef HAVE_LCMS2
 		if (!sRGB)
 			mark_thumbnail_lq(surface);
@@ -817,21 +826,21 @@ read_wide_thumbnail(const char *path, const Stat *st, GError **error)
 		return surface;
 	}
 
-	cairo_surface_destroy(surface);
+	fiv_io_image_unref(image);
 	return NULL;
 }
 
 static cairo_surface_t *
 read_png_thumbnail(const char *path, const Stat *st, GError **error)
 {
-	cairo_surface_t *surface = fiv_io_open_png_thumbnail(path, error);
-	if (!surface)
+	FivIoImage *image = fiv_io_open_png_thumbnail(path, error);
+	if (!image)
 		return NULL;
 
-	GHashTable *texts = cairo_surface_get_user_data(surface, &fiv_io_key_text);
+	GHashTable *texts = image->text;
 	if (!texts) {
 		set_error(error, "not a thumbnail");
-		cairo_surface_destroy(surface);
+		fiv_io_image_unref(image);
 		return NULL;
 	}
 
@@ -843,16 +852,16 @@ read_png_thumbnail(const char *path, const Stat *st, GError **error)
 	if (!text_uri || strcmp(text_uri, st->uri) ||
 		!text_mtime || atol(text_mtime) != st->mtime) {
 		set_error(error, "mismatch or not a thumbnail");
-		cairo_surface_destroy(surface);
+		fiv_io_image_unref(image);
 		return NULL;
 	}
 	if (text_size && strtoull(text_size, NULL, 10) != st->size) {
 		set_error(error, "file size mismatch");
-		cairo_surface_destroy(surface);
+		fiv_io_image_unref(image);
 		return NULL;
 	}
 
-	return surface;
+	return fiv_io_image_to_surface(image);
 }
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

fiv-view.c

@@ -63,10 +63,10 @@ struct _FivView {
 
 	gchar *messages;                    ///< Image load information
 	gchar *uri;                         ///< Path to the current image (if any)
-	cairo_surface_t *image;             ///< The loaded image (sequence)
-	cairo_surface_t *page;              ///< Current page within image, weak
-	cairo_surface_t *page_scaled;       ///< Current page within image, scaled
-	cairo_surface_t *frame;             ///< Current frame within page, weak
+	FivIoImage *image;                  ///< The loaded image (sequence)
+	FivIoImage *page;                   ///< Current page within image, weak
+	FivIoImage *page_scaled;            ///< Current page within image, scaled
+	FivIoImage *frame;                  ///< Current frame within page, weak
 	FivIoOrientation orientation;       ///< Current page orientation
 	bool enable_cms : 1;                ///< Smooth scaling toggle
 	bool filter : 1;                    ///< Smooth scaling toggle
@@ -77,7 +77,7 @@ struct _FivView {
 	double scale;                       ///< Scaling factor
 	double drag_start[2];               ///< Adjustment values for drag origin
 
-	cairo_surface_t *enhance_swap;      ///< Quick swap in/out
+	FivIoImage *enhance_swap;           ///< Quick swap in/out
 	FivIoProfile screen_cms_profile;    ///< Target colour profile for widget
 
 	int remaining_loops;                ///< Greater than zero if limited
@@ -234,9 +234,9 @@ fiv_view_finalize(GObject *gobject)
 {
 	FivView *self = FIV_VIEW(gobject);
 	g_clear_pointer(&self->screen_cms_profile, fiv_io_profile_free);
-	g_clear_pointer(&self->enhance_swap, cairo_surface_destroy);
-	g_clear_pointer(&self->image, cairo_surface_destroy);
-	g_clear_pointer(&self->page_scaled, cairo_surface_destroy);
+	g_clear_pointer(&self->enhance_swap, fiv_io_image_unref);
+	g_clear_pointer(&self->image, fiv_io_image_unref);
+	g_clear_pointer(&self->page_scaled, fiv_io_image_unref);
 	g_free(self->uri);
 	g_free(self->messages);
 
@@ -283,15 +283,13 @@ fiv_view_get_property(
 		g_value_set_boolean(value, !!self->image);
 		break;
 	case PROP_CAN_ANIMATE:
-		g_value_set_boolean(value, self->page &&
-			cairo_surface_get_user_data(self->page, &fiv_io_key_frame_next));
+		g_value_set_boolean(value, self->page && self->page->frame_next);
 		break;
 	case PROP_HAS_PREVIOUS_PAGE:
 		g_value_set_boolean(value, self->image && self->page != self->image);
 		break;
 	case PROP_HAS_NEXT_PAGE:
-		g_value_set_boolean(value, self->page &&
-			cairo_surface_get_user_data(self->page, &fiv_io_key_page_next));
+		g_value_set_boolean(value, self->page && self->page->page_next);
 		break;
 
 	case PROP_HADJUSTMENT:
@@ -403,20 +401,27 @@ static void
 prescale_page(FivView *self)
 {
 	FivIoRenderClosure *closure = NULL;
-	if (!self->image || !(closure =
-			cairo_surface_get_user_data(self->page, &fiv_io_key_render)))
+	if (!self->image || !(closure = self->page->render))
 		return;
 
 	// TODO(p): Restart the animation. No vector formats currently animate.
 	g_return_if_fail(!self->frame_update_connection);
 
 	// If it fails, the previous frame pointer may become invalid.
-	g_clear_pointer(&self->page_scaled, cairo_surface_destroy);
+	g_clear_pointer(&self->page_scaled, fiv_io_image_unref);
 	self->frame = self->page_scaled = closure->render(closure, self->scale);
 	if (!self->page_scaled)
 		self->frame = self->page;
 }
 
+static void
+set_source_image(FivView *self, cairo_t *cr)
+{
+	cairo_surface_t *surface = fiv_io_image_to_surface_noref(self->frame);
+	cairo_set_source_surface(cr, surface, 0, 0);
+	cairo_surface_destroy(surface);
+}
+
 static void
 fiv_view_size_allocate(GtkWidget *widget, GtkAllocation *allocation)
 {
@@ -606,37 +611,19 @@ fiv_view_draw(GtkWidget *widget, cairo_t *cr)
 
 	// Then all frames are pre-scaled.
 	if (self->page_scaled) {
-		cairo_set_source_surface(cr, self->frame, 0, 0);
+		set_source_image(self, cr);
 		cairo_pattern_set_matrix(cairo_get_source(cr), &matrix);
 		cairo_paint(cr);
 		return TRUE;
 	}
 
-	// FIXME: Recording surfaces do not work well with CAIRO_SURFACE_TYPE_XLIB,
-	// we always get a shitty pixmap, where transparency contains junk.
-	if (cairo_surface_get_type(self->frame) == CAIRO_SURFACE_TYPE_RECORDING) {
-		cairo_surface_t *image =
-			cairo_image_surface_create(CAIRO_FORMAT_ARGB32, dw, dh);
-		cairo_t *tcr = cairo_create(image);
-		cairo_scale(tcr, self->scale, self->scale);
-		cairo_set_source_surface(tcr, self->frame, 0, 0);
-		cairo_pattern_set_matrix(cairo_get_source(tcr), &matrix);
-		cairo_paint(tcr);
-		cairo_destroy(tcr);
-
-		cairo_set_source_surface(cr, image, 0, 0);
-		cairo_paint(cr);
-		cairo_surface_destroy(image);
-		return TRUE;
-	}
-
 	// XXX: The rounding together with padding may result in up to
 	// a pixel's worth of made-up picture data.
 	cairo_rectangle(cr, 0, 0, dw, dh);
 	cairo_clip(cr);
 
 	cairo_scale(cr, self->scale, self->scale);
-	cairo_set_source_surface(cr, self->frame, 0, 0);
+	set_source_image(self, cr);
 
 	cairo_pattern_t *pattern = cairo_get_source(cr);
 	cairo_pattern_set_matrix(pattern, &matrix);
@@ -810,15 +797,13 @@ stop_animating(FivView *self)
 
 	self->frame_time = 0;
 	self->frame_update_connection = 0;
-	self->remaining_loops = 0;
 	g_object_notify_by_pspec(G_OBJECT(self), view_properties[PROP_PLAYING]);
 }
 
 static gboolean
 advance_frame(FivView *self)
 {
-	cairo_surface_t *next =
-		cairo_surface_get_user_data(self->frame, &fiv_io_key_frame_next);
+	FivIoImage *next = self->frame->frame_next;
 	if (next) {
 		self->frame = next;
 	} else {
@@ -836,8 +821,7 @@ advance_animation(FivView *self, GdkFrameClock *clock)
 	gint64 now = gdk_frame_clock_get_frame_time(clock);
 	while (true) {
 		// TODO(p): See if infinite frames can actually happen, and how.
-		intptr_t duration = (intptr_t) cairo_surface_get_user_data(
-			self->frame, &fiv_io_key_frame_duration);
+		int64_t duration = self->frame->frame_duration;
 		if (duration < 0)
 			return FALSE;
 
@@ -875,32 +859,39 @@ start_animating(FivView *self)
 	stop_animating(self);
 
 	GdkFrameClock *clock = gtk_widget_get_frame_clock(GTK_WIDGET(self));
-	if (!clock || !self->image ||
-		!cairo_surface_get_user_data(self->page, &fiv_io_key_frame_next))
+	if (!clock || !self->image || !self->page->frame_next)
 		return;
 
 	self->frame_time = gdk_frame_clock_get_frame_time(clock);
 	self->frame_update_connection = g_signal_connect(
 		clock, "update", G_CALLBACK(on_frame_clock_update), self);
-	self->remaining_loops =
-		(uintptr_t) cairo_surface_get_user_data(self->page, &fiv_io_key_loops);
+
+	// Only restart looping the animation if it has stopped at the end.
+	if (!self->remaining_loops) {
+		self->remaining_loops = self->page->loops;
+		if (self->remaining_loops && !self->frame->frame_next) {
+			self->frame = self->page;
+			gtk_widget_queue_draw(GTK_WIDGET(self));
+		}
+	}
 
 	gdk_frame_clock_begin_updating(clock);
 	g_object_notify_by_pspec(G_OBJECT(self), view_properties[PROP_PLAYING]);
 }
 
 static void
-switch_page(FivView *self, cairo_surface_t *page)
+switch_page(FivView *self, FivIoImage *page)
 {
-	g_clear_pointer(&self->page_scaled, cairo_surface_destroy);
+	g_clear_pointer(&self->page_scaled, fiv_io_image_unref);
 	self->frame = self->page = page;
 	prescale_page(self);
 
 	if (!self->page ||
-		(self->orientation = (uintptr_t) cairo_surface_get_user_data(
-			 self->page, &fiv_io_key_orientation)) == FivIoOrientationUnknown)
+		(self->orientation = self->page->orientation) ==
+			FivIoOrientationUnknown)
 		self->orientation = FivIoOrientation0;
 
+	self->remaining_loops = 0;
 	start_animating(self);
 	gtk_widget_queue_resize(GTK_WIDGET(self));
 
@@ -1027,7 +1018,7 @@ copy(FivView *self)
 	cairo_surface_t *transformed =
 		cairo_image_surface_create(CAIRO_FORMAT_ARGB32, w, h);
 	cairo_t *cr = cairo_create(transformed);
-	cairo_set_source_surface(cr, self->frame, 0, 0);
+	set_source_image(self, cr);
 	cairo_pattern_set_matrix(cairo_get_source(cr), &matrix);
 	cairo_paint(cr);
 	cairo_destroy(cr);
@@ -1065,7 +1056,7 @@ on_draw_page(G_GNUC_UNUSED GtkPrintOperation *operation,
 
 	cairo_t *cr = gtk_print_context_get_cairo_context(context);
 	cairo_scale(cr, scale, scale);
-	cairo_set_source_surface(cr, self->frame, 0, 0);
+	set_source_image(self, cr);
 	cairo_pattern_set_matrix(cairo_get_source(cr), &matrix);
 	cairo_paint(cr);
 }
@@ -1100,7 +1091,7 @@ print(FivView *self)
 }
 
 static gboolean
-save_as(FivView *self, cairo_surface_t *frame)
+save_as(FivView *self, FivIoImage *frame)
 {
 	GtkWindow *window = get_toplevel(GTK_WIDGET(self));
 	FivIoProfile target = NULL;
@@ -1362,7 +1353,7 @@ fiv_view_init(FivView *self)
 
 // --- Public interface --------------------------------------------------------
 
-static cairo_surface_t *
+static FivIoImage *
 open_without_swapping_in(FivView *self, const char *uri)
 {
 	FivIoOpenContext ctx = {
@@ -1374,7 +1365,7 @@ open_without_swapping_in(FivView *self, const char *uri)
 	};
 
 	GError *error = NULL;
-	cairo_surface_t *surface = fiv_io_open(&ctx, &error);
+	FivIoImage *image = fiv_io_open(&ctx, &error);
 	if (error) {
 		g_ptr_array_add(ctx.warnings, g_strdup(error->message));
 		g_error_free(error);
@@ -1387,7 +1378,7 @@ open_without_swapping_in(FivView *self, const char *uri)
 	}
 
 	g_ptr_array_free(ctx.warnings, TRUE);
-	return surface;
+	return image;
 }
 
 // TODO(p): Progressive picture loading, or at least async/cancellable.
@@ -1395,18 +1386,18 @@ gboolean
 fiv_view_set_uri(FivView *self, const char *uri)
 {
 	// This is extremely expensive, and only works sometimes.
-	g_clear_pointer(&self->enhance_swap, cairo_surface_destroy);
+	g_clear_pointer(&self->enhance_swap, fiv_io_image_unref);
 	if (self->enhance) {
 		self->enhance = FALSE;
 		g_object_notify_by_pspec(
 			G_OBJECT(self), view_properties[PROP_ENHANCE]);
 	}
 
-	cairo_surface_t *surface = open_without_swapping_in(self, uri);
-	g_clear_pointer(&self->image, cairo_surface_destroy);
+	FivIoImage *image = open_without_swapping_in(self, uri);
+	g_clear_pointer(&self->image, fiv_io_image_unref);
 
 	self->frame = self->page = NULL;
-	self->image = surface;
+	self->image = image;
 	switch_page(self, self->image);
 
 	// Otherwise, adjustment values and zoom are retained implicitly.
@@ -1418,15 +1409,15 @@ fiv_view_set_uri(FivView *self, const char *uri)
 
 	g_object_notify_by_pspec(G_OBJECT(self), view_properties[PROP_MESSAGES]);
 	g_object_notify_by_pspec(G_OBJECT(self), view_properties[PROP_HAS_IMAGE]);
-	return surface != NULL;
+	return image != NULL;
 }
 
 static void
 page_step(FivView *self, int step)
 {
-	cairo_user_data_key_t *key =
-		step < 0 ? &fiv_io_key_page_previous : &fiv_io_key_page_next;
-	cairo_surface_t *page = cairo_surface_get_user_data(self->page, key);
+	FivIoImage *page = step < 0
+		? self->page->page_previous
+		: self->page->page_next;
 	if (page)
 		switch_page(self, page);
 }
@@ -1435,31 +1426,35 @@ static void
 frame_step(FivView *self, int step)
 {
 	stop_animating(self);
-	cairo_user_data_key_t *key =
-		step < 0 ? &fiv_io_key_frame_previous : &fiv_io_key_frame_next;
-	if (!step || !(self->frame = cairo_surface_get_user_data(self->frame, key)))
+
+	if (step > 0) {
+		// Decrease the loop counter as if running on a timer.
+		(void) advance_frame(self);
+	} else if (!step || !(self->frame = self->frame->frame_previous)) {
 		self->frame = self->page;
+		self->remaining_loops = 0;
+	}
 	gtk_widget_queue_draw(GTK_WIDGET(self));
 }
 
 static gboolean
 reload(FivView *self)
 {
-	cairo_surface_t *surface = open_without_swapping_in(self, self->uri);
+	FivIoImage *image = open_without_swapping_in(self, self->uri);
 	g_object_notify_by_pspec(G_OBJECT(self), view_properties[PROP_MESSAGES]);
-	if (!surface)
+	if (!image)
 		return FALSE;
 
-	g_clear_pointer(&self->image, cairo_surface_destroy);
-	g_clear_pointer(&self->enhance_swap, cairo_surface_destroy);
-	switch_page(self, (self->image = surface));
+	g_clear_pointer(&self->image, fiv_io_image_unref);
+	g_clear_pointer(&self->enhance_swap, fiv_io_image_unref);
+	switch_page(self, (self->image = image));
 	return TRUE;
 }
 
 static void
 swap_enhanced_image(FivView *self)
 {
-	cairo_surface_t *saved = self->image;
+	FivIoImage *saved = self->image;
 	self->image = self->page = self->frame = NULL;
 
 	if (self->enhance_swap) {
@@ -1546,9 +1541,8 @@ fiv_view_command(FivView *self, FivViewCommand command)
 	break; case FIV_VIEW_COMMAND_PAGE_NEXT:
 		page_step(self, +1);
 	break; case FIV_VIEW_COMMAND_PAGE_LAST:
-		for (cairo_surface_t *s = self->page;
-			 (s = cairo_surface_get_user_data(s, &fiv_io_key_page_next)); )
-			self->page = s;
+		for (FivIoImage *I = self->page; (I = I->page_next); )
+			self->page = I;
 		switch_page(self, self->page);
 
 	break; case FIV_VIEW_COMMAND_FRAME_FIRST:

meson.build

@@ -161,11 +161,14 @@ tiff_tables = custom_target('tiff-tables.h',
 )
 
 desktops = ['fiv.desktop', 'fiv-browse.desktop']
-exe = executable('fiv', 'fiv.c', 'fiv-view.c', 'fiv-io.c', 'fiv-context-menu.c',
+iolib = static_library('fiv-io', 'fiv-io.c', 'xdg.c', tiff_tables,
+	dependencies : dependencies).extract_all_objects(recursive : true)
+exe = executable('fiv', 'fiv.c', 'fiv-view.c', 'fiv-context-menu.c',
 	'fiv-browser.c', 'fiv-sidebar.c', 'fiv-thumbnail.c', 'fiv-collection.c',
-	'fiv-io-model.c', 'xdg.c', tiff_tables, gresources, rc, config,
-	install : true,
+	'fiv-io-model.c', gresources, rc, config,
+	objects : iolib,
 	dependencies : dependencies,
+	install : true,
 	win_subsystem : 'windows',
 )
 
@@ -193,8 +196,9 @@ if get_option('tools').enabled()
 	endforeach
 
 	if gdkpixbuf.found()
-		executable('benchmark-io', 'tools/benchmark-io.c', 'fiv-io.c', 'xdg.c',
-			tiff_tables, dependencies : [dependencies, gdkpixbuf])
+		executable('benchmark-io', 'tools/benchmark-io.c',
+			objects : iolib,
+			dependencies : [dependencies, gdkpixbuf])
 	endif
 endif
 

tools/benchmark-io.c

@@ -41,14 +41,14 @@ one_file(const char *filename)
 		.warnings = g_ptr_array_new_with_free_func(g_free),
 	};
 
-	cairo_surface_t *loaded_by_us = fiv_io_open(&ctx, NULL);
+	FivIoImage *loaded_by_us = fiv_io_open(&ctx, NULL);
 	g_clear_object(&file);
 	g_free((char *) ctx.uri);
 	g_ptr_array_free(ctx.warnings, TRUE);
 	if (!loaded_by_us)
 		return;
 
-	cairo_surface_destroy(loaded_by_us);
+	fiv_io_image_unref(loaded_by_us);
 	us = timestamp() - since_us;
 
 	double since_pixbuf = timestamp(), pixbuf = 0;