}
}
+
+/**
+ * gdk_pixbuf_apply_embedded_orientation:
+ * @src: A #GdkPixbuf.
+ *
+ * Takes an existing pixbuf and checks for the presence of an
+ * associated "orientation" option, which may be provided by the
+ * jpeg loader (which reads the exif orientation tag) or the
+ * tiff loader (which reads the tiff orientation tag, and
+ * compensates it for the partial transforms performed by
+ * libtiff). If an orientation option/tag is present, the
+ * appropriate transform will be performed so that the pixbuf
+ * is oriented correctly.
+ *
+ * Return value: A newly-created pixbuf, or a reference to the
+ * input pixbuf (with an increased reference count).
+ *
+ * Since 2.12
+ **/
+GdkPixbuf *
+gdk_pixbuf_apply_embedded_orientation (GdkPixbuf *src)
+{
+ const gchar *orientation_string;
+ int transform = 0;
+ GdkPixbuf *temp;
+ GdkPixbuf *dest;
+
+ g_return_val_if_fail (src != NULL, NULL);
+
+ /* Read the orientation option associated with the pixbuf */
+ orientation_string = gdk_pixbuf_get_option (src, "orientation");
+
+ if (orientation_string) {
+ /* If an orientation option was found, convert the
+ orientation string into an integer. */
+ transform = (int) g_ascii_strtoll (orientation_string, NULL, 10);
+ }
+
+ /* Apply the actual transforms, which involve rotations and flips.
+ The meaning of orientation values 1-8 and the required transforms
+ are defined by the TIFF and EXIF (for JPEGs) standards. */
+ switch (transform) {
+ case 1:
+ dest = src;
+ g_object_ref (dest);
+ break;
+ case 2:
+ dest = gdk_pixbuf_flip (src, TRUE);
+ break;
+ case 3:
+ dest = gdk_pixbuf_rotate_simple (src, GDK_PIXBUF_ROTATE_UPSIDEDOWN);
+ break;
+ case 4:
+ dest = gdk_pixbuf_flip (src, FALSE);
+ break;
+ case 5:
+ temp = gdk_pixbuf_rotate_simple (src, GDK_PIXBUF_ROTATE_CLOCKWISE);
+ dest = gdk_pixbuf_flip (temp, TRUE);
+ g_object_unref (temp);
+ break;
+ case 6:
+ dest = gdk_pixbuf_rotate_simple (src, GDK_PIXBUF_ROTATE_CLOCKWISE);
+ break;
+ case 7:
+ temp = gdk_pixbuf_rotate_simple (src, GDK_PIXBUF_ROTATE_CLOCKWISE);
+ dest = gdk_pixbuf_flip (temp, FALSE);
+ g_object_unref (temp);
+ break;
+ case 8:
+ dest = gdk_pixbuf_rotate_simple (src, GDK_PIXBUF_ROTATE_COUNTERCLOCKWISE);
+ break;
+ default:
+ /* if no orientation tag was present */
+ dest = src;
+ g_object_ref (dest);
+ break;
+ }
+
+ return dest;
+}
+
+
#define __GDK_PIXBUF_UTIL_C__
#include "gdk-pixbuf-aliasdef.c"
* @key: a nul-terminated string.
*
* Looks up @key in the list of options that may have been attached to the
- * @pixbuf when it was loaded.
+ * @pixbuf when it was loaded, or that may have been attached by another
+ * function using gdk_pixbuf_set_option().
+ *
+ * For instance, the ANI loader provides "Title" and "Artist" options.
+ * The ICO, XBM, and XPM loaders provide "x_hot" and "y_hot" hot-spot
+ * options for cursor definitions. The PNG loader provides the tEXt ancillary
+ * chunk key/value pairs as options. Since 2.12, the TIFF and JPEG loaders
+ * return an "orientation" option string that corresponds to the embedded
+ * TIFF/Exif orientation tag (if present).
*
* Return value: the value associated with @key. This is a nul-terminated
* string that should not be freed or %NULL if @key was not found.
projects / gtk4.git / commitdiff