[css-images-3] image-orientation: from-image | none applies to decorative images as well as content images. w3c#5245 w3c#5294

Author: fantasai

css-images-3/Overview.bs

@@ -1530,16 +1530,22 @@ Image Processing {#image-processing}
 	unless use cases other than “correct for incorrect orientation” are raised for its other values.
 
 	This property specifies an orthogonal rotation to be applied to an image before it is laid out.
-	It applies only to content images
+	It applies to content images
 	(e.g. replaced elements and generated content),
-	not decorative images
+	as well as decorative images applied via CSS
 	(such as 'background-image').
-	CSS layout processing applies to the image <em>after</em> rotation.
+	It does not apply to the rendering of images outside the document,
+	e.g. favicons in the UA’s navigation toolbars or menus, etc.
+
+	CSS layout processing applies to the image <em>after</em> rotation,
+	exactly as if the image were originally encoded in its rotated form.
 	This implies, for example:
 
 	* The intrinsic height and width are derived from the rotated rather than the original image dimensions.
 	* The height (width) property applies to the vertical (horizontal) dimension of the image,
 		<em>after</em> rotation.
+	* The hotspot coordinates of an image 'cursor' are relative to the image after rotation.
+	* Border images (see 'border-image') are sliced after rotation.
 
 	Values have the following meanings:
 
@@ -1570,13 +1576,19 @@ Image Processing {#image-processing}
 			rounding away from 0
 			(so ''45deg'' rounds to ''90deg'', etc).
 
+			This value only applies to content images;
+			decorative images continue to behave as ''from-image''.
+
 		<dt><dfn><<angle>>? flip</dfn>
 		<dd>
 			Identical to the plain <<angle>> case,
 			except that after rotation the image is flipped horizontally.
 			If the <<angle>> is omitted,
 			it defaults to ''0deg''.
 
+			This value only applies to content images;
+			decorative images continue to behave as ''from-image''.
+
 			Note: This value is only necessary to represent all 8 possible EXIF orientations that <a value for=image-orientation>from-image</a> can produce.
 	</dl>