wayland: Update the color management protocol

No functional changes, just minor updates to track the latest upstream version.

src/video/wayland/SDL_waylandcolor.c

@@ -236,9 +236,9 @@ static void image_description_handle_failed(void *data,
     }
 }
 
-static void image_description_handle_ready(void *data,
+static void image_description_handle_ready2(void *data,
-                                           struct wp_image_description_v1 *wp_image_description_v1,
+                                            struct wp_image_description_v1 *wp_image_description_v1,
-                                           uint32_t identity)
+                                            uint32_t identity_hi, uint32_t identity_lo)
 {
     Wayland_ColorInfoState *state = (Wayland_ColorInfoState *)data;
 
@@ -263,9 +263,17 @@ static void image_description_handle_ready(void *data,
     }
 }
 
+static void image_description_handle_ready(void *data,
+                                           struct wp_image_description_v1 *wp_image_description_v1,
+                                           uint32_t identity)
+{
+    image_description_handle_ready2(data, wp_image_description_v1, 0, identity);
+}
+
 static const struct wp_image_description_v1_listener image_description_listener = {
     image_description_handle_failed,
-    image_description_handle_ready
+    image_description_handle_ready,
+    image_description_handle_ready2
 };
 
 void Wayland_GetColorInfoForWindow(SDL_WindowData *window_data, bool defer_event_processing)

src/video/wayland/SDL_waylandvideo.c

@@ -1331,7 +1331,7 @@ static void handle_registry_global(void *data, struct wl_registry *registry, uin
     } else if (SDL_strcmp(interface, "frog_color_management_factory_v1") == 0) {
         d->frog_color_management_factory_v1 = wl_registry_bind(d->registry, id, &frog_color_management_factory_v1_interface, 1);
     } else if (SDL_strcmp(interface, "wp_color_manager_v1") == 0) {
-        d->wp_color_manager_v1 = wl_registry_bind(d->registry, id, &wp_color_manager_v1_interface, 1);
+        d->wp_color_manager_v1 = wl_registry_bind(d->registry, id, &wp_color_manager_v1_interface, SDL_min(version, 2));
         Wayland_InitColorManager(d);
     } else if (SDL_strcmp(interface, "wp_pointer_warp_v1") == 0) {
         d->wp_pointer_warp_v1 = wl_registry_bind(d->registry, id, &wp_pointer_warp_v1_interface, 1);

src/video/wayland/SDL_waylandwindow.c

@@ -1706,16 +1706,25 @@ static const struct frog_color_managed_surface_listener frog_surface_listener =
     frog_preferred_metadata_handler
 };
 
-static void handle_surface_feedback_preferred_changed(void *data,
+
-                                                      struct wp_color_management_surface_feedback_v1 *wp_color_management_surface_feedback_v1,
+static void handle_surface_feedback_preferred_changed2(void *data,
-                                                      uint32_t identity)
+                                                       struct wp_color_management_surface_feedback_v1 *wp_color_management_surface_feedback_v1,
+                                                       uint32_t identity_hi, uint32_t identity_lo)
 {
     SDL_WindowData *wind = (SDL_WindowData *)data;
     Wayland_GetColorInfoForWindow(wind, false);
 }
 
+static void handle_surface_feedback_preferred_changed(void *data,
+                                                      struct wp_color_management_surface_feedback_v1 *wp_color_management_surface_feedback_v1,
+                                                      uint32_t identity)
+{
+    handle_surface_feedback_preferred_changed2(data, wp_color_management_surface_feedback_v1, 0, identity);
+}
+
 static const struct wp_color_management_surface_feedback_v1_listener color_management_surface_feedback_listener = {
-    handle_surface_feedback_preferred_changed
+    handle_surface_feedback_preferred_changed,
+    handle_surface_feedback_preferred_changed2
 };
 
 static void Wayland_SetKeyboardFocus(SDL_Window *window, bool set_focus)

wayland-protocols/color-management-v1.xml

@@ -31,9 +31,14 @@
   <description summary="color management protocol">
     The aim of the color management extension is to allow clients to know
     the color properties of outputs, and to tell the compositor about the color
-    properties of their content on surfaces. Doing this enables a compositor
+    properties of their content on surfaces. All surface contents must be
-    to perform automatic color management of content for different outputs
+    readily intended for some display, but not necessarily for the display at
-    according to how content is intended to look like.
+    hand. Doing this enables a compositor to perform automatic color management
+    of content for different outputs according to how content is intended to
+    look like.
+
+    For an introduction, see the section "Color management" in the Wayland
+    documentation at https://wayland.freedesktop.org/docs/html/ .
 
     The color properties are represented as an image description object which
     is immutable after it has been created. A wl_output always has an
@@ -43,16 +48,17 @@
     description on a wl_surface to denote the color characteristics of the
     surface contents.
 
-    An image description includes SDR and HDR colorimetry and encoding, HDR
+    An image description essentially defines a display and (indirectly) its
-    metadata, and viewing environment parameters. An image description does
+    viewing environment. An image description includes SDR and HDR colorimetry
-    not include the properties set through color-representation extension.
+    and encoding, HDR metadata, and some parameters related to the viewing
-    It is expected that the color-representation extension is used in
+    environment. An image description does not include the properties set
-    conjunction with the color management extension when necessary,
+    through color-representation extension. It is expected that the
-    particularly with the YUV family of pixel formats.
+    color-representation extension is used in conjunction with the
+    color-management extension when necessary, particularly with the YUV family
+    of pixel formats.
 
-    Recommendation ITU-T H.273
+    The normative appendix for this protocol is in the appendix.md file beside
-    "Coding-independent code points for video signal type identification"
+    this XML file.
-    shall be referred to as simply H.273 here.
 
     The color-and-hdr repository
     (https://gitlab.freedesktop.org/pq/color-and-hdr) contains
@@ -71,7 +77,7 @@
     only be done by creating a new major version of the extension.
   </description>
 
-  <interface name="wp_color_manager_v1" version="1">
+  <interface name="wp_color_manager_v1" version="2">
     <description summary="color manager singleton">
       A singleton global interface used for getting color management extensions
       for wl_surface and wl_output objects, and for creating client defined
@@ -118,6 +124,14 @@
              summary="ICC-absolute colorimetric"/>
       <entry name="relative_bpc" value="4"
              summary="media-relative colorimetric + black point compensation"/>
+      <entry name="absolute_no_adaptation" value="5" since="2">
+        <description summary="ICC-absolute colorimetric without adaptation">
+          This rendering intent is a modified absolute rendering intent that
+          assumes the viewer is not adapted to the display white point, so no
+          chromatic adaptation between surface and display is done.
+          This can be useful for color proofing applications.
+        </description>
+      </entry>
     </enum>
 
     <enum name="feature">
@@ -149,18 +163,14 @@
         </description>
       </entry>
       <entry name="windows_scrgb" value="7"
-             summary="get_windows_scrgb request"/>
+             summary="create_windows_scrgb request"/>
     </enum>
 
     <enum name="primaries">
       <description summary="named color primaries">
-        Named color primaries used to encode well-known sets of primaries. H.273
+        Named color primaries used to encode well-known sets of primaries.
-        is the authority, when it comes to the exact values of primaries and
-        authoritative specifications, where an equivalent code point exists.
 
         A value of 0 is invalid and will never be present in the list of enums.
-
-        Descriptions do list the specifications for convenience.
       </description>
 
       <entry name="srgb" value="1">
@@ -173,7 +183,6 @@
           - IEC 61966-2-4
           - Society of Motion Picture and Television Engineers (SMPTE) RP 177
             (1993) Annex B
-          Equivalent to H.273 ColourPrimaries code point 1.
         </description>
       </entry>
       <entry name="pal_m" value="2">
@@ -184,7 +193,6 @@
             Recommendation for transmission standards for color television
           - United States Federal Communications Commission (2003) Title 47 Code
             of Federal Regulations 73.682 (a)(20)
-          Equivalent to H.273 ColourPrimaries code point 4.
         </description>
       </entry>
       <entry name="pal" value="3">
@@ -194,7 +202,6 @@
           - Rec. ITU-R BT.601-7 625
           - Rec. ITU-R BT.1358-0 625 (historical)
           - Rec. ITU-R BT.1700-0 625 PAL and 625 SECAM
-          Equivalent to H.273 ColourPrimaries code point 5.
         </description>
       </entry>
       <entry name="ntsc" value="4">
@@ -205,13 +212,13 @@
           - Rec. ITU-R BT.1700-0 NTSC
           - SMPTE 170M (2004)
           - SMPTE 240M (1999) (historical)
-          Equivalent to H.273 ColourPrimaries code point 6 and 7.
         </description>
       </entry>
       <entry name="generic_film" value="5">
         <description summary="Generic film with colour filters using Illuminant C">
-          Color primaries as defined by H.273 for generic film.
+          Color primaries as defined by Recommendation ITU-T H.273
-          Equivalent to H.273 ColourPrimaries code point 8.
+          "Coding-independent code points for video signal type identification"
+          for "generic film".
         </description>
       </entry>
       <entry name="bt2020" value="6">
@@ -219,7 +226,6 @@
           Color primaries as defined by
           - Rec. ITU-R BT.2020-2
           - Rec. ITU-R BT.2100-0
-          Equivalent to H.273 ColourPrimaries code point 9.
         </description>
       </entry>
       <entry name="cie1931_xyz" value="7">
@@ -228,21 +234,18 @@
           space by
           - SMPTE ST 428-1
           - (CIE 1931 XYZ as in ISO 11664-1)
-          Equivalent to H.273 ColourPrimaries code point 10.
         </description>
       </entry>
       <entry name="dci_p3" value="8">
         <description summary="Color primaries of the DCI P3 color space as defined by the SMPTE RP 431 standard">
           Color primaries as defined by Digital Cinema System and published in
-          SMPTE RP 431-2 (2011). Equivalent to H.273 ColourPrimaries code point
+          SMPTE RP 431-2 (2011).
-          11.
         </description>
       </entry>
       <entry name="display_p3" value="9">
         <description summary="Color primaries of Display P3 variant of the DCI-P3 color space as defined by the SMPTE EG 432 standard">
           Color primaries as defined by Digital Cinema System and published in
           SMPTE EG 432-1 (2010).
-          Equivalent to H.273 ColourPrimaries code point 12.
         </description>
       </entry>
       <entry name="adobe_rgb" value="10">
@@ -256,13 +259,11 @@
     <enum name="transfer_function">
       <description summary="named transfer functions">
         Named transfer functions used to represent well-known transfer
-        characteristics. H.273 is the authority, when it comes to the exact
+        characteristics of displays.
-        formulas and authoritative specifications, where an equivalent code
-        point exists.
 
         A value of 0 is invalid and will never be present in the list of enums.
 
-        Descriptions do list the specifications for convenience.
+        See appendix.md for the formulae.
       </description>
 
       <entry name="bt1886" value="1">
@@ -271,8 +272,6 @@
           - Rec. ITU-R BT.601-7 525 and 625
           - Rec. ITU-R BT.709-6
           - Rec. ITU-R BT.2020-2
-          These recommendations are referred to by H.273 TransferCharacteristics
-          code points 1, 6, 14, and 15, which are all equivalent.
 
           This TF implies these default luminances from Rec. ITU-R BT.2035:
           - primary color volume minimum: 0.01 cd/m²
@@ -289,65 +288,57 @@
           - United States Federal Communications Commission (2003) Title 47 Code
             of Federal Regulations 73.682 (a) (20)
           - Rec. ITU-R BT.1700-0 625 PAL and 625 SECAM
-          Equivalent to H.273 TransferCharacteristics code point 4.
+          - IEC 61966-2-1 (reference display)
         </description>
       </entry>
       <entry name="gamma28" value="3">
         <description summary="Assumed display gamma 2.8 transfer function">
           Transfer characteristics as defined by
           - Rec. ITU-R BT.470-6 System B, G (historical)
-          Equivalent to H.273 TransferCharacteristics code point 5.
         </description>
       </entry>
       <entry name="st240" value="4">
         <description summary="SMPTE ST 240 transfer function">
           Transfer characteristics as defined by
           - SMPTE ST 240 (1999)
-          Equivalent to H.273 TransferCharacteristics code point 7.
         </description>
       </entry>
       <entry name="ext_linear" value="5">
         <description summary="extended linear transfer function">
           Linear transfer function defined over all real numbers.
           Normalised electrical values are equal the normalised optical values.
-
-          The differences to H.273 TransferCharacteristics code point 8 are
-          the definition over all real numbers.
         </description>
       </entry>
       <entry name="log_100" value="6">
         <description summary="logarithmic 100:1 transfer function">
           Logarithmic transfer characteristic (100:1 range).
-          Equivalent to H.273 TransferCharacteristics code point 9.
         </description>
       </entry>
       <entry name="log_316" value="7">
         <description summary="logarithmic (100*Sqrt(10) : 1) transfer function">
           Logarithmic transfer characteristic (100 * Sqrt(10) : 1 range).
-          Equivalent to H.273 TransferCharacteristics code point 10.
         </description>
       </entry>
       <entry name="xvycc" value="8">
         <description summary="IEC 61966-2-4 transfer function">
           Transfer characteristics as defined by
           - IEC 61966-2-4
-          Equivalent to H.273 TransferCharacteristics code point 11.
         </description>
       </entry>
-      <entry name="srgb" value="9">
+      <entry name="srgb" value="9" deprecated-since="2">
-        <description summary="sRGB piece-wise transfer function">
+        <description summary="Deprecated (ambiguous sRGB transfer function)">
           Transfer characteristics as defined by
           - IEC 61966-2-1 sRGB
-          Equivalent to H.273 TransferCharacteristics code point 13 with
+
-          MatrixCoefficients set to 0.
+          As a rule of thumb, use gamma22 for video, motion picture and
+          computer graphics, or compound_power_2_4 for ICC calibrated print
+          workflows.
         </description>
       </entry>
-      <entry name="ext_srgb" value="10">
+      <entry name="ext_srgb" value="10" deprecated-since="2">
-        <description summary="Extended sRGB piece-wise transfer function">
+        <description summary="Deprecated (Extended sRGB piece-wise transfer function)">
           Transfer characteristics as defined by
           - IEC 61966-2-1 sYCC
-          Equivalent to H.273 TransferCharacteristics code point 13 with
-          MatrixCoefficients set to anything but 0.
         </description>
       </entry>
       <entry name="st2084_pq" value="11">
@@ -355,7 +346,6 @@
           Transfer characteristics as defined by
           - SMPTE ST 2084 (2014) for 10-, 12-, 14- and 16-bit systems
           - Rec. ITU-R BT.2100-2 perceptual quantization (PQ) system
-          Equivalent to H.273 TransferCharacteristics code point 16.
 
           This TF implies these default luminances
           - primary color volume minimum: 0.005 cd/m²
@@ -373,7 +363,6 @@
         <description summary="SMPTE ST 428 transfer function">
           Transfer characteristics as defined by
           - SMPTE ST 428-1 (2019)
-          Equivalent to H.273 TransferCharacteristics code point 17.
         </description>
       </entry>
       <entry name="hlg" value="13">
@@ -381,7 +370,6 @@
           Transfer characteristics as defined by
           - ARIB STD-B67 (2015)
           - Rec. ITU-R BT.2100-2 hybrid log-gamma (HLG) system
-          Equivalent to H.273 TransferCharacteristics code point 18.
 
           This TF implies these default luminances
           - primary color volume minimum: 0.005 cd/m²
@@ -398,6 +386,12 @@
           ARIB STD-B67 or BT.2100.
         </description>
       </entry>
+      <entry name="compound_power_2_4" value="14" since="2">
+        <description summary="IEC 61966-2-1 encoding function">
+          Encoding characteristics as defined by IEC 61966-2-1, for displays
+          that invert the encoding function.
+        </description>
+      </entry>
     </enum>
 
     <request name="get_output">
@@ -531,6 +525,9 @@
       <description summary="supported rendering intent">
         When this object is created, it shall immediately send this event once
         for each rendering intent the compositor supports.
+
+        A compositor must not advertise intents that are deprecated in the
+        bound version of the interface.
       </description>
 
       <arg name="render_intent" type="uint" enum="render_intent"
@@ -541,6 +538,9 @@
       <description summary="supported features">
         When this object is created, it shall immediately send this event once
         for each compositor supported feature listed in the enumeration.
+
+        A compositor must not advertise features that are deprecated in the
+        bound version of the interface.
       </description>
 
       <arg name="feature" type="uint" enum="feature"
@@ -552,6 +552,9 @@
         When this object is created, it shall immediately send this event once
         for each named transfer function the compositor supports with the
         parametric image description creator.
+
+        A compositor must not advertise transfer functions that are deprecated
+        in the bound version of the interface.
       </description>
 
       <arg name="tf" type="uint" enum="transfer_function"
@@ -563,6 +566,9 @@
         When this object is created, it shall immediately send this event once
         for each named set of primaries the compositor supports with the
         parametric image description creator.
+
+        A compositor must not advertise names that are deprecated in the
+        bound version of the interface.
       </description>
 
       <arg name="primaries" type="uint" enum="primaries"
@@ -575,9 +581,23 @@
         transfer functions and named primaries have been sent.
       </description>
     </event>
+
+    <request name="get_image_description" since="2">
+      <description summary="create an image description from a reference">
+        This request retrieves the image description backing a reference.
+
+        The get_information request can be used if and only if the request that
+        creates the reference allows it.
+      </description>
+
+      <arg name="image_description"
+           type="new_id" interface="wp_image_description_v1"/>
+      <arg name="reference"
+           type="object" interface="wp_image_description_reference_v1"/>
+    </request>
   </interface>
 
-  <interface name="wp_color_management_output_v1" version="1">
+  <interface name="wp_color_management_output_v1" version="2">
     <description summary="output color properties">
       A wp_color_management_output_v1 describes the color properties of an
       output.
@@ -647,7 +667,7 @@
     </request>
   </interface>
 
-  <interface name="wp_color_management_surface_v1" version="1">
+  <interface name="wp_color_management_surface_v1" version="2">
     <description summary="color management extension to a surface">
         A wp_color_management_surface_v1 allows the client to set the color
         space and HDR properties of a surface.
@@ -693,18 +713,18 @@
         All image descriptions which are ready (see wp_image_description_v1)
         are allowed and must always be accepted by the compositor.
 
-        A rendering intent provides the client's preference on how content
+        When an image description is set on a surface, it establishes an
-        colors should be mapped to each output. The render_intent value must
+        explicit link between surface pixel values and surface colorimetry.
-        be one advertised by the compositor with
+        This link may be undefined for some pixel values, see the image
+        description creator interfaces for the conditions. Non-finite
+        floating-point values (NaN, Inf) always have an undefined colorimetry.
+
+        A rendering intent provides the client's preference on how surface
+        colorimetry should be mapped to each output. The render_intent value
+        must be one advertised by the compositor with
         wp_color_manager_v1.render_intent event, otherwise the protocol error
         render_intent is raised.
 
-        When an image description is set on a surface, the Transfer
-        Characteristics of the image description defines the valid range of
-        the nominal (real-valued) color channel values. The processing of
-        out-of-range color channel values is undefined, but compositors are
-        recommended to clamp the values to the valid range when possible.
-
         By default, a surface does not have an associated image description
         nor a rendering intent. The handling of color on such surfaces is
         compositor implementation defined. Compositors should handle such
@@ -735,7 +755,7 @@
     </request>
   </interface>
 
-  <interface name="wp_color_management_surface_feedback_v1" version="1">
+  <interface name="wp_color_management_surface_feedback_v1" version="2">
     <description summary="color management extension to a surface">
         A wp_color_management_surface_feedback_v1 allows the client to get the
         preferred image description of a surface.
@@ -758,27 +778,14 @@
              summary="attempted to use an unsupported feature"/>
     </enum>
 
-    <event name="preferred_changed">
+    <event name="preferred_changed" deprecated-since="2">
-      <description summary="the preferred image description changed">
+      <description summary="the preferred image description changed (32-bit)">
-        The preferred image description is the one which likely has the most
+        Starting from interface version 2, 'preferred_changed2' is sent instead
-        performance and/or quality benefits for the compositor if used by the
+        of this event. See the 'preferred_changed2' event for the definition.
-        client for its wl_surface contents. This event is sent whenever the
-        compositor changes the wl_surface's preferred image description.
-
-        This event sends the identity of the new preferred state as the argument,
-        so clients who are aware of the image description already can reuse it.
-        Otherwise, if the client client wants to know what the preferred image
-        description is, it shall use the get_preferred request.
-
-        The preferred image description is not automatically used for anything.
-        It is only a hint, and clients may set any valid image description with
-        set_image_description, but there might be performance and color accuracy
-        improvements by providing the wl_surface contents in the preferred
-        image description. Therefore clients that can, should render according
-        to the preferred image description
       </description>
 
-      <arg name="identity" type="uint" summary="image description id number"/>
+      <arg name="identity" type="uint"
+           summary="the 32-bit image description id number"/>
     </event>
 
     <request name="get_preferred">
@@ -835,9 +842,38 @@
       <arg name="image_description"
            type="new_id" interface="wp_image_description_v1"/>
     </request>
+
+    <!-- Version 2 additions -->
+
+    <event name="preferred_changed2" since="2">
+      <description summary="the preferred image description changed">
+        The preferred image description is the one which likely has the most
+        performance and/or quality benefits for the compositor if used by the
+        client for its wl_surface contents. This event is sent whenever the
+        compositor changes the wl_surface's preferred image description.
+
+        This event sends the identity of the new preferred state as the argument,
+        so clients who are aware of the image description already can reuse it.
+        Otherwise, if the client client wants to know what the preferred image
+        description is, it shall use the get_preferred request.
+
+        The preferred image description is not automatically used for anything.
+        It is only a hint, and clients may set any valid image description with
+        set_image_description, but there might be performance and color accuracy
+        improvements by providing the wl_surface contents in the preferred
+        image description. Therefore clients that can, should render according
+        to the preferred image description
+      </description>
+
+      <arg name="identity_hi" type="uint"
+           summary="high 32 bits of the 64-bit image description id number"/>
+      <arg name="identity_lo" type="uint"
+           summary="low 32 bits of the 64-bit image description id number"/>
+    </event>
+
   </interface>
 
-  <interface name="wp_image_description_creator_icc_v1" version="1">
+  <interface name="wp_image_description_creator_icc_v1" version="2">
     <description summary="holder of image description ICC information">
       This type of object is used for collecting all the information required
       to create a wp_image_description_v1 object from an ICC file. A complete
@@ -853,6 +889,10 @@
       Once all properties have been set, the create request must be used to
       create the image description object, destroying the creator in the
       process.
+
+      The link between a pixel value (a device value in ICC) and its respective
+      colorimetry is defined by the details of the particular ICC profile.
+      Those details also determine when colorimetry becomes undefined.
     </description>
 
     <enum name="error">
@@ -949,7 +989,7 @@
     </request>
   </interface>
 
-  <interface name="wp_image_description_creator_params_v1" version="1">
+  <interface name="wp_image_description_creator_params_v1" version="2">
     <description summary="holder of image description parameters">
       This type of object is used for collecting all the parameters required
       to create a wp_image_description_v1 object. A complete set of required
@@ -978,6 +1018,20 @@
       Once all properties have been set, the create request must be used to
       create the image description object, destroying the creator in the
       process.
+
+      A viewer, who is viewing the display defined by the resulting image
+      description (the viewing environment included), is assumed to be fully
+      adapted to the primary color volume's white point.
+
+      Any of the following conditions will cause the colorimetry of a pixel
+      to become undefined:
+      - Values outside of the defined range of the transfer characteristic.
+      - Tristimulus that exceeds the target color volume.
+      - If extended_target_volume is not supported: tristimulus that exceeds
+      the primary color volume.
+
+      The closest correspondence to an image description created through this
+      interface is the Display class of profiles in ICC.
     </description>
 
     <enum name="error">
@@ -1006,14 +1060,16 @@
         complete, the protocol error incomplete_set is raised. For the
         definition of a complete set, see the description of this interface.
 
-        The protocol error invalid_luminance is raised if any of the following
+        When both max_cll and max_fall are set, max_fall must be less or equal
-        requirements is not met:
+        to max_cll otherwise the invalid_luminance protocol error is raised.
+
+        In version 1, these following conditions also result in the
+        invalid_luminance protocol error. Version 2 and later do not have this
+        requirement.
         - When max_cll is set, it must be greater than min L and less or equal
           to max L of the mastering luminance range.
         - When max_fall is set, it must be greater than min L and less or equal
           to max L of the mastering luminance range.
-        - When both max_cll and max_fall are set, max_fall must be less or equal
-          to max_cll.
 
         If the particular combination of the parameter set is not supported
         by the compositor, the resulting image description object shall
@@ -1039,7 +1095,7 @@
         functions.
 
         When the resulting image description is attached to an image, the
-        content should be encoded and decoded according to the industry standard
+        content should be decoded according to the industry standard
         practices for the transfer characteristic.
 
         Only names advertised with wp_color_manager_v1 event supported_tf_named
@@ -1061,9 +1117,6 @@
         range of the curve are all finite real numbers. This curve represents
         the conversion from electrical to optical color channel values.
 
-        When the resulting image description is attached to an image, the
-        content should be encoded with the inverse of the power curve.
-
         The curve exponent shall be multiplied by 10000 to get the argument eexp
         value to carry the precision of 4 decimals.
 
@@ -1129,8 +1182,8 @@
     <request name="set_luminances">
       <description summary="primary color volume luminance range and reference white">
         Sets the primary color volume luminance range and the reference white
-        luminance level. These values include the minimum display emission
+        luminance level. These values include the minimum display emission, but
-        and ambient flare luminances, assumed to be optically additive and have
+        not external flare. The minimum display emission is assumed to have
         the chromaticity of the primary color volume white point.
 
         The default luminances from
@@ -1310,13 +1363,15 @@
     </request>
   </interface>
 
-  <interface name="wp_image_description_v1" version="1">
+  <interface name="wp_image_description_v1" version="2">
     <description summary="Colorimetric image description">
-      An image description carries information about the color encoding used on
+      An image description carries information about the pixel color encoding
-      a surface when attached to a wl_surface via
+      and its intended display and viewing environment. The image description is
+      attached to a wl_surface via
       wp_color_management_surface_v1.set_image_description. A compositor can use
       this information to decode pixel values into colorimetrically meaningful
-      quantities.
+      quantities, which allows the compositor to transform the surface contents
+      to become suitable for various displays and viewing environments.
 
       Note, that the wp_image_description_v1 object is not ready to be used
       immediately after creation. The object eventually delivers either the
@@ -1385,38 +1440,22 @@
            summary="ad hoc human-readable explanation"/>
     </event>
 
-    <event name="ready">
+    <event name="ready" deprecated-since="2">
-      <description summary="indication that the object is ready to be used">
+      <description summary="the object is ready to be used (32-bit)">
-        Once this event has been sent, the wp_image_description_v1 object is
+        Starting from interface version 2, the 'ready2' event is sent instead
-        deemed "ready". Ready objects can be used to send requests and can be
+        of this event.
-        used through other interfaces.
 
-        Every ready wp_image_description_v1 protocol object refers to an
+        For the definition of this event, see the 'ready2' event. The
-        underlying image description record in the compositor. Multiple protocol
+        difference to this event is as follows.
-        objects may end up referring to the same record. Clients may identify
-        these "copies" by comparing their id numbers: if the numbers from two
-        protocol objects are identical, the protocol objects refer to the same
-        image description record. Two different image description records
-        cannot have the same id number simultaneously. The id number does not
-        change during the lifetime of the image description record.
 
         The id number is valid only as long as the protocol object is alive. If
         all protocol objects referring to the same image description record are
         destroyed, the id number may be recycled for a different image
         description record.
-
-        Image description id number is not a protocol object id. Zero is
-        reserved as an invalid id number. It shall not be possible for a client
-        to refer to an image description by its id number in protocol. The id
-        numbers might not be portable between Wayland connections. A compositor
-        shall not send an invalid id number.
-
-        This identity allows clients to de-duplicate image description records
-        and avoid get_information request if they already have the image
-        description information.
       </description>
 
-      <arg name="identity" type="uint" summary="image description id number"/>
+      <arg name="identity" type="uint"
+           summary="the 32-bit image description id number"/>
     </event>
 
     <request name="get_information">
@@ -1433,9 +1472,45 @@
       <arg name="information"
            type="new_id" interface="wp_image_description_info_v1"/>
     </request>
+
+    <!-- Version 2 additions -->
+
+    <event name="ready2" since="2">
+      <description summary="the object is ready to be used">
+        Once this event has been sent, the wp_image_description_v1 object is
+        deemed "ready". Ready objects can be used to send requests and can be
+        used through other interfaces.
+
+        Every ready wp_image_description_v1 protocol object refers to an
+        underlying image description record in the compositor. Multiple protocol
+        objects may end up referring to the same record. Clients may identify
+        these "copies" by comparing their id numbers: if the numbers from two
+        protocol objects are identical, the protocol objects refer to the same
+        image description record. Two different image description records
+        cannot have the same id number simultaneously. The id number does not
+        change during the lifetime of the image description record.
+
+        Image description id number is not a protocol object id. Zero is
+        reserved as an invalid id number. It shall not be possible for a client
+        to refer to an image description by its id number in protocol. The id
+        numbers might not be portable between Wayland connections. A compositor
+        shall not send an invalid id number.
+
+        Compositors must not recycle image description id numbers.
+
+        This identity allows clients to de-duplicate image description records
+        and avoid get_information request if they already have the image
+        description information.
+      </description>
+
+      <arg name="identity_hi" type="uint"
+           summary="high 32 bits of the 64-bit image description id number"/>
+      <arg name="identity_lo" type="uint"
+           summary="low 32 bits of the 64-bit image description id number"/>
+    </event>
   </interface>
 
-  <interface name="wp_image_description_info_v1" version="1">
+  <interface name="wp_image_description_info_v1" version="2">
     <description summary="Colorimetric image description information">
       Sends all matching events describing an image description object exactly
       once and finally sends the 'done' event.
@@ -1628,4 +1703,22 @@
            summary="Maximum frame-average light level (cd/m²)"/>
     </event>
   </interface>
+
+  <interface name="wp_image_description_reference_v1" version="1">
+    <description summary="Reference to an image description">
+      This object is a reference to an image description. This interface is
+      frozen at version 1 to allow other protocols to create
+      wp_image_description_v1 objects.
+
+      The wp_color_manager_v1.get_image_description request can be used to
+      retrieve the underlying image description.
+    </description>
+
+    <request name="destroy" type="destructor">
+      <description summary="destroy the reference">
+        Destroy this object. This has no effect on the referenced image
+        description.
+      </description>
+    </request>
+  </interface>
 </protocol>