dgud · elblake · May 11, 2026
diff --git a/plugins_src/commands/Makefile b/plugins_src/commands/Makefile
@@ -51,6 +51,9 @@ MODULES= \
 	wpc_intersect_vertex \
 	wpc_isometric_view \
 	wpc_magnet_mask \
+	wpc_metadata \
+	wpc_metadata_dc \
+	wpc_metadata_units \
 	wpc_move_planar \
 	wpc_numeric_camera \
 	wpc_plane_cut \

diff --git a/plugins_src/commands/wpc_metadata.erl b/plugins_src/commands/wpc_metadata.erl
@@ -0,0 +1,223 @@
+%%
+%%  wpc_metadata.erl --
+%%
+%%     Metadata functionality
+%%
+%%  Copyright (c) 2026 Edward Blake
+%%
+%%  See the file "license.terms" for information on usage and redistribution
+%%  of this file, and for a DISCLAIMER OF ALL WARRANTIES.
+%%
+%%     $Id$
+%%
+
+-module(wpc_metadata).
+-export([init/0,menu/2,command/2]).
+
+-include_lib("wings/src/wings.hrl").
+
+init() ->
+    true.
+
+menu({tools},Menu) ->
+    metadata_submenu(Menu);
+menu({tools,metadata},Menu) ->
+    metadata_menu_entry(Menu);
+menu(_,Menu) -> Menu.
+
+metadata_submenu([]) ->
+    [{?__(1,"Metadata"), {metadata, []}}];
+metadata_submenu([A|Menu]) ->
+    [A|metadata_submenu(Menu)].
+
+metadata_menu_entry([]) ->
+    [{?__(1,"Scene"),scene,
+      ?__(2,"Set scene metadata")},
+     {?__(3,"Object"),object,
+      ?__(4,"Set object metadata")}];
+metadata_menu_entry([A|Menu]) ->
+    [A|metadata_menu_entry(Menu)].
+
+command({tools,{metadata,scene}},St) ->
+    set_scene_metadata(St);
+command({tools,{metadata,object}},St) ->
+    set_obj_metadata(St);
+command(_,_) ->
+    next.
+
+%%%
+%%%
+
+%%
+%% Set Scene Metadata
+%%
+
+set_scene_metadata(#st{pst=Pst}=St) ->
+    List = metadata_plugins(scene),
+    QsFrames = metadata_tab_frames(scene,
+        fun (Name) -> get_metadata(Name,Pst) end, List),
+    Frame = [{oframe, QsFrames, 1, [{style, buttons}]}],
+    wings_dialog:dialog(?__(1,"Scene Metadata"), {preview,Frame},
+        fun
+            ({dialog_preview,Args}) ->
+                {preview,St,set_scene_metadata_1(Args, List, St)};
+            (cancel) ->
+                St;
+            (Args) ->
+                {commit,St,set_scene_metadata_1(Args, List, St)}
+        end).
+
+set_scene_metadata_1(Args, List, #st{pst=Pst}=St) ->
+    Metadata = get_pst_metadata(Pst),
+    Metadata_2 = lists:foldl(
+        fun({Name, _, Mod}, Metadata_1) ->
+            update_metadata(Name, Mod, scene, Args, Metadata_1)
+        end, Metadata, List),
+    St#st{pst=update_pst_metadata(Metadata_2, Pst)}.
+
+
+%%
+%% Object metadata.
+%%
+set_obj_metadata(#st{sel=[_|_],selmode=body}=St) ->
+    List = metadata_plugins(object),
+    QsFrames = metadata_tab_frames(object,
+        fun (Name) -> get_obj_metadata(Name, St) end, List),
+    Frame = [{oframe, QsFrames, 1, [{style, buttons}]}],
+    wings_dialog:dialog(?__(1,"Object Metadata: ") ++ obj_names(St), {preview,Frame},
+        fun
+            ({dialog_preview,Args}) ->
+                {preview,St,set_obj_metadata_1(Args, List, St)};
+            (cancel) ->
+                St;
+            (Args) ->
+                {commit,St,set_obj_metadata_1(Args, List, St)}
+        end);
+set_obj_metadata(#st{sel=[]}=_St) ->
+    wings_u:error_msg(?__(3,"Need at least one object selected."));
+set_obj_metadata(#st{selmode=SelMode}=St) when SelMode =/= body ->
+    set_obj_metadata(wings_sel_conv:mode(body, St)).
+
+set_obj_metadata_1(Args, List, St) ->
+    wings_sel:map(fun (_, #we{pst=Pst}=We) ->
+        Metadata = get_pst_metadata(Pst),
+        Metadata_2 = lists:foldl(
+            fun({Name, _, Mod}, Metadata_1) ->
+                update_metadata(Name, Mod, object, Args, Metadata_1)
+            end, Metadata, List),
+        We#we{pst=update_pst_metadata(Metadata_2, Pst)}
+    end, St).
+
+obj_names(St) ->
+    {Extra, StrList} =
+        wings_sel:fold(
+            fun
+                (_, #we{name=ObjName}=_We, {0, Acc}) when length(Acc) < 3 ->
+                    {0, [ObjName|Acc]};
+                (_, #we{name=_}=_We, {C, Acc}) ->
+                    {C + 1, Acc}
+            end, {0, []}, St),
+    lists:flatten(lists:join(?__(1,", "), lists:reverse(StrList)) ++
+        if
+            Extra =:= 1 -> io_lib:format(?__(2,", ~w more object"), [Extra]);
+            Extra > 1   -> io_lib:format(?__(3,", ~w more objects"), [Extra]);
+            true        -> ""
+        end).
+
+%%%
+%%%
+
+%% Find the metadata plugins
+%%
+metadata_plugins(Scope) ->
+    Plugins = get(wings_plugins),
+    lists:append([ try_metadata_plugin(Scope, Pl) || Pl <- Plugins])
+        ++ [{comments, ?__(2,"Comments"), 0}].
+
+%% Create Tab frames for dialog
+%%
+metadata_tab_frames(Scope, Fun, List) ->
+    [{TabName, module_metadata_dialog(Mod, Name, Scope, Fun(Name))}
+        || {Name, TabName, Mod} <- List].
+
+%%%
+%%%
+
+update_metadata(Name, Mod, Scope, Args, Metadata) ->
+    MetadataC = case proplists:get_value(Name, Metadata, []) of
+        MetadataC_0 when is_list(MetadataC_0) -> MetadataC_0;
+        _ -> []
+    end,
+    MetadataC_1 = module_metadata_update(Mod, Name, Scope, MetadataC, Args),
+    case length(MetadataC_1) =:= 0 of
+        true ->
+            proplists:delete(Name, Metadata);
+        false ->
+            orddict:store(Name, MetadataC_1, orddict:from_list(proplists:delete(Name, Metadata)))
+    end.
+
+get_pst_metadata(Pst) ->
+    case gb_trees:lookup(metadata,Pst) of
+        none -> [];
+        {value, Metadata} when is_list(Metadata) -> Metadata;
+        {value, _} -> []
+    end.
+
+update_pst_metadata(Metadata, Pst) ->
+    gb_trees:enter(metadata, Metadata, Pst).
+
+get_metadata(Name, Pst) ->
+    Metadata = get_pst_metadata(Pst),
+    case proplists:get_value(Name, Metadata, []) of
+        MetadataC when is_list(MetadataC) -> MetadataC;
+        _ -> []
+    end.
+
+
+get_obj_metadata(Name, St) ->
+    wings_sel:fold(fun (_, #we{pst=Pst}=_We, Acc) ->
+        Metadata = get_pst_metadata(Pst),
+        case proplists:get_value(Name,Metadata,Acc) of
+            MetadataC when is_list(MetadataC) -> MetadataC;
+            _ -> []
+        end
+    end, [], St).
+
+
+module_metadata_dialog(0, comments, _Scope, MetadataC) ->
+    metadata_comments_dialog(MetadataC);
+module_metadata_dialog(Mod, Name, Scope, MetadataC) when is_atom(Mod) ->
+    Mod:metadata_dialog(Scope, Name, MetadataC).
+
+module_metadata_update(0, comments, _Scope, MetadataC, Args) ->
+    metadata_comments_update(MetadataC, Args);
+module_metadata_update(Mod, Name, Scope, MetadataC, Args) when is_atom(Mod) ->
+    Mod:metadata_update(Scope, Name, MetadataC, Args).
+
+try_metadata_plugin(Scope, Pl) ->
+    try Pl:metadata_names(Scope) of
+        Ret -> Ret
+    catch
+        error:_ -> []
+    end.
+
+
+%% Free-form comments
+%%
+
+metadata_comments_dialog(MetadataComments) when is_list(MetadataComments) ->
+    Val = proplists:get_value(comments, MetadataComments, ""),
+    {vframe,[
+        {label,?__(12,"Comments")},
+        {text,Val,[{key,comments},{width,50}]}
+    ]}.
+
+metadata_comments_update(MetadataComments, Args) when is_list(MetadataComments) ->
+    case proplists:get_value(comments, Args, "") of
+        "" ->
+            proplists:delete(comments, MetadataComments);
+        Creator ->
+            orddict:store(comments, Creator, orddict:from_list(proplists:delete(comments, MetadataComments)))
+    end.
+
+
diff --git a/plugins_src/commands/wpc_metadata_dc.erl b/plugins_src/commands/wpc_metadata_dc.erl
@@ -0,0 +1,121 @@
+%%
+%%  wpc_metadata_dc.erl --
+%%
+%%     Plugin that implements Dublin Core metadata
+%%
+%%  Copyright (c) 2026 Edward Blake
+%%
+%%  See the file "license.terms" for information on usage and redistribution
+%%  of this file, and for a DISCLAIMER OF ALL WARRANTIES.
+%%
+%%     $Id$
+%%
+
+-module(wpc_metadata_dc).
+-export([init/0,menu/2,command/2]).
+-export([metadata_names/1]).
+-export([metadata_dialog/3]).
+-export([metadata_update/4]).
+
+-include_lib("wings/src/wings.hrl").
+
+init() ->
+    true.
+menu(_,Menu) -> Menu.
+command(_,_) ->
+    next.
+
+%%%
+%%%
+
+%% The dublin core elements
+%%
+elements() ->
+    [
+        {text,{title,
+            ?__(1,"Title:"),
+            ?__(2,"The name of the resource")}},
+        {text,{creator,
+            ?__(3,"Creator:"),
+            ?__(4,"The person or entity that primarily created the resource.")}},
+        {text,{subject,
+            ?__(5,"Subject:"),
+            ?__(6,"The topic or keywords of the resource.")}},
+        {text,{description,
+            ?__(7,"Description:"),
+            ?__(8,"A description of the resource")}},
+        {text,{publisher,
+            ?__(9,"Publisher:"),
+            ?__(10,"The publisher of the resource")}},
+        {text,{contributor,
+            ?__(11,"Other Contributors:"),
+            ?__(12,"Other persons or entities that contributed towards the creation of the resource")}},
+        {text,{date,
+            ?__(13,"Date:"),
+            ?__(14,"A date specifying the creation or availability of the resource")}},
+        {text,{identifier,
+            ?__(15,"Identifier:"),
+            ?__(16,"An identifier (such as a URI, string or number) that distinguishes the resource.")}},
+        {text,{format,
+            ?__(17,"Format:"),
+            ?__(18,"The data format and dimensions of the resource. Software and hardware related to the resource can be specified here.")}},
+        {text,{source,
+            ?__(19,"Source:"),
+            ?__(20,"Identifiers to other resources that are a source for the current resource.")}},
+        {text,{coverage,
+            ?__(21,"Coverage:"),
+            ?__(22,"The geographic or temporal coverage of the resource.")}},
+        {text,{language,
+            ?__(23,"Language:"),
+            ?__(24,"The language of the resource.")}},
+        {text,{relation,
+            ?__(25,"Relation:"),
+            ?__(26,"Identifiers to other resources with a relation to the current resource.")}},
+        {text,{rights,
+            ?__(27,"Rights:"),
+            ?__(28,"Information on rights of the resource.")}},
+        {text,{type,
+            ?__(29,"Type:"),
+            ?__(30,"A category of media of the resource.")}}
+    ].
+
+
+%%%
+%%%
+
+metadata_names(_Scope) ->
+    [{dc,?__(1,"General"),?MODULE}].
+
+metadata_dialog(_Scope, _Name, MetadataDC) when is_list(MetadataDC) ->
+    List_0 = [V || {C,V} <- elements(), C =:= text],
+    {vframe,[{label_column,[
+        text_field(Name, FieldStr, FieldInfo, MetadataDC)
+        || {Name,FieldStr,FieldInfo} <- List_0]}]}.
+
+metadata_update(_Scope, _Name, MetadataDC, Args) when is_list(MetadataDC) ->
+    List = [Name || {Name,_,_} <- [V || {C,V} <- elements(), C =:= text]],
+    lists:foldl(
+        fun (FieldName, Acc) ->
+            update(FieldName, Acc, Args)
+        end, MetadataDC, List).
+
+%%%
+%%%
+
+text_field(Name, FieldName, FieldInfo, MetadataDC) when is_list(MetadataDC) ->
+    Val = proplists:get_value(Name, MetadataDC, ""),
+    {FieldName,{text,Val,[{key,Name},{width,50},{info,FieldInfo}]}}.
+
+
+update(Name, Acc, Args) ->
+    case proplists:get_value(Name, Args, 1) of
+        "" ->
+            proplists:delete(Name, Acc);
+        Creator ->
+            orddict:store(Name, Creator, orddict:from_list(proplists:delete(Name, Acc)))
+    end.
+
+
+
+
+