osc.lua: add sub-margin option

DOCS/interface-changes/osc-margins.txt

@@ -1 +1,2 @@
 add `osc-dynamic_margins` option
+add `osc-sub-margin` option

DOCS/man/osc.rst

@@ -408,6 +408,18 @@ Configurable Options
     applied when the OSC appears and removed when it hides. Without this
     option, margins are only applied when ``visibility`` is set to ``always``.
 
+``sub_margins``
+    Default: yes
+
+    Whether to adjust ``--sub-margin-y`` so that subtitles do not overlap
+    with the OSC. The offset is derived from the bottom OSC margin and added
+    on top of the current ``--sub-margin-y`` value. Requires
+    ``dynamic_margins`` or ``visibility=always`` to take effect.
+
+    With ``boxvideo`` enabled and ``--sub-use-margins=no``, subtitles are
+    already confined to the video area and this option has no additional
+    effect.
+
 ``windowcontrols``
     Default: auto (Show window controls if there is no window border)
 

player/lua/osc.lua

@@ -49,6 +49,7 @@ local user_opts = {
     boxmaxchars = 80,           -- title crop threshold for box layout
     boxvideo = false,           -- apply osc_param.video_margins to video
     dynamic_margins = false,    -- update margins dynamically with OSC visibility
+    sub_margins = true,         -- adjust sub-margin-y to not overlap with OSC
     windowcontrols = "auto",    -- whether to show window controls
     windowcontrols_alignment = "right", -- which side to show window controls on
     windowcontrols_title = "${media-title}", -- same as title but for windowcontrols
@@ -541,6 +542,18 @@ local function cache_enabled()
     return state.cache_state and #state.cache_state["seekable-ranges"] > 0
 end
 
+local function set_margin_offset(prop, offset)
+    if offset > 0 then
+        if not state[prop] then
+            state[prop] = mp.get_property_number(prop)
+        end
+        mp.set_property_number(prop, state[prop] + offset)
+    elseif state[prop] then
+        mp.set_property_number(prop, state[prop])
+        state[prop] = nil
+    end
+end
+
 local function reset_margins()
     if state.using_video_margins then
         for _, mopt in ipairs(margins_opts) do
@@ -548,6 +561,7 @@ local function reset_margins()
         end
         state.using_video_margins = false
     end
+    set_margin_offset("sub-margin-y", 0)
 end
 
 local function update_margins()
@@ -586,6 +600,23 @@ local function update_margins()
         reset_margins()
     end
 
+    local function get_margin(ent)
+        local margin = 0
+        if user_opts[ent .. "_margins"] then
+            local align = mp.get_property(ent .. "-align-y")
+            if align == "top" and top_vis then
+                margin = margins.t
+            elseif align == "bottom" and bottom_vis then
+                margin = margins.b
+            end
+        end
+        if ent == "sub" and user_opts.boxvideo and mp.get_property_bool("sub-use-margins") then
+            margin = 0
+        end
+        return margin * osc_param.playresy
+    end
+    set_margin_offset("sub-margin-y", get_margin("sub"))
+
     mp.set_property_native("user-data/osc/margins", margins)
 end