separate display logic from main code

1 files changed, 322 insertions, 0 deletions

diff --git a/osd.lua b/osd.lua
new file mode 100644
index 0000000..e7bb9eb
--- /dev/null
+++ b/osd.lua
@@ -0,0 +1,322 @@
+-- Copyright 2025 David Vazgenovich Shakaryan
+
+local config = require('config')
+
+local mp_utils = require('mp.utils')
+
+local osd = {}
+local mt = {}
+mt.__index = mt
+
+local colours = {}
+for k, v in pairs(config.colours) do
+	-- constructed backwards as ASS colour tags expect BGR but we configure
+	-- them as RGB
+	tag = '&}'
+	for byte in v:gmatch('..') do
+		tag = byte:upper() .. tag
+	end
+	colours[k] = '{\\c&H' .. tag
+end
+
+local cursor_glyph = '{\\p1\\pbo' .. math.floor(config.font_size / 5) .. '}' ..
+	'm 0 0 l ' .. math.ceil(config.font_size / 32) .. ' 0 ' ..
+	math.ceil(config.font_size / 32) .. ' ' .. config.font_size ..
+	' 0 ' .. config.font_size .. '{\\p0}'
+
+local function asscape(str)
+	-- remove newlines before escaping, since we don't want output to
+	-- unexpectedly span multiple lines
+	return mp.command_native({'escape-ass', (str:gsub('\n', ' '))})
+end
+
+function osd.new()
+	local lines = math.floor((720 / config.font_size) + 0.5) - 1
+	local t = {
+		fg = mp.create_osd_overlay('ass-events'),
+		bg = mp.create_osd_overlay('ass-events'),
+		width = 0,
+		height = 0,
+		scale = 1,
+		lines = lines,
+		padding = math.floor((720 - (lines * config.font_size)) / 2),
+		img = nil,
+	}
+
+	t.bg.z = -1
+	t.bg.data = '{\\pos(0,0)\\alpha&H' .. config.bg_alpha .. '&\\c&H&}' ..
+		'{\\p1}m 0 0 l 7680 0 7680 720 0 720{\\p0}'
+
+	return setmetatable(t, mt)
+end
+
+function mt:resize(w, h)
+	self.width = w
+	self.height = h
+	self.scale = h / 720
+end
+
+function mt:menu_lines(depth)
+	if depth > 1 then
+		-- leaves an extra line for padding between titles and options
+		return self.lines - depth
+	else
+		return self.lines
+	end
+end
+
+function mt:menu_title(menu)
+	local str = asscape(menu.title)
+	local col = menu.search_active and colours.selected or colours.title
+
+	if menu.type == 'search' then
+		str = str:gsub('<text>', asscape(menu.search_text))
+
+		if str:find('<text_with_cursor>', 1, true) then
+			str = str:gsub('<text_with_cursor>',
+				asscape(menu.search_text:sub(
+						1, menu.search_cursor - 1)) ..
+					cursor_glyph ..
+					asscape(menu.search_text:sub(
+						menu.search_cursor)))
+		end
+
+		str = str:gsub('<colours.info>', colours.info)
+		str = str:gsub('<num_matches>', #menu.options)
+		str = str:gsub('<num_total>', #menu.search_options)
+	end
+
+	return col .. ' » ' .. str
+end
+
+function mt:option_icons(opt, info)
+	local str = ''
+	if info.selected then
+		str = colours.selected .. '› '
+	end
+	if info.playing then
+		str = str .. colours.icon_playing .. '\226\143\186 '
+	end
+	if info.favourited then
+		str = str .. colours.icon_favourite .. '★ '
+	end
+	if opt.active then
+		str = str .. colours.icon_active .. '\226\143\186 '
+	end
+	return str
+end
+
+function mt:option_text(opt, info)
+	local str = opt.name
+	local col = colours.option
+	if info.selected then
+		col = info.empty and colours.selected_empty or colours.selected
+	elseif info.empty then
+		col = colours.group_empty
+	elseif opt.type == 'group' then
+		col = colours.group
+	end
+
+	if opt.matches then
+		local buf = ''
+		local hl_col = info.empty and colours.search_hl_empty or
+			colours.search_hl
+		local n = 0
+
+		for _, match in ipairs(opt.matches) do
+			buf = buf .. col ..
+				asscape(str:sub(n + 1, match.start - 1)) ..
+				hl_col ..
+				asscape(str:sub(match.start, match.stop))
+			n = match.stop
+		end
+		str = buf .. col .. asscape(str:sub(n + 1))
+	else
+		str = col .. asscape(str)
+	end
+
+	if opt.type == 'group' then
+		str = col .. '[' .. str .. ']'
+	end
+
+	if opt.info and #opt.info > 0 then
+		str = str .. colours.info .. ' (' .. asscape(opt.info) .. ')'
+	end
+
+	return str
+end
+
+function mt:option_path(opt, info)
+	if not opt.path or #opt.path == 0 then
+		return ''
+	end
+
+	local str = info.empty and colours.search_path_empty or
+		colours.search_path
+	for i = #opt.path, 1, -1 do
+		str = str .. ' « ' .. asscape(opt.path[i].name)
+	end
+	return str
+end
+
+function mt:update_image(path, menu_res)
+	-- images require *real* dimensions and coordinates, unlike other OSD
+	-- functions which scale the given values automatically
+	local padding = self.scale * self.padding
+	local start = self.scale * menu_res.x1
+	local fs = self.scale * config.font_size
+
+	-- width is generally computed to 2/3 (standard aspect ratio of movie
+	-- posters) of OSD height. when longer OSD text extends into this area,
+	-- the remaining space is used, with a minimum font-size-derived value
+	-- when there is not enough (or any) space left, which may overlap the
+	-- tail end of text.
+	--
+	-- for consistency, any source images with a different aspect ratio are
+	-- resized, confining them to the area of a "standard" poster.
+	--
+	-- because we have only the total width of the current OSD text, we
+	-- cannot slightly reduce the image width to avoid overlapping some
+	-- longer line at the bottom, as we do not know where the offending
+	-- line is. if it were possible to place images *under* text, maybe
+	-- we'd allow overlap, but mpv currently hard-codes this order.
+	local ratio = 2/3
+	local w = math.floor(math.max(3 * fs * ratio,
+			math.min(self.width - start - 2*padding,
+				(self.height - 2*padding) * ratio)))
+	local h = math.floor(w / ratio)
+	local x = math.floor(self.width - padding - w)
+	local y = math.floor(padding)
+
+	local disp
+	if self.img and self.img.loaded and path == self.img.path and
+			w == self.img.cmd.w and h == self.img.cmd.h then
+		if x == self.img.cmd.x and y == self.img.cmd.y then
+			return
+		end
+
+		disp = true
+	else
+		local f = mp_utils.file_info(path)
+		if f then
+			local cmd = 'magick \'' .. path .. '\'' ..
+				' -background none' ..
+				' -gravity northwest' ..
+				' -depth 8' ..
+				' -resize ' .. w .. 'x' .. h ..
+				' -extent ' .. w .. 'x' .. h ..
+				' tmp.bgra'
+			print('exec: ' .. cmd)
+			os.execute(cmd)
+			disp = true
+		end
+	end
+
+	self.img = {
+		path = path,
+		cmd = {
+			name = 'overlay-add',
+			id = 0,
+			file = 'tmp.bgra',
+			w = w,
+			h = h,
+			x = x,
+			y = y,
+			fmt = 'bgra',
+			offset = 0,
+			stride = 4*w,
+		},
+	}
+
+	if disp then
+		self.img.loaded = true
+		if not self.fg.hidden then
+			mp.command_native(self.img.cmd)
+		end
+	else
+		mp.command_native(
+			{name = 'overlay-remove', id = self.img.cmd.id})
+	end
+end
+
+function mt:remove_image()
+	mp.command_native({name = 'overlay-remove', id = self.img.cmd.id})
+	self.img = nil
+end
+
+function mt:redraw(menus, depth, favourites, playing_id)
+	local out = {}
+
+	if depth > 1 then
+		for i = 2, depth do
+			out[#out+1] = self:menu_title(menus[i])
+		end
+		out[#out+1] = ' ' -- space character for correct line height
+	end
+
+	local menu = menus[depth]
+
+	local img
+	if menu.img_url then
+		img = get_image_path(menu.img_url, true)
+	end
+
+	for i = menu.view_top, math.min(
+			menu.view_top + self:menu_lines(depth) - 1,
+			#menu.options) do
+		local opt = menu.options[i]
+
+		local selected = i == menu.cursor and not menu.search_active
+		local info = {
+			selected = selected,
+			empty = (opt.type == 'group' and not opt.lazy and
+				#opt.children == 0),
+			playing = not not (opt.id and opt.id == playing_id),
+			favourited = not not (opt.id and favourites[opt.id]),
+		}
+		out[#out+1] = self:option_icons(opt, info) ..
+			self:option_text(opt, info) ..
+			self:option_path(opt, info)
+
+		if selected and opt.image and opt.image ~= '' then
+			img = get_image_path(opt.image, true)
+		end
+	end
+
+	-- \q2 disables line wrapping
+	self.fg.data = '{\\q2\\fs' .. config.font_size ..
+		'\\pos(' .. self.padding .. ',' .. self.padding .. ')}' ..
+		table.concat(out, '\\N')
+
+	self.fg.compute_bounds = not not img
+	local res = self.fg:update()
+	if img then
+		self:update_image(img, res)
+	elseif self.img then
+		self:remove_image()
+	end
+	self.bg:update()
+end
+
+function mt:toggle_hidden()
+	self.fg.hidden = not self.fg.hidden
+	self.fg:update()
+	self.bg.hidden = self.fg.hidden
+	self.bg:update()
+
+	if self.img then
+		if self.fg.hidden then
+			mp.command_native({
+				name = 'overlay-remove',
+				id = self.img.cmd.id})
+		else
+			mp.command_native(self.img.cmd)
+		end
+	end
+end
+
+function mt:is_hidden()
+	return self.fg.hidden
+end
+
+return osd