async loading of images

1 files changed, 64 insertions, 43 deletions

diff --git a/osd.lua b/osd.lua
index a61f12e..7f44f60 100644
--- a/osd.lua
+++ b/osd.lua
@@ -44,7 +44,6 @@ function osd.new(init)
 		scale = 1,
 		lines = lines,
 		padding = math.floor((720 - (lines * config.font_size)) / 2),
-		img = nil,
 	}, mt)
 	t.bg.z = -1
 
@@ -174,13 +173,15 @@ end
 function mt:load_img()
 	local f = mp_utils.file_info(self.img.path)
 	if not f then
-		return false
+		return
+	end
+
+	if self.magick_cmd_id then
+		mp.abort_async_command(self.magick_cmd_id)
 	end
 
-	local cmd = {
+	local magick_cmd = {
 		'magick', self.img.path,
-		'-background', 'none',
-		'-gravity', 'northwest',
 		'-depth', '8',
 		'-resize', string.format(
 			'x%%[fx:max(%d, min(%d, %d*h/w))]',
@@ -188,41 +189,49 @@ function mt:load_img()
 		'-print', '%w %h',
 		'tmp.bgra'
 	}
-	print('exec: ' .. mp_utils.to_string(cmd))
-	local res = mp.command_native({
+	print('exec: ' .. mp_utils.to_string(magick_cmd))
+	self.img.magick_cmd = magick_cmd
+	self.magick_cmd = magick_cmd
+	self.magick_cmd_id = mp.command_native_async({
 		name = 'subprocess',
-		args = cmd,
+		args = magick_cmd,
 		capture_stdout = true,
 		playback_only = false,
-	})
-	if not res or res.status ~= 0 then
-		return false
-	end
+	}, function (_, res)
+		if magick_cmd ~= self.magick_cmd then
+			return
+		end
 
-	local w, h = res.stdout:match('(.+) (.+)')
-	self.img.cmd = {
-		name = 'overlay-add',
-		id = 0,
-		file = 'tmp.bgra',
-		w = w,
-		h = h,
-		x = self.img.right - w,
-		y = self.img.top,
-		fmt = 'bgra',
-		offset = 0,
-		stride = 4*w,
-	}
+		self.magick_cmd = nil
+		self.magick_cmd_id = nil
+
+		if not self.img or not res or res.status ~= 0 then
+			return
+		end
+
+		local w, h = res.stdout:match('(.+) (.+)')
+		self.img.cmd = {
+			name = 'overlay-add',
+			id = 0,
+			file = 'tmp.bgra',
+			w = w,
+			h = h,
+			x = self.img.right - w,
+			y = self.img.top,
+			fmt = 'bgra',
+			offset = 0,
+			stride = 4*w,
+		}
 
-	return true
+		self:draw_img()
+	end)
 end
 
 function mt:clear_img(purge)
-	if not self.img then
-		return
-	end
-
-	if self.img.cmd then
-		mp.command_native({name = 'overlay-remove', id = self.img.cmd.id})
+	if self.img_overlay_id then
+		mp.command_native(
+			{name = 'overlay-remove', id = self.img_overlay_id})
+		self.img_overlay_id = nil
 	end
 
 	if purge then
@@ -235,16 +244,20 @@ function mt:draw_img()
 		return
 	end
 
-	if not (self.img.cmd or self:load_img()) then
-		self:clear_img()
+	if not self.img.magick_cmd then
+		self:load_img()
 		return
 	end
 
-	if not self:is_hidden() then
+	if self.img.cmd and not self:is_hidden() then
 		mp.command_native(self.img.cmd)
+		self.img_overlay_id = self.img.cmd.id
 	end
 end
 
+-- returns (upd, new)
+-- upd: if anything changed, e.g. position
+-- new: if the image also changed, i.e. different path or size
 function mt:set_img(path, menu_res)
 	-- images require *real* dimensions and coordinates, unlike other OSD
 	-- functions which scale the given values automatically
@@ -272,18 +285,21 @@ function mt:set_img(path, menu_res)
 	local top = math.floor(padding)
 	local right = math.floor(self.width - padding)
 
-	if self.img and self.img.cmd and path == self.img.path and
-			min_h == self.img.min_h and max_h == self.img.max_h and
+	if self.img and path == self.img.path and
+			min_h == self.img.min_h and
+			max_h == self.img.max_h and
 			max_w == self.img.max_w then
 		if top == self.img.top and right == self.img.right then
-			return false
+			return false, false
 		end
 
 		self.img.top = top
-		self.img.cmd.y = top
 		self.img.right = right
-		self.img.cmd.x = right - self.img.cmd.w
-		return true
+		if self.img.cmd then
+			self.img.cmd.x = right - self.img.cmd.w
+			self.img.cmd.y = top
+		end
+		return true, false
 	end
 
 	self.img = {
@@ -294,7 +310,7 @@ function mt:set_img(path, menu_res)
 		top = top,
 		right = right,
 	}
-	return true
+	return true, true
 end
 
 function mt:draw_scrollbar(state)
@@ -380,6 +396,7 @@ function mt:redraw(state)
 
 	self.fg.compute_bounds = not not img
 	local res = self.fg:update()
+	self.fg.compute_bounds = false
 	self.bg:update()
 	if img and self.img_path_func then
 		local path = self.img_path_func(img, function(path)
@@ -388,7 +405,11 @@ function mt:redraw(state)
 			end
 		end)
 
-		if self:set_img(path, res) then
+		local upd, new = self:set_img(path, res)
+		if upd then
+			if new then
+				self:clear_img()
+			end
 			self:draw_img()
 		end
 	else