perf: optimize rendering and always use shallow delete for kitty images

lua/image/backends/kitty/init.lua

@@ -52,11 +52,13 @@ backend.render = function(image, x, y, width, height)
       display_virtual_placeholder = with_virtual_placeholders and 1 or 0,
       quiet = 2,
     }, image.cropped_path)
+    -- utils.debug("[kitty] transmitted image " .. image.id .. " (" .. image.internal_id .. ")")
   end
   if backend.features.crop then
-    if not transmitted_images[image.id] then
+    local preprocessing_hash = ("%s-%s"):format(image.id, image.resize_hash)
+    if transmitted_images[image.id] ~= preprocessing_hash then
       transmit()
-      transmitted_images[image.id] = true
+      transmitted_images[image.id] = preprocessing_hash
     end
   else
     local preprocessing_hash = ("%s-%s-%s"):format(image.id, image.resize_hash, image.crop_hash)
@@ -126,6 +128,8 @@ backend.render = function(image, x, y, width, height)
   image.is_rendered = true
   backend.state.images[image.id] = image
   helpers.restore_cursor()
+
+  -- utils.debug("[kitty] rendered image", image.id, "(" .. image.internal_id .. ")")
 end
 
 backend.clear = function(image_id, shallow)
@@ -135,7 +139,7 @@ backend.clear = function(image_id, shallow)
     if not image then return end
     helpers.write_graphics({
       action = codes.control.action.delete,
-      display_delete = shallow and "i" or "I",
+      display_delete = "i",
       image_id = image.internal_id,
       quiet = 2,
     })
@@ -144,6 +148,7 @@ backend.clear = function(image_id, shallow)
       backend.state.images[image_id] = nil
       transmitted_images[image.id] = nil
     end
+    -- utils.debug("[kitty] cleared image", image.id, "(" .. image.internal_id .. ")", "shallow:", shallow)
     return
   end
 
@@ -153,12 +158,14 @@ backend.clear = function(image_id, shallow)
     display_delete = "a",
     quiet = 2,
   })
+  -- utils.debug("[kitty] cleared all")
   for id, image in pairs(backend.state.images) do
     image.is_rendered = false
     if not shallow then
       backend.state.images[id] = nil
       transmitted_images[image.id] = nil
     end
+    -- utils.debug("[kitty] cleared image (all)", image.id, "shallow:", shallow)
   end
 end
 

lua/image/image.lua

@@ -34,6 +34,11 @@ function Image:render(geometry)
   local was_rendered = renderer.render(self)
   -- utils.log("render result", self.id, was_rendered)
 
+  if self.is_rendered and not was_rendered then
+    -- shallow clear if render was prevented
+    self.global_state.backend.clear(self.id, true)
+  end
+
   -- virtual padding
   if self.buffer and self.with_virtual_padding then
     local row = self.geometry.y
@@ -42,48 +47,62 @@ function Image:render(geometry)
 
     local previous_extmark = buf_extmark_map[self.buffer .. ":" .. row]
 
+    -- clear previous extmark if rendering was prevented
     if not was_rendered and previous_extmark then
-      self.global_state.backend.clear(self.id, true)
-      vim.api.nvim_buf_del_extmark(self.buffer, self.global_state.extmarks_namespace, previous_extmark.id)
+      if vim.api.nvim_buf_is_valid(self.buffer) then
+        vim.api.nvim_buf_del_extmark(self.buffer, self.global_state.extmarks_namespace, previous_extmark.id)
+      end
       buf_extmark_map[self.buffer .. ":" .. row] = nil
       return
     end
 
-    if previous_extmark then
-      if previous_extmark.height == height then return end
-      vim.api.nvim_buf_del_extmark(self.buffer, self.global_state.extmarks_namespace, previous_extmark.id)
-    end
-
+    -- create extmark if outdated or it doesn't exist
     if was_rendered then
-      local text = string.rep(" ", width)
-      local filler = {}
-      for _ = 0, height - 1 do
-        filler[#filler + 1] = { { text, "" } }
+      if previous_extmark then
+        if previous_extmark.height == height then return end
+        vim.api.nvim_buf_del_extmark(self.buffer, self.global_state.extmarks_namespace, previous_extmark.id)
       end
-      vim.api.nvim_buf_set_extmark(self.buffer, self.global_state.extmarks_namespace, row - 1, 0, {
-        id = self.internal_id,
-        virt_lines = filler,
-      })
-      buf_extmark_map[self.buffer .. ":" .. row] = { id = self.internal_id, height = height }
 
-      -- rerender any images that are below this one
-      for _, image in pairs(self.global_state.images) do
-        if image.buffer == self.buffer and image.geometry.y > self.geometry.y then image:render() end
+      if was_rendered then
+        local text = string.rep(" ", width)
+        local filler = {}
+        for _ = 0, height - 1 do
+          filler[#filler + 1] = { { text, "" } }
+        end
+        vim.api.nvim_buf_set_extmark(self.buffer, self.global_state.extmarks_namespace, row - 1, 0, {
+          id = self.internal_id,
+          virt_lines = filler,
+        })
+        buf_extmark_map[self.buffer .. ":" .. row] = { id = self.internal_id, height = height }
+
+        -- rerender any images that are below this one
+        -- TODO: only the one after
+        -- TODO: should this be here?
+        for _, image in pairs(self.global_state.images) do
+          if image.buffer == self.buffer and image.geometry.y > self.geometry.y then image:render() end
+        end
       end
     end
   end
 end
 
-function Image:clear()
-  self.global_state.backend.clear(self.id)
+---@param shallow? boolean
+function Image:clear(shallow)
+  if not self.is_rendered then return end
+
+  -- utils.debug(("[image] clear %s, shallow: %s"):format(self.id, shallow))
+  self.global_state.backend.clear(self.id, shallow or false)
   self.rendered_geometry = {
     x = nil,
     y = nil,
     width = nil,
     height = nil,
   }
-  if self.buffer then
-    vim.api.nvim_buf_del_extmark(self.buffer, self.global_state.extmarks_namespace, self.internal_id)
+
+  if self.with_virtual_padding and self.buffer then
+    if vim.api.nvim_buf_is_valid(self.buffer) then
+      vim.api.nvim_buf_del_extmark(self.buffer, self.global_state.extmarks_namespace, self.internal_id)
+    end
     buf_extmark_map[self.buffer .. ":" .. self.geometry.y] = nil
   end
 end
@@ -207,7 +226,8 @@ local from_file = function(path, options, state)
     },
     with_virtual_padding = opts.with_virtual_padding or false,
     is_rendered = false,
-    crop_resize_hash = nil,
+    crop_hash = nil,
+    resize_hash = nil,
   }, state)
 
   return instance

lua/image/init.lua

@@ -107,7 +107,7 @@ api.setup = function(options)
         vim.defer_fn(function()
           if needs_clear then
             for _, curr in ipairs(api.get_images({ buffer = prev.bufnr })) do
-              curr:clear()
+              curr:clear(true)
             end
           elseif needs_rerender then
             for _, current_image in ipairs(api.get_images({ window = winid })) do
@@ -147,12 +147,14 @@ api.setup = function(options)
         local is_buffer_binding_valid = win_buf_map[current_image.window] == current_image.buffer
 
         local should_clear = false
+        local shallow = false
         if is_window_bound and not is_window_binding_valid then
           should_clear = true
         elseif is_buffer_bound and not is_buffer_binding_valid then
           should_clear = true
+          shallow = true
         end
-        if should_clear then current_image:clear() end
+        if should_clear then current_image:clear(shallow) end
       end
     end,
   })

lua/image/integrations/markdown.lua

@@ -110,8 +110,12 @@ local render = function(ctx)
         end
       end
 
+      -- clear previous images
       for _, image in ipairs(previous_images) do
-        if not vim.tbl_contains(new_image_ids, image.id) then image:clear() end
+        if not vim.tbl_contains(new_image_ids, image.id) then
+          -- utils.debug("[markdown] clearing removed image", image.id)
+          image:clear()
+        end
       end
     end
   end

lua/image/integrations/neorg.lua

@@ -141,7 +141,7 @@ local setup_autocommands = function(ctx)
         local current_window = vim.api.nvim_get_current_win()
         local images = ctx.api.get_images({ window = current_window })
         for _, image in ipairs(images) do
-          image:clear()
+          image:clear(true)
         end
       end,
     })

lua/image/renderer.lua

@@ -324,8 +324,8 @@ local render = function(image)
   end
 
   -- crop
-  local crop_hash = ("%d-%d-%d-%d"):format(0, crop_offset_top, pixel_width, cropped_pixel_height)
   if needs_crop then
+    local crop_hash = ("%d-%d-%d-%d"):format(0, crop_offset_top, pixel_width, cropped_pixel_height)
     if (needs_resize and image.resize_hash ~= resize_hash) or image.crop_hash ~= crop_hash then
       local cropped_image = magick.load_image(image.resized_path or image.path)
       cropped_image:set_format("png")

lua/types.lua

@@ -102,7 +102,7 @@
 ---@field crop_hash? string
 ---@field global_state State
 ---@field render fun(self: Image, geometry?: ImageGeometry)
----@field clear fun(self: Image)
+---@field clear fun(self: Image, shallow?: boolean)
 ---@field move fun(self: Image, x: number, y: number)
 ---@field brightness fun(self: Image, brightness: number)
 ---@field saturation fun(self: Image, saturation: number)
@@ -151,4 +151,4 @@
 ---@field display_cursor_policy 0|1
 ---@field display_virtual_placeholder 0|1
 ---@field display_zindex number
----@field display_delete "a"|"i"|"I"|"p"
+---@field display_delete "a"|"A"|"i"|"I"|"p"