Stability and Bugfixes

* Editor: Auto-save on a background goroutine so you don't randomly freeze
  the editor up during.
* Fix actor linking issues when you drag and re-place a linked doodad: the
  level was too eagerly calling PruneLinks() whenever a doodad was 'destroyed'
  (such as the one just picked up) breaking half of the link connection.
* Chunk unloader: do not unload a chunk that has been modified (Set or Delete
  called on), keep them in memory until the next ZIP file save to flush them
  out to disk.
* Link Tool: if you clicked an actor and don't want to connect a link, click
  the first actor again to de-select it.

Updates to the `doodad` tool:

* `doodad edit-level --resize <int>` can re-chunk a level to use a different
  chunk size than the default 128. Large chunk sizes 512+ lead to performance
  problems.

cmd/doodad/commands/edit_level.go

@@ -1,6 +1,7 @@
 package commands
 
 import (
+	"errors"
 	"fmt"
 
 	"git.kirsle.net/apps/doodle/pkg/level"
@@ -23,6 +24,11 @@ func init() {
 				Aliases: []string{"q"},
 				Usage:   "limit output (don't show doodad data at the end)",
 			},
+			&cli.StringFlag{
+				Name:    "output",
+				Aliases: []string{"o"},
+				Usage:   "write to a different output file than the input (especially for --resize)",
+			},
 			&cli.StringFlag{
 				Name:  "title",
 				Usage: "set the level title",
@@ -41,7 +47,11 @@ func init() {
 			},
 			&cli.StringFlag{
 				Name:  "max-size",
-				Usage: "set the page max size (WxH format, like 2550x3300)",
+				Usage: "set the bounded level page max size (WxH format, like 2550x3300)",
+			},
+			&cli.IntFlag{
+				Name:  "resize",
+				Usage: "change the chunk size, and re-encode the whole level into chunks of the new size",
 			},
 			&cli.StringFlag{
 				Name:  "wallpaper",
@@ -94,6 +104,11 @@ func editLevel(c *cli.Context, filename string) error {
 
 	log.Info("File: %s", filename)
 
+	// Migrating it to a different chunk size?
+	if c.Int("resize") > 0 {
+		return rechunkLevel(c, filename, lvl)
+	}
+
 	/***************************
 	* Update level properties *
 	***************************/
@@ -199,3 +214,45 @@ func editLevel(c *cli.Context, filename string) error {
 
 	return showLevel(c, filename)
 }
+
+// doodad edit-level --resize CHUNK_SIZE
+//
+// Handles the deep operation of re-copying the old level into a new level
+// at the new chunk size.
+func rechunkLevel(c *cli.Context, filename string, lvl *level.Level) error {
+	var chunkSize = c.Int("resize")
+	log.Info("Resizing the level's chunk size.")
+	log.Info("Current chunk size: %d", lvl.Chunker.Size)
+	log.Info("Target chunk size: %d", chunkSize)
+
+	if output := c.String("output"); output != "" {
+		filename = output
+		log.Info("Output file will be: %s", filename)
+	}
+
+	if chunkSize == lvl.Chunker.Size {
+		return errors.New("the level already has the target chunk size")
+	}
+
+	// Keep the level's current Chunker, and set a new one.
+	var oldChunker = lvl.Chunker
+	lvl.Chunker = level.NewChunker(chunkSize)
+
+	// Iterate all the Pixels of the old chunker.
+	log.Info("Copying pixels from old chunker into new chunker (this may take a while)...")
+	for pixel := range oldChunker.IterPixels() {
+		lvl.Chunker.Set(
+			pixel.Point(),
+			pixel.Swatch,
+		)
+	}
+
+	log.Info("Writing new data to filename: %s", filename)
+	if err := lvl.WriteFile(filename); err != nil {
+		log.Error(err.Error())
+	}
+
+	return showLevel(c, filename)
+
+	return nil
+}

pkg/editor_scene.go

@@ -521,25 +521,38 @@ func (s *EditorScene) SaveLevel(filename string) error {
 		log.Error("Error publishing level: %s", err.Error())
 	}
 
+	s.lastAutosaveAt = time.Now()
 	return m.WriteFile(filename)
 }
 
 // AutoSave takes an autosave snapshot of the level or drawing.
 func (s *EditorScene) AutoSave() error {
-	var filename = "_autosave.level"
+	var (
+		filename = "_autosave.level"
+		err      error
+	)
 
+	s.d.FlashError("Beginning AutoSave() in a background thread")
+
+	// Trigger the auto-save in the background to not block the main thread.
+	go func() {
+		var err error
 		switch s.DrawingType {
 		case enum.LevelDrawing:
+			err = s.Level.WriteFile(filename)
 			s.d.Flash("Automatically saved level to %s", filename)
-		return s.Level.WriteFile(filename)
 		case enum.DoodadDrawing:
 			filename = "_autosave.doodad"
-
+			err = s.Doodad.WriteFile(filename)
 			s.d.Flash("Automatically saved doodad to %s", filename)
-		return s.Doodad.WriteFile(filename)
 		}
 
-	return nil
+		if err != nil {
+			s.d.FlashError("Error saving %s: %s", filename, err)
+		}
+	}()
+
+	return err
 }
 
 // LoadDoodad loads a doodad from disk.

pkg/editor_ui.go

@@ -407,7 +407,6 @@ func (u *EditorUI) SetupCanvas(d *Doodle) *uix.Canvas {
 			for _, actor := range actors {
 				u.Scene.Level.Actors.Remove(actor.Actor)
 			}
-			u.Scene.Level.PruneLinks()
 			drawing.InstallActors(u.Scene.Level.Actors)
 		}
 	}

pkg/level/chunk.go

@@ -35,7 +35,9 @@ type Chunk struct {
 	texture            render.Texturer
 	textureMasked      render.Texturer
 	textureMaskedColor render.Color
-	dirty              bool
+
+	dirty    bool // Chunk is changed and needs textures redrawn
+	modified bool // Chunk is changed and is held in memory til next Zipfile save
 }
 
 // JSONChunk holds a lightweight (interface-free) copy of the Chunk for
@@ -240,17 +242,35 @@ func (c *Chunk) Teardown() int {
 }
 
 // Set proxies to the accessor and flags the texture as dirty.
+//
+// It also marks the chunk as "Modified" so it will be kept in memory until the drawing
+// is next saved to disk and the chunk written out to the zipfile.
 func (c *Chunk) Set(p render.Point, sw *Swatch) error {
 	c.dirty = true
+	c.modified = true
 	return c.Accessor.Set(p, sw)
 }
 
-// Delete proxies to the accessor and flags the texture as dirty.
+// Delete proxies to the accessor and flags the texture as dirty and marks the chunk "Modified".
 func (c *Chunk) Delete(p render.Point) error {
 	c.dirty = true
+	c.modified = true
 	return c.Accessor.Delete(p)
 }
 
+/*
+IsModified returns the chunk's Modified flag. This is most likely to occur in the Editor when
+the user is drawing onto the level. Modified chunks are not unloaded from memory ever, until
+they can be saved back to disk in the Zipfile format. During regular gameplay, chunks are
+loaded and unloaded as needed.
+
+The modified flag is flipped on Set() or Delete() and is never unflipped. On file save,
+the Chunker is reloaded from scratch to hold chunks cached from zipfile members.
+*/
+func (c *Chunk) IsModified() bool {
+	return c.modified
+}
+
 // Rect returns the bounding coordinates that the Chunk has pixels for.
 func (c *Chunk) Rect() render.Rect {
 	// Lowest and highest chunks.

pkg/level/chunker.go

@@ -432,10 +432,18 @@ func (c *Chunker) FreeChunk(p render.Point) bool {
 		return false
 	}
 
+	// If this chunk has been modified since it was last loaded from ZIP, hang onto it
+	// in memory until the next save so we don't lose it.
+	if chunk, ok := c.Chunks[p]; ok {
+		if chunk.IsModified() {
+			return false
+		}
+
 		// Don't delete empty chunks, hang on until next zipfile save.
 		if chunk, ok := c.Chunks[p]; ok && chunk.Len() == 0 {
 			return false
 		}
+	}
 
 	delete(c.Chunks, p)
 	return true

pkg/level/chunker_zipfile.go

@@ -204,3 +204,13 @@ func ChunksInZipfile(zf *zip.Reader, layer int) []render.Point {
 
 	return result
 }
+
+// ChunkInZipfile tests whether the chunk exists in the zipfile.
+func ChunkInZipfile(zf *zip.Reader, layer int, coord render.Point) bool {
+	for _, chunk := range ChunksInZipfile(zf, layer) {
+		if chunk == coord {
+			return true
+		}
+	}
+	return false
+}

pkg/play_scene.go

@@ -395,6 +395,14 @@ func (s *PlayScene) setupPlayer(playerCharacterFilename string) {
 	}
 
 	s.installPlayerDoodad(playerCharacterFilename, spawn, centerIn)
+
+	// Scroll the level canvas to center on the start point.
+	scroll := render.Point{
+		X: -(spawn.X - (s.d.width / 2)),
+		Y: -(spawn.Y - (s.d.height / 2)),
+	}
+	log.Info("Scrolling level viewport to spawn (%s) location: %s", spawn, scroll)
+	s.drawing.ScrollTo(scroll)
 }
 
 // Load and install the player doodad onto the level.

pkg/uix/canvas_editable.go

@@ -517,15 +517,6 @@ func (w *Canvas) loopEditable(ev *event.State) error {
 		var WP = w.WorldIndexAt(cursor)
 
 		for _, actor := range w.actors {
-			// Permanently color the actor if it's the current subject of the
-			// Link Tool (after 1st click, until 2nd click of other actor)
-			if w.linkFirst == actor {
-				actor.Canvas.Configure(ui.Config{
-					Background: render.RGBA(255, 153, 255, 153),
-				})
-				continue
-			}
-
 			// Compute the bounding box on screen where this doodad
 			// visually appears.
 			var scrollBias = render.Point{
@@ -567,6 +558,14 @@ func (w *Canvas) loopEditable(ev *event.State) error {
 				actor.Canvas.SetBorderSize(0)
 				actor.Canvas.SetBackground(render.RGBA(0, 0, 1, 0)) // TODO
 			}
+
+			// Permanently color the actor if it's the current subject of the
+			// Link Tool (after 1st click, until 2nd click of other actor)
+			if w.linkFirst == actor {
+				actor.Canvas.Configure(ui.Config{
+					Background: render.RGBA(255, 153, 255, 153),
+				})
+			}
 		}
 	}
 

pkg/uix/canvas_link_tool.go

@@ -4,16 +4,10 @@ import (
 	"errors"
 	"sort"
 
-	"git.kirsle.net/apps/doodle/pkg/drawtool"
+	"git.kirsle.net/apps/doodle/pkg/log"
 	"git.kirsle.net/apps/doodle/pkg/shmem"
 )
 
-// LinkStart initializes the Link tool.
-func (w *Canvas) LinkStart() {
-	w.Tool = drawtool.LinkTool
-	w.linkFirst = nil
-}
-
 // LinkAdd adds an actor to be linked in the Link tool.
 func (w *Canvas) LinkAdd(a *Actor) error {
 	if w.linkFirst == nil {
@@ -22,6 +16,10 @@ func (w *Canvas) LinkAdd(a *Actor) error {
 		shmem.Flash("Doodad '%s' selected, click the next Doodad to link it to",
 			a.Doodad().Title,
 		)
+	} else if w.linkFirst == a {
+		// Clicked the same doodad twice, deselect it.
+		shmem.Flash("De-selected the doodad for linking.")
+		w.linkFirst = nil
 	} else {
 		// Second click, call the OnLinkActors handler with the two actors.
 		if w.OnLinkActors != nil {
@@ -66,3 +64,39 @@ func (w *Canvas) GetLinkedActors(a *Actor) []*Actor {
 	}
 	return result
 }
+
+// PrintLinks is a debug function that describes all actor links to console.
+func (w *Canvas) PrintLinks() {
+	log.Error("### BEGIN Canvas.PrintLinks() ###")
+
+	// Map all of the actors by their IDs so we can look them up from their links
+	var actors = map[string]*Actor{}
+	for _, actor := range w.actors {
+		actors[actor.ID()] = actor
+	}
+
+	for _, actor := range w.actors {
+		var id = actor.ID()
+		if len(id) > 8 {
+			id = id[:8]
+		}
+
+		if len(actor.Actor.Links) > 0 {
+			log.Info("Actor %s (%s) at %s has %d links:", id, actor.Actor.Filename, actor.Position(), len(actor.Actor.Links))
+			for _, link := range actor.Actor.Links {
+				if otherActor, ok := actors[link]; ok {
+					var linkId = link
+					if len(linkId) > 8 {
+						linkId = linkId[:8]
+					}
+
+					log.Info("\tTo %s (%s) at %s", linkId, otherActor.Actor.Filename, otherActor.Position())
+				} else {
+					log.Error("\tTo unknown actor ID %s!", link)
+				}
+			}
+		}
+	}
+
+	log.Error("### END Canvas.PrintLinks() ###")
+}