Make Fire Deadly

* Touching "fire" pixels in a level will pop up the End Level alert box
  saying you've died by fire and can restart the level.
* Update level.WriteFile() to prune broken links between actors before
  save. So when a linked actor is deleted, the leftover link data is
  cleaned up.
* Slight optimization in Canvas.drawStrokes: if either end of the stroke
  is not within view of the screen, don't show the stroke.

pkg/filesystem/filesystem.go

@@ -85,6 +85,11 @@ Returns the file path and an error if not found anywhere.
 func FindFile(filename string) (string, error) {
 	var filetype string
 
+	// If the filename has path separators, return it as-is.
+	if strings.ContainsRune(filename, filepath.Separator) {
+		return filename, nil
+	}
+
 	// Any hint on what type of file we're looking for?
 	if strings.HasSuffix(filename, enum.LevelExt) {
 		filetype = enum.LevelExt

pkg/level/fmt_maintenance.go

@@ -0,0 +1,35 @@
+package level
+
+import "git.kirsle.net/apps/doodle/pkg/log"
+
+// Maintenance functions for the file format on disk.
+
+// PruneLinks cleans up any Actor Links that can not be resolved in the
+// level data. For example, if actors were linked in Edit Mode and one
+// actor is deleted leaving a broken link.
+//
+// Returns the number of broken links pruned.
+//
+// This is called automatically in WriteFile.
+func (m *Level) PruneLinks() int {
+	var count int
+	for id, actor := range m.Actors {
+		var newLinks []string
+
+		for _, linkID := range actor.Links {
+			if _, ok := m.Actors[linkID]; !ok {
+				log.Warn("Level.PruneLinks: actor %s (%s) was linked to unresolved actor %s",
+					id,
+					actor.Filename,
+					linkID,
+				)
+				count++
+				continue
+			}
+			newLinks = append(newLinks, linkID)
+		}
+
+		actor.Links = newLinks
+	}
+	return count
+}

pkg/level/fmt_readwrite.go

@@ -104,6 +104,9 @@ func (m *Level) WriteFile(filename string) error {
 	m.Version = 1
 	m.GameVersion = branding.Version
 
+	// Maintenance functions, clean up cruft before save.
+	m.PruneLinks()
+
 	bin, err := m.ToJSON()
 	if err != nil {
 		return err

pkg/main_scene.go

@@ -6,7 +6,6 @@ import (
 	"git.kirsle.net/apps/doodle/lib/ui"
 	"git.kirsle.net/apps/doodle/pkg/balance"
 	"git.kirsle.net/apps/doodle/pkg/branding"
-	"git.kirsle.net/apps/doodle/pkg/filesystem"
 	"git.kirsle.net/apps/doodle/pkg/level"
 	"git.kirsle.net/apps/doodle/pkg/log"
 	"git.kirsle.net/apps/doodle/pkg/scripting"
@@ -89,19 +88,15 @@ func (s *MainScene) SetupDemoLevel(d *Doodle) error {
 		H: int32(d.height),
 	})
 
-	// Title screen level to load.
-	lvlName, _ := filesystem.FindFile("example1.level")
-	lvl, err := level.LoadJSON(lvlName)
-	if err != nil {
-		log.Error("Error loading title-screen.level: %s", err)
-	}
+	s.scripting = scripting.NewSupervisor()
+	s.canvas.SetScriptSupervisor(s.scripting)
 
+	// Title screen level to load.
+	if lvl, err := level.LoadFile("example1.level"); err == nil {
 		s.canvas.LoadLevel(d.Engine, lvl)
 		s.canvas.InstallActors(lvl.Actors)
 
 		// Load all actor scripts.
-	s.scripting = scripting.NewSupervisor()
-	s.canvas.SetScriptSupervisor(s.scripting)
 		if err := s.scripting.InstallScripts(lvl); err != nil {
 			log.Error("Error with title screen level scripts: %s", err)
 		}
@@ -110,6 +105,9 @@ func (s *MainScene) SetupDemoLevel(d *Doodle) error {
 		if err := s.canvas.InstallScripts(); err != nil {
 			log.Error("Error running actor main() functions: %s", err)
 		}
+	} else {
+		log.Error("Error loading title-screen.level: %s", err)
+	}
 
 	return nil
 }

pkg/play_scene.go

@@ -36,6 +36,7 @@ type PlayScene struct {
 	// The alert box shows up when the level goal is reached and includes
 	// buttons what to do next.
 	alertBox          *ui.Window
+	alertBoxLabel     *ui.Label
 	alertReplayButton *ui.Button // Replay level
 	alertEditButton   *ui.Button // Edit Level
 	alertNextButton   *ui.Button // Next Level
@@ -120,6 +121,7 @@ func (s *PlayScene) Setup(d *Doodle) error {
 	s.drawing.OnLevelCollision = func(a *uix.Actor, col *collision.Collide) {
 		if col.InFire {
 			a.Canvas.MaskColor = render.Black
+			s.DieByFire()
 		} else if col.InWater {
 			a.Canvas.MaskColor = render.DarkBlue
 		} else {
@@ -201,11 +203,11 @@ func (s *PlayScene) SetupAlertbox() {
 		 * Frame for selecting User Levels
 		 ******************/
 
-		label1 := ui.NewLabel(ui.Label{
+		s.alertBoxLabel = ui.NewLabel(ui.Label{
 			Text: "Congratulations on clearing the level!",
 			Font: balance.LabelFont,
 		})
-		frame.Pack(label1, ui.Pack{
+		frame.Pack(s.alertBoxLabel, ui.Pack{
 			Anchor: ui.N,
 			FillX:  true,
 			PadY:   16,
@@ -277,6 +279,24 @@ func (s *PlayScene) RestartLevel() {
 	})
 }
 
+// DieByFire ends the level by fire.
+func (s *PlayScene) DieByFire() {
+	log.Info("Watch out for fire!")
+	s.alertBox.Title = "You've died!"
+	s.alertBoxLabel.Text = "Watch out for fire!"
+
+	s.alertReplayButton.Show()
+	if s.CanEdit {
+		s.alertEditButton.Show()
+	}
+	s.alertExitButton.Show()
+
+	s.alertBox.Show()
+
+	// Stop the simulation.
+	s.running = false
+}
+
 // Loop the editor scene.
 func (s *PlayScene) Loop(d *Doodle, ev *events.State) error {
 	// Update debug overlay values.

pkg/uix/canvas_strokes.go

@@ -188,6 +188,24 @@ func (w *Canvas) drawStrokes(e render.Engine, strokes []*drawtool.Stroke) {
 	)
 
 	for _, stroke := range strokes {
+		// If none of this stroke is in our viewport, don't waste time
+		// looping through it.
+		if stroke.Shape == drawtool.Freehand {
+			if len(stroke.Points) >= 2 {
+				if !stroke.Points[0].Inside(VP) && !stroke.Points[len(stroke.Points)-1].Inside(VP) {
+					continue
+				}
+			}
+		} else {
+			// TODO: a very long line that starts and ends outside the viewport
+			// but passes thru it would disappear when both ends are out of
+			// view.
+			if !stroke.PointA.Inside(VP) && !stroke.PointB.Inside(VP) {
+				continue
+			}
+		}
+
+		// Iter the points and draw what's visible.
 		for point := range stroke.IterPoints() {
 			if !point.Inside(VP) {
 				continue