New Doodad: Anvil

* The Anvil doodad is affected by gravity and becomes dangerous when
  falling. If it lands on the player character, you die! If it lands on
  any other mobile doodad, it destroys it! It can land on solid doodads
  such as the Electric Trapdoor and the Crumbly Floor. It will activate
  a Crumbly Floor if it lands on one, and can activate buttons and
  switches that it passes.
* JavaScript API: FailLevel(message) can be called from a doodad to kill
  the player character. The Anvil does this if it collides with the
  player while it's been falling.

dev-assets/doodads/box/box.js

@@ -41,9 +41,6 @@ function main() {
     // When we receive power, we reset to our original position.
     var origPoint = Self.Position();
     Message.Subscribe("power", function (powered) {
-        console.error("Box received power! %+v", powered);
-        console.error("MoveTo: %+v", origPoint);
-        console.error("Keys: %+v", Object.keys(Self));
         Self.MoveTo(origPoint);
         Self.SetVelocity(Vector(0, 0));
     });

dev-assets/doodads/build.sh

@@ -58,6 +58,10 @@ objects() {
 	cd box/
 	make
 	cd ..
+
+	cd crumbly-floor/
+	make
+	cd ..
 }
 
 onoff() {

dev-assets/doodads/objects/Makefile

@@ -2,10 +2,16 @@ ALL: build
 
 .PHONY: build
 build:
+	# Start Flag
+	doodad convert -t "Start Flag" start-flag.png start-flag.doodad
+
+	# Exit Flag
 	doodad convert -t "Exit Flag" exit-flag.png exit-flag.doodad
 	doodad install-script exit-flag.js exit-flag.doodad
 
-	doodad convert -t "Start Flag" start-flag.png start-flag.doodad
+	# Anvil
+	doodad convert -t "Anvil" anvil.png anvil.doodad
+	doodad install-script anvil.js anvil.doodad
 
 	for i in *.doodad; do\
 		doodad edit-doodad --tag "category=objects" $${i};\

dev-assets/doodads/objects/anvil.js

@@ -0,0 +1,51 @@
+// Anvil
+var falling = false;
+
+function main() {
+    // Note: doodad is not "solid" but hurts if it falls on you.
+    Self.SetHitbox(0, 0, 48, 25);
+    Self.SetMobile(true);
+    Self.SetGravity(true);
+
+    // Monitor our Y position to tell if we've been falling.
+    var lastPoint = Self.Position();
+    setInterval(function () {
+        var nowAt = Self.Position();
+        if (nowAt.Y > lastPoint.Y) {
+            falling = true;
+        } else {
+            falling = false;
+        }
+        lastPoint = nowAt;
+    }, 100);
+
+    Events.OnCollide(function (e) {
+        if (!e.Settled) {
+            return;
+        }
+
+        // Were we falling?
+        if (falling) {
+            if (e.InHitbox) {
+                if (e.Actor.IsPlayer()) {
+                    // Fatal to the player.
+                    Sound.Play("crumbly-break.wav");
+                    FailLevel("Watch out for anvils!");
+                    return;
+                }
+                else if (e.Actor.IsMobile()) {
+                    // Destroy mobile doodads.
+                    Sound.Play("crumbly-break.wav");
+                    e.Actor.Destroy();
+                }
+            }
+        }
+    });
+
+    // When we receive power, we reset to our original position.
+    var origPoint = Self.Position();
+    Message.Subscribe("power", function (powered) {
+        Self.MoveTo(origPoint);
+        Self.SetVelocity(Vector(0, 0));
+    });
+}

dev-assets/doodads/switches/switch.js

@@ -13,7 +13,7 @@ function main() {
 	});
 
 	Events.OnCollide(function (e) {
-		if (!e.Settled) {
+		if (!e.Settled || !e.Actor.IsMobile()) {
 			return;
 		}
 

dev-assets/doodads/trapdoors/electric-trapdoor.js

@@ -49,6 +49,11 @@ function setPoweredState(powered) {
         Self.PlayAnimation("open", function () {
             isOpen = true;
             animating = false;
+
+            // Had we lost power quickly?
+            if (!powerState) {
+                setPoweredState(false);
+            }
         });
     } else {
         animating = true;

docs/Doodad Scripts.md

@@ -30,6 +30,7 @@ type API interface {
 
     // Game functions.k
     EndLevel()  // Exit the current level with a victory
+    FailLevel(message)
 
     /************************************
      * Event Handler Callback Functions *

pkg/play_scene.go

@@ -41,6 +41,7 @@ type PlayScene struct {
 	// buttons what to do next.
 	alertBox          *ui.Window
 	alertBoxLabel     *ui.Label
+	alertBoxValue     string
 	alertReplayButton *ui.Button // Replay level
 	alertEditButton   *ui.Button // Edit Level
 	alertNextButton   *ui.Button // Next Level
@@ -118,6 +119,29 @@ func (s *PlayScene) setupAsync(d *Doodle) error {
 		s.alertExitButton.Show()
 
 		// Show the alert box.
+		s.alertBox.Title = "Level Completed"
+		s.alertBoxValue = "Congratulations on clearing the level!"
+		s.alertBox.Show()
+	})
+	s.scripting.OnLevelFail(func(message string) {
+		d.Flash(message)
+
+		// Pause the simulation.
+		s.running = false
+
+		// Toggle the relevant buttons on.
+		if s.CanEdit {
+			s.alertEditButton.Show()
+		}
+		s.alertNextButton.Hide()
+
+		// Always-visible buttons.
+		s.alertReplayButton.Show()
+		s.alertExitButton.Show()
+
+		// Show the alert box.
+		s.alertBox.Title = "You've died!"
+		s.alertBoxValue = message
 		s.alertBox.Show()
 	})
 
@@ -310,7 +334,7 @@ func (s *PlayScene) SetupAlertbox() {
 		 ******************/
 
 		s.alertBoxLabel = ui.NewLabel(ui.Label{
-			Text: "Congratulations on clearing the level!",
+			TextVariable: &s.alertBoxValue,
 			Font:         balance.LabelFont,
 		})
 		frame.Pack(s.alertBoxLabel, ui.Pack{
@@ -390,7 +414,7 @@ func (s *PlayScene) RestartLevel() {
 func (s *PlayScene) DieByFire(name string) {
 	log.Info("Watch out for %s!", name)
 	s.alertBox.Title = "You've died!"
-	s.alertBoxLabel.Text = fmt.Sprintf("Watch out for %s!", name)
+	s.alertBoxValue = fmt.Sprintf("Watch out for %s!", name)
 
 	s.alertReplayButton.Show()
 	if s.CanEdit {

pkg/scripting/pubsub.go

@@ -19,6 +19,8 @@ This adds the global methods `Message.Subscribe(name, func)` and
 `Message.Publish(name, args)` to the JavaScript VM's scope.
 */
 func RegisterPublishHooks(s *Supervisor, vm *VM) {
+	log.Error("RegisterPublishHooks called with %+v %+v", s, vm)
+
 	// Goroutine to watch the VM's inbound channel and invoke Subscribe handlers
 	// for any matching messages received.
 	go func() {

pkg/scripting/scripting.go

@@ -17,6 +17,7 @@ type Supervisor struct {
 
 	// Global event handlers.
 	onLevelExit func()
+	onLevelFail func(message string)
 }
 
 // NewSupervisor creates a new JavaScript Supervior.

pkg/scripting/supervisor_events.go

@@ -10,14 +10,25 @@ Names registered:
 */
 func RegisterEventHooks(s *Supervisor, vm *VM) {
 	vm.Set("EndLevel", func() {
-		if s.onLevelExit == nil {
-			panic("JS EndLevel(): no OnLevelExit handler attached to script supervisor")
+		if s.onLevelFail == nil {
+			panic("JS FailLevel(): No OnLevelFail handler attached to script supervisor")
 		}
 		s.onLevelExit()
 	})
+	vm.Set("FailLevel", func(message string) {
+		if s.onLevelFail == nil {
+			panic("JS FailLevel(): No OnLevelFail handler attached to script supervisor")
+		}
+		s.onLevelFail(message)
+	})
 }
 
 // OnLevelExit registers an event hook for when a Level Exit doodad is reached.
 func (s *Supervisor) OnLevelExit(handler func()) {
 	s.onLevelExit = handler
 }
+
+// OnLevelFail registers an event hook for level failures (doodads killing the player).
+func (s *Supervisor) OnLevelFail(handler func(string)) {
+	s.onLevelFail = handler
+}

pkg/uix/actor_collision.go

@@ -207,6 +207,7 @@ func (w *Canvas) loopActorCollision() error {
 							// Are they on top?
 							aHitbox := collision.SizePlusHitbox(collision.GetBoundingRect(a), a.Hitbox())
 							if render.AbsInt(test.Y+test.H-aHitbox.Y) == 0 {
+								// log.Error("ActorCollision: onTop=true at Y=%s", test.Y)
 								onTop = true
 								onTopY = test.Y
 							}
@@ -217,6 +218,7 @@ func (w *Canvas) loopActorCollision() error {
 									lockY = lastGoodBox.Y
 								}
 								if onTop {
+									// log.Error("ActorCollision: setGrounded(true)", test.Y)
 									b.SetGrounded(true)
 								}
 							}