Technical Doodad: Checkpoint Region

The Checkpoint Region acts as an invisible checkpoint flag, remembering
the player's location should they need to respawn there.

New cheat: `show all actors` during Play Mode will make every hidden
actor visible. Useful to see your technical doodads during gameplay!

Developer shell: `Execute(command string)` is available to the
JavaScript interpreter. It simulates another command being run on the
developer console.

dev-assets/doodads/regions/Makefile

@@ -6,6 +6,10 @@ build:
 	doodad convert -t "Goal Region" goal-128.png reg-goal.doodad
 	doodad install-script goal.js reg-goal.doodad
 
+	# Checkpoint Region
+	doodad convert -t "Checkpoint Region" checkpoint-128.png reg-checkpoint.doodad
+	doodad install-script checkpoint.js reg-checkpoint.doodad
+
 	# Fire Region
 	doodad convert -t "Fire Region" fire-128.png reg-fire.doodad
 	doodad install-script fire.js reg-fire.doodad

dev-assets/doodads/regions/checkpoint.js

@@ -0,0 +1,38 @@
+// Checkpoint Region
+// Acts like an invisible checkpoint flag.
+var isCurrentCheckpoint = false;
+
+function main() {
+    Self.Hide();
+    setActive(false);
+
+    // Checkpoints broadcast to all of their peers so they all
+    // know which one is the most recently activated.
+    Message.Subscribe("broadcast:checkpoint", function (currentID) {
+        setActive(false);
+    });
+
+    Events.OnCollide(function (e) {
+        if (isCurrentCheckpoint || !e.Settled) {
+            return;
+        }
+
+        // Only care about the player character.
+        if (!e.Actor.IsPlayer()) {
+            return;
+        }
+
+        // Set the player checkpoint.
+        SetCheckpoint(Self.Position());
+        setActive(true);
+        Message.Broadcast("broadcast:checkpoint", Self.ID())
+    });
+}
+
+function setActive(v) {
+    if (v && !isCurrentCheckpoint) {
+        Flash("Checkpoint!");
+    }
+
+    isCurrentCheckpoint = v;
+}

pkg/cheats.go

@@ -1,6 +1,8 @@
 package doodle
 
-import "git.kirsle.net/apps/doodle/pkg/balance"
+import (
+	"git.kirsle.net/apps/doodle/pkg/balance"
+)
 
 // cheatCommand is a subroutine of the Command.Run() method of the Doodle
 // developer shell (commands.go). It looks for special cheat codes entered
@@ -68,6 +70,16 @@ func (c Command) cheatCommand(d *Doodle) bool {
 			d.Flash("Use this cheat in Play Mode to disable clipping for the player character.")
 		}
 
+	case "show all actors":
+		if isPlay {
+			for _, actor := range playScene.drawing.Actors() {
+				actor.Show()
+			}
+			d.Flash("All invisible actors made visible.")
+		} else {
+			d.Flash("Use this cheat in Play Mode to show hidden actors, such as technical doodads.")
+		}
+
 	case "give all keys":
 		if isPlay {
 			playScene.Player.AddItem("key-red.doodad", 0)

pkg/shell.go

@@ -77,6 +77,7 @@ func NewShell(d *Doodle) Shell {
 	// Make the Doodle instance available to the shell.
 	bindings := map[string]interface{}{
 		"d":       d,
+		"Execute": s.Execute,
 		"RGBA":    render.RGBA,
 		"Point":   render.NewPoint,
 		"Rect":    render.NewRect,