Messages!

rooms/sample.tmj

@@ -96,6 +96,11 @@
                          "name":"interactEvent",
                          "type":"string",
                          "value":"show_message"
+                        }, 
+                        {
+                         "name":"messageText",
+                         "type":"string",
+                         "value":"I'm just a humble box!"
                         }],
                  "rotation":0,
                  "type":"",

src/game.js

@@ -1,6 +1,7 @@
 import Player from "./player.js"
 import Input from "./input.js"
 import Event from "./event.js"
+import Message from "./message.js"
 
 export default class Game {
   constructor(canvas) {
@@ -16,8 +17,10 @@ export default class Game {
     this.events = {
       "log_test": new Event("log_test", () => console.log("Log events work!")),
       "change_color": new Event("change_color", object => object.setProperty("color", "blue")),
-      "show_message": new Event("show_message", object => console.log("Message from " + object.name))
+      "show_message": new Event("show_message", object => this.message = new Message(this, object.getProperty("messageText")))
     }
+
+    this.message = null
   }
 
   triggerEvent(eventName, object) {
@@ -36,9 +39,13 @@ export default class Game {
     this.currentRoom.objects.forEach(roomObject => this.actors.push(roomObject))
   }
 
+  closeMessage(message) {
+    this.message = null
+  }
+
   loop(timestamp) {
     const dt = timestamp - this.timestamp
-    this.timestamp = timestamp
+    this.timestamp= timestamp
     this.tick(dt)
     this.draw()
 
@@ -46,13 +53,19 @@ export default class Game {
   }
 
   tick(dt) {
+    if (this.message) {
+      this.message?.tick(dt)
+    } else {
       this.actors.forEach(actor => actor.tick(dt))
       Object.values(this.events).forEach(e => e.nextFrame())
     }
+    this.input.tick()
+  }
 
   draw() {
     const { canvas, ctx } = this
     this.currentRoom.draw(ctx)
     this.actors.forEach(actor => actor.draw(ctx))
+    this.message?.draw(ctx)
   }
 }

src/input.js

@@ -12,11 +12,17 @@ export default class Input {
     this.inputsToKeys = Object.fromEntries(Object.keys(this.keysToInputs).map(key => [this.keysToInputs[key], key]))
 
     this.inputPressed = Object.fromEntries(Object.keys(this.inputsToKeys).map(key => [key, false]))
+    this.inputJustPressed = Object.fromEntries(Object.keys(this.inputsToKeys).map(key => [key, false]))
   }
 
   initialize() {
-    window.addEventListener("keydown", key => this.inputPressed[this.keyFromInput(key.key)] = true)
-    window.addEventListener("keyup", key => this.inputPressed[this.keyFromInput(key.key)] = false)
+    window.addEventListener("keydown", key => {
+      this.inputJustPressed[this.keyFromInput(key.key)] = true
+      this.inputPressed[this.keyFromInput(key.key)] = true
+    })
+    window.addEventListener("keyup", key => {
+      this.inputPressed[this.keyFromInput(key.key)] = false
+    })
     return this
   }
 
@@ -24,6 +30,14 @@ export default class Input {
     return !!this.inputPressed[inputName]
   }
 
+  isInputJustPressed(inputName) {
+    return !!this.inputJustPressed[inputName]
+  }
+
+  tick() {
+    this.inputJustPressed = Object.fromEntries(Object.keys(this.inputsToKeys).map(key => [key, false]))
+  }
+
   keyFromInput(input) {
     return this.keysToInputs[input]
   }

src/message.js

@@ -0,0 +1,47 @@
+export default class Message {
+  constructor(game, text) {
+    this.game = game
+    this.text = text
+    this.textColor = "white"
+    this.backgroundColor = "black"
+    this.textIndex = 0
+    this.textProgress = 0.0
+    this.textSpeed = 0.08 // seconds per character
+    this.backgroundHeight = 40
+    this.textSize = 30
+  }
+
+  tick(dt) {
+    this.textProgress += (dt / 1000.0) / this.textSpeed
+    this.textIndex = Math.floor(this.textProgress)
+
+    const ijp = this.game.input.isInputJustPressed("interact")
+    if (ijp) {
+      if (this.messageComplete()) {
+	this.game.closeMessage(this)
+      } else {
+	this.textProgress = this.text.length
+      }
+    }
+  }
+
+  draw(ctx) {
+    ctx.fillStyle = this.backgroundColor
+    ctx.fillRect(0, 0, ctx.canvas.width, this.backgroundHeight)
+    ctx.font = `bold ${this.textSize}px sans-serif`
+    ctx.textBaseline = "top"
+    ctx.fillStyle = this.textColor
+    ctx.fillText(this.text.substring(0, this.textIndex), 5, 5)
+    if (this.messageComplete()) {
+      ctx.fillRect(
+	ctx.canvas.width - 20, 
+	this.backgroundHeight - 20, 
+	10, 10
+      )
+    }
+  }
+
+  messageComplete() {
+    return this.textIndex >= this.text.length + 3
+  }
+}