pong: reset counter on idle and increase idle length

src/pong.ts

@@ -45,6 +45,7 @@ class Paddle {
     isLeft: boolean;
     score: number;
     dy: number;
+    idleCounter: number;
 
     constructor(_geometry: Box, _isLeft: boolean) {
         this.geometry = _geometry;
@@ -53,6 +54,7 @@ class Paddle {
         this.isBot = true;
         this.score = 0;
         this.dy = 0;
+        this.idleCounter = 0;
     }
 
     scored() {
@@ -81,13 +83,13 @@ class PongCore {
         this.grid = 15; // size of grid squares
         this.paddleHeight = this.grid * 5;
         this.paddleHeightMax = this.canvas.height - this.grid - this.paddleHeight;
-        this.timeout = 32; // speed in ms
+        this.timeout = 4; // speed in ms
         this.width = this.canvas.width;
         this.height = this.canvas.height;
         this.gameover = false;
         this.paddleSpeed = 6;
         this.ball = new Ball(new Box(this.width / 2, this.height / 2, this.grid, this.grid));
-        this.left = new Paddle(new Box(this.width / 2, this.height / 2 - this.paddleHeight / 2, this.grid, this.paddleHeight), true);
+        this.left = new Paddle(new Box(this.grid * 2, this.height / 2 - this.paddleHeight / 2, this.grid, this.paddleHeight), true);
         this.right = new Paddle(new Box(this.width - this.grid * 3, this.height / 2 - this.paddleHeight / 2, this.grid, this.paddleHeight), false);
     }
 
@@ -122,8 +124,13 @@ class PongCore {
 
     // Simulate game logic
     simulate() {
-        this.botInput(this.left);
-        this.botInput(this.right);
+        if (this.ball.dx < 0) {
+            this.botInput(this.left);
+            this.botIdle(this.right);
+        } else {
+            this.botInput(this.right);
+            this.botIdle(this.left);
+        }
 
         // move paddles by their velocity
         this.left.geometry.y += this.left.dy;
@@ -246,6 +253,27 @@ class PongCore {
         if (ballRegion > paddleRegion) player.dy = player.speed; 
         if (ballRegion === paddleRegion) player.dy = 0; 
     }
+
+    // Randomly move the bot paddle when ball not towards it
+    botIdle(player: Paddle) {
+        player.idleCounter++;
+        if (player.idleCounter < 20)
+            return;
+        else
+            player.idleCounter = 0;
+        let direction: number = Math.floor(Math.random() * 3);
+        switch (direction) {
+            case 0:
+                player.dy = 0;
+                break;
+            case 1:
+                player.dy = -player.speed;
+                break;
+            case 2:
+                player.dy = player.speed;
+                break;
+        }
+    }
 }
 
 // listen to keyboard events to move the paddles