Add bot API to handle experience updates

bot/event.go

@@ -18,6 +18,13 @@ type eventBroker struct {
 	PluginMessage  func(channel string, data []byte) error
 	HeldItemChange func(slot int) error
 
+	// ExperienceChange will be called every time player's experience level updates.
+	// Parameters:
+	//   bar - state of the experience bar from 0.0 to 1.0;
+	//   level - current level;
+	//   total - total amount of experience received from level 0.
+	ExperienceChange func(bar float32, level int32, total int32) error
+
 	WindowsItem       func(id byte, slots []entity.Slot) error
 	WindowsItemChange func(id byte, slotID int, slot entity.Slot) error
 

bot/ingame.go

@@ -130,6 +130,8 @@ func (c *Client) handlePacket(p pk.Packet) (disconnect bool, err error) {
 		err = handleSoundEffect(c, p)
 	case data.NamedSoundEffect:
 		err = handleNamedSoundEffect(c, p)
+	case data.SetExperience:
+		err = handleSetExperience(c, p)
 	default:
 		// fmt.Printf("ignore pack id %X\n", p.ID)
 	}
@@ -612,6 +614,26 @@ func handleWindowItemsPacket(c *Client, p pk.Packet) (err error) {
 	return c.Events.WindowsItem(byte(windowID), slots)
 }
 
+func handleSetExperience(c *Client, p pk.Packet) (err error) {
+	var (
+		bar   pk.Float
+		level pk.VarInt
+		total pk.VarInt
+	)
+
+	if err := p.Scan(&bar, &level, &total); err != nil {
+		return err
+	}
+
+	c.Level = int32(level)
+
+	if c.Events.ExperienceChange != nil {
+		return c.Events.ExperienceChange(float32(bar), int32(level), int32(total))
+	}
+
+	return nil
+}
+
 func sendPlayerPositionAndLookPacket(c *Client) {
 	c.conn.WritePacket(pk.Marshal(
 		data.PlayerPositionAndLookServerbound,

bot/world/entity/player/player.go

@@ -16,4 +16,6 @@ type Player struct {
 	Health         float32 //血量
 	Food           int32   //饱食度
 	FoodSaturation float32 //食物饱和度
+
+	Level int32
 }