Add elytra flying support and rocket support (#3163)

* Add elytra flying support and rocket support

* Add example and docs

* Elytra and firework handling moved to entities

* Add support for older versions and add test

* Documentation

* Bump deps

* Bump mc data

* Update package.json

---------

Co-authored-by: Romain Beaumont <romain.rom1@gmail.com>

Author: lkwilson

docs/api.md

@@ -136,6 +136,7 @@
       - [bot.foodSaturation](#botfoodsaturation)
       - [bot.oxygenLevel](#botoxygenlevel)
       - [bot.physics](#botphysics)
+      - [bot.fireworkRocketDuration](#botfireworkrocketduration)
       - [bot.simpleClick.leftMouse (slot)](#botsimpleclickleftmouse-slot)
       - [bot.simpleClick.rightMouse (slot)](#botsimpleclickrightmouse-slot)
       - [bot.time.doDaylightCycle](#bottimedodaylightcycle)
@@ -197,6 +198,7 @@
       - ["entityEquip" (entity)](#entityequip-entity)
       - ["entitySleep" (entity)](#entitysleep-entity)
       - ["entitySpawn" (entity)](#entityspawn-entity)
+      - ["entityElytraFlew" (entity)](#entityelytraflew-entity)
       - ["itemDrop" (entity)](#itemdrop-entity)
       - ["playerCollect" (collector, collected)](#playercollect-collector-collected)
       - ["entityGone" (entity)](#entitygone-entity)
@@ -223,6 +225,7 @@
       - ["blockBreakProgressEnd" (block, entity)](#blockbreakprogressend-block-entity)
       - ["diggingCompleted" (block)](#diggingcompleted-block)
       - ["diggingAborted" (block)](#diggingaborted-block)
+      - ["usedFirework"](#usedfirework)
       - ["move"](#move)
       - ["forcedMove"](#forcedmove)
       - ["mount"](#mount)
@@ -293,6 +296,7 @@
       - [bot.unequip(destination)](#botunequipdestination)
       - [bot.tossStack(item)](#bottossstackitem)
       - [bot.toss(itemType, metadata, count)](#bottossitemtype-metadata-count)
+      - [bot.elytraFly()](#botelytrafly)
       - [bot.dig(block, [forceLook = true], [digFace])](#botdigblock-forcelook--true-digface)
       - [bot.stopDigging()](#botstopdigging)
       - [bot.digTime(block)](#botdigtimeblock)
@@ -1037,6 +1041,10 @@ Number in the range [0, 20] respresenting the number of water-icons known as oxy
 Edit these numbers to tweak gravity, jump speed, terminal velocity, etc.
 Do this at your own risk.
 
+#### bot.fireworkRocketDuration
+
+How many physics ticks worth of firework rocket boost are left.
+
 #### bot.simpleClick.leftMouse (slot)
 
 abstraction over `bot.clickWindow(slot, 0, 0)`
@@ -1301,6 +1309,10 @@ Fires when an attribute of an entity changes.
 #### "entityEquip" (entity)
 #### "entitySleep" (entity)
 #### "entitySpawn" (entity)
+#### "entityElytraFlew" (entity)
+
+An entity started elytra flying.
+
 #### "itemDrop" (entity)
 #### "playerCollect" (collector, collected)
 
@@ -1417,6 +1429,10 @@ This occurs whether the process was completed or aborted.
 
  * `block` - the block that still exists
 
+#### "usedfirework"
+
+Fires when the bot uses a firework while elytra flying.
+
 #### "move"
 
 Fires when the bot moves. If you want the current position, use
@@ -1851,6 +1867,11 @@ This function returns a `Promise`, with `void` as its argument once tossing is c
    to match any metadata
  * `count` - how many you want to toss. `null` is an alias for `1`.
 
+#### bot.elytraFly()
+
+This function returns a `Promise`, with `void` as its argument once activating
+elytra flight is complete. It will throw an Error if it fails.
+
 #### bot.dig(block, [forceLook = true], [digFace])
 
 This function returns a `Promise`, with `void` as its argument when the block is broken or you are interrupted.
@@ -1946,7 +1967,9 @@ Use fishing rod
 
 #### bot.activateItem(offHand=false)
 
-Activates the currently held item. This is how you eat, shoot bows, throw an egg, etc.
+Activates the currently held item. This is how you eat, shoot bows, throw an
+egg, activate firework rockets, etc.
+
 Optional parameter is `false` for main hand and `true` for off hand.
 
 #### bot.deactivateItem()

examples/elytra.js

@@ -0,0 +1,66 @@
+// This example will shoot the player that said "fire" in chat, when it is said in chat.
+const mineflayer = require('mineflayer')
+
+if (process.argv.length < 4 || process.argv.length > 6) {
+  console.log('Usage : node elytra.js <host> <port> [<name>] [<password>]')
+  process.exit(1)
+}
+
+const bot = mineflayer.createBot({
+  host: process.argv[2],
+  port: parseInt(process.argv[3]),
+  username: process.argv[4] ? process.argv[4] : 'elytraer',
+  password: process.argv[5]
+})
+
+bot.on('error', err => {
+  console.log(err)
+})
+
+bot.on('kicked', err => {
+  console.log(err)
+})
+
+bot.on('spawn', async function () {
+  bot.chat(`/give ${bot.username} minecraft:elytra`)
+  bot.chat(`/give ${bot.username} minecraft:firework_rocket 64`)
+
+  await sleep(1000)
+  const elytraItem = bot.inventory.slots.find(item => item?.name === 'elytra')
+  if (elytraItem == null) {
+    console.log('no elytra')
+    return
+  }
+  await bot.equip(elytraItem, 'torso')
+  const fireworkItem = bot.inventory.slots.find(item => item?.name === 'firework_rocket')
+  if (fireworkItem == null) {
+    console.log('no fireworks')
+    return
+  }
+  await bot.equip(fireworkItem, 'hand')
+})
+
+bot.on('chat', async (username, message) => {
+  if (message === 'fly') {
+    await bot.look(bot.entity.yaw, 50 * Math.PI / 180)
+    bot.setControlState('jump', true)
+    bot.setControlState('jump', false)
+    await sleep(50)
+
+    // try to fly
+    try {
+      await bot.elytraFly()
+    } catch (err) {
+      bot.chat(`Failed to fly: ${err}`)
+      return
+    }
+    await sleep(50)
+
+    // use rocket
+    bot.activateItem()
+  }
+})
+
+function sleep (ms) {
+  return new Promise(resolve => setTimeout(resolve, ms))
+}

index.d.ts

@@ -92,6 +92,8 @@ export interface BotEvents {
   entityEquip: (entity: Entity) => Promise<void> | void
   entitySleep: (entity: Entity) => Promise<void> | void
   entitySpawn: (entity: Entity) => Promise<void> | void
+  entityElytraFlew: (entity: Entity) => Promise<void> | void
+  usedFirework: () => Promise<void> | void
   itemDrop: (entity: Entity) => Promise<void> | void
   playerCollect: (collector: Entity, collected: Entity) => Promise<void> | void
   entityAttributes: (entity: Entity) => Promise<void> | void
@@ -164,6 +166,7 @@ export interface Bot extends TypedEmitter<BotEvents> {
   version: string
   entity: Entity
   entities: { [id: string]: Entity }
+  fireworkRocketDuration: number
   spawnPoint: Vec3
   game: GameState
   player: Player
@@ -260,6 +263,8 @@ export interface Bot extends TypedEmitter<BotEvents> {
 
   wake: () => Promise<void>
 
+  elytraFly: () => Promise<void>
+
   setControlState: (control: ControlState, state: boolean) => void
 
   getControlState: (control: ControlState) => boolean

lib/plugins/entities.js

@@ -358,6 +358,70 @@ function inject (bot) {
     }
   })
 
+  bot.fireworkRocketDuration = 0
+  function setElytraFlyingState (entity, elytraFlying) {
+    let startedFlying = false
+    if (elytraFlying) {
+      startedFlying = !entity.elytraFlying
+      entity.elytraFlying = true
+    } else if (entity.elytraFlying) {
+      entity.elytraFlying = false
+    }
+    if (bot.fireworkRocketDuration !== 0 && entity.id === bot.entity?.id && !elytraFlying) {
+      bot.fireworkRocketDuration = 0
+      knownFireworks.splice(0, knownFireworks.length)
+    }
+
+    if (startedFlying) {
+      bot.emit('entityElytraFlew', entity)
+    }
+  }
+
+  const knownFireworks = []
+  function handleBotUsedFireworkRocket (fireworkEntityId, fireworkInfo) {
+    if (knownFireworks.includes(fireworkEntityId)) return
+    knownFireworks.push(fireworkEntityId)
+    let flightDur = 1
+    if (fireworkInfo?.nbtData != null) {
+      let nbt = fireworkInfo.nbtData
+      if (nbt.type === 'compound' && nbt.value.Fireworks != null) {
+        nbt = nbt.value.Fireworks
+        if (nbt.type === 'compound' && nbt.value.Flight != null) {
+          nbt = nbt.value.Flight
+          if (nbt.type === 'int') {
+            flightDur += nbt.value
+          }
+        }
+      }
+    }
+    const baseDuration = 10 * flightDur
+    const randomDuration = Math.floor(Math.random() * 6) + Math.floor(Math.random() * 7)
+    bot.fireworkRocketDuration = baseDuration + randomDuration
+
+    bot.emit('usedFirework')
+  }
+
+  let fireworkEntityName
+  if (bot.supportFeature('fireworkNamePlural')) {
+    fireworkEntityName = 'fireworks_rocket'
+  } else if (bot.supportFeature('fireworkNameSingular')) {
+    fireworkEntityName = 'firework_rocket'
+  }
+
+  let fireworkMetadataIdx
+  let fireworkMetadataIsOpt
+  if (bot.supportFeature('fireworkMetadataVarInt7')) {
+    fireworkMetadataIdx = 7
+    fireworkMetadataIsOpt = false
+  } else if (bot.supportFeature('fireworkMetadataOptVarInt8')) {
+    fireworkMetadataIdx = 8
+    fireworkMetadataIsOpt = true
+  } else if (bot.supportFeature('fireworkMetadataOptVarInt9')) {
+    fireworkMetadataIdx = 9
+    fireworkMetadataIsOpt = true
+  }
+  const hasFireworkSupport = fireworkEntityName !== undefined && fireworkMetadataIdx !== undefined && fireworkMetadataIsOpt !== undefined
+
   bot._client.on('entity_metadata', (packet) => {
     // entity metadata
     const entity = fetchEntity(packet.entityId)
@@ -374,7 +438,25 @@ function inject (bot) {
       if (metas.sleeping_pos || metas.pose === 2) {
         bot.emit('entitySleep', entity)
       }
+
+      if (hasFireworkSupport && fireworkEntityName === entity.name && metas.attached_to_target !== undefined) {
+        // fireworkMetadataOptVarInt9 and later is implied by
+        // mcDataHasEntityMetadata, so no need to check metadata index and type
+        // (eg fireworkMetadataOptVarInt8)
+        if (metas.attached_to_target !== 0) {
+          const entityId = metas.attached_to_target - 1
+          if (entityId === bot.entity?.id) {
+            handleBotUsedFireworkRocket(entity.id, metas.fireworks_item)
+          }
+        }
+      }
+
       if (metas.shared_flags != null) {
+        if (bot.supportFeature('hasElytraFlying')) {
+          const elytraFlying = metas.shared_flags & 0x80
+          setElytraFlyingState(entity, Boolean(elytraFlying))
+        }
+
         if (metas.shared_flags & 2) {
           entity.crouching = true
           bot.emit('entityCrouch', entity)
@@ -396,16 +478,38 @@ function inject (bot) {
         bot.emit('entitySleep', entity)
       }
 
-      const bitField = packet.metadata.find(p => p.key === 0)
-      if (bitField === undefined) {
-        return
+      if (hasFireworkSupport && fireworkEntityName === entity.name) {
+        const attachedToTarget = packet.metadata.find(e => e.key === fireworkMetadataIdx)
+        if (attachedToTarget !== undefined) {
+          let entityId
+          if (fireworkMetadataIsOpt) {
+            if (attachedToTarget.value !== 0) {
+              entityId = attachedToTarget.value - 1
+            } // else, not attached to an entity
+          } else {
+            entityId = attachedToTarget.value
+          }
+          if (entityId !== undefined && entityId === bot.entity?.id) {
+            const fireworksItem = packet.metadata.find(e => e.key === (fireworkMetadataIdx - 1))
+            handleBotUsedFireworkRocket(entity.id, fireworksItem?.value)
+          }
+        }
       }
-      if ((bitField.value & 2) !== 0) {
-        entity.crouching = true
-        bot.emit('entityCrouch', entity)
-      } else if (entity.crouching) { // prevent the initial entity_metadata packet from firing off an uncrouch event
-        entity.crouching = false
-        bot.emit('entityUncrouch', entity)
+
+      const bitField = packet.metadata.find(p => p.key === 0)
+      if (bitField !== undefined) {
+        if (bot.supportFeature('hasElytraFlying')) {
+          const elytraFlying = bitField.value & 0x80
+          setElytraFlyingState(entity, Boolean(elytraFlying))
+        }
+
+        if ((bitField.value & 2) !== 0) {
+          entity.crouching = true
+          bot.emit('entityCrouch', entity)
+        } else if (entity.crouching) { // prevent the initial entity_metadata packet from firing off an uncrouch event
+          entity.crouching = false
+          bot.emit('entityUncrouch', entity)
+        }
       }
     }
   })

lib/plugins/physics.js

@@ -192,6 +192,44 @@ function inject (bot, { physicsEnabled, maxCatchupTicks }) {
 
   bot.physics = physics
 
+  function getEffectLevel (mcData, effectName, effects) {
+    const effectDescriptor = mcData.effectsByName[effectName]
+    if (!effectDescriptor) {
+      return 0
+    }
+    const effectInfo = effects[effectDescriptor.id]
+    if (!effectInfo) {
+      return 0
+    }
+    return effectInfo.amplifier + 1
+  }
+
+  bot.elytraFly = async () => {
+    if (bot.entity.elytraFlying) {
+      throw new Error('Already elytra flying')
+    } else if (bot.entity.onGround) {
+      throw new Error('Unable to fly from ground')
+    } else if (bot.entity.isInWater) {
+      throw new Error('Unable to elytra fly while in water')
+    }
+
+    const mcData = require('minecraft-data')(bot.version)
+    if (getEffectLevel(mcData, 'Levitation', bot.entity.effects) > 0) {
+      throw new Error('Unable to elytra fly with levitation effect')
+    }
+
+    const torsoSlot = bot.getEquipmentDestSlot('torso')
+    const item = bot.inventory.slots[torsoSlot]
+    if (item == null || item.name !== 'elytra') {
+      throw new Error('Elytra must be equip to start flying')
+    }
+    bot._client.write('entity_action', {
+      entityId: bot.entity.id,
+      actionId: 8,
+      jumpBoost: 0
+    })
+  }
+
   bot.setControlState = (control, state) => {
     assert.ok(control in controlState, `invalid control: ${control}`)
     assert.ok(typeof state === 'boolean', `invalid state: ${state}`)

package.json

@@ -21,7 +21,7 @@
   },
   "license": "MIT",
   "dependencies": {
-    "minecraft-data": "^3.37.0",
+    "minecraft-data": "^3.44.0",
     "minecraft-protocol": "^1.44.0",
     "prismarine-biome": "^1.1.1",
     "prismarine-block": "^1.17.0",
@@ -30,7 +30,7 @@
     "prismarine-entity": "^2.3.0",
     "prismarine-item": "^1.14.0",
     "prismarine-nbt": "^2.0.0",
-    "prismarine-physics": "^1.7.0",
+    "prismarine-physics": "^1.8.0",
     "prismarine-recipe": "^1.3.0",
     "prismarine-registry": "^1.5.0",
     "prismarine-windows": "^2.8.0",