name: wurst-tutorials description: WurstScript tutorials covering spell creation, legacy map migration, save/load systems, hot code reload, and advanced techniques

WurstScript Tutorials

Practical guides for common Warcraft III modding tasks.

Spell Creation

Basic Targeted Spell

package LightningBolt

import ClosureEvents
import DamageSystem

public constant LIGHTNING_BOLT_ID = 'A001'
constant DAMAGE = 150.
constant FX_PATH = "Abilities\\Spells\\Human\\Thunderclap\\ThunderclapCaster.mdl"

init
    EventListener.onTargetCast(LIGHTNING_BOLT_ID) (caster, target) ->
        flashEffect(FX_PATH, target.getPos())
        caster.damageTarget(target, DAMAGE, ATTACK_TYPE_MAGIC)

Area of Effect Spell

package NovaSpell

import ClosureEvents
import ClosureForGroups
import DamageSystem

public constant NOVA_ID = 'A002'
constant DAMAGE = 100.
constant RADIUS = 300.

init
    EventListener.onCast(NOVA_ID) caster ->
        let pos = caster.getPos()
        flashEffect("Abilities\\Spells\\Undead\\FrostNova\\FrostNovaTarget.mdl", pos)
        
        forUnitsInRange(pos, RADIUS) target ->
            if target.isEnemyOf(caster.getOwner()) and target.isAlive()
                caster.damageTarget(target, DAMAGE, ATTACK_TYPE_MAGIC)

Channeled/Timed Spell

package RainOfFire

import ClosureEvents
import ClosureTimers
import ClosureForGroups

public constant RAIN_OF_FIRE_ID = 'A003'
constant TICK_DAMAGE = 25.
constant RADIUS = 200.
constant DURATION = 5.
constant TICK_INTERVAL = 0.5

init
    EventListener.onPointCast(RAIN_OF_FIRE_ID) (caster, targetPos) ->
        var elapsed = 0.
        
        doPeriodically(TICK_INTERVAL) cb ->
            elapsed += TICK_INTERVAL
            
            flashEffect("Abilities\\Spells\\Demon\\RainOfFire\\RainOfFireTarget.mdl", targetPos)
            
            forUnitsInRange(targetPos, RADIUS) u ->
                if u.isEnemyOf(caster.getOwner())
                    caster.damageTarget(u, TICK_DAMAGE)
            
            if elapsed >= DURATION
                destroy cb

Projectile Spell

package Fireball

import ClosureEvents
import ClosureTimers
import DamageSystem

public constant FIREBALL_ID = 'A004'
constant SPEED = 800.
constant DAMAGE = 200.
constant COLLISION = 80.

init
    EventListener.onPointCast(FIREBALL_ID) (caster, targetPos) ->
        let startPos = caster.getPos()
        let direction = startPos.angleTo(targetPos)
        var currentPos = startPos
        
        let fx = addEffect("Abilities\\Weapons\\RedDragonBreath\\RedDragonMissile.mdl", startPos)
            ..setYaw(direction)
        
        doPeriodically(0.03) cb ->
            currentPos = currentPos.polarOffset(direction, SPEED * 0.03)
            fx.setPos(currentPos)
            
            // Check collision
            let hit = findNearestEnemy(currentPos, COLLISION, caster.getOwner())
            if hit != null
                flashEffect("Abilities\\Spells\\Other\\Incinerate\\IncinerateBuff.mdl", currentPos)
                caster.damageTarget(hit, DAMAGE, ATTACK_TYPE_MAGIC)
                fx.destr()
                destroy cb
            else if currentPos.distanceTo(startPos) > 1200
                fx.destr()
                destroy cb

Legacy Map Migration

Working with Existing Jass Maps

1. Create wurst project in map's directory
2. Keep existing Jass - Wurst compiles alongside
3. Gradually migrate code to Wurst packages

Calling Jass from Wurst

package Interop

// Call existing Jass functions directly
native MyJassFunction takes integer i returns nothing

// Reference Jass globals
@extern var myJassGlobal: int

init
    MyJassFunction(5)
    myJassGlobal = 10

Migrating Triggers

// Old Jass trigger
// function Trig_Init_Actions takes nothing returns nothing
//     call DisplayTimedTextToPlayer(...)
// endfunction

// Wurst equivalent
package MigratedTrigger

init
    CreateTrigger()
        ..registerAnyUnitEvent(EVENT_PLAYER_UNIT_DEATH)
        ..addAction() ->
            let dying = GetTriggerUnit()
            // trigger logic

vJass to Wurst

Save/Load System

Basic Save System

package SaveLoad

import Serialization
import StringUtils
import FileIO

constant SAVE_FILENAME = "MyMapSave"

public class PlayerData
    int level
    int gold
    int array[6] items
    
    function serialize() returns string
        var data = level.toString() + "|"
        data += gold.toString() + "|"
        for i = 0 to 5
            data += items[i].toString() + "|"
        return data
    
    static function deserialize(string data) returns PlayerData
        let parts = data.split("|")
        let pd = new PlayerData()
        pd.level = parts.get(0).toInt()
        pd.gold = parts.get(1).toInt()
        for i = 0 to 5
            pd.items[i] = parts.get(i + 2).toInt()
        return pd

public function savePlayer(player p, PlayerData data)
    let encoded = data.serialize()
    // Add checksum/encryption here
    FileIO.write(SAVE_FILENAME + p.getId().toString(), encoded)

public function loadPlayer(player p) returns PlayerData
    let content = FileIO.read(SAVE_FILENAME + p.getId().toString())
    if content != null and content != ""
        return PlayerData.deserialize(content)
    return new PlayerData()

Codeless Save (Hash-based)

package CodeSave

import Charsets

// Generate save code from data
public function generateCode(int level, int gold, int checksum) returns string
    var code = ""
    code += encodeValue(level, 2)
    code += encodeValue(gold, 4)
    code += encodeValue(checksum, 2)
    return code

function encodeValue(int value, int digits) returns string
    var result = ""
    var remaining = value
    for i = 0 to digits - 1
        let digit = remaining mod CHARSET.length()
        result = CHARSET.charAt(digit) + result
        remaining = remaining div CHARSET.length()
    return result

Hot Code Reload (JHCR)

Setup

1. Install JHCR: https://github.com/lep/jhcr
2. Add to wurst.build:

buildMapData:
  jhcr: true

Usage

1. Run map normally
2. Edit code
3. Save file
4. Game reloads code automatically

Limitations

• Can't add new global variables
• Can't change class structures
• Function signatures must stay same
• Init blocks don't re-run

Hot-Reload Friendly Code

package HotReloadFriendly

// Use functions instead of init globals
function getDamageAmount() returns real
    return 100.  // Can change this value

// Config in functions
function setupSpell()
    EventListener.onCast(SPELL_ID) caster ->
        caster.damageTarget(target, getDamageAmount())

Common Patterns

Singleton Pattern

package MySingleton

public class GameManager
    private static GameManager instance = null
    
    static function getInstance() returns GameManager
        if instance == null
            instance = new GameManager()
        return instance
    
    private construct()
        // private constructor

Factory Pattern

package UnitFactory

interface UnitSpawner
    function spawn(vec2 pos) returns unit

class FootmanSpawner implements UnitSpawner
    override function spawn(vec2 pos) returns unit
        return createUnit(players[0], 'hfoo', pos, angle(0))

class KnightSpawner implements UnitSpawner
    override function spawn(vec2 pos) returns unit
        return createUnit(players[0], 'hkni', pos, angle(0))

Observer Pattern

package EventSystem

interface GameEventListener
    function onEvent(string eventType, int data)

let listeners = new LinkedList<GameEventListener>()

public function addListener(GameEventListener listener)
    listeners.add(listener)

public function fireEvent(string eventType, int data)
    for listener in listeners
        listener.onEvent(eventType, data)

State Machine

package StateMachine

enum UnitState
    IDLE
    MOVING
    ATTACKING
    DEAD

class StatefulUnit
    unit u
    UnitState state = IDLE
    
    function update()
        switch state
            case IDLE
                if hasTarget()
                    state = MOVING
            case MOVING
                moveToTarget()
                if inRange()
                    state = ATTACKING
            case ATTACKING
                attack()
                if targetDead()
                    state = IDLE
            case DEAD
                skip

Performance Tips

Avoid Leaks

// Bad - leaks group
forUnitsInRange(pos, 500) u ->
    // ...

// Good - use stdlib which handles cleanup
import ClosureForGroups
forUnitsInRange(pos, 500) u ->
    // properly cleaned up

Batch Operations

// Bad - many timer instances
for i = 0 to 100
    doAfter(1.0) ->
        doThing(i)

// Good - single timer
doPeriodically(0.03) cb ->
    // batch process

Object Pooling

class Projectile
    static LinkedList<Projectile> pool = new LinkedList<Projectile>()
    
    static function get() returns Projectile
        if pool.isEmpty()
            return new Projectile()
        return pool.pop()
    
    function release()
        pool.push(this)

Resources

• Full Tutorial List: https://wurstlang.org/tutorials.html
• Beginner Guide: https://wurstlang.org/tutorials/wurstbeginner.html
• Legacy Maps Guide: https://wurstlang.org/tutorials/legacymaps.html
• Discord: https://discord.gg/mSHZpWcadz