Plants vs. Zombies Online Battle
Introduction
This project adds the multiplayer battle to Plants vs. Zombies via reverse engineering, inline hook and dynamic-link library injection. Two online players can defend and attack as Plant and Zombie respectively.
Getting Started
Prerequisites
Building
Set the location to the project folder and run:
mkdir -p build
cd build
cmake .. -G "Visual Studio 17 2022" -A Win32
cmake --build .
Two dynamic-link libraries plant.dll and zombie.dll will be generated in build/bin folder. Copy them to the game root folder.
IPv6
The default IP version is IPv4. Enable the following statement in libs/game/CMakeLists.txt if you want to build IPv6 libraries.
target_compile_definitions(game PRIVATE INET6=1)
Usage
The project only works with Plants vs. Zombies 1.0.0.1051 CHINESE version, provided in game folder.
The MD5 of PlantsVsZombies.exe is 37B729B4056131722A556E646AC915E9.
In order to activate online functions, plant.dll and zombie.dll must be injected into the game when it starts. You can directly use this simple injection tool: Dll-Injector.
Playing as Plant
If a player plays as the plant, the game will launch as a server.
Dll-Injector -f PlantsVsZombies.exe plant.dll
Or use Start-OnlineGame.ps1 directly. It needs to be copied to the game root folder.
Start-OnlineGame.ps1 -Role Plant
Start I, Zombie Endless level, the game will pause and wait for a client to connect.
Playing as Zombie
If a player plays as the zombie, the game will launch as a client.
Dll-Injector -f PlantsVsZombies.exe zombie.dll
Or use Start-OnlineGame.ps1.
Start-OnlineGame.ps1 -Role Zombie
Start I, Zombie Endless level, the game will try to connect to the server.
I, Zombie Endless
If the modification has been loaded successfully, I, Zombie Endless level will be converted into an online level. If your current progress does not have this level, you can copy game/userdata to C:\ProgramData\PopCap Games\PlantsVsZombies\userdata. Remember to back up your own save-files before copying.
In the Chinese version of the game, you can start this level as follows:
-
Select “解谜模式”, which means “Puzzle” in English.
-
Select “我是僵尸无尽版”, the final level. It is “I, Zombie Endless” in English.
-
The game will display a dialog box shown as below. Select “继续”, the left button, meaning “Continue” in English.
Before starting an online battle, the progress of this level must be empty. Otherwise the battlefields of two online players will be different. If that happens, you need to restart the game without the modification, enter this level again but select “新游戏”, the right button, to reset the progress. It means “New Game”.
Configurations
Copy online_config.ini to the game root folder. You can set the server’s IP address and port number in it.
[Network]
ServerIP=127.0.0.1
Port=10000
Documents
The code comment style follows the Doxygen specification.
docs/Key Data and Functions.md describes key data and functions obtained by reverse engineering.
Class Diagram
classDiagram
namespace state {
class Role {
<<enumeration>>
Plante
Zombie
}
class Config {
vector~int~ zombies
vector~int~ plants
string server_ip
int port
}
class State
}
State --> Role
State --> Config
State --> TcpSocket
namespace network {
class IpAddr {
<<interface>>
Version() int
}
class Ipv4Addr
class Ipv6Addr
class Socket {
SetAddr(IpAddr)
Bind()
Close()
}
class TcpSocket {
<<>>
Connect(IpAddr)
Send(data) size
Recv(buffer) size
}
class Listener {
Bind(IpAddr)
Listen()
Accept() TcpSocket
Close()
}
class Packet {
Recv(TcpSocket)$ Packet
Send(TcpSocket)
Write(data) size
Read() data
}
}
IpAddr <|.. Ipv4Addr
IpAddr <|.. Ipv6Addr
Socket --> IpAddr
Socket <|-- TcpSocket
Listener --> TcpSocket
Packet ..> TcpSocket
class Mod {
<<interface>>
Enable()
Disable()
}
class ModLoader {
Add(Mod)
Load()
}
ModLoader o-- Mod
class RemoveDefaultPlants
Mod <|.. RemoveDefaultPlants
class SetSunAmount
Mod <|.. SetSunAmount
class Hook {
<<interface>>
#From() address
#To() address
#JumpRet() optional~address~
}
Mod <|-- Hook
class BeforeLoadLevel
Hook <|.. BeforeLoadLevel
BeforeLoadLevel ..> CreateZombie
BeforeLoadLevel ..> CreatePlant
BeforeLoadLevel ..> LevelEnd
BeforeLoadLevel ..> Listener
BeforeLoadLevel ..> State
class AfterLoadLevel
Hook <|.. AfterLoadLevel
AfterLoadLevel ..> RemoveDefaultPlants
AfterLoadLevel ..> InitSlots
class InitSlots
Hook <|.. InitSlots
InitSlots ..> State
class LevelEnd
Hook <|.. LevelEnd
LevelEnd ..> State
LevelEnd ..> Packet
class CreateZombie
Hook <|.. CreateZombie
CreateZombie ..> State
CreateZombie ..> Packet
class CreatePlant
Hook <|.. CreatePlant
CreatePlant ..> State
CreatePlant ..> Packet
class Startup {
Run()
Stop()
}
Startup --> ModLoader
Startup --> State
Issues & Bugs
- The game sometimes crashes when creating zombies.
- If the progress of I, Zombie Endless level is not empty, two players will have different battlefields.
- In order to simplify the code, the running menu and automatic pause are disabled.
License
Distributed under the MIT License. See LICENSE for more information.
评论