Hooking respawn

[arawra]

Want to make sure I am hooking the right function.

I have two other questions also. Does this take place every time a player spawns, or only at round start? I see that there is one parameter for RoundRespawn, but I'm not sure what it is and a quick google didn't pull anything up for me. For CS:Source, Allied Modders says there are no arguments.

Syntax: Select all

import memory

from memory import Convention, Argument, Return

from memory.hooks import PreHook

from basetypes import TakeDamageInfo

from core import PLATFORM

# Signature and symbol for CCSPlayer::RoundRespawn
if PLATFORM == 'windows':
    ON_PLAYER_SPAWN_IDENTIFIER = b'\x55\x8B\xEC\x83\xEC\x08\x56\x8B\xF1\x8B\x0D\x2A\x2A\x2A\x2A\x57'
else:
    ON_PLAYER_SPAWN_IDENTIFIER = '_ZN9CCSPlayer12RoundRespawnEv'     
    
# Get the server file
server = memory.find_binary('cstrike/bin/server')

# Search for the function pointer and convert it into a Function object
OnPlayerSpawn = server[ON_PLAYER_SPAWN_IDENTIFIER].make_function(
        Convention.THISCALL,
        (Argument.POINTER, Argument.POINTER),
        Return.VOID
        
# =============================================================================
# Functions
# =============================================================================

@PreHook(OnPlayerSpawn)
def pre_player_spawn(args):
    '''
    Called at round start OR whenever a player spawns?
    '''
    
    # Convert the second pointer to a Player? object
    player = memory.make_object(NotSureWhichObject, args[1])

    # Modify health?
    player.health += 20

[Ayuto]

I think that function is called whenever a players spawns. It's correct to say that the function does not take any arguments, but since it's a member function there is also a "this" pointer you have to count as an argument. (FYI: On Linux the "this" pointer is pushed onto the stack just like an argument. On Windows it's stored in the ECX register.)

So, you script should look ike this:

Syntax: Select all

import memory

from memory import Convention, Argument, Return
from memory.hooks import PreHook

from core import PLATFORM
from players.entity import PlayerEntity

# Signature and symbol for CCSPlayer::RoundRespawn
if PLATFORM == 'windows':
    ON_PLAYER_SPAWN_IDENTIFIER = b'\x55\x8B\xEC\x83\xEC\x08\x56\x8B\xF1\x8B\x0D\x2A\x2A\x2A\x2A\x57'
else:
    ON_PLAYER_SPAWN_IDENTIFIER = '_ZN9CCSPlayer12RoundRespawnEv'

# Get the server file
server = memory.find_binary('cstrike/bin/server')

# Search for the function pointer and convert it into a Function object
OnPlayerSpawn = server[ON_PLAYER_SPAWN_IDENTIFIER].make_function(
        Convention.THISCALL,
        (Argument.POINTER,),
        Return.VOID
    )

# =============================================================================
# Functions
# =============================================================================
@PreHook(OnPlayerSpawn)
def pre_player_spawn(args):
    '''
    Called whenever a player spawns.
    '''

    # If we would have reconstructed the CCSPlayer class you would do this:
    # player = make_object(CCSPlayer, args[0])
    
    player = PlayerEntity(index_from_pointer(args[0]))