Help! Changing parameters whose classes are unknown and calling methods

[slaimmials]

im newbie in modding, dont kill me pls :)

First problem
I found the method I needed:

I hooked it:

int (*old_TakeDamageHook)(void *instance, void* attackResult);
int TakeDamageHook(void *instance, void* attackResult) {
    if (godmode) {
        //im stuck here, attackResult have a Field "Damage", how can i edit it?
    }
    return old_TakeDamageHook(instance, attackResult);
}

but I dont know how to change its parameters, because it is an unknown class.

Second problem

i need to call it, but how?
i tried this:

void (*DieHook)(void *instance) = (void (*)(void*))(0x12340B4);
DieHook();

but it doesnt work.

 

[Wxrnin]

Firstly, the "TakeDamage" method you can NOP it by HEX patching it. NOP will fully disable that method.

Secondly, for the "Die" method, you can hook it like this:

void (*Is_die)(void *instance);
void Die(void *instance) {
    if(instance!=nullptr) {
        if(IsDead) {
            Buy_vvip(instance);
            IsDead=false;  // because we only want to call the method once
        }
    }
    Is_die(instance);
}

Adding the hook with an update method is better and prefferable.