Przejdź do treści

Hooking Daedalus

Daedalus hooking is one of the most powerful features of this plugin. Hooking is a mechanism that allows you to replace any scripted object with a new one. To do this, you must define a new object with the same type, name and in the same namespace.

Hook/replacement will be performed only if the MergeMode setting is set to true for the current script in the META block or in the parameter of the same name in the .ini file of the mod.

Warning

If you forget to turn on the MergeMode, the compilation will fail with the redefinition error.

When an object (instance, function or variable) is hooked/replaced, the original one is available under the same name with the _old suffix (PC_Hero -> PC_Hero_old). This allows you to refer to the old object.

Function hook example

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
func void ZS_Attack_Loop()
{
    // if the enemy is a player and has no weapon, then
    // also sheath the weapon.
    if (Npc_IsPlayer(other) && !Npc_HasReadiedWeapon(other))
    {
        return LOOP_END;
    };

    // otherwise call the original function
    return ZS_Attack_Loop_Old();
};

This kind of substitution works for instances and variables too.

Warning

While hooking an instances, you have to take care not to call the prototype. Prototype should be always changed back to the original class.

This is wrong
1
2
3
4
5
instance pc_hero(Npc_Default)
{
    pc_hero_old();
    name = "Pepe";
};
This leads to a double call of prototype Npc_Default which is considered an unsafe practice with undefined behaviour.

The correct way is to call it like this: 

1
2
3
4
5
instance pc_hero(C_NPC) // no prototype Npc_Default
{
    pc_hero_old();
    name = "Pepe";
};
This way the prototype is called in the original function pc_hero_old() and not for the second time when creating the new hooked instance.

Dialogue hook example

The hooking mechanism is designed to introduce new dialogues into the game as well as replacing old ones with hooks. The scripter can create new merchants, quests, dialogues, as well as attach svm phrases to them.

All new or replaced dialogues will immediately become available, including from saves. In the event that new dialogs are disabled (plugin or script removed), the engine will continue to keep them in the save file, which will allow the dialogs to return at any time with the same state they were in the last time.

Warning

Currently not working as intended (I think). The old dialogue is still used and as a result you will end up with both the old and the new dialogue (unless you edit the old condition function).

1
2
3
4
5
instance DIA_XARDAS_HELLO(C_INFO)
{
    DIA_XARDAS_HELLO_old();
    important = FALSE;
};