Hook scripts are specially named scripts that are run by sfall at specific points to allow mods to override normally hardcoded behaviour in a more flexible way than sfall's normal ini configuration.
In addition to the bit of code it overrides, the script will be run once when first loaded and again at each player reload to allow for setup. Hook scripts have access to a set of arguments supplied to sfall, but aren't required to use them all. They also return one or more values, but again they're optional, and you only need to return a value if you want to override the default.
To aid in mods compatibility, avoid using hs_xxx .int scripts. Instead it is recommended to use a normal global script combined with register_hook_proc or register_hook.
Used to return the new values from the script. Each time it's called it sets the next value, or if you've already set all return values it does nothing.
Changes argument value. The argument number (argNum) is 0-indexed. This is useful if you have several hook scripts attached to one hook point (see below).
Used from a normal global script if you want to run it at the same point a full hook script would normally run. In case of this function, "start" proc will be executed in a current global script. You can use all above functions like normal.
The same as register_hook, except that you specifically define which procedure in the current script should be called as a hook (instead of "start" by default). Pass procedure the same as how you use dialog option functions. This IS the recommended way to use hook scripts, as it gives both modularity (each mod logic in a separate global script, no conflicts if you don't use "hs_*.int" scripts) and flexibility (you can place all related hook scripts for specific mod in a single script!).
Works very similar to register_hook_proc, except that it registers the current script at the end of the hook script execution chain (i.e. the script will be executed after all previously registered scripts for the same hook, including the hs_*.int script). All scripts hooked to a single hook point with this function are executed in exact order of how they were registered, as opposed to the description below, which refers to using register_hook/register_hook_proc functions.
NOTE: you can hook several scripts to a single hook point, for example if it's different mods from different authors or just some different aspects of one larger mod. In this case scripts are executed in reverse order of how they were registered. When one of the scripts in a chain returns value with "set_sfall_return", the next script may override this value if calls "set_sfall_return" again. Sometimes you need to multiply certain value in a chain of hook scripts.
Mod B also want to affect hit chances globally, by increasing them by 50%. Now in order for both mods to work well together, we need to add this line to Mod A hook script:
So if you combine both mods together, they will run in chain and the end result will be a 75% from original hit chance (hook register order doesn't matter in this case, if you use "set_sfall_arg" in both hooks).
Note that the first time a game is loaded, this script doesn't run before the initial interface is drawn, so if the script effects the AP cost of whatever is in the player's hands at the time the wrong AP cost will be shown. It will be fixed the next time the interface is redrawn.
Runs after Fallout has calculated the death animation. Lets you set your own custom frame id, so more powerful than hs_deathanim1, but performs no validation.
When using critter_dmg function, this script will also run. In that case weapon pid will be -1 and attacker will point to an object with obj_art_fid == 0x20001F5.
Does not run for critters in the knockdown/out state.
1) Game calculates how much damage each target will get. This includes primary target as well as all extras (explosions and bursts). This happens BEFORE the actual attack animation.
2) AI decides whether it is safe to use area attack (burst, grenades), if he might hit friendlies.
Does not run for misses, or non-combat damage like dynamite explosions.
int arg4 - The special effect flags for the target (use bwand DAM_* to check specific flags)
int arg5 - The special effect flags for the attacker (use bwand DAM_* to check specific flags)
int arg6 - The weapon used in the attack
int arg7 - The bodypart that was struck
int arg8 - Damage Multiplier (this is divided by 2, so a value of 3 does 1.5x damage, and 8 does 4x damage. Usually it's 2; for critical hits, the value is taken from the critical table; with Silent Death perk and the corresponding attack conditions, the value will be doubled)
int arg9 - Number of bullets actually hit the target (1 for melee attacks)
int arg10 - The amount of knockback to the target
int arg11 - Attack Type (see ATKTYPE_* constants)
mixed arg12 - computed attack data (see C_ATTACK_* for offsets and use get/set_object_data functions to get/set the data)
Runs immediately after a critter dies for any reason. No return values; this is just a convenience for when you need to do something after death for a large number of different critters and don't want to have to script each and every one of them.
Runs when the AI is trying to pick a target in combat. Fallout first chooses a list of 4 likely suspects, then normally sorts them in order of weakness/distance/etc depending on the AI caps of the attacker.
The return values can include critters that weren't in the list of possible targets, but the additional targets may still be discarded later on in the combat turn if they are out of the attackers perception or the chance of a successful hit is too low. The list of possible targets often includes duplicated entries, but this is fixed in sfall 4.2.3/3.8.23.
Use sfall_return to give the 4 targets, in order of preference. If you want to specify less than 4 targets, fill in the extra spaces with 0's or pass -1 to skip the return value.
To add proper check for ammo before shooting and proper calculation of number of burst rounds (hook type 1 and 2 in arg4), set Misc.CheckWeaponAmmoCost=1 in ddraw.ini
int arg1 - Number of bullets in burst (1 for single shots)
int arg2 - Ammo cost calculated by original function (this is basically 2 for Super Cattle Prod and Mega Power Fist)
int arg3 - Type of hook (0 - when subtracting ammo after single shot attack, 1 - when checking for "out of ammo" before attack, 2 - when calculating number of burst rounds, 3 - when subtracting ammo after burst attack)
This is fired before the default handlers are called, which you can override. In this case you should write your own skill use handler entirely, or otherwise nothing will happen (this includes fade in/fade out, time lapsing and messages - all of this can be scripted; to get vanilla text messages - use message_str_game() along with sprintf()).
This is fired before the default handlers are called, which you can override. In this case you MUST provide message of the result to player ("You steal the %s", "You are caught planting the %s", etc.).
NOTE: obj_can_see_obj calls this first when deciding if critter can possibly see another critter with regard to perception, lighting, sneak factors. If check fails, the end result is false. If check succeeds (e.g. critter is within perception range), another check is made if there is any blocking tile between two critters (which includes stuff like windows, large bushes, barrels, etc.) and if there is - check still fails. You can override "within perception" check by returning 0 or 1, OR, as a convenience, you can also override blocking check after the perception check by returning 2 instead. In this case you should add "line of sight" check inside your hook script, otherwise critters will detect you through walls.
int ret0 - overrides the returned result of the function: 0 - not in range (can't see), 1 - in range (will see if not blocked), 2 - forced detection (will see regardless, only used in obj_can_see_obj scripting function which is called by every critter in the game)
int arg0 - Target slot (0 - main backpack, 1 - left hand, 2 - right hand, 3 - armor slot, 4 - weapon, when reloading it by dropping ammo, 5 - container, like bag/backpack, 6 - dropping on the ground,
7 - picking up item, 8 - dropping item on the character portrait)
