.DT
combat
Discworld living help
combat
Name
.SI 5
combat - How things beat each other up.
.EI
.SH Description
.SP 5 5
Combat on Discworld lives in /std/living/combat.c There are no combat
rounds as such. Every 2 seconds the heart_beat() function checks to
see if the player (or npc) is fighting anyone, if the conditions are
right to do an attack, and if so calls do_attack() which performs the
attack itself.
Combat uses an data class called attack (defined in combat.h) to store
all the information about the current attack. The class is passed to,
and returned by, each stage of combat, gradually having all its fields
filled in.
A combat attack is broken down into several steps shown in pseudo-code
as follows:
.EP
.SI 5
do_attack() {
choose_opponent()
do {
choose_defender()
choose_attack()
choose_defense()
calc_attack_modifier()
calc_defense_modifier()
determine outcome
} while(i < 1 && defender != opponent)
calc_damage()
calc_armour_protection()
write_messages()
adjust_hp
damage_weapon()
after_attack()
}
.EI
.SP 5 5
Each of the functions listed above (the lines ending with braces) can
be overridden using the combat special system (see register_special)
and has defined pre and post conditions (see the help for each function).
.EP
.SH Interfaces
.SP 5 5
The combat system provides a number of interfaces, or hooks that can
be utilised when coding. Which you use depends on your requirements.
.EP
.SH Coding an NPC
.SP 5 5
When coding an NPC the easiest interface is to overload combat
functions. Some functions are provided for exactly this purpose. The
start_combat() and end_combat() methods have no role except that they
are called at the start and end of combat. You can define your own
functions within your NPC and the combat system will call them
appropriately.
If you require your NPC to do something during combat you can use
add_combat_action. This allows you to register a callback that will be
called at approximately the rate of your choosing.
.EP
See also
.SP 5 5
attack, query_attacker_list, set_damage_chance, set_natural, set_protector
set_concentrate
.EP
