Category:Structure access: Difference between revisions

One of the hallmarks of EDuke32's CON scripting advancements is the ability to access many of the game's internal data structures.

Usage

Struct access was designed with the syntax of an array of a struct type in the C programming language.

The index in [square brackets] is an ID number that has different meanings for different structs. Most simple uses of struct access will suffice to use the gamevar THISACTOR as an index, which usually means the current sprite but is also usable as a magic token for different meanings with non-sprite structures. Other times, you may know an ID from a command like findnearactor or espawn (from gamevar RETURN). On occasion you may also loop through all or a selection of ID numbers.

Getters & Setters

Get/set commands are the original methods of CON struct access that date back to DOS EDuke.

get<struct>[<id>].<member> <gamevar>
set<struct>[<id>].<member> <value>

The get commands fetch one of the members of a structure into a gamevar.

The set commands assign the value provided to the member.

<id> can be omitted entirely, which implies an id of THISACTOR.

The commands with the "var" suffix are used to access custom members for a struct, which are really just that ID's gamevars which have the per-<struct> flag set. So setactorvar[THISACTOR].temp 0 is the same as setvar temp 0.

Quick Access

More recently added, structs can be used in place of gamevars, in the form <struct>[<id>].<member>. For example:

ifvarg userdef[].executions 10000
{
    redefinequote 117 You have way too much time on your hands.
    echo 117
}

With quick access, structures are always read-only. Attempting to use a gamevar-writing command on a quick access structure will result in a compiler error.

Quick struct access cannot be used as an index to other quick struct accesses.

Structs