Editing ACS scripting

For the upcoming Hexen implementation, Eternity supports ACS scripts. As well as it can run the vanilla Hexen ACS script bytecodes, it can run the modern ACS as produced for ZDoom, and it's designed to be compatible with the functions and definitions provided in ''zcommon.acs''.

Comprehensive information regarding the ACS language for Hexen can be found at the [http://doomlegacy.sourceforge.net/hosted/hexenspec09.txt Official Hexen Technical Specs] by Ben Morris and Ben Gokey.

Most or all of the [[Detailed parameterized linedef specification|parameterized]] specials can be called from ACS as functions, though the equivalent numbers they use (as listed in ''zspecial.acs'') are from the Hexen and UDMF namespaces. This is also to keep easy compatibility with ''zcommon.acs'', so there will be as little need as possible to rewrite the include files.
{{Backto|Editing reference}}

== Using ACS for your map ==

=== Doom (classic) format maps ===
This information does not apply for UDMF or Hexen format maps.

ACS scripts can be loaded with Doom-format maps through the help of [[MapInfo|EMAPINFO]] and [[ExtraData]]. The MapInfo entry for the map needs at least a specifier for its ExtraData lump and compiled ACS lump (setting the '''extradata''' and '''acsscript''' entries).

The script can be written in a text editor and compiled using the '''acc''' tool (see https://devbuilds.drdteam.org/ACC/). After obtaining the behavior lump (usually with the .o extension), import it in a wad and place it between lumps '''A_START''' and '''A_END'''. The '''acsscript''' entry from EMAPINFO should then reference this compiled lump.

Wad tools like SLADE also have the capability to compile ACS scripts from source lumps, and will automatically place them inside '''A_START''' and '''A_END''', creating these marker lumps if necessary.

''Important'': do not place the compiled ACS script as a BEHAVIOR lump after the level lumps, as it is done in Hexen or UDMF format maps. This will cause Eternity to assume your map is designed in the Hexen format (with Hexen-format THINGS and LINEDEFS), despite it being in the Doom format, resulting in errors or unpredictable effects when loading the level.

ACS scripts will be callable from map linedefs by using the parameterized script specials or the legacy non-parameterized specials.

=== Hexen format ===
Most editors which support ZDoom and Hexen editing should have the ability to compile scripts built-in. Otherwise, you can still use the command-line '''acc''' tool and import the resulting '''.o''' file into a '''BEHAVIOR''' lump after the last level lump ('''BLOCKMAP''').

=== UDMF format ===
This is similar to the Hexen format, except that '''BEHAVIOR''' has to be placed within the '''TEXTMAP''' - '''ENDMAP''' lump range.

== Calling ACS scripts from actor frames ==

Eternity actors can call ACS scripts directly, by using the [[StartScript]] codepointer. Named scripts are also supported, and generally recommended, using the [[StartScriptNamed]] codepointer.

== Testing ACS scripts from console ==

ACS scripts can be tested from the [[console]] by using the '''puke''' command.

== ACS details ==
*[[ACS spawn IDs]]
*[[ACS built-in functions]]
*[[ACS directives]]

[[Category:Editing reference]]
[[Category:ACS]]
@@ Line 11: / Line 11: @@
 This information does not apply for UDMF or Hexen format maps.
-ACS scripts can be loaded with Doom-format maps through the help of [[MapInfo|EMAPINFO]]. The MapInfo entry for the map needs a specifier for the compiled ACS lump (setting the '''acsscript''' entry).
+ACS scripts can be loaded with Doom-format maps through the help of [[MapInfo|EMAPINFO]] and [[ExtraData]]. The MapInfo entry for the map needs at least a specifier for its ExtraData lump and compiled ACS lump (setting the '''extradata''' and '''acsscript''' entries).
 The script can be written in a text editor and compiled using the '''acc''' tool (see https://devbuilds.drdteam.org/ACC/). After obtaining the behavior lump (usually with the .o extension), import it in a wad and place it between lumps '''A_START''' and '''A_END'''. The '''acsscript''' entry from EMAPINFO should then reference this compiled lump.
@@ Line 35: / Line 35: @@
 ACS scripts can be tested from the [[console]] by using the '''puke''' command.
-== Example ==
-An ACS script typically looks like this:
- #include "zcommon.acs"
- script 1 OPEN
- {
-     // Put map initialization actions here
- }
- script 2 (void)
- {
-     // This script is called from the map and has no parameters
- }
- script 3 (int a, int b)
- {
-     // This script has two arguments, a and b.
- }
 == ACS details ==
 *[[ACS spawn IDs]]
 *[[ACS built-in functions]]
-*[[ACS constants]]
 *[[ACS directives]]
-*[[ACS libraries]]
+[[Category:Editing reference]]
 [[Category:ACS]]
-[[Category:Editing reference]]