Editing User:Altazimuth/Code Guide

Eternity's code is built up of .cpp (C++ source code) and .h (header) files split into various prefixes (though dependencies such as libpng may use regular C source files). Each one refers to specific facets of the code. Functions from these files will also be appropriately prefixed (note that the files have lower case prefixes, which functions have upper case).

{| class="wikitable" style="text-align: center;"
|+ Source File Classification
|-
! style="width: 100px;" | Prefix/Visual Studio Folder Name
! Meaning
! Explanation
! Further Reading
|-
! A_
| Action Pointer Code || Code and functions associated with actor states/frames || [[List of codepointers]]
|-
! ACS_
| ACS Code || Code and functions that handle the loading and execution of Action Code Script || [[ACS scripting]]
|-
! AM_
| Automap Code || Code and functions associated with the Automap || [http://doomwiki.org/wiki/Automap Automap]
|-
! AMX_ 
| Small Code || Code and functions to handle Small '''(DEPRECATED)''' || [[Small]]
|-
! C_
| Console Code || Code and functions associated with the Console || [[Console]]
|-
! Cam
| Camera Code || Line of sight checking for cameras ||
|-
! Confuse
| libConfuse Code || Code and functions associated with the libConfuse configuration file parser library || [https://github.com/martinh/libconfuse libConfuse on GitHub]
|-
! D_
| || ||
|-
! doom
| || ||
|-
! E_
| Eternity Extensions || Code and functions handling things that Eternity introduces like Eternity Definition Files and ExtraData || [[EDF]] and [[ExtraData]]
|-
!EV_
| Line Action Code || Code and functions handling the generalised line action system || [[Line actions]]
|-
! F_
| Finale Code || Code and functions that handle game completion, final screen animations, and screen wipe effects ||
|-
! G_
| Game Code || ||
|-
! GL
| OpenGL Code || Code and functions that initialise and handle the OpenGL backend of the engine ||
|-
! HAL
| Hardware Abstraction Layer Code || Code that introduces layers of abstraction between software and hardware || [https://en.wikipedia.org/wiki/Hardware_abstraction_layer Hardware abstraction layer]
|-
! HU_
| Head-up Display Code || Code and functions that handle the overlay and display of the player's HUD ||
|-
! IN
| Intermission Code || Code and functions that handle level intermission screens ||
|-
! M_
| || ||
|-
! MetaAPI
| || ||
|-
! Misc
| Miscellaneous Code || ||
|-
! Mn_
| Menu Code || Code and functions that run the menu engine ||
|-
! P_
| || ||
|-
! R_
| Rendering Code || Code and functions that handle the rendering of the game ||
|-
! S_
| Sound Code || Code and functions that handle sound loading and playback ||
|-
! SDL_
| SDL Code || Mid-level code that uses the Simple DirectMedia Layer ||
|-
! ST_
| Status Bar Code || Code and functions that handle and define the status bar and palette indicates (e.g. bersek) ||
|-
! T_
| Plane Mover Code || General plane mover routines (e.g. crushers, platforms, lifts) ||
|-
! TXT_
| Text Code || Code and functions that handle the display of text ||
|-
! V_
| Video Code || Code and functions that load and verify patches/pngs, store images internally, handle buffers, and various other video functionality  ||
|-
! W_
| WAD/Resource Code || Code functions that define and handles WADs/ZIPs, their loading, their formats, lump handling ||
|-
! Win32
| Windows Code || Code needed specifically for Windows machines ||
|-
! XL_
| Parsing Code || Parsing code for EMAPINFO, Hexen MAPINFO, MUSINFO, Hexen Script Lumps (SNDINFO/MUSINFO), and SNDINFO ||
|-
! Z_
| Zone Memory Allocation Code || Code to perform zone memory allocation, and to define the zone API ||
|}

== Basic Control Flow ==
The "main" (where we start) is located in i_main.cpp. In here various systems are initialised and then the real main function where the program happens is called: D_DoomMain(), located in d_main.cpp. In here D_DoomInit() and some other initialisation is performed. From here the game enters its main game loop within the block of code after the while(1).
@@ Line 16: / Line 16: @@
 |-
 ! AM_
-| Automap Code || Code and functions associated with the Automap || {{doomwiki|Automap}}
+| Automap Code || Code and functions associated with the Automap || [http://doomwiki.org/wiki/Automap Automap]
 |-
 ! AMX_
@@ Line 28: / Line 28: @@
 |-
 ! Confuse
-| libConfuse Code || Code and functions associated with the libConfuse configuration file parser library ||
+| libConfuse Code || Code and functions associated with the libConfuse configuration file parser library || [https://github.com/martinh/libconfuse libConfuse on GitHub]
 |-
 ! D_
-| Core Code || Core engine code such as initialisation, main loop, and high-level netcode ||
+| || ||
 |-
 ! doom
-| Doom Code || Files that came from the original Doom engine||
+| || ||
 |-
 ! E_
@@ Line 40: / Line 40: @@
 |-
 !EV_
-| Events Code || Code and functions handling in-game events, as well as the line system and sector specials || [[Action specials]]
+| Line Action Code || Code and functions handling the generalised line action system || [[Line actions]]
 |-
 ! F_
@@ Line 46: / Line 46: @@
 |-
 ! G_
-| Game State FSA Code || Contains the finite-state automaton for game state, as well as demo playback and recording ||
+| Game Code || ||
 |-
 ! GL
@@ Line 61: / Line 61: @@
 |-
 ! M_
-| Miscellaneous Utilities || ||
+| || ||
 |-
 ! MetaAPI
-| Metatables and objects || Handles stuff like storage of multiple types in an associative array, or provision of an adapter class for storage of qstrings as metatable properties ||
+| || ||
 |-
 ! Misc
@@ Line 73: / Line 73: @@
 |-
 ! P_
-| Playsim/Playloop || Covers a huge range of stuff like animations, portals, chasecam, etc. ||
+| || ||
 |-
 ! R_