steamworks.gmk

Steamworks SDK support for GameMaker 8.1 and earlier.

Installation

Add Output.gmk/steam_api.dll to the Included Files (menu: Resources - Included Files).
Add Output.gmk/Steamworks.gmk.dll to the Included Files.
Create a steam_appid.txt file containing your Steam App ID, and add it to the Included Files

Sample file is included in Output.gmk/steam_appid.txt.
Drag Output.gmk/Steamworks.gmk.gml onto a GameMaker window with the project open to import the scripts.
Create an object (say, obj_steam),
- Mark it as persistent
- Add the following into the Create event:
```
 steam_init_dll();
 steam_init(480); // replace `480` with your Steam App ID
```
  This will initialize Steam API and request the user stats&achievements (if any).
- Add the following into the Step event:
```
 steam_update_callbacks();
```
  This is required by Steam API in order to receive API events.
  
  Should you forget to call this function, the user will only receive achievements after they close the game.
- Add the object into the game's first room (so that it is created on game start).
  
  If the game's first room is a menu, make a separate "init" room that has the object and goes to the actual first room via room_goto_next() in Room Creation Code.
If everything was done correctly, upon launching the game Steam will detect you as playing the game, and you'll be able to use Steam API functions as you wish.

Once installed, you can use the included steam_ scripts to call the supported DLL functions.

Every script includes a short description of what it does.

Script naming closely follows that of built-in GameMaker-Studio functions.

Official documentation should be helpful too.

Steam Overlay (default: Shift+Tab) will not show up unless the game is ran from Steam itself

This is due to pre-GMS versions of GameMaker not being able to comply with the required initialization order.
Achievements and stats can take a few moments to load. You can check whether they are done loading yet via steam_stats_ready() function.

Emilios Manolidis, for sponsoring initial development of this library for Emerge: Cities of the Apocalypse.