SDL_GameControllerDB
A community sourced database of game controller mappings to be used with SDL2 Game Controller functionality.
Usage
Download gamecontrollerdb.txt, place it in your app's directory and load it.
For example :
SDL_GameControllerAddMappingsFromFile("gamecontrollerdb.txt");
The database is compatible with SDL v2.0.10 and newer. Older SDL versions are no longer supported.
Create New Mappings
A mapping looks like this :
030000004c050000c405000000010000,PS4 Controller,a:b1,b:b2,back:b8,dpdown:h0.4,dpleft:h0.8,dpright:h0.2,dpup:h0.1,guide:b12,leftshoulder:b4,leftstick:b10,lefttrigger:a3,leftx:a0,lefty:a1,rightshoulder:b5,rightstick:b11,righttrigger:a4,rightx:a2,righty:a5,start:b9,x:b0,y:b3,platform:Mac OS X,
It includes controller GUID (030000004c050000c405000000010000), a name (PS4 Controller), button / axis mappings (leftshoulder:b4) and a platform (platform:Mac OS X).
Please make sure to check that the name is a good description of the controller. If relevant, include the controller's name and model number.
Mapping Tools
There are a few different tools that let you create mappings.
SDL2 Gamepad Tool
Third party cross-platform tool with GUI (Windows, macOS and Linux). Likely the easiest tool to use.
SDL2 Gamepad Mapper
Open source replacement for older SDL2 Gamepad Tool.
SDL2 ControllerMap
The controllermap utility provided with SDL2 is the official tool to create these mappings, it runs on all the platforms SDL runs (Windows, Mac, Linux, iOS, Android, etc).
Steam
In Steam's Big Picture mode, configure your joystick. Then look in [steam_installation_directory]/config/config.vdf in your Steam installation directory for the SDL_GamepadBind entry. It is one of the last entries, it will look something like this:
"SDL_GamepadBind" "030000004c050000c405000000010000,PS4 Controller,platform:Windows,a:b1,b:b2,back:b8,dpdown:h0.4,dpleft:h0.8,dpright:h0.2,dpup:h0.1,guide:b12,leftshoulder:b4,leftstick:b10,lefttrigger:a3,leftx:a0,lefty:a1,rightshoulder:b5,rightstick:b11,righttrigger:a4,rightx:a2,righty:a5,start:b9,x:b0,y:b3,"
GNOME Games
GNOME Games allows users to configure their own gamepads. The gamepad file the user generates is located at ~/.var/app/org.gnome.Games/config/libmanette/gamecontrollerdb when installed from the flatpak. (GNU/Linux)