Porting Godot 4: Input
Implementing input is a mostly freeform system in Godot 4; most of the platform code could be doing pretty much anything, as long as it updates the Input singleton.
The input singleton can be split into two general groups: Joypad, and regular events.
- Keyboard and mouse are implemented as regular events, which means the engine only expects/reacts to one source for those inputs. Inputs are passed to the API in a "This input has occurred" format.
- Up to 16 independent
Joypadsources can be connected at once. EachJoypadhas a unique ID, which is retrieved and managed by the singleton. Inputs from joypads are passed to the API in a "This input has occurred on this device" format, with an attached ID referring to the source Joypad.
A couple of notes:
- Input types for the Joypad and mouse are stored in enumerators, which can be found in
core/input/input_enum.h(as of writing this) - The input singleton itself is in
core/input/input.h. Do not call theInputclass for the API directly: Instead, grab a pointer to the singleton viaInput:get_singleton()and call functions from that.
| Function name | Return value | Parameters | Description |
|---|---|---|---|
joy_button(int p_device, JoyButton p_button, bool p_pressed) |
void |
p_device: The ID of the input device being processedp_button: A value corresponding to an entry in the JoyButton enump_pressed: Whether the button is pressed (true) or not (false). |
Processes a standard button input from a joypad device. |
joy_hat(int p_device, BitField<HatMask> p_val) |
void |
p_device: The ID of the input device being processed.p_val: A bitfield HatMask value representing which direction(s) are being held down. |
Processes d-pad inputs from a joypad device. |
joy_axis(int p_device, JoyAxis p_axis, float p_value) |
void |
p_device: The ID of the input device being processed.p_axis: Which axis is being processed, based on the JoyAxis enum.p_value: The new value of the axis being processed. |
Processes an axis input on a joypad device. |
- A function to process inputs, which should probably be run every loop within
OS:run()for your platform. - Your input system must talk to the
Inputsingleton for Godot to process inputs.
- Implementing keyboard.
- Implementing more than one input type (eg. keyboard and joypads). If you are implementing a singular Joypad (eg. handheld), you still need to make sure it is mapped to an ID.
