Banshee Engine Docs

Input polling

Input polling refers to the process of querying the input system to check if a user interacted with an input device in some way. This may include checking if the user pressed a keyboard, mouse or a gamepad button or moved the mouse or an analog axis.

All the input is handled through the Input class, which can be globally accessed through the GetInput method.

Button presses

Use the following methods to check if a button has been pressed, released or is currently being held down:

  • Input::IsButtonDown - Checks if the button was pressed this frame. Only valid for one frame.
  • Input::IsButtonHeld - Checks if the button is currently being held. This is valid for the first frame the button is pressed, and for any following frame until it is released.
  • Input::IsButtonUp - Checks if the button was released this frame. Only valid for one frame.

These methods work on any kind of input device buttons, including keyboard, gamepad and mouse. Use ButtonCode to choose which button to query for.

Vector3 position(Vector3::kZero);

// Move 5 units forward for every frame while W key is pressed
if (GetInput().IsButtonHeld(ButtonCode::W))
	position.z += 5.0f;

Analog input

Moving the mouse, gamepad sticks or triggers results in an analog input. While buttons can only be toggled on or off, analog input is received in a specific range (for example, anywhere between -1 and 1). This allows more precise input for applications that require it.

Analog input is represented through the concept of axes. Use Input::GetAxisValue to get a value for a specific axis. Check InputAxis for a list of all supported axes.

Vector3 position(Vector3::kZero);

// Move forward or backwards depending on how much the user moves the left gamepad stick
position.z += GetInput().GetAxisValue(InputAxis::LeftStickY);

Most axes report their input in range [-1, 1], with the exception of mouse axes, which are unbound.

Mouse input

Often it is useful to receive mouse position directly, rather than dealing with raw mouse axis data. Use Input::GetPointerPosition to retrieve the current position of the mouse cursor, in coordinates relative to the screen.

Use Input::GetPointerDelta to get the difference in coordinates between the position of the mouse on the previous and current frame.

Vector2I screenPosition = GetInput().GetPointerPosition();

You can also check if the left mouse button has been double-clicked by checking Input::IsPointerDoubleClicked.

if (GetInput().IsPointerDoubleClicked())
	B3D_LOG(Info, LogGeneric, "Mouse double-clicked!");