Handling Input

In order for the player to interact with the game, we need to handle the keyboard, mouse, and gamepad inputs. This can be achieved by using the InputSystem class, which provides a set of methods to retrieve information about the different input events.

To use the InputSystem class, you must first retrieve its instance by calling the InputSystem::Get method.

Mouse input

To check the current position of the mouse, you can use the GetMousePosition method, which returns the position in screen coordinates. Alternatively, you can use the GetMouseDelta method to check how much the mouse has moved since the last frame. Furthermore, you can manually alter the mouse position by using the SetMousePosition method.

If you need to check the state of a mouse button, there are three methods that can help you: IsMouseButtonDown allows you to check if a button is currently down, while WasMouseButtonPressed and WasMouseButtonReleased tell you if a button was pressed or released in the current frame.

You can also check how the mouse scroll varied since the last frame by using the GetMouseScroll method.

Finally, the input system allows you to change the mouse behavior by using the SetMouseMode method, which can be set to Normal, Hidden, Locked, or Confined.

void MyEntity::Update(float deltaTime)
{
    // Retrieve the input system instance
    InputSystem& inputSystem = InputSystem::Get();

    // Get the mouse position
    Vector2 mousePosition = inputSystem.GetMousePosition();

    // Get the mouse delta
    Vector2 mouseDelta = inputSystem.GetMouseDelta();

    // Check if the left mouse button is down
    if (inputSystem.IsMouseButtonDown(MouseButton::Left))
    {
        // Do something
    }

    // Check if the right mouse button was pressed
    if (inputSystem.WasMouseButtonPressed(MouseButton::Right))
    {
        // Do something
    }

    // Check if the middle mouse button was released
    if (inputSystem.WasMouseButtonReleased(MouseButton::Middle))
    {
        // Do something
    }

    // Get the mouse scroll
    float mouseScroll = inputSystem.GetMouseScroll();

    // Set the mouse mode to hidden
    inputSystem.SetMouseMode(MouseMode::Hidden);
}

Keyboard input

Detecting keyboard input is very similar to detecting mouse input. Similarly to the mouse, you can check if a key is currently down by using the IsKeyDown method, or if a key was pressed or released in the current frame by using the WasKeyPressed and WasKeyReleased methods. Additionally, you can check if a key was repeated in the current frame using the WasKeyRepeated method.

void MyEntity::Update(float deltaTime)
{
    // Retrieve the input system instance
    InputSystem& inputSystem = InputSystem::Get();

    // Check if the 'A' key is down
    if (inputSystem.IsKeyDown(KeyCode::A))
    {
        // Do something
    }

    // Check if the '1' key was pressed
    if (inputSystem.WasKeyPressed(KeyCode::Num1))
    {
        // Do something
    }

    // Check if the F12 key was released
    if (inputSystem.WasKeyReleased(KeyCode::F12))
    {
        // Do something
    }

    // Check if the space key was repeated
    if (inputSystem.WasKeyRepeated(KeyCode::Space))
    {
        // Do something
    }
}

Gamepad input

At the moment, gamepad input is not supported by the engine.