input-system

Input System in FlatRedBall2

All input is accessed through Engine.Input from inside any entity or screen. The input manager exposes keyboard, cursor (mouse/touch), and up to four gamepads.

Accessing Input Devices

// Works in Entity.CustomActivity, Screen.CustomActivity, or anywhere Engine is available:
var keyboard = Engine.Input.Keyboard;       // IKeyboard
var cursor   = Engine.Input.Cursor;         // ICursor
var gamepad0 = Engine.Input.GetGamepad(0);  // IGamepad, index 0–3

GetGamepad(int index) throws ArgumentOutOfRangeException for index values outside 0–3.

IKeyboard

IKeyboard kb = Engine.Input.Keyboard;

bool held       = kb.IsKeyDown(Keys.Space);         // true every frame while held
bool pressed    = kb.WasKeyPressed(Keys.Space);     // true only on first frame down
bool released   = kb.WasKeyJustReleased(Keys.Space);// true only on first frame up

ICursor (Mouse / Touch)

ICursor cursor = Engine.Input.Cursor;

bool clicking       = cursor.PrimaryDown;           // left mouse button or touch held
bool justClicked    = cursor.PrimaryPressed;        // left mouse button or touch just started
Vector2 worldPos    = cursor.WorldPosition;         // position in world space (Y+ up)
Vector2 screenPos   = cursor.ScreenPosition;        // position in screen pixels

bool overShape  = cursor.IsOver(myCircle);          // hit-test against any IShape
bool overEntity = cursor.IsOver(this);              // hit-test against an entity's shapes

IGamepad

IGamepad pad = Engine.Input.GetGamepad(0);

bool held       = pad.IsButtonDown(Buttons.A);
bool justPressed  = pad.WasButtonJustPressed(Buttons.A);
bool justReleased = pad.WasButtonJustReleased(Buttons.A);

float axisValue = pad.GetAxis(GamepadAxis.LeftStickX);  // -1.0 to 1.0

KeyboardInput2D — Directional Movement from Four Keys

KeyboardInput2D implements I2DInput and maps four keys to a normalized X/Y pair.

using FlatRedBall2.Input;
using Microsoft.Xna.Framework.Input;

public class Player : Entity
{
    private KeyboardInput2D _movement = null!;

    public override void CustomInitialize()
    {
        _movement = new KeyboardInput2D(
            Engine.Input.Keyboard,
            Keys.Left,   // left  → X = -1
            Keys.Right,  // right → X = +1
            Keys.Up,     // up    → Y = +1
            Keys.Down);  // down  → Y = -1
    }

    public override void CustomActivity(FrameTime time)
    {
        const float Speed = 200f;
        VelocityX = _movement.X * Speed;
        VelocityY = _movement.Y * Speed;
    }
}