Simulating Input ​

Every twodog.Testing.FixtureBase exposes Input, a TestInput helper in 2dog.engine. Use godot.Input in an xUnit collection or Godot.Input in a derived NUnit fixture. Both use the same implementation on the engine thread.

Aim at a Control ​

csharp
godot.Engine.Iteration(); // Settle layout first.
godot.Input.Click(playButton);
godot.Input.Click(playButton, localPosition: new Vector2(10, 10));

Click(control) transforms its center, or the supplied control-local point, into its owning viewport's coordinates. It sends mouse motion, a press and a release through Viewport.PushInput. Godot chooses the recipient through its normal input and GUI stages. The helper does not call _GuiInput, emit Pressed, grab focus explicitly, or guarantee that the aimed-at control receives the event.

Foreground controls, mouse filters, clipping, visibility, disabled buttons, paused processing and viewport input suppression retain their normal behavior. An _Input handler can consume the event before GUI handling. Assert the resulting signal or state to distinguish a received click from a blocked one. Layout, animation and deferred changes still need frames; clicks do not advance the engine automatically.

Headless windows can have a small root viewport. Check GetVisibleRect() or create a SubViewport with an explicit size for isolated UI tests, as in the NUnit example. Aiming at a point outside the viewport does not make it visible or clickable.

For an explicit viewport-local point:

csharp
godot.Input.Click(new Vector2(80, 40)); // Root viewport.
godot.Input.Click(new Vector2(80, 40), viewport: gameViewport);

The control overload targets its owning viewport. It does not simulate forwarding through an outer SubViewportContainer, another window or the OS. To test outer overlays or forwarding, inject at the outer viewport's coordinates instead. Tests of desktop window focus and OS input delivery need a windowed integration test.

Keyboard Focus and Custom Events ​

PushToViewport accepts any InputEvent, in viewport coordinates. Keyboard events go to the existing focus owner; they are not addressed to a control. To test focus acquisition, click or tab through the UI first.

csharp
using var down = new InputEventKey { Keycode = Key.Space, Pressed = true };
using var up = new InputEventKey { Keycode = Key.Space, Pressed = false };
try { godot.Input.PushToViewport(down, gameViewport); }
finally { godot.Input.PushToViewport(up, gameViewport); }

Touch, drag and wheel tests can construct the corresponding Godot events and send them through this same method. The caller owns and disposes custom events. For hover tests in a manually managed standalone SubViewport, call viewport.NotifyMouseEntered() once when the pointer enters, and NotifyMouseExited() when it leaves. Windows and SubViewportContainer manage these notifications during normal input forwarding; the helper does not force mouse-enter notifications on every click.

Global Input Polling ​

Viewport delivery is local routing. It does not update global Godot.Input.IsKeyPressed, IsMouseButtonPressed or action state. Use Send when the code under test polls Input or when testing normal window delivery:

csharp
using var down = new InputEventKey { Keycode = Key.F13, Pressed = true };
using var up = new InputEventKey { Keycode = Key.F13, Pressed = false };
try
{
    godot.Input.Send(down);
    // Godot.Input.IsKeyPressed(Key.F13) is now true.
    godot.Engine.Iteration(); // Let _Process/_PhysicsProcess react if needed.
}
finally { godot.Input.Send(up); }

Send calls Input.ParseInputEvent and flushes buffered events immediately. This also flushes any other pending input. Window routing and project input emulation apply; event coordinates follow Godot's device/window conventions. Use a fresh event object for every press and release, and always release held keys, actions and mouse buttons in finally. The fixture is shared across tests. Do not send the same event through both methods: that would deliver it twice.

These modes follow Godot's documented viewport delivery and input server APIs. GUI event consumption does not clear global polling state.