Input System in Raftel Engine

This tutorial shows how to use Raftel Engine's input system to handle keyboard and mouse interactions.

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Input System Basics

The Raftel Engine input system is accessed through the input member of your window object. Before checking any input, you must update the input system at the beginning of each frame:

Input Update

// Update at the start of each frame
windowOpt->input->updateKeys();

Keyboard Input

Raftel Engine provides methods to check different key states:

isKeyDown()

Checks if a key is currently held down.

if (windowOpt->input->isKeyDown(Raftel::Input::Keys::Key_W)) {
    // W key is down - move forward
}

isKeyUp()

Checks if a key is currently not pressed.

if (windowOpt->input->isKeyUp(Raftel::Input::Keys::Key_W)) {
    // W key is up
}

isKeyPressed()

Checks if a key was just pressed this frame.

if (windowOpt->input->isKeyPressed(Raftel::Input::Keys::Key_Space)) {
    // Space was just pressed - jump
}

isKeyRelease()

Checks if a key was just released this frame.

if (windowOpt->input->isKeyRelease(Raftel::Input::Keys::Key_Escape)) {
    // Escape was just released - toggle menu
}

Mouse Input

Raftel Engine also supports mouse input detection:

Mouse Buttons

if (windowOpt->input->isMouseButtonDown(
    Raftel::Input::Buttons::Mouse_Left)) {
    // Left mouse button is being held down
}

Mouse Position

glm::vec2 mousePos = windowOpt->input->getMousePosition();
// mousePos.x and mousePos.y contain coordinates

Mouse Movement

glm::vec2 mouseDelta = windowOpt->input->getMouseDelta();
// mouseDelta.x and mouseDelta.y contain movement

Mouse Wheel

glm::vec2 scrollDelta = windowOpt->input->getScrollDelta();
// scrollDelta.y contains vertical scroll amount

Example: Moving a Shape with Keyboard

This example shows how to move a triangle with WASD keys and rotate it with Q and E:

Movement and Rotation

// Set up direction vector
Raftel::Vec2 dir = {0, 0};
const float speed = 0.5f;

// Check WASD keys for movement
if (windowOpt->input->isKeyDown(Raftel::Input::Keys::Key_W)) {
    dir.y = speed;  // Move up
}
if (windowOpt->input->isKeyDown(Raftel::Input::Keys::Key_A)) {
    dir.x = -speed;  // Move left
}
if (windowOpt->input->isKeyDown(Raftel::Input::Keys::Key_D)) {
    dir.x = speed;  // Move right
}
if (windowOpt->input->isKeyDown(Raftel::Input::Keys::Key_S)) {
    dir.y = -speed;  // Move down
}

// Check Q and E for rotation
if (windowOpt->input->isKeyDown(Raftel::Input::Keys::Key_Q)) {
    triangle.tr.Rotate(angle * deltaTime);  // Rotate counter-clockwise
}
if (windowOpt->input->isKeyDown(Raftel::Input::Keys::Key_E)) {
    triangle.tr.Rotate(-angle * deltaTime);  // Rotate clockwise
}

// Apply movement
triangle.tr.velocity_ = dir;
triangle.tr.Translate(deltaTime);

Next Steps

Loading 3D Meshes

Learn how to load and render 3D models in your application.

Input System API

View the full API reference for the Input system.

For complete details, see the Input API Reference.

Previous: Drawing a Triangle Next: Loading 3D Meshes