Input, Collisions, and Triggers

This guide focuses on gameplay reactions: keys, collisions, and trigger zones.

Input Methods You Will Use Most

The Input facade exposes common checks:

Input::isKeyPressed(...)
Input::isKeyDown(...)
Input::isKeyUp(...)
Input::getAxis(...)

Prefer KeyCode enum values over hardcoded strings in gameplay code.

Example: Movement Input

<?php

use Sendama\Engine\Core\Behaviours\Behaviour;
use Sendama\Engine\Core\Vector2;
use Sendama\Engine\IO\Input;
use Sendama\Engine\IO\Enumerations\KeyCode;

final class PlayerMove extends Behaviour
{
    public function onUpdate(): void
    {
        $motion = new Vector2();

        if (Input::isKeyPressed(KeyCode::a)) {
            $motion->setX(-1);
        }

        if (Input::isKeyPressed(KeyCode::d)) {
            $motion->setX(1);
        }

        $this->getTransform()->translate($motion);
    }
}

Collision And Trigger Hooks

Use these hooks in behavior scripts:

onCollisionEnter()
onCollisionStay()
onCollisionExit()
onTriggerEnter()
onTriggerStay()
onTriggerExit()

Example: Trigger A Door

<?php

use Sendama\Engine\Core\Behaviours\Behaviour;
use Sendama\Engine\Physics\Interfaces\CollisionInterface;

final class ExitDoor extends Behaviour
{
    public function onTriggerEnter(CollisionInterface $other): void
    {
        if ($other->getGameObject()->hasTag('player')) {
            loadScene('Level 02');
        }
    }
}

Reliable Trigger Pattern

put trigger behavior on door/portal object
ensure player object has expected tag
run into trigger in play mode
verify callback runs with log output

Debug Checklist

If events do not fire:

verify collider setup on both interacting objects
verify active state of objects
verify tags and callback logic
verify scene object is not deactivated