ridder/dist/input.js

A straightforward game engine for simple data-driven games in JavaScript

import { getCameraPosition } from "./camera.js";
import { canvas, scale } from "./canvas.js";
import { InputCode } from "./consts.js";
import { vec } from "./vector.js";
const inputsDown = {};
const inputsPressed = {};
const inputsReleased = {};
const mousePosition = vec();
const mousePositionInWorld = vec();
/**
 * Add the event listeners to listen to key and mouse events.
 */
export function setupInput() {
    window.addEventListener("keydown", (event) => {
        event.preventDefault();
        onDown(event.code);
    });
    window.addEventListener("keyup", (event) => {
        event.preventDefault();
        onUp(event.code);
    });
    canvas.addEventListener("pointerdown", (event) => {
        event.preventDefault();
        onPointerEvent(event);
        const code = getMouseButtonCode(event.button);
        if (code) {
            onDown(code);
        }
    });
    canvas.addEventListener("pointerup", (event) => {
        event.preventDefault();
        onPointerEvent(event);
        const code = getMouseButtonCode(event.button);
        if (code) {
            onUp(code);
        }
    });
    canvas.addEventListener("pointermove", (event) => {
        event.preventDefault();
        onPointerEvent(event);
    });
    // Disable context menu to enable right mouse button as input.
    canvas.addEventListener("contextmenu", (event) => {
        event.preventDefault();
    });
    // Prevent sticky keys when the window loses focus or is minimized.
    window.addEventListener("focus", resetInputs);
    window.addEventListener("blur", resetInputs);
    document.addEventListener("visibilitychange", resetInputs);
}
/**
 * Handle key or mouse down event.
 */
function onDown(code) {
    if (inputsDown[code])
        return;
    inputsDown[code] = true;
    inputsPressed[code] = true;
    inputsReleased[code] = false;
}
/**
 * Handle key or mouse up event.
 */
function onUp(code) {
    inputsDown[code] = false;
    inputsPressed[code] = false;
    inputsReleased[code] = true;
}
/**
 * Handle generic pointer event.
 */
function onPointerEvent(event) {
    mousePosition.x = event.clientX / scale.x;
    mousePosition.y = event.clientY / scale.y;
    const camera = getCameraPosition();
    mousePositionInWorld.x = mousePosition.x + camera.x;
    mousePositionInWorld.y = mousePosition.y + camera.y;
}
/**
 * Translate the numerical mouse button to a string, similar to the key codes.
 */
function getMouseButtonCode(button) {
    switch (button) {
        case 0:
            return InputCode.MOUSE_LEFT;
        case 1:
            return InputCode.MOUSE_MIDDLE;
        case 2:
            return InputCode.MOUSE_RIGHT;
        default:
            return null;
    }
}
/**
 * Reset a single input's state back to `false`.
 */
export function resetInput(code) {
    inputsDown[code] = false;
    inputsPressed[code] = false;
    inputsReleased[code] = false;
}
/**
 * Reset the pressed and released inputs back to `false`.
 */
export function resetInputs() {
    for (const key in inputsPressed) {
        inputsPressed[key] = false;
    }
    for (const key in inputsReleased) {
        inputsReleased[key] = false;
    }
}
/**
 * Reset all inputs back to `false`.
 */
export function resetAllInputs() {
    for (const key in inputsDown) {
        inputsDown[key] = false;
    }
    for (const key in inputsPressed) {
        inputsPressed[key] = false;
    }
    for (const key in inputsReleased) {
        inputsReleased[key] = false;
    }
}
/**
 * Returns `true` if the input is currently pressed.
 *
 * Optionally consumes the input so that sequential calls in the current frame return `false`.
 */
export function isInputPressed(code, consume = false) {
    const isPressed = !!inputsPressed[code];
    if (isPressed && consume) {
        inputsDown[code] = false;
        inputsPressed[code] = false;
    }
    return isPressed;
}
/**
 * Returns `true` if the input is currently down.
 *
 * Optionally consumes the input so that sequential calls in the current frame return `false`.
 */
export function isInputDown(code, consume = false) {
    const isDown = !!inputsDown[code];
    if (isDown && consume) {
        inputsDown[code] = false;
        inputsPressed[code] = false;
    }
    return isDown;
}
/**
 * Returns `true` if the input is currently released.
 */
export function isInputReleased(code, consume = false) {
    const isReleased = !!inputsReleased[code];
    if (isReleased && consume) {
        inputsReleased[code] = false;
    }
    return isReleased;
}
/**
 * Get the current mouse position on the canvas.
 * @param inWorld Whether or not to get the mouse position affected by the camera.
 */
export function getMousePosition(inWorld) {
    return inWorld ? mousePositionInWorld : mousePosition;
}