splatjs/lib/systems/constrain-to-playable-area.js

A 2D HTML5 Canvas game engine

"use strict";

module.exports = function(ecs) {
	ecs.addEach(function(entity, elapsed) { // jshint ignore:line
		if (entity.position.x < entity.playableArea.x) {
			entity.position.x = entity.playableArea.x;
		}
		if (entity.position.x + entity.size.width > entity.playableArea.x + entity.playableArea.width) {
			entity.position.x = entity.playableArea.x + entity.playableArea.width - entity.size.width;
		}
		if (entity.position.y < entity.playableArea.y) {
			entity.position.y = entity.playableArea.y;
		}
		if (entity.position.y + entity.size.height > entity.playableArea.y + entity.playableArea.height) {
			entity.position.y = entity.playableArea.y + entity.playableArea.height - entity.size.height;
		}
	}, ["position", "size", "playableArea"]);
};