if (!("WebGLFloatArray" in window))
	WebGLFloatArray = window.CanvasFloatArray;
if (!("WebGLByteArray" in window))
	WebGLByteArray = window.CanvasByteArray;
if (!("WebGLIntArray" in window))
	WebGLIntArray = window.CanvasIntArray;
if (!("WebGLShortArray" in window))
	WebGLShortArray = window.CanvasShortArray;
if (!("WebGLUnsignedByteArray" in window))
	WebGLUnsignedByteArray = window.CanvasUnsignedByteArray;
if (!("WebGLUnsignedIntArray" in window))
	WebGLUnsignedIntArray = window.CanvasUnsignedIntArray;
if (!("WebGLUnsignedShortArray" in window))
	WebGLUnsignedShortArray = window.CanvasUnsignedShortArray;

const UPDATE_INTERVAL = 1.0 / 80.0

function setProjection(gl) {
	gl.projectionMatrix.loadIdentity();
	gl.projectionMatrix.applyPerspective(60, document.getElementById("webGLCanvas").width / document.getElementById("webGLCanvas").height, 1.5, 400.0);
}

function initWebGL() {
	var canvas = document.getElementById("webGLCanvas");
	var gl;
	var vshader, fshader;
	
	try {
		gl = canvas.getContext("webkit-3d");
	} catch (error) {}
	
	if (gl == null) {
		try {
			gl = canvas.getContext("moz-webgl");
		} catch (error) {}
	}
	
	if (gl == null) {
		alert("No WebGL context found");
		return null;
	}
	
	vshader = gl.createShader(gl.VERTEX_SHADER);
	gl.shaderSource(vshader, document.getElementById("vshader").text);
	gl.compileShader(vshader);
	
	fshader = gl.createShader(gl.FRAGMENT_SHADER);
	gl.shaderSource(fshader, document.getElementById("fshader").text);
	gl.compileShader(fshader);
	
	gl.program = gl.createProgram();
	gl.attachShader(gl.program, vshader);
	gl.attachShader(gl.program, fshader);
	
	gl.linkProgram(gl.program);
	gl.useProgram(gl.program);
	
	gl.uniform4f(gl.getUniformLocation(gl.program, "clearColor"), 0.0, 0.25, 0.5, 1.0);
	gl.clearColor(0.0, 0.25, 0.5, 1.0);
	gl.clearDepth(1.0);
	
	gl.enable(gl.DEPTH_TEST);
	gl.enable(gl.BLEND);
	gl.blendFunc(gl.SRC_ALPHA, gl.ONE_MINUS_SRC_ALPHA);
	
	gl.projectionMatrix = new Matrix();
	gl.modelviewMatrix = new Matrix();
	
	setProjection(gl);
	
	return gl;
}

function initGameLevel(game) {
	game.level = GameLevels.createLevel(game.levelIndex);
	game.state = new GameState(game.level, game.player);
	game.stateController = new GameStateController(game.state);
	game.playerController = new PlayerController(game.player, game.soundEffects);
	game.player.position.x = game.level.playerStartPosition.x;
	game.player.position.y = game.level.playerStartPosition.y;
	game.player.position.z = game.level.playerStartPosition.z;
	game.player.velocity = new Vector3();
	game.camera.position = Vector3.withValues(game.player.position.x, game.player.position.y, game.player.position.z + 100.0);
	game.cameraController = new PlayerCameraController(game.camera, game.player);
	game.renderer = new GameRenderer(game.state, game.camera);
}

function initGame() {
	var game = new Object();
	
	game.runLoop = new FixedIntervalRunLoop(UPDATE_INTERVAL, function() { return new Date().getTime() / 1000; }, function() { run(game); });
	game.soundEffects = new SoundEffects(soundsLoaded, game);
	game.levelIndex = 0;
	game.camera = new Camera();
	game.player = new Player(game.soundEffects);
	initGameLevel(game);
	
	return game;
}

function run(game) {
	game.playerController.update();
	game.stateController.update();
	game.cameraController.update();
	
	if (game.state.goalReached) {
		game.levelIndex++;
		if (game.levelIndex == GameLevels.numberOfLevels()) {
			game.soundEffects.play("allLevelsComplete");
		} else {
			game.soundEffects.play("levelComplete");
		}
		game.levelIndex %= GameLevels.numberOfLevels();
		initGameLevel(game);
	} else if (game.player.position.y < game.level.bottomHeight) {
		game.soundEffects.play("die");
		initGameLevel(game);
	}
}

function draw(gl, game) {
	var error;
	
	gl.clear(gl.COLOR_BUFFER_BIT | gl.DEPTH_BUFFER_BIT);
	
	game.renderer.render(gl);
	
	error = gl.getError();
	if (error != 0) {
		console.log("GL error: " + error);
	}
}

function update(gl, game) {
	game.runLoop.run();
	draw(gl, game);
}

function start() {
	var game = initGame();
	game.runLoop.pause();
}

function soundsLoaded(game) {
	var gl = initWebGL();
	$("loadingText").style.display = "none";
	$("webGLCanvas").style.display = "block";
	document.body.onkeydown = function(event) { keyDown(event, game); }
	document.body.onkeyup = function(event) { keyUp(event, game); }
	setInterval(function() {update(gl, game);}, UPDATE_INTERVAL);
	game.runLoop.resume();
}

function keyDown(event, game) {
	if (event.keyCode == "R".charCodeAt(0)) {
		initGameLevel(game);
	} else {
		game.playerController.keyDown(event.keyCode);
	}
}

function keyUp(event, game) {
	game.playerController.keyUp(event.keyCode);
}