helicopter_game_sketch.js

/*
2017.10.09 -- Aidan Nelson

A quick and dirty clone of the helicopter game as I remember playing it in 
middle school math class on ebaumsworld -- circa 2002.  For Intro to Computational
Media at ITP.

Questions that came up:
	1. should helicopter controls go into helicopter class?
	2. should the function returning an intersection go into the wall or helicopter
			class?
	3. how to monitor an ongoing keypress?
	4. can an object delete itself?
	5. calling 'height' and 'width' from within class OK ?
	6. how to space out walls properly with increasing speed?
*/

////////////////////////////////////////////

//variable for helicopter object
let heli;

//variable for gamestate
let gameOver = false;
let isFirstGo = true;


//game speed and max speed
let speed = 0;


//empty array to hold the walls
let walls = [];

//wall parameters
let wallHeight = 200;
let wallWidth = 50;


//variable for background color
let bg_col;

//difficulty should be a value between 0 and 10, higher numbers being more difficult
let difficulty = 14;

let framesElapsed = 0;

////////////////////////////////////////////


function setup() {
	createCanvas(600, 400);

	//create the helicopter object
	heli = new Heli();

	//define background colors for normal gamestate
	bg_col = color(119, 151, 198);

	//start off with a set of short walls:
	for (let x = 0; x < 50; x++) {
		//top walls
		let shortWallWidth = width / 50;
		walls.push(new Wall(speed, x * shortWallWidth, 0, shortWallWidth, random(20, 30)));
		//bottom walls
		let wh = random(20, 30); // wall height
		walls.push(new Wall(speed, x * shortWallWidth, height - wh, shortWallWidth, wh));
		framesElapsed = 10;
	}
}



function draw() {
	//display the game
	displayGame();

	//update the game
	updateGame();
}





function displayGame() {

	if (isFirstGo) { //splash screen
		//text box
		fill(119, 151, 198);
		rectMode(CENTER);
		rect(width / 2, height / 2, width, height);

		//text
		textSize(50);
		textAlign(CENTER, CENTER);
		fill(255);
		text("HELICOPTER", width / 2, height / 2 - 10);
		textSize(20);
		text("space to play", width / 2, height / 2 + 30);
	} else if (gameOver) { //special parameters for game over state
		//stop game and set color
		speed = 0;
		bg_col = color(255, 0, 0);

		//text box
		fill(0);
		rectMode(CENTER);
		rect(width / 2, height / 2, width, 100);

		//text
		textSize(50);
		textAlign(CENTER, CENTER);
		fill(255);
		text("GAME OVER", width / 2, height / 2 - 10);
		textSize(20);
		text("space to resume", width / 2, height / 2 + 30);
	} else { //play state

		//display the background as bg_col;
		background(bg_col);
		//display the helicopter every frame
		heli.run();

		//iterate through walls list backwards
		for (let i = walls.length - 1; i >= 0; i--) {
			//run the walls
			walls[i].run();
			//splice from the array those walls which are out of the screen
			if (walls[i].isOut()) {
				walls.splice(i, 1);
			}
		}
	}
}

function updateGame() {
	//check if the game is over:
	checkIfGameOver();


	if (isFirstGo) {
		if (keyIsDown(32)) {
			resetGame();
			isFirstGo = false;
		}
	} else if (gameOver) { //check for gameover state
		heli.stop();
		//space to resume game
		if (keyIsDown(32)) {
			resetGame();
		}
	} else { //game is not over!
		// add a new wall on right of window every time a wall...
		if (framesElapsed * speed >= wallWidth) {
			addWalls();
			framesElapsed = 0;
		}
		//check for keypresses!
		if (keyIsDown(32)) {
			heli.yspeed -= 1;
		}
	}

	//move frame marker:
	framesElapsed += 1;


}

function checkIfGameOver() {
	//iterate throug walls list backwards, checking if ball is in each wall
	for (let i = walls.length - 1; i >= 0; i--) {
		if (heli.isIn(walls[i])) {
			gameOver = true;
		}
	}
}


//add walls
function addWalls() {
	//top walls
	walls.push(new Wall(speed, windowWidth, 0, wallWidth, random(20, 10 * difficulty)));
	//bottom walls
	let wh = random(20, 10 * difficulty); // wall height
	walls.push(new Wall(speed, windowWidth, height - wh, wallWidth, wh));
}


function resetGame() {
	gameOver = false;
	walls.splice(0, walls.length);
	speed = 5;
	bg_col = color(119, 151, 198);
	//reset helicopter to starting state
	heli.reset();
	//start off with a set of short walls:
	for (let x = 0; x < 50; x++) {
		//top walls
		let shortWallWidth = width / 50;
		walls.push(new Wall(speed, x * shortWallWidth, 0, shortWallWidth, random(20, 30)));
		//bottom walls
		let wh = random(20, 30); // wall height
		walls.push(new Wall(speed, x * shortWallWidth, height - wh, shortWallWidth, wh));
		framesElapsed = 10;
	}
}