(function(window){
var Game = {
init: function(){
this.c = document.getElementById("game");
this.c.width = this.c.width;
this.c.height = this.c.height;
this.ctx = this.c.getContext("2d");
this.color = "rgba(20,20,20,.7)";
this.bullets = [];
this.enemyBullets = [];
this.enemies = [];
this.particles = [];
this.bulletIndex = 0;
this.enemyBulletIndex = 0;
this.enemyIndex = 0;
this.particleIndex = 0;
this.maxParticles = 10;
this.maxEnemies = 6;
this.enemiesAlive = 0;
this.currentFrame = 0;
this.maxLives = 3;
this.life = 0;
this.binding();
this.player = new Player();
this.score = 0;
this.paused = false;
this.shooting = false;
this.oneShot = false;
this.isGameOver = false;
this.requestAnimationFrame = window.requestAnimationFrame || window.webkitRequestAnimationFrame || window.mozRequestAnimationFrame;
for(var i = 0; i<this.maxEnemies; i++){
new Enemy();
this.enemiesAlive++;
}
this.invincibleMode(2000);
this.loop();
},
binding: function(){
window.addEventListener("keydown", this.buttonDown);
window.addEventListener("keyup", this.buttonUp);
window.addEventListener("keypress", this.keyPressed);
this.c.addEventListener("click", this.clicked);
},
clicked: function(){
if(!Game.paused) {
Game.pause();
} else {
if(Game.isGameOver){
Game.init();
} else {
Game.unPause();
Game.loop();
Game.invincibleMode(1000);
}
}
},
keyPressed: function(e){
if(e.keyCode === 32){
if(!Game.player.invincible && !Game.oneShot){
Game.player.shoot();
Game.oneShot = true;
}
if(Game.isGameOver){
Game.init();
}
e.preventDefault();
}
},
buttonUp: function(e){
if(e.keyCode === 32){
Game.shooting = false;
Game.oneShot = false;
e.preventDefault();
}
if(e.keyCode === 37 || e.keyCode === 65){
Game.player.movingLeft = false;
}
if(e.keyCode === 39 || e.keyCode === 68){
Game.player.movingRight = false;
}
},
buttonDown: function(e){
if(e.keyCode === 32){
Game.shooting = true;
}
if(e.keyCode === 37 || e.keyCode === 65){
Game.player.movingLeft = true;
}
if(e.keyCode === 39 || e.keyCode === 68){
Game.player.movingRight = true;
}
},
random: function(min, max){
return Math.floor(Math.random() * (max - min) + min);
},
invincibleMode: function(s){
this.player.invincible = true;
setTimeout(function(){
Game.player.invincible = false;
}, s);
},
collision: function(a, b){
return !(
((a.y + a.height) < (b.y)) ||
(a.y > (b.y + b.height)) ||
((a.x + a.width) < b.x) ||
(a.x > (b.x + b.width))
)
},
clear: function(){
this.ctx.fillStyle = Game.color;
this.ctx.fillRect(0, 0, this.c.width, this.c.height);
},
pause: function(){
this.paused = true;
},
unPause: function(){
this.paused = false;
},
gameOver: function(){
this.isGameOver = true;
this.clear();
var message = "Game Over";
var message2 = "Score: " + Game.score;
var message3 = "Click or press Spacebar to Play Again";
this.pause();
this.ctx.fillStyle = "white";
this.ctx.font = "bold 30px Lato, sans-serif";
this.ctx.fillText(message, this.c.width/2 - this.ctx.measureText(message).width/2, this.c.height/2 - 50);
this.ctx.fillText(message2, this.c.width/2 - this.ctx.measureText(message2).width/2, this.c.height/2 - 5);
this.ctx.font = "bold 16px Lato, sans-serif";
this.ctx.fillText(message3, this.c.width/2 - this.ctx.measureText(message3).width/2, this.c.height/2 + 30);
},
updateScore: function(){
this.ctx.fillStyle = "white";
this.ctx.font = "16px Lato, sans-serif";
this.ctx.fillText("Score: " + this.score, 8, 20);
this.ctx.fillText("Lives: " + (this.maxLives - this.life), 8, 40);
},
loop: function(){
if(!Game.paused){
Game.clear();
for(var i in Game.enemies){
var currentEnemy = Game.enemies[i];
currentEnemy.draw();
currentEnemy.update();
if(Game.currentFrame % currentEnemy.shootingSpeed === 0){
currentEnemy.shoot();
}
}
for(var x in Game.enemyBullets){
Game.enemyBullets[x].draw();
Game.enemyBullets[x].update();
}
for(var z in Game.bullets){
Game.bullets[z].draw();
Game.bullets[z].update();
}
if(Game.player.invincible){
if(Game.currentFrame % 20 === 0){
Game.player.draw();
}
} else {
Game.player.draw();
}
for(var i in Game.particles){
Game.particles[i].draw();
}
Game.player.update();
Game.updateScore();
Game.currentFrame = Game.requestAnimationFrame.call(window, Game.loop);
}
}
};
var Player = function(){
this.width = 60;
this.height = 20;
this.x = Game.c.width/2 - this.width/2;
this.y = Game.c.height - this.height;
this.movingLeft = false;
this.movingRight = false;
this.speed = 8;
this.invincible = false;
this.color = "white";
};
Player.prototype.die = function(){
if(Game.life < Game.maxLives){
Game.invincibleMode(2000);
Game.life++;
} else {
Game.pause();
Game.gameOver();
}
};
Player.prototype.draw = function(){
Game.ctx.fillStyle = this.color;
Game.ctx.fillRect(this.x, this.y, this.width, this.height);
};
Player.prototype.update = function(){
if(this.movingLeft && this.x > 0){
this.x -= this.speed;
}
if(this.movingRight && this.x + this.width < Game.c.width){
this.x += this.speed;
}
if(Game.shooting && Game.currentFrame % 10 === 0){
this.shoot();
}
for(var i in Game.enemyBullets){
var currentBullet = Game.enemyBullets[i];
if(Game.collision(currentBullet, this) && !Game.player.invincible){
this.die();
delete Game.enemyBullets[i];
}
}
};
Player.prototype.shoot = function(){
Game.bullets[Game.bulletIndex] = new Bullet(this.x + this.width/2);
Game.bulletIndex++;
};
var Bullet = function(x){
this.width = 8;
this.height = 20;
this.x = x;
this.y = Game.c.height - 10;
this.vy = 8;
this.index = Game.bulletIndex;
this.active = true;
this.color = "white";
};
Bullet.prototype.draw = function(){
Game.ctx.fillStyle = this.color;
Game.ctx.fillRect(this.x, this.y, this.width, this.height);
};
Bullet.prototype.update = function(){
this.y -= this.vy;
if(this.y < 0){
delete Game.bullets[this.index];
}
};
var Enemy = function(){
this.width = 60;
this.height = 20;
this.x = Game.random(0, (Game.c.width - this.width));
this.y = Game.random(10, 40);
this.vy = Game.random(1, 3) * .1;
this.index = Game.enemyIndex;
Game.enemies[Game.enemyIndex] = this;
Game.enemyIndex++;
this.speed = Game.random(2, 3);
this.shootingSpeed = Game.random(30, 80);
this.movingLeft = Math.random() < 0.5 ? true : false;
this.color = "hsl("+ Game.random(0, 360) +", 60%, 50%)";
};
Enemy.prototype.draw = function(){
Game.ctx.fillStyle = this.color;
Game.ctx.fillRect(this.x, this.y, this.width, this.height);
};
Enemy.prototype.update = function(){
if(this.movingLeft){
if(this.x > 0){
this.x -= this.speed;
this.y += this.vy;
} else {
this.movingLeft = false;
}
} else {
if(this.x + this.width < Game.c.width){
this.x += this.speed;
this.y += this.vy;
} else {
this.movingLeft = true;
}
}
for(var i in Game.bullets){
var currentBullet = Game.bullets[i];
if(Game.collision(currentBullet, this)){
this.die();
delete Game.bullets[i];
}
}
};
Enemy.prototype.die = function(){
this.explode();
delete Game.enemies[this.index];
Game.score += 15;
Game.enemiesAlive = Game.enemiesAlive > 1 ? Game.enemiesAlive - 1 : 0;
if(Game.enemiesAlive < Game.maxEnemies){
Game.enemiesAlive++;
setTimeout(function(){
new Enemy();
}, 2000);
}
};
Enemy.prototype.explode = function(){
for(var i=0; i<Game.maxParticles; i++){
new Particle(this.x + this.width/2, this.y, this.color);
}
};
Enemy.prototype.shoot = function(){
new EnemyBullet(this.x + this.width/2, this.y, this.color);
};
var EnemyBullet = function(x, y, color){
this.width = 8;
this.height = 20;
this.x = x;
this.y = y;
this.vy = 6;
this.color = color;
this.index = Game.enemyBulletIndex;
Game.enemyBullets[Game.enemyBulletIndex] = this;
Game.enemyBulletIndex++;
};
EnemyBullet.prototype.draw = function(){
Game.ctx.fillStyle = this.color;
Game.ctx.fillRect(this.x, this.y, this.width, this.height);
};
EnemyBullet.prototype.update = function(){
this.y += this.vy;
if(this.y > Game.c.height){
delete Game.enemyBullets[this.index];
}
};
var Particle = function(x, y, color){
this.x = x;
this.y = y;
this.vx = Game.random(-5, 5);
this.vy = Game.random(-5, 5);
this.color = color || "orange";
Game.particles[Game.particleIndex] = this;
this.id = Game.particleIndex;
Game.particleIndex++;
this.life = 0;
this.gravity = .05;
this.size = 40;
this.maxlife = 100;
}
Particle.prototype.draw = function(){
this.x += this.vx;
this.y += this.vy;
this.vy += this.gravity;
this.size *= .89;
Game.ctx.fillStyle = this.color;
Game.ctx.fillRect(this.x, this.y, this.size, this.size);
this.life++;
if(this.life >= this.maxlife){
delete Game.particles[this.id];
}
};
Game.init();
}(window));