Jets Shootout

*Featured Game Created by r8w9

Have fun playing this fun Jet Game and view the well commented Source code to learn more about creating your own games

Source Code

HTML CSS and JavaScript

<!DOCTYPE html>
<html>
<head>

<title>Page Title</title>
<style>
* {
padding: 0;
margin: 0;
overflow: hidden;
background: url("https://i.ibb.co/MD65KNh/heaven.jpg") no-repeat center fixed;
-webkit-background-size: cover;
-moz-background-size: cover;
-o-background-size: cover;
background-size: cover;
}
</style>
</head>
<body>
<canvas></canvas>
</body>
<script>
alert("Collect more than 500 points to WIN!");
/*-----------ONLOAD INITIALIZATION-----------*/
window.onload = function(){
var canvas = document.querySelector("canvas");
var c = canvas.getContext("2d");
canvas.width = window.innerWidth;
canvas.height = window.innerHeight;

/*-----------MOUSE/TOUCH & CONTROLS-----------*/
//mouse and touch objects

var mouse = {
x: window.innerWidth/2,
y: window.innerHeight-33
};

var touch = {
x: window.innerWidth/2,
y: window.innerHeight-33
};

//event listener for mouse object
canvas.addEventListener("mousemove", function(event){
mouse.x = event.clientX;
//mouse.y = event.clientY;
});
//eventListener to mouse object
canvas.addEventListener("touchmove", function(event){
var rect = canvas.getBoundingClientRect();
var root = document.documentElement;
var touch = event.changedTouches[0];
var touchX = parseInt(touch.clientX);
var touchY = parseInt(touch.clientY) - rect.top - root.scrollTop;
event.preventDefault();
mouse.x = touchX;
//mouse.y = touchY;
});

/*-----------GAME VARIABLES-----------*/
//player
var _players = [];
var player_width = 64;
var player_height = 64;
var playerImg = new Image();
playerImg.src = "https://i.ibb.co/k9xW3wx/jet.png";
var health = 100;

//bullet array
var _bullets = []; //array to hold n bullets
var bullet_width = 6;
var bullet_height = 8;
var bullet_speed = 8;

var _bullets2 = []; //array to hold n bullets [boss]

//health array
var _healthkits = []; //array to hold n health kits
var healthkitImg = new Image();
healthkitImg.src = "https://image.ibb.co/iTrjuU/hospital.png"; //"https://image.ibb.co/gFvSEU/first_aid_kit.png";
var healthkit_width = 32;
var healthkit_height = 32;

//boss array
var _boss = []; //array for boss
var bossImg = new Image(); //boss image
bossImg.src = "https://i.ibb.co/L8g3tSX/airplane.png"; //boss src image
var boss_width = 64;
var boss_height = 64;
var boss_speed = 2; //speed of boss
var boss_health = 100;

//timing variables - this variables are used in main game loop function for handling delayed function calling
var lastTime = 0;
var lastTime2 = 0;
var lastTime3 = 0;

/*-----------GAME OBJECTS-----------*/

//Player object
function Player(x, y, width, height){
this.x = x;
this.y = y;
this.width = width;
this.height = height;

this.draw = function(){
c.beginPath();
c.drawImage(playerImg, mouse.x - player_width/2, mouse.y - player_height/2); //draw player and center cursor
};

this.update = function(){
this.draw();
};
}

//Bullet object
function Bullet(x, y, width, height, speed){
this.x = x;
this.y = y;
this.width = width;
this.height = height;
this.speed = speed;

this.draw = function(){
c.beginPath();
c.rect(this.x, this.y, this.width, this.height);
c.fillStyle = "#fff";
c.fill();
c.stroke();
};

this.update = function(){
this.y -= this.speed;
this.draw();
};
}

//Health kit object
function Healthkit(x, y, width, height, speed){
this.x = x;
this.y = y;
this.width = width;
this.height = height;
this.speed = speed;

this.draw = function(){
c.beginPath();
c.drawImage(healthkitImg, this.x, this.y);
};

this.update = function(){
this.x += this.speed;
this.draw();
};
}

//Boss object
function Boss(x, y, width, height, speed){
this.x = x;
this.y = y;
this.width = width;
this.height = height;
this.speed = speed;

this.draw = function(){
c.beginPath();
c.drawImage(bossImg, this.x, this.y);
};

this.update = function(){
//this.x += this.speed;
if(this.x + boss_width/2 + 5 < mouse.x){ // 5 for smooth
this.x += this.speed;
}
else if(this.x + boss_width/2 > mouse.x) {
this.x -= this.speed;
}

this.draw();
};
}

/*-----------_new OBJECT-----------*/
//draw Player
for (var _ = 0; _<1; _++){ //draw player, only once
var __player = new Player(mouse.x, mouse.y, player_width, player_height);
_players.push(__player);
}

function drawBoss(){ //draw boss, only once
for (var _ = 0; _<1; _++){
var x = Math.random()*(canvas.width - boss_width);
var y = 0;
var width = boss_width;
var height = boss_height;
var speed = boss_speed;
var __boss = new Boss(x, y, width, height, speed);
_boss.push(__boss); //push boss to my boss array
}
}drawBoss();

/*
******************** NOTE FOR ME *********************
By moving function drawHealthkits() from ln 198 to animate function (gameloop)
and by using vars lastTime, lastTime2, lastTime3 I can manage
timing of each function with currentTime and lastTime comparision.
currentTime and lastTime in function:

function animate(currentTime){
..
if(currentTime > lastTime + 1000){ // + 1000 gives me 1000ms (1s) delay
lastTime = currentTime
}
}
*/

/* DRAW HEALTHKITS is moved to animate function (gameloop) to avoid setInterval
//draw health kits
function drawHealthkits(){
for (var _ = 0; _<1; _++){ //healthkits
var x = -healthkit_width;
var y = canvas.height/2;
var width = healthkit_width;
var height = healthkit_height;
var speed = Math.random()*2.6;
var __healthkit = new Healthkit(x, y, width, height, speed);
_healthkits.push(__healthkit); //push enemy to my array of enemies
}
}setInterval(drawHealthkits, 9000); //draw healthkits every 9000ms (9s)
*/

//draw bullet
//var __bullet = new Bullet(mouse.x-bullet_width/2, mouse.y-player_height, bullet_width, bullet_height, bullet_speed);

/*Older fire function - called with setInterval - now moved to animate func (game loop)
//fire bullet function
function fire(){ //fire bullet from mouse.x on x axis, y axis, width, height, speed
for (var _ = 0; _<1; _++){
var x = mouse.x-bullet_width/2;
var y = mouse.y-player_height;
var speed = bullet_speed;
var __bullet = new Bullet(x, y, bullet_width, bullet_height, bullet_speed);
_bullets.push(__bullet); //push bullet to my array of bullets
}
}//setInterval(fire, 1234);
*/

//event listener for fire function - now disabled
canvas.addEventListener("click", function(){
//fire();
});

/*-----------COLLISION DETECTION-----------*/
function collision(a,b){
return a.x < b.x + b.width &&
a.x + a.width > b.x &&
a.y < b.y + b.height &&
a.y + a.height > b.y;
}
function collision2(a,b){
return mouse.x - a.width/2 < b.x + b.width &&
mouse.x + a.width/2 > b.x &&
mouse.y < b.y + b.height &&
mouse.y + a.height > b.y;
}
/*-----------BOSS_HEALTH-----------*/
c.fillStyle = "white";
c.font = "1em Arial";

/*-----------DIRTY ERROR HANDLING-----------*/
function stoperror() {
return true;
}
window.onerror = stoperror;

/*-----------GAME LOOP-----------*/
function animate(currentTime){ //currentTime for handling timing (firing, drawing healthkits)
requestAnimationFrame(animate); //animate
c.beginPath(); //begin
c.clearRect(0, 0, window.innerWidth, window.innerHeight); //clear canvas
c.fillText(health, mouse.x + 32, mouse.y); //health
for(var i=0; i<_boss.length; i++){
c.fillText(boss_health, _boss[i].x + boss_width , 20); //boss_health
}

/*-----------__player, __bullet, __enemy update, __healthkit update-----------*/
//update _player
for (var i=0; i < _players.length; i++){
_players[i].update();
//console.log(_players[i].hp); //deleted this.hp for clarity
}

//update bullets from bullets array
for (var i=0; i < _bullets.length; i++){
_bullets[i].update();
if (_bullets[i].y < 0 || _bullets[i].y > canvas.height){
_bullets.splice(i, 1);
}
}

//update bullets2 from bullets array
for (var i=0; i < _bullets2.length; i++){
_bullets2[i].update();
if (_bullets2[i].y < 0 || _bullets2[i].y > canvas.height){
_bullets2.splice(i, 1);
}
}

//draw healthkits
for(var h=0; h < _healthkits.length; h++){
_healthkits[h].update();
}

/**************** FIRE BULLETS FUNCTION ****************/
function fire(){ //fire bullet from mouse.x on x axis, y axis, width, height, speed
for (var _ = 0; _<1; _++){
if(currentTime >= lastTime2 + 1000){ //fire every 1000ms (1s)
lastTime2 = currentTime;
var x = mouse.x-bullet_width/2;
var y = mouse.y-player_height;
var speed = bullet_speed;
var __bullet = new Bullet(x, y, bullet_width, bullet_height, bullet_speed);
_bullets.push(__bullet); //push bullet to my array of bullets
}
}
}fire();

/**************** BOSS FIRE BULLETS FUNCTION ****************/
//with currentTime and lastTime comparison we can shoot every .5 second (500ms)
for(var i=0; i<_boss.length; i++){
_boss[i].update();
if(currentTime >= lastTime + 500){
lastTime = currentTime;

for (var _ = 0; _<1; _++){
var x = _boss[i].x+boss_width/2;
var y = boss_height;
var speed = 10;
var __bullet2 = new Bullet(x, y, bullet_width, bullet_height, -speed);
_bullets2.push(__bullet2); //push bullet to my array of bullets
}
}
}

/**************** DRAW HEALTHKITS FUNCTION ****************/
function drawHealthkits(){ //draw health kits every 9000ms (9s)
for(var _ = 0; _<1; _++){ //draw healthkit
if(currentTime >= lastTime3 + 9000){ //draw it every 9s with currentTime and lastTime comparision
lastTime3 = currentTime;
var x = -healthkit_width; //starting x axis position
var y = canvas.height/2; //y axis postion - centered
var width = healthkit_width;
var height = healthkit_height;
var speed = Math.random()*3.5; //healthkit's speed
var __healthkit = new Healthkit(x, y, width, height, speed);
_healthkits.push(__healthkit); //push healthkits to array
}
}
}drawHealthkits();

/*
****************** COLLISIONS, BOOM! ******************

_ ,-, _
,--, /: :\/': :`\/: :\
|`; ' `,' `.; `: |
| | | ' | |.
| : | |BOOM!| ||
| :. | : | : | : | \
\__/: :.. : :.. | :.. | )
`---',\___/,\___/ /'
`==._ .. . /'
`-::-'

*/

/***********BOSS AND BULLETS COLLISIONS***********/
//1. loop over both boss and bullets to detect collisions
for(var jl = _boss.length-1; jl >= 0; jl--){
for(var ll = _bullets.length-1; ll >= 0; ll--){
if(collision(_boss[jl], _bullets[ll])){
_bullets.splice(ll, 1);
//boss.splice(jl, 1);
boss_health -= 10;
if(boss_health == 0){
alert("You WON this round! You get extra hp!");
health += 100;
boss_health = 100;
}
else if(health >= 500){
alert("You WON! You collected more than 500 points!");
health = 100;
boss_health = 100;
}
}
}
}

/***********PLAYER AND BULLETS COLLISIONS***********/
//2. loop over both player and bullets to detect collisions
for(var q2 = _players.length-1; q2 >= 0; q2--){
for(var q3 = _bullets2.length-1; q3 >= 0; q3--){
if(collision2(_players[q2], _bullets2[q3])){
_bullets2.splice(q3, 1);
health -= 10;
if(health == 0){
alert("You LOST this round! Boss now gets extra hp!");
health = 100;
boss_health += 100;
}

else if(boss_health >= 500){
alert("You LOST! Enemy collected more than 500 points!");
health = 100;
boss_health = 100;
}
}
}
}

/***********HEALTHKITS AND BULLETS COLLISIONS***********/
//loop over both healthkits and bullets to detect collisions
for(var hh = _healthkits.length-1; hh >= 0; hh--){
for(var hhh = _bullets.length-1; hhh >= 0; hhh--){
if(collision(_healthkits[hh], _bullets[hhh])){
_healthkits.splice(hh, 1);
_bullets.splice(hhh, 1);
health += 100;
}
}
}

/***********HEALTHKITS AND BULLETS [FROM BOSS] COLLISIONS***********/
//loop over both healthkits and bullets to detect collisions [boss bullets]
for(var hh = _healthkits.length-1; hh >= 0; hh--){
for(var hhh = _bullets2.length-1; hhh >= 0; hhh--){
if(collision(_healthkits[hh], _bullets2[hhh])){
_healthkits.splice(hh, 1);
_bullets2.splice(hhh, 1);
boss_health += 100;
}
}
}

} //animate func
animate();

}; //end of onload func

</script>
</html>

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Jets Shootout

Jets Shootout

*Featured Game Created by r8w9

Click here to run this code

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