Javascript
Making Simple Catch Star Game with Javascript-Phaser 3 Framework
Phaser framework is a free javascript library created especially for game developers. It contains many ready-made functions and structures and makes it easier for javascript game programmers. Many interactive html5 applications with visual content, not just games, can be created with the help of Javascript-Phaser.
Here we will prepare the Catch Star game step by step. With this activitiy you will catch important gains and tips in the use of Phaser 3 framework. And then you can develop your own game.
IMPORTANT:Before developing this application on your own computer, you must install one of the server applications, such as Xampp, on your computer. Otherwise, you will not see the output of the code.
What will you learn while making this game?
- Using horizontal and vertical spritesheet in Phaser,
- Giving desired color textures to texts and shapes with Phaser,
- To move a character in 4 directions in Phaser,
- Interacting between characters in Phaser,
- Using functions and conditions (if-else) structures at Javascript.
Scenario of the game:
The aim of this game is to reach the door after collecting at least 8 stars with the character that we direct with the arrow keys of the keyboard. While doing this, the bombs should be avoided. Touching the bombs in 10 times will kill you and the game will fail.
Now let's go step by step to the construction of the game.
First of all, the screen dimensions of the game and the coordinate structure in Phaser are as follows:
The coordinate dimensions given in the following coding are according to scaling above.
Step 1: Embedding game code into the internet page and creating the basic foldering and coding structure
Since the game is a javascript based structure, we create the basic structure in tags as follows. The basic structure codes and related explanations are given below.
<script type="text/javascript">
var config = {
type: Phaser.AUTO,
width: 1024, //Defining game scene width
height: 768, //Defining game scene height
physics: {
default: 'arcade',
arcade: {
debug: false
}
},
scene: {
preload: preload, //Defining preloaded materials
create: create, //Defining objects and animations
update: update //Events in the flow of the game
}
};
var game = new Phaser.Game(config); //We create the phaser object whose settings are given in config above
function preload ()
{
}
function create ()
{
}
function update ()
{
}
</script>To access the code above which is embedded in a web page page:
On this page, you can view the source from the right-click menu and see how javascript code is embedded in web page. Also you will see how to import Phaser3 framework to the web page. Please look between tags for this.
You can use softwares such as Atom, Brackets, Notepad ++ for creating the web page. When saving the page, change the extension of web page such as html, htm, php, asp, aspx.
Step 2: Adding background and main character (bobi) to the game
As screenshot above, you can edit your code structure to add the background image and main character to the game as follows:
<script type="text/javascript">
var config = {
type: Phaser.AUTO,
width: 1024, //Defining game scene width
height: 768, //Defining game scene heght
physics: {
default: 'arcade',
arcade: {
debug: false
}
},
scene: {
preload: preload, //Defining preloaded materials
create: create, //Defining objects and animations
update: update //Events in the flow of the game
}
};
var game = new Phaser.Game(config); //We create the phaser object whose settings are given in config above
function preload ()
{
this.load.image('bg', 'images/bg.png'); //The images to be created must be preloaded in this way
this.load.spritesheet('bobihorizontal', 'images/bobihorizontal.png', { frameWidth: 114, frameHeight: 300 }); //With this code, we load the sequence of horizontal character images of our character
this.load.spritesheet('bobiup', 'images/bobiup.png', { frameWidth: 111, frameHeight: 312 }); //With this code, we load the sequence of up going character images of our character
this.load.spritesheet('bobidown', 'images/bobidown.png', { frameWidth: 111, frameHeight: 312 }); //With this code, we load the sequence of down going character images of our character
this.load.image('star', 'images/star.png');
this.load.image('bomba', 'images/bomba.png');
this.load.image('doorimg', 'images/door.png');
}
function create ()
{
background = this.add.image(512, 384, 'bg'); //We assign value to variable and add to scene
bobi = this.physics.add.sprite(100, 450, 'bobihorizontal').setScale(0.3); //We assign preloaded image to variable and add to scene
}
function update ()
{
}
</script>To access the code above which is embedded in a web page page:
Step 3: Coding the main character's movements
Main character Bobi is coded according to the arrow keys of the keyboard as follows. With this code Bobi can go up,down,left,right.
<script type="text/javascript">
var config = {
type: Phaser.AUTO,
width: 1024, //Defining game scene width
height: 768, //Defining game scene heght
physics: {
default: 'arcade',
arcade: {
debug: false
}
},
scene: {
preload: preload, //Defining preloaded materials
create: create, //Defining objects and animations
update: update //Events in the flow of the game
}
};
var game = new Phaser.Game(config); //We create the phaser object whose settings are given in config above
//We define variables that we will use throughout the game
var cursors;
function preload ()
{
this.load.image('bg', 'images/bg.png'); //The images to be created must be preloaded in this way
this.load.spritesheet('bobihorizontal', 'images/bobihorizontal.png', { frameWidth: 114, frameHeight: 300 }); //With this code, we load the sequence of horizontal character images of our character
this.load.spritesheet('bobiup', 'images/bobiup.png', { frameWidth: 111, frameHeight: 312 }); //With this code, we load the sequence of up going character images of our character
this.load.spritesheet('bobidown', 'images/bobidown.png', { frameWidth: 111, frameHeight: 312 }); //With this code, we load the sequence of down going character images of our character
}
function create ()
{
background = this.add.image(512, 384, 'bg'); //We assign value to variable and add to scene
bobi = this.physics.add.sprite(100, 450, 'bobihorizontal').setScale(0.3); //We assign preloaded image to variable and add to scene
cursors = this.input.keyboard.createCursorKeys(); //We defined keys
//Creating characters move events
this.anims.create({
key: 'up',
frames: this.anims.generateFrameNumbers('bobiup', { start: 0, end: 3 }),
frameRate: 10,
repeat: -1
});
this.anims.create({
key: 'down',
frames: this.anims.generateFrameNumbers('bobidown', { start: 0, end: 3 }),
frameRate: 10,
repeat: -1
});
this.anims.create({
key: 'left',
frames: this.anims.generateFrameNumbers('bobihorizontal', { start: 0, end: 3 }),
frameRate: 10,
repeat: -1
});
this.anims.create({
key: 'turn',
frames: [ { key: 'bobihorizontal', frame: 4 } ],
frameRate: 20
});
this.anims.create({
key: 'right',
frames: this.anims.generateFrameNumbers('bobihorizontal', { start: 5, end: 8 }),
frameRate: 10,
repeat: -1
});
}
function update ()
{
if (cursors.up.isDown)
{
bobi.setVelocityY(-160);
bobi.anims.play('up', true);
}
else if (cursors.down.isDown)
{
bobi.setVelocityY(160);
bobi.anims.play('down', true);
}
else
{
bobi.setVelocityY(0);
}
if (cursors.left.isDown)
{
bobi.setVelocityX(-160);
bobi.anims.play('left', true);
}
else if (cursors.right.isDown)
{
bobi.setVelocityX(160);
bobi.anims.play('right', true);
}
else
{
bobi.setVelocityX(0);
}
if (!(cursors.left.isDown||cursors.right.isDown||cursors.up.isDown||cursors.down.isDown))
{
bobi.anims.play('turn');
}
}
</script>To access the code above which is embedded in a web page page:
Step 4: Identifying star and bomb character groups and arrange them on the scene at random places each time
The main character will earn points when he touches the stars we will place, and his life will decrease when he touches the bombs. We will define bombs and stars as "staticGroup" and place them on the stage. Stars and bombs will be placed randomly on the screen each time the game is loaded. We've identified 50 bombs and 15 stars here. You can change these numbers. Here's our code:
<script type="text/javascript">
var config = {
type: Phaser.AUTO,
width: 1024, //Defining game scene width
height: 768, //Defining game scene heght
physics: {
default: 'arcade',
arcade: {
debug: false
}
},
scene: {
preload: preload, //Defining preloaded materials
create: create, //Defining objects and animations
update: update //Events in the flow of the game
}
};
var game = new Phaser.Game(config); //We create the phaser object whose settings are given in config above
//We define variables that we will use throughout the game
var cursors;
var stars;
var bombs;
function preload ()
{
this.load.image('bg', 'images/bg.png'); //The images to be created must be preloaded in this way
this.load.spritesheet('bobihorizontal', 'images/bobihorizontal.png', { frameWidth: 114, frameHeight: 300 }); //With this code, we load the sequence of horizontal character images of our character
this.load.spritesheet('bobiup', 'images/bobiup.png', { frameWidth: 111, frameHeight: 312 }); //With this code, we load the sequence of up going character images of our character
this.load.spritesheet('bobidown', 'images/bobidown.png', { frameWidth: 111, frameHeight: 312 }); //With this code, we load the sequence of down going character images of our character
this.load.image('star', 'images/star.png');
this.load.image('bomb', 'images/bomb.png');
}
function create ()
{
background = this.add.image(512, 384, 'bg'); //We assign value to variable and add to scene
bobi = this.physics.add.sprite(100, 450, 'bobihorizontal').setScale(0.3); //We assign preloaded image to variable and add to scene
cursors = this.input.keyboard.createCursorKeys();
cursors = this.input.keyboard.createCursorKeys(); //We defined keys
bombs = this.physics.add.staticGroup();
for (i = 0; i < 50; i++)
{
x = Phaser.Math.Between(0, 1024);
y = Phaser.Math.Between(0, 768);
bombs.create(x, y, 'bomb').refreshBody();
}
stars = this.physics.add.staticGroup();
for (i = 0; i < 15; i++)
{
x = Phaser.Math.Between(0, 1024);
y = Phaser.Math.Between(0, 768);
stars.create(x, y, 'star').refreshBody();
}
//Creating characters move events
this.anims.create({
key: 'up',
frames: this.anims.generateFrameNumbers('bobiup', { start: 0, end: 3 }),
frameRate: 10,
repeat: -1
});
this.anims.create({
key: 'down',
frames: this.anims.generateFrameNumbers('bobidown', { start: 0, end: 3 }),
frameRate: 10,
repeat: -1
});
this.anims.create({
key: 'left',
frames: this.anims.generateFrameNumbers('bobihorizontal', { start: 0, end: 3 }),
frameRate: 10,
repeat: -1
});
this.anims.create({
key: 'turn',
frames: [ { key: 'bobihorizontal', frame: 4 } ],
frameRate: 20
});
this.anims.create({
key: 'right',
frames: this.anims.generateFrameNumbers('bobihorizontal', { start: 5, end: 8 }),
frameRate: 10,
repeat: -1
});
function update ()
{
if (cursors.up.isDown)
{
bobi.setVelocityY(-160);
bobi.anims.play('up', true);
}
else if (cursors.down.isDown)
{
bobi.setVelocityY(160);
bobi.anims.play('down', true);
}
else
{
bobi.setVelocityY(0);
}
if (cursors.left.isDown)
{
bobi.setVelocityX(-160);
bobi.anims.play('left', true);
}
else if (cursors.right.isDown)
{
bobi.setVelocityX(160);
bobi.anims.play('right', true);
}
else
{
bobi.setVelocityX(0);
}
if (!(cursors.left.isDown||cursors.right.isDown||cursors.up.isDown||cursors.down.isDown))
{
bobi.anims.play('turn');
}
}
</script>To access the code above which is embedded in a web page
click here.
Step 5: Adding texts and door and defining main character's interaction with objects
The main character who gets enough points in the game will reach the door and the game will end successfully. In this section we will add the door and define the interaction between objects with overlap function. Here's our code:
<script type="text/javascript">
var config = {
type: Phaser.AUTO,
width: 1024, //Defining game scene width
height: 768, //Defining game scene heght
physics: {
default: 'arcade',
arcade: {
debug: false
}
},
scene: {
preload: preload, //Defining preloaded materials
create: create, //Defining objects and animations
update: update //Events in the flow of the game
}
};
var game = new Phaser.Game(config); //We create the phaser object whose settings are given in config above
//We define variables that we will use throughout the game
var cursors;
var stars;
var bombs;
var door;
var background;
var bobi;
var health=100;
var score=0;
var scoreTxt;
var healthTxt;
var infoTxt;
function preload ()
{
this.load.image('bg', 'images/bg.png'); //The images to be created must be preloaded in this way
this.load.spritesheet('bobihorizontal', 'images/bobihorizontal.png', { frameWidth: 114, frameHeight: 300 }); //With this code, we load the sequence of horizontal character images of our character
this.load.spritesheet('bobiup', 'images/bobiup.png', { frameWidth: 111, frameHeight: 312 }); //With this code, we load the sequence of up going character images of our character
this.load.spritesheet('bobidown', 'images/bobidown.png', { frameWidth: 111, frameHeight: 312 }); //With this code, we load the sequence of down going character images of our character
this.load.image('star', 'images/star.png');
this.load.image('bomb', 'images/bomb.png');
this.load.image('doorimg', 'images/door.png');
}
function create ()
{
background = this.add.image(512, 384, 'bg'); //We assign value to variable and add to scene
bobi = this.physics.add.sprite(100, 450, 'bobihorizontal').setScale(0.3); //We assign preloaded image to variable and add to scene
cursors = this.input.keyboard.createCursorKeys(); //We defined keys
bombs = this.physics.add.staticGroup();
for (i = 0; i < 50; i++)
{
x = Phaser.Math.Between(0, 1024);
y = Phaser.Math.Between(0, 768);
bombs.create(x, y, 'bomb').refreshBody();
}
stars = this.physics.add.staticGroup();
for (i = 0; i < 15; i++)
{
x = Phaser.Math.Between(0, 1024);
y = Phaser.Math.Between(0, 768);
stars.create(x, y, 'star').refreshBody();
}
door = this.physics.add.sprite(x, y, 'doorimg').setScale(0.5);
//We define the interaction of the main character of the game with other objects by overlap
this.physics.add.overlap(bobi, stars, catchStar, null, this);
this.physics.add.overlap(bobi, bombs, hitBomb, null, this);
this.physics.add.overlap(bobi, door, newScene, null, this);
//Creating characters move events
this.anims.create({
key: 'up',
frames: this.anims.generateFrameNumbers('bobiup', { start: 0, end: 3 }),
frameRate: 10,
repeat: -1
});
this.anims.create({
key: 'down',
frames: this.anims.generateFrameNumbers('bobidown', { start: 0, end: 3 }),
frameRate: 10,
repeat: -1
});
this.anims.create({
key: 'left',
frames: this.anims.generateFrameNumbers('bobihorizontal', { start: 0, end: 3 }),
frameRate: 10,
repeat: -1
});
this.anims.create({
key: 'turn',
frames: [ { key: 'bobihorizontal', frame: 4 } ],
frameRate: 20
});
this.anims.create({
key: 'right',
frames: this.anims.generateFrameNumbers('bobihorizontal', { start: 5, end: 8 }),
frameRate: 10,
repeat: -1
});
//Creating texts
scoreTxt = this.add.text(16, 16, 'Score: 0', { font: "bold 24px Verdana", fill: "#fff", boundsAlignH: "center", boundsAlignV: "middle" });
healthTxt = this.add.text(16, 46, 'Health: 100', {font: "bold 24px Verdana", fill: "#fff", boundsAlignH: "center", boundsAlignV: "middle"});
infoTxt = this.add.text(this.scene.centerX, this.scene.centerY, '', { font: "bold 64px Verdana", fill: "#fff", boundsAlignH: "center", boundsAlignV: "middle" })
}
function update ()
{
if (cursors.up.isDown)
{
bobi.setVelocityY(-160);
bobi.anims.play('up', true);
}
else if (cursors.down.isDown)
{
bobi.setVelocityY(160);
bobi.anims.play('down', true);
}
else
{
bobi.setVelocityY(0);
}
if (cursors.left.isDown)
{
bobi.setVelocityX(-160);
bobi.anims.play('left', true);
}
else if (cursors.right.isDown)
{
bobi.setVelocityX(160);
bobi.anims.play('right', true);
}
else
{
bobi.setVelocityX(0);
}
if (!(cursors.left.isDown||cursors.right.isDown||cursors.up.isDown||cursors.down.isDown))
{
bobi.anims.play('turn');
}
}
//Functions that will work with the main characters interaction with other objects
function hitBomb (bobi, bombs)function hitBomb (bobi, bombs)
{
}
function hitBomb (bobi, bombs)
{
}
function newScene (bobi, door)
{
}
</script>To access the code above which is embedded in a web page page:
Step 6: Completing the game by creating functions related interactions
In the previous step, we have defined the functions that will take place when the main character interacts with other objects with the overlap function. These were BombCarp, StarBalls, and new Stage functions. Tasks of these functions will be as follows;
With hitBomb function;
- Hiding bomb that the main character touches,
- Health value will be reduced and displayed on the screen.
With catchStar function;
- Hiding star that the main character touches,
- Score value will be increased and displayed on the screen.
With newScene function;
Check if the main character collects at least 8 stars,
If the main character has collected at least 8 stars, it will come to the center of the screen with its original size,
- "CONGRATULATIONS" text will be shown on screen,
- Other things will disappear and be removed.
If the main character has not collected at least 8 stars,
When bobi reach the door, the message "Collect at least 8 stars" will appear for 1 second. Disappearance will occur with the hideText function.
Apart from these functions, at this stage, in the update function, the events that will happen when the character touches the bombs and game failed. Detailed descriptions of the codes are in source code below:
<script type="text/javascript">
var config = {
type: Phaser.AUTO,
width: 1024, //Defining game scene width
height: 768, //Defining game scene heght
physics: {
default: 'arcade',
arcade: {
debug: false
}
},
scene: {
preload: preload, //Defining preloaded materials
create: create, //Defining objects and animations
update: update //Events in the flow of the game
}
};
var game = new Phaser.Game(config); //We create the phaser object whose settings are given in config above
//We define variables that we will use throughout the game
var cursors;
var stars;
var bombs;
var door;
var background;
var bobi;
var health=100;
var score=0;
var scoreTxt;
var healthTxt;
var infoTxt;
function preload ()
{
this.load.image('bg', 'images/bg.png'); //The images to be created must be preloaded in this way
this.load.spritesheet('bobihorizontal', 'images/bobihorizontal.png', { frameWidth: 114, frameHeight: 300 }); //With this code, we load the sequence of horizontal character images of our character
this.load.spritesheet('bobiup', 'images/bobiup.png', { frameWidth: 111, frameHeight: 312 }); //With this code, we load the sequence of up going character images of our character
this.load.spritesheet('bobidown', 'images/bobidown.png', { frameWidth: 111, frameHeight: 312 }); //With this code, we load the sequence of down going character images of our character
this.load.image('star', 'images/star.png');
this.load.image('bomb', 'images/bomb.png');
this.load.image('doorimg', 'images/door.png');
}
function create ()
{
background = this.add.image(512, 384, 'bg'); //We assign value to variable and add to scene
bobi = this.physics.add.sprite(100, 450, 'bobihorizontal').setScale(0.3); //We assign preloaded image to variable and add to scene
cursors = this.input.keyboard.createCursorKeys(); //We defined keys
bombs = this.physics.add.staticGroup();
for (i = 0; i < 50; i++)
{
x = Phaser.Math.Between(0, 1024);
y = Phaser.Math.Between(0, 768);
bombs.create(x, y, 'bomb').refreshBody();
}
stars = this.physics.add.staticGroup();
for (i = 0; i < 15; i++)
{
x = Phaser.Math.Between(0, 1024);
y = Phaser.Math.Between(0, 768);
stars.create(x, y, 'star').refreshBody();
}
door = this.physics.add.sprite(x, y, 'doorimg').setScale(0.5);
//We define the interaction of the main character of the game with other objects by overlap
this.physics.add.overlap(bobi, stars, catchStar, null, this);
this.physics.add.overlap(bobi, bombs, hitBomb, null, this);
this.physics.add.overlap(bobi, door, newScene, null, this);
//Creating characters move events
this.anims.create({
key: 'up',
frames: this.anims.generateFrameNumbers('bobiup', { start: 0, end: 3 }),
frameRate: 10,
repeat: -1
});
this.anims.create({
key: 'down',
frames: this.anims.generateFrameNumbers('bobidown', { start: 0, end: 3 }),
frameRate: 10,
repeat: -1
});
this.anims.create({
key: 'left',
frames: this.anims.generateFrameNumbers('bobihorizontal', { start: 0, end: 3 }),
frameRate: 10,
repeat: -1
});
this.anims.create({
key: 'turn',
frames: [ { key: 'bobihorizontal', frame: 4 } ],
frameRate: 20
});
this.anims.create({
key: 'right',
frames: this.anims.generateFrameNumbers('bobihorizontal', { start: 5, end: 8 }),
frameRate: 10,
repeat: -1
});
//Creating texts
scoreTxt = this.add.text(16, 16, 'Score: 0', { font: "bold 24px Verdana", fill: "#fff", boundsAlignH: "center", boundsAlignV: "middle" });
healthTxt = this.add.text(16, 46, 'Health: 100', {font: "bold 24px Verdana", fill: "#fff", boundsAlignH: "center", boundsAlignV: "middle"});
infoTxt = this.add.text(this.scene.centerX, this.scene.centerY, '', { font: "bold 64px Verdana", fill: "#fff", boundsAlignH: "center", boundsAlignV: "middle" })
}
function update ()
{
if (cursors.up.isDown)
{
bobi.setVelocityY(-160);
bobi.anims.play('up', true);
}
else if (cursors.down.isDown)
{
bobi.setVelocityY(160);
bobi.anims.play('down', true);
}
else
{
bobi.setVelocityY(0);
}
if (cursors.left.isDown)
{
bobi.setVelocityX(-160);
bobi.anims.play('left', true);
}
else if (cursors.right.isDown)
{
bobi.setVelocityX(160);
bobi.anims.play('right', true);
}
else
{
bobi.setVelocityX(0);
}
if (!(cursors.left.isDown||cursors.right.isDown||cursors.up.isDown||cursors.down.isDown))
{
bobi.anims.play('turn');
}
if (health < 10)
{
infoTxt = this.add.text(this.scene.centerX, this.scene.centerY, 'GAME OVER', { font: "bold 64px Verdana", fill: "#fff", boundsAlignH: "center", boundsAlignV: "middle" })
infoTxt.setTint(0xff00ff, 0xffff00, 0x0000ff, 0xff0000);
Phaser.Display.Align.In.Center(infoTxt, this.add.zone(512, 354, 1024, 768));
bobi.destroy();
background.destroy();
healthTxt.destroy();
door.destroy();
Phaser.Actions.SetVisible(bombs.getChildren(), false);
bombs.clear();
Phaser.Actions.SetVisible(stars.getChildren(), false);
stars.clear();
return;
}
}
//Functions that will work with the main characters interaction with other objects
function hitBomb (bobi, bombs)
{
bombs.disableBody(true, true);
health -= 10;
healthTxt.setText('Health: ' + health);
}
function catchStar (bobi, stars)
{
stars.disableBody(true, true);
score += 10;
scoreTxt.setText('score: ' + score);
}
function newScene (bobi, door)
{
if (score>70){
infoTxt.setVisible(true);
infoTxt.setText('CONGRATULATIONS!!');
infoTxt.setTint(0xff00ff, 0xffff00, 0x0000ff, 0xff0000);
Phaser.Display.Align.In.Center(infoTxt, this.add.zone(512, 354, 1024, 768));
bobi.setX(512);
bobi.setY(500);
bobi.setScale(1);
bobi.disableInteractive();
background.destroy();
door.destroy();
Phaser.Actions.SetVisible(bombs.getChildren(), false);
bombs.clear();
Phaser.Actions.SetVisible(stars.getChildren(), false);
stars.clear();
bobi.anims.play('turn');
}
else {
infoTxt.setVisible(true);
infoTxt.setText('En az 8 yıldız toplayın');
infoTxt.setTint(0xff00ff, 0xffff00, 0x0000ff, 0xff0000);
Phaser.Display.Align.In.Center(infoTxt, this.add.zone(512, 354, 1024, 768));
this.time.delayedCall(1000, infoTxthide, [], this);
}
}
function infoTxthide ()
{
infoTxt.setVisible(false);
}
</script>To access this source code embedded in the website (also the final version of the game) CLICK HERE.
The sample game described in the construction steps here should be considered as an example of the use of basic Javascript-Phaser3. You can make use of the features in this game to develop your own original games and applications. We wish to see your comments and contributions about this event in the comments section below.
For downloading full game with all files CLICK HERE.
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COMMENTS
Njaim
Spriteseheets. i like it