About one year ago I showed you how to build a HTML5 platformer prototype inspired by iOS hit “Yeah Bunny” thanks to Phaser and ARCADE physics, giving you a source code commented line by line.
I made it using Phaser CE 2.8.0 so it’s a bit oudated now, that’s why I rewrote the code to make it compatible with the brand new Phaser 3.6.0 version.
This prototype won’t let you miss Super Mario, as you the bunny runs automatically, changes direction each time it hits an obstacle, can perform jump, double jump and wall jump as well as slide down the walls.
Uh, and since levels in Yeah Bunny are larger than the screen, the camera follows automatically the bunny – yeah, you control a bunny.
Test the game:
Click or tap to jump, double jump or wall jump.
Rewriting the code to Phaser 3 was quite easy, I only found camera startFollow method to have less options than the old follow method.
By looking at the source code you can check the differences between this Phaser 3 prototype and the old Phaser 2 prototype, as well as learn now to:
* import tile based levels
* configure ARCADE physics
* wait for player input
* check for collisions between a sprite and the environment
* move the camera to follow player movement
Have a look at the source code:
var game;
var gameOptions = {
// player gravity
playerGravity: 900,
// player friction when on wall
playerGrip: 100,
// player horizontal speed
playerSpeed: 200,
// player jump force
playerJump: 400,
// player double jump force
playerDoubleJump: 300
}
window.onload = function() {
var gameConfig = {
type: Phaser.CANVAS,
width: 640,
height: 480,
backgroundColor: 0x444444,
physics: {
default: "arcade",
arcade: {
gravity: {
y: 0
}
}
},
scene: [preloadGame, playGame]
}
game = new Phaser.Game(gameConfig);
}
class preloadGame extends Phaser.Scene{
constructor(){
super("PreloadGame");
}
preload(){
this.load.tilemapTiledJSON("level", "level.json");
this.load.image("tile", "tile.png");
this.load.image("hero", "hero.png");
}
create(){
this.scene.start("PlayGame");
}
}
class playGame extends Phaser.Scene{
constructor(){
super("PlayGame");
}
create(){
// creation of "level" tilemap
this.map = this.make.tilemap({
key: "level"
});
// adding tiles (actually one tile) to tilemap
var tile = this.map.addTilesetImage("tileset01", "tile");
// tile 1 (the black tile) has the collision enabled
this.map.setCollision(1);
// which layer should we render? That's right, "layer01"
this.layer = this.map.createStaticLayer("layer01", tile);
// adding the hero sprite and enabling ARCADE physics for the hero
this.hero = this.physics.add.sprite(300, 376, "hero");
// setting hero horizontal speed
this.hero.body.velocity.x = gameOptions.playerSpeed;
// the hero can jump
this.canJump = true;
// the hern cannot double jump
this.canDoubleJump = false;
// the hero is not on the wall
this.onWall = false;
// waiting for player input
this.input.on("pointerdown", this.handleJump, this);
// set workd bounds to allow camera to follow the player
this.cameras.main.setBounds(0, 0, 1920, 1440);
// making the camera follow the player
this.cameras.main.startFollow(this.hero);
}
handleJump(){
// the hero can jump when:
// canJump is true AND the hero is on the ground (blocked.down)
// OR
// the hero is on the wall
if((this.canJump && this.hero.body.blocked.down) || this.onWall){
// applying jump force
this.hero.body.velocity.y = -gameOptions.playerJump;
// is the hero on a wall?
if(this.onWall){
// change the horizontal velocity too. This way the hero will jump off the wall
this.setPlayerXVelocity(true);
}
// hero can't jump anymore
this.canJump = false;
// hero is not on the wall anymore
this.onWall = false;
// the hero can now double jump
this.canDoubleJump = true;
}
else{
// cam the hero make the doubple jump?
if(this.canDoubleJump){
// the hero can't double jump anymore
this.canDoubleJump = false;
// applying double jump force
this.hero.body.velocity.y = -gameOptions.playerDoubleJump;
}
}
}
update(){
// set some default gravity values. Look at the function for more information
this.setDefaultValues();
// handling collision between the hero and the tiles
this.physics.world.collide(this.hero, this.layer, function(hero, layer){
// some temporary variables to determine if the player is blocked only once
var blockedDown = hero.body.blocked.down;
var blockedLeft = hero.body.blocked.left
var blockedRight = hero.body.blocked.right;
// if the hero hits something, no double jump is allowed
this.canDoubleJump = false;
// hero on the ground
if(blockedDown){
// hero can jump
this.canJump = true;
}
// hero on the ground and touching a wall on the right
if(blockedRight){
// horizontal flipping hero sprite
hero.flipX = true;
}
// hero on the ground and touching a wall on the right
if(blockedLeft){
// default orientation of hero sprite
hero.flipX = false;
}
// hero NOT on the ground and touching a wall
if((blockedRight || blockedLeft) && !blockedDown){
// hero on a wall
hero.scene.onWall = true;
// remove gravity
hero.body.gravity.y = 0;
// setting new y velocity
hero.body.velocity.y = gameOptions.playerGrip;
}
// adjusting hero speed according to the direction it's moving
this.setPlayerXVelocity(!this.onWall || blockedDown);
}, null, this)
}
// default values to be set at the beginning of each update cycle,
// which may be changed according to what happens into "collide" callback function
// (if called)
setDefaultValues(){
this.hero.body.gravity.y = gameOptions.playerGravity;
this.onWall = false;
this.setPlayerXVelocity(true);
}
// sets player velocity according to the direction it's facing, unless "defaultDirection"
// is false, in this case multiplies the velocity by -1
setPlayerXVelocity(defaultDirection){
this.hero.body.velocity.x = gameOptions.playerSpeed * (this.hero.flipX ? -1 : 1) * (defaultDirection ? 1 : -1);
}
}
You can really do a lot of stuff with just a few lines using Phaser 3, next time we’ll see how to add coins and enemies, meanwhile download the source code.
