memory management/performance/bottlenecks

[ranom]

Hello! i'm creating a bullet-hell type game in phaser. When alot of bullet sprites are being created ingame (~10 sprites/second, size = 5x5 px), i get consistent lagspikes, and graphic bugs caused by the lag... Is this normal? Anything i can do to increase performance?

 

Here's the code to create bullet sprites:

...this.bulletGroup = game.add.group();this.bulletGroup.enableBody = true;this.bulletGroup.physicsBodyType = Phaser.Physics.ARCADE;this.bulletList = []...this.timeCheck = game.time.now;	this.shoot = function(bulletSpeed, bulletRate, bulletTexture){	if (game.time.now > this.timeCheck + bulletRate) {		            var bullet = this.bulletGroup.create(this.sprite.x, this.sprite.y, bulletTexture);	    bullet.anchor.setTo(0.5,0.5);	    game.physics.arcade.moveToXY(bullet, player.sprite.x, player.sprite.y, bulletSpeed);                         this.bulletList.push(bullet);            this.timeCheck = game.time.now;	}};	this.shoot_update = function(type, phase){	for(var i = 0; i < this.bulletList.length; i++){	    this.bulletList[i].body.x += Math.sin(phase*0.1)*5;	}};// this.shoot and this.shoot_update are called in update()

[ranom]

I managed to fix the lag spikes by creating invisible sprites before updating. I grab an invisible sprite each 0.1 second, set it's alpha to 1 and update the coordinates.

Is there a better way?

[morosenerd]

I lack the specific JS/Phaser-fu to give you exact code, but generally you should be pooling your bullets (and other resources in fact). Basically, when you create a group (in the state's create function), immediately add X bullets and temporarily hide them by using the kill() function. Then, when you need a bullet, find the first "killed" (inactive) and use revive().

 

I did it a lot in AS3/Haxe, and the performance gain there was huge, I suspect it should also help here.

[SeanEBaby]

See this example for how to do what morosenerd is describing.

[lewster32]

Yeah, this example also shows it applied to bullets: http://gamemechanicexplorer.com/#bullets-2

 

A word of caution: setting a sprite's alpha to 0 has no effect on performance - as far as the renderer is concerned it's still drawing the sprite, you just can't see it. If you need to stop a sprite being rendered entirely, use sprite.visible = false.

[ranom]

thanks! i'll check that out.

[Claudiovc]

By the way, maybe you could extract the Math.sin() from the loop...I don't know the size of you bulletList array, but, since it doesn't depend on the loop variable...

this.shoot_update = function(type, phase){        var dx = Math.sin(phase*0.1)*5;	for(var i = 0; i < this.bulletList.length; i++){	    this.bulletList[i].body.x += dx;	}}

Maybe it'll be just a little improvement....but the topic is about the performance, so why not =)

I think you could use bulletGroup.forEach() for the loop, as well.