Forums » Help » mouse or keyboard event in update()

I think the event in update() is inefficient. Because user may triger a event infrequent especially in non-action game. But the update() run continuously.
I see the pong example. It also set the catch event function in update()

update: function() {
		
		if( ig.input.state('up') ) {
			this.vel.y = -100;
		}
		else if( ig.input.state('down') ) {
			this.vel.y = 100;
		}
		else {
			this.vel.y = 0
		}
		
		this.parent();
	}

I think event is a moment thing , when triger a event that change the entity's state instead of using update() to catch a lot of vacant event . Because the update() is used in setInterval may run the function 1000 times by 1 second.So the catch event should not put in update function.

But i don't know how to use the event efficiently.

It really shouldn't be changed. If it's done any less frequently than it is right now, you could receive input a frame or two (or more) behind the output that prompted the frame.

Imagine a platform game like Biolab Disaster where keyboard response was 1 frame behind. You could travel 2-3 pixels between frames in some circumstances, which is enough to be the difference between standing and falling off a ledge.

Technically you are correct, but the performance hit for the update() is really minuscule. Ask the Debug Panel or your Browser's profiler if you don't trust me :)

Evented input is great for user interfaces - such as websites - but somewhat awkward to work with for real-time games. It was a conscious decision that Impact&039;s API doesn't use any events or callbacks at all. Knowing that all #update() functions are called once per frame makes your project much more easy to reason about.

Thanks, the reason is I just think game as website. So i was confused why impactjs has not any function like jquery's event and callback. The reason is also jquery hasn't develop a html5 game engine I guess.
Yet I create any callback function in impact entity class as to transfer data to server-side in my Social Game.