Need a little help culling my asteroids

[Uhfgood]

Don't know if culling is the proper term, but essentially when the asteroids are off the screen completely, I would like to essentially be able to disable them, not really sure wht to do, I guess here's a body enable/disable -- and the visibility flag on sprites --

 

Basically i do wraparound by creating 4 sprites, one primary and 3 "cloned" sprites -- the 3 clones need only collisions to be handled when they're completely or partially on screen.  I still need physics on the primary asteroids because they move around and stuff, the clones only are updated based on position.

 

So I guess I'm just asking is messing with the body and visibility flags the thing I should do on the clones when they're off screen, or should I disable them some other way?

[lewster32]

You have sprite.events.onOutOfBounds and sprite.events.onEnterBounds (these events and more are rather hidden away sadly) if you want to disable the body, though a cleaner way would be to simply skip over sprites that have visible set to false in your collision processCallback:

game.physics.arcade.collide(player, asteroids, function(player, asteroid) {  // your collision code here}, function(player, asteroid) {  // if this function returns true, the separation routine is run and the collision happens - so we can just return the visible property, which will only run collisions on visible asteroids  return asteroid.visible;});

[Uhfgood]

Would I still have to check if it's out of bounds and set it to invisible -- or do you mean use the sprite events to do that?

[lewster32]

Setting sprite.autoCull = true will stop rendering sprites outside the camera, though the tradeoff is their bounds must be checked. A faster way would probably be to just check each frame if the sprite's x and y coordinates are outside of the screen, and if so, set sprite.visible to false.

function update() {  group.forEach(function(sprite) {    if (sprite.x - sprite.width < 0 || sprite.x + sprite.width > game.world.width || sprite.y - sprite.height < 0 || sprite.y + sprite.height > game.world.height) {      sprite.visible = false;    }    else {      sprite.visible = true;    }  });}

[Uhfgood]

Thank you sir, I will try this (both suggestions)!