High-Performance JavaScript - HTML5 Game Development Insights - page 44

As the chapter demo source code demonstrates, using a pool is pretty straightforward and doesn't call for a
lot of changes:
//
// Our step function called on each Request Animation Frame (RAF)
//
// in this step we recycle our particle
demo.recyclingStep = function( particles ) {
var i;
for (i = 0; i < demo.settings.rate; i++) {
var min = -10,
max = 10,
velx = min + Math.random() * (max - min),
vely = min + Math.random() * (max - min),
w = demo.settings.size,
h = demo.settings.size,
life = demo.settings.life;
particles.getFree()
.setup( demo.settings.width * 0.5, demo.settings.height * 0.5, w, h, life )
.setVel( velx, vely );
}
for (i = 0; i < particles.elements.length; i++) {
var particle = particles.elements[i];
if( particle.allocated === true ){
if( particle.life === 0 )
particles.free( particle );
else if(demo.settings.cull === true && demo.isInBounds(particle) === false)
particles.free( particle );
else
demo.integrate( particle );
particle.life--;
}
}
if( demo.settings.render === true )
demo.draw( demo.particles.elements );
};